Forestry Authority Forestry Commission

REPORT ON FOREST RESEARCH 1994

Forestry Commission HMSO ARCHIVE REPORT ON FOREST RESEARCH

for the year ended March 1994

LONDON: HMSO © Crown copyright 1994 Applications for reproduction A d v is o r y C o m m it t e e o n F o r e s t R e s e a r c h should be made to HMSO ISBN 0 11 710327 6 Membership at 31 March 1994 FDC 945.4: (410) The abbreviated title of this Report is Chairm an Rep. Forest Res., Edin. 1994 D r J.P. D e m p s t e r , B .S c ., D.I.C., Ph.D., D.Sc. The Limes, The Green, Hilton, Huntingdon, Cambridgeshire, PE18 9NA.

Secretary Dr J. Evans, B.Sc., Ph.D., D.Sc., F.I.C. For. Forestry Commission, Alice Holt Lodge.

M em bers P r o f e s s o r E.C. C o c k in g , Ph.D., D.Sc., F.I.Biol., F.R.S. Department of Botany, School of Biological Sciences, University Park, Nottingham, NG7 2RD.

P r o f e s s o r R.M. C o r m a c k , B.Sc., M.A., Ph.D., F.R.S.Ed. Statistics Division, Department of Mathematical Sciences, North Haugh, St. Andrews, Fife, KY16 9SS.

D r M.P. D e n n e , B.Sc., Ph.D. School of Agricultural and Forest Sciences, University College of North Wales, Bangor, Gwynedd, LL57 2UW.

P r o f e s s o r D . H e n d e r s o n , B .S c ., F.R.S.Ed., F.L.S. Larachan, 54 Lonemore, Gairloch, Ross-shire, IV21 2 D B .

P r o f e s s o r J.M. H i r s t , D.Sc., B.Sc., Ph.D., F.I.Biol., F.R.S. The Cottage, Butcombe, Bristol, BS18 6XQ.

P r o f e s s o r H.G. M i l l e r , B.Sc., Ph.D., D.Sc., F.R.S.Ed. Department of Forestry, University of Aberdeen, St. Machar Drive, Aberdeen, AB9 2UU.

Dr W.E.S. M u t c h , O.B.E., B.Sc., Ph.D., F.I.C.For. 19 Barnton Grove, Edinburgh, EH4 6EQ.

D r M.B. U s h e r , B.Sc., Ph.D. Scottish Natural Heritage, 12 Hope Terrace, Edinburgh, EH9 4AS. CONTENTS

Introduction byD. A. Burdekin, Director Research 1 Branch Reports Entomology 5 Environmental Research 10 Forest Products 14 Mensuration 19 Mycorrhiza Research Unit 23 Pathology 24 Plant Production 30 Silviculture (North) 33 Silviculture (South) 40 Tree Improvement 45 Wildlife and Conservation Research 50 Wildlife Ecology 53 Communications 58 Statistics and Computing (North) 60 Statistics and Computing (South) 61 Appendices 1 Publications by Research Division staff 63 2 Research Division organisation 70 3 Research Division branches and their project groups at 31 March 1994 71 4 Net expenditure of Research Division 1993/94 73 5 Contract work done by Research Division 74 6 Research contracts awarded by Research Division 76 7 Staff employed in Research Division at 31 March 1994 78 8 Addresses of research locations 82 Index 85 INTRODUCTION

by David Burdekin Director Research

This Research Report contrasts strongly with that of 30 years ago. Not only has the quality of the publication improved but the content has changed to reflect the changing priorities and the use of increasingly sophisticated tech­ niques. The reason for the historical interest will emerge in due course. Some of the subjects reported on in the 1964 annual report such as forest entomology and forest pathology are still with us. Others have become much less significant because know­ ledge and techniques have improved as a result of the application of research findings. This is particularly the case for research into nursery practice, establishment techniques on impover­ ished upland sites, species choice and vegeta­ tion control. But new problems and opportuni­ ties have arisen and the report illustrates the increasing emphasis on environmental research, tree improvement and the establishment of trees on former agricultural land. The 1964 report referred to the installation of the first computer in Research Division, an International Computers and Tabulators SIRIUS. It had seven kilobytes of memory whereas the current Sun System has 200 megabytes i.e. a near 30 000 fold increase in capacity. Foliar autumn of 1993. The document emphasises the analysis was in its infancy and only concerned importance of research being directed at wealth with three macro nutrients. Today 23 elements creation and improving the quality of life. can be analysed per sample and analysis can Forestry research can meet both of these crite­ proceed 24 hours a day using the latest spectro- ria. Increasing emphasis is being given to serv­ span equipment. A third contrast has been the ing customers, to being efficient in the use of level of control of the environment such that resources and to competing for research con­ today trees are being grown experimentally in tracts. These have created a need for additional open-top chambers which simulate the elevated skills amongst researchers and research man­ carbon dioxide and ozone concentrations agers. As part of the follow up to the White expected in 50 years time. Also, the 1964 report Paper the Division was visited by members of a made no direct reference to work at the Northern team scrutinising public sector research estab­ Research Station which was to open in 1970 on lishments. Their report was awaited at time of the Bush Estate of Edinburgh University. going to press. The management of research has also Very significant advances have been made changed in this time. The Government’s White over the past 30 years. Some of the latest Paper on Science and Technology entitled achievements in our current forest research are Realising our potential was published in the highlighted below.

1 INTRODUCTION

ing in the post-war period reaching maturity. In R e s e a r c h h ig h l ig h t s order to maximise returns on these sawlogs information is needed on quality as well as quantity. The following is a selection of highlights from A major initiative was started during the year the research described in this report. It is neces­ to develop a method for predicting sawlog grade sarily a somewhat arbitrary choice but in the and outturn from data on standing trees. An ini­ current climate of customer-oriented research a tial study confirmed the importance of straight­ range of examples are discussed in this context. ness and that this can be consistently assessed within the crop. The method is being developed Impact of insects on tree growth to improve forecasts of assortments at both the There is currently little recorded evidence of stand and strategic level and to help managers the impact of insect pest populations on the decide on the optimum timing of felling. incremental growth of trees. Serious losses are The importance of management practices on often proclaimed but measurements are often log quality and timber strength is becoming lacking. increasingly apparent. Detailed investigations of Annual records of populations of B upalus data from spacing experiments in non-thinned piniaria, the pine looper moth, have been Sitka spruce have shown that yields of struc­ taken since the 1950s. Regression analyses tural grade timber are likely to be reduced if ini­ have indicated that some 40-60 per cent of the tial planting spacings are greater than two variation in increment is related to the insect metres. A publication of these results (Brazier numbers. and Mobbs, 1993) in Forestry won the award for The unique set of data for pine looper popu­ the best paper of the year (the Percy Stubbs and lations is not available for other forest pests. John Bolton King and Edward Garfitt prize for Experimental studies have therefore been initi­ Silviculture awarded by the Institute of ated where insect numbers are artificially con­ Chartered Foresters). trolled. Populations are either reduced by insec­ ticidal control or enhanced by introduction of Biotechnology and tree improvement the pest insect. These studies are using both The Tree Improvement Branch has had a long­ Elatobium abietinum, the spruce aphid, and term interest in biochemical markers for iden­ Rhyacionia buoliana, pine shoot moth, as mod­ tifying tree populations, including native Scots els. pine. More recently, however, the Branch has commissioned research at Nottingham Climate change and enhanced COz University to investigate techniques for intro­ Research on environmental issues, including ducing new genes into Sitka spruce. This that related to climate change, is being given a research has the ultimate aim of producing high priority. genetically transformed plants. Three open-top chamber experiments com­ Two techniques for the delivery of new genes paring tree growth in filtered and ambient air have been tested. The first used a bacterium, have recently been concluded. Two of these Agrobacterium tumefaciens, as the vector and experiments, at Alice Holt and at Glendevon, the second was by means of particle gun. Both have been converted into trials with enhanced techniques were successful using a marker gene C02. At Glendevon, in a joint project with and the project has been extended for a further Edinburgh University and funded by the year to confirm these results. European Union, the growth of trees is being tested in air with twice the current concentra­ Windthrow prediction tions of C02, with variants of nutrition and There have been significant milestones in the water supply. Significant increased growth was progress of research and technology transfer on noted in the first season especially with addi­ windthrow. The Windthrow Hazard Classifica­ tional nutrients and C 02. At Alice Holt a differ­ tion has been substantially updated, for the first ent array of treatments is being installed, time since the early 1980s. More accurate esti­ including the interacting effects of C02 and mates of site windiness are now available and ozone. this has resulted in a reduction in the area defined as being in the highest risk category. Timber quality This new information has been transmitted to The sawlog volume potential from British the forest growers through publications and forests is expected to more than double in the seminars. At the same time, researchers at the next 15 years as a result of the increased plant­ Northern Research Station organised a very suc­

2 INTRODUCTION

cessful international conference in Edinburgh sents the timber industry, farming, land use, on Wind and wind-related damage to trees. environmental and conservation interests, and has assisted FRCC through identifying research priorities concerned with four topics: land use, low-intensity silviculture, deer and squirrel A d v is o r y C o m m it t e e o n F o r e s t R e s e a r c h research needs, and marketing low quality broadleaves. The Forum fulfils an important Three Visiting Groups were set up and reported part of the technology foresight process. during the year - the branches involved were The FRCC has appointed Dr John Rodwell, Plant Production, Entomology and Site Studies Department of the Environmental Sciences, (North). University of Lancaster, to chair FRCC’s Mr J. MacLeod (Director, National Institute of Forestry and Conservation Related Working Agricultural Botany) and Professor E. Roberts Group. This sub-committee helps to coordinate (Reading University) complimented the Plant research and identify priorities by bringing Production Branch on its income earning capac­ together senior scientists from the Institute of ity and the high calibre of its seed research. Terrestrial Ecology, the Forestry Commission Professor M. Claridge (Cardiff University) and English Nature (also representing the inter­ together with Professor J. Whittaker (Lancaster ests of Scottish Natural Heritage and the University) and Professor J. Waage (International Countryside Council for Wales). Institute of Biological Control) reported on the Nearly £21 million was spent in total on Entomology Branch. High quality research into forestry and related tree research in Britain in the impact of forest insects on trees and into the 1993. This is a small increase over 1992, owing effects of stressed trees on insect populations was to the inclusion of projects funded by agencies recognised. Income targets, however, were prov­ not previously incorporated in the annual colla­ ing more difficult to meet. Dr D.C. Malcolm tion of research. Research on environmental (Edinburgh University) and Mr C. Spiers and conservation aspects continues to attract (Scottish Agricultural College) were impressed increased support. For the first time since FRCC by the new and developing, ecologically based, began collating research information in 1982, site classification system being investigated by half of all research in 1993 concerned Site Studies (North) Branch. The group sup­ broadleaved tree species, predominantly oak, ported the decision to amalgamate the branch ash, beech, birch, sycamore, poplar and willow. with the Wildlife and Conservation Research Research linked to new woodland initiatives, Branch as the interests of the two were now coin­ notably planting on farmland and community ciding. forests, continues at a high level. The annual field visit of the Advisory Committee included visits to Mathrafal, Hafren and Wyre forests in Wales and the Welsh bor­ ders to see research on insect pest problems and T h a n k s the role of management in promoting insect bio­ diversity. This was in preparation for a Visiting Standards of achievement in the Research Group in 1993 to Entomology Branch. Plant Division have continued to rise at a time when Production and Site Studies (North) branches demands on forestry research have never been were also reviewed by Visiting Groups. greater. As mentioned earlier, progress over the past 30 years has been outstanding. In the Report for 1964, the post of pathologist was noted as vacant, it was filled by the follow­ F o r e s t r y R e s e a r c h C oordination ing year. The appointee became Director some C o m m it t e e twenty five years later and is now close to retirement. His successor has already been The Forestry Research Coordination Committee appointed and takes on a challenging pro­ (FRCC), which brings together all the govern­ gramme and a truly expert team of researchers. ment departments and organisations sponsoring To them I would like to express my sincere research on forestry, met four times during the thanks and best wishes for the future. Forest year. The Research Users’ Forum, established in research has tremendous potential and I am 1992, met on two occasions. The Forum repre­ convinced that much will be realised.

3 ENTOMOLOGY

Pine wood nematode continues to be a signif­ O v e r v ie w icant international plant health issue and dur­ ing the year the Head of Branch was appointed leader of a European Union (EU) Technical Preparation for, and scrutiny by, a Visiting Team that held several meetings with Canadian Group to assess the content and direction of and USA counterparts and jointly organised an the research programme provided the opportu­ international meeting on the nematode in nity to examine and set out the aims of the Brussels. The EU-Canada-USA report from that Branch which are reproduced below: meeting is now being used extensively as the “The principal aim of the Branch is to main source of information on the biology and develop, through high quality research, an in- plant health implications of this important for­ depth understanding of the processes governing est pest. the dynamics of insects on trees and to apply this knowledge to management of forest insects H u g h E v a n s to reduce damage to trees and to enhance insect biodiversity.” Secondary objectives are: • To study the interactions between tree geno­ The great European spruce bark beetle - type, environment and insect feeding strategy D endroctonus m ic a n s as a basis for describing the underlying eco­ logical principles. • To investigate the impacts of insects on tree Following the discovery of Dendroctonus health, growth and performance as a basis form icans in Britain in 1982, a comprehensive, determining pest status and the need forintegrated control strategy has been developed. intervention. Restricting the movement of infested timber, and the breeding and release of the specific • To respond to damaging insect outbreaks by predator Rbizophagus grandis have contributed developing effective pest management strate­ to the decline in both the number of new out­ gies using biological agents or best available breaks and the rate of spread of D.micans. The pesticide application technologies that have R. grandis breeding and release programme con­ minimal impact on the environment. tinues and all new infested sites are treated. • To enhance biodiversity, especially of rare Since 1984, when surveys of spruce forests in and beneficial insects, by provision of the main infested area ceased, annual monitor­ appropriate habitats based on knowledge of ing to detect changes in the D. m icans popula­ the role of forest structural components. tions has continued. This survey provides infor­ • To provide an advisory service to the forest mation on D. m ican s populations in the absence industry exploiting fully the expertise within of further control measures. The trend in per­ the Branch. centage infested trees per site is shown in Excellent progress has been made within Figure 1, where comparison is made between the Stress topic, where work has concen­ consecutive years and with the 1984 survey trated on the effects of light and nutrient results. Although the data relative to 1984 show regimes on the physical, chemical and bio­ a steady overall increase, the year on year fig­ logical attributes of Sitka spruce. Research ures show a declining trend in population into the biology of Hylobius abietis, a major change, including negative values for 1991 and pest of restocking, has been strengthened as1992. After sanitation felling was stopped in part of a major project to develop an inte­1984 populations rose dramatically between grated approach for its management in the1985 and 1986 (32%). In the following years, future. the number of infested trees per site shows a

5 ENTOMOLOGY

200 r oil. The active ingredient in Dimilin® (difluben- zuron) interferes with the deposition of chitin, which is an essential component of the cuticle of insects. Larvae behave and feed normally until they moult and some plant damage still occurs after treatment, so to minimise damage it is necessary for the chemical to be applied as soon as possible after larvae hatch from the egg. The areas at risk were sprayed using a target Q. specific, ultra low volume, incremental spray­ - 5 0 L-l------1------1------1------1______I______I i I i ing technique. This allowed a satisfactory level 84 85 86 87 88 89 90 91 92 93 of control to be obtained using the smallest Figure 1. Percentage change in numbers of trees amount of insecticide compatible with this aim, infested per site relative to previous year and to 1984that, depending on population densities, was a result. quarter of that recommended by the manufac­ turers. The diluted insecticide was applied, at a rate of one litre ha-1, from a helicopter equipped small steady increase only, followed by a reduc­ with small motorised spinning disc applicators. tion in 1992 and a slight increase for 1993. These have been developed to generate droplets This decline is linked to increasing evidence within a very narrow size range and to give that R. grandis are present at most D. m icans greater control over spray drift pattern, resulting infestations, even at sites where they were not in increased accuracy of insecticide placement. introduced intentionally. R. grandis have been By carefully controlling droplet size, it is possi­ found at all new sites containing over 100 ble to ensure that nearly all of the droplets infested trees. This confirms that the predator is reach their target. Larger droplets that would highly mobile and can find well-established D. normally fall directly to the ground, and very m icans infestations even on the outer edge of small ones that would create spray drift are the outbreak zone. Despite these encouraging avoided. findings, it remains good practice to release R. The spray rig has been developed by grandis at newly found sites, since the predator Research Division and is entirely self contained is less likely to find small, isolated, infestations. (see Plate 1). It is equipped with a generator to It is possible that the trends in Figure 1 show provide 110 volts AC power for the pumps and the start of a cycle often associated with preda- droplet generators which are fed from a 300 tor-prey interactions where populations typi­ litre spray tank. During operation, the spray rig cally fluctuate around a mean value reflecting hangs four metres beneath the aircraft (see Plate the density-dependent activity of the predator. 2). Because the system is independent of the air­ Future surveys will determine whether this is craft and is fixed to the cargo hook with no per­ the case. manent attachment, it can be attached or detached quickly, reducing helicopter down N ic k F ie l d in g a n d A l a n W a t e r s time and enabling rapid jettisoning should an emergency arise. The flow rate can be calibrated away from the aircraft and it can then be quickly rigged to any helicopter without the C o n t r o l o f p in e b e a u t y m o t h in S c o t l a n d need for attachments specific to a particular make of helicopter. It is entirely self powered, Counts of pupae in the late autumn of 1992 making the spray heads and thus droplet spec­ identified several forest areas in North Scotland trum independent of air speed, ensuring that that were likely to have dangerously high popu­ the spray drift can be predicted and confined to lations of pine beauty moth (PBM) [Panolis the target area. flam m ed). Pupal surveys provide a quantitative For optimum control of drift, spraying is measure of population levels and give sufficient undertaken in winds of more than five knots notice of outbreak populations to allow a spray (2.5 m sec-1) with the spray rig at five metres operation to be mounted in the following above the crop. Wind speeds above five knots spring. The areas of forest at risk were con­ over a forest canopy result in a very turbulent firmed by counting eggs during early May. air flow around the tops of the trees. Droplets of Nearly 4000 ha of lodgepole pine in north a size generated by the special nozzles (70-80 Scotland were subsequently sprayed during pm diameter) remain in this turbulent flow May, using Dimilin® (Zeneca) ODC in diesel until they impact on fine or irregular surfaces

6 ENTOMOLOGY

such as tree needles, larvae or even the fine together with the remaining trees from a 35- hairs on the target larvae. Ninety-five percent of year-old, south facing stand, partially wind- the insecticide applied using this technique is thrown in October 1987. D. pin i was also caught by the top metre or so of the trees, the reported damaging pine Christmas trees at sev­ zone where most of the caterpillars are feeding. eral localities in southern England and in East The method of application allows a very small Anglia. Damage by the aphids Cinara confinis quantity of insecticide to be effective against the to Nordmann fir and Adelges cooleyi to Douglas insect pest, whilst ensuring that very little fir draw attention to the increasing popularity of reaches any non-target areas, such as areas of these trees as alternatives to Norway spruce at water within the crop or other vegetation out­ Christmas. Large colonies of the spruce bark side the forest, through spray drift. aphid, Cinara piceae, were reported on the The helicopter was equipped with an elec­ stems of Norway spruce grown-on from tronic track guidance system to ensure that Christmas trees, especially in south England, positioning and direction were correct to within East Anglia, the west Midlands and Lancashire. narrow pre-defined limits. The track guidance Severe defoliation of young broadleaved trees printouts showed that the precision of flight by the green leaf weevil, Phyllobius pyri, was was excellent. Follow up examinations of widely reported from farm woodland and sprayed areas found that larvae only survived in amenity planting schemes. Many species were areas that were specifically excluded from treat­ affected but damage was particularly serious on ment zones. By the end of July, most larvae sur­ beech, cherry and hazel in the Cotswold area; viving in non-treated areas had died, probably ash was noted as being little affected. Larvae of killed by a combination of an entomopatho- the brown-tail moth, Euproctis chrysorrhoea, genic fungus (Entomophthora spp.) and the were again evident on rosaceous trees in the adverse climatic conditions (low temperatures south-east, particularly around the Thames and high rainfall). Although this combination of estuary and in the coastal areas of Kent, Sussex agents may have controlled the populations in and Hampshire. Larvae of the lackey moth, the spray areas, it would undoubtedly have Malacosoma neustria, defoliated street trees in occurred too late to save the crop, as was seen the Portsmouth area and alongside parts of the in some untreated areas. M4 motorway. Overall, the spray operation was very suc­ Other defoliators seen damaging amenity cessful, despite several days when spraying trees included the sawflies Caliroa cerasi on could not take place due to unsuitable weather rosaceous trees and C. annulipes on oak and conditions. Pupal surveys in autumn 1993 have lime. The ash sawfly, Tomostethus nigritus, shown that there are no known PBM popula­ caused defoliation of pollarded ash trees in tions of any significance north of the Great London soon after they flushed in May. This is Glen. the third consecutive year such damage has occurred, there having been no earlier cases S t u a r t H e r it a g e , A l a s d a ir H e n d r y , recorded by the Entomology Advisory Service. R o g e r M o o r e , D a v id J o h n s o n a n d H u g h E v a n s Damage to ball-rooted semi-mature pines by the pine shoot beetle, Tomicus piniperda, has again caused serious losses of valuable trees where these were planted near to stands of A d v is o r y w o r k a n d p l a n t h ea lt h more mature pine. In Warwickshire all the Scots pine planted at one site were killed as a A dvisory result of T. pin iperda breeding galleries girdling Apart from the defoliation of lodgepole pine by and ring barking the main stem. However, adja­ Panolis flammea in Scotland (see above) and cent Corsican pine survived with only some quite widespread needle loss caused byshoot damage caused by the adult beetles’ matu­ Elatobium abietinum on both Sitka and Norway ration feeding. spruce, especially in the western parts of During 1991 and 1992 there had been many Britain, there were few other reports of insect enquiries concerning damage caused to oak damage to trees in forest plantations. In south­heartwood in sawlogs by the oak pinhole borer, ern England the winter moth,Operophtera bru- Platypus cylindrus. These diminished during m ata, caused almost complete defoliation of 1993 but another beetle, the nationally very rare oak in Richmond Park and at Epping by the end Lymexylon navale, was found in boards con­ of May. The second generation larvae of theverted from oak blown in 1987 on the large pine sawfly,Diprion pini, defoliated about Norfolk/Suffolk border. This insect has not been two ha of young Scots pine natural regenerationfound before in East Anglia.

7 ENTOMOLOGY

Plant health o.6 r In 1993 there was an unprecedented number of interceptions of the spruce bark beetles Ips typographus and I. amitinus in imported pallet 0.4 - wood and dunnage from eastern Europe. Adults of I. typographus were also caught in a pheromone trap at Tilbury Dock, Essex. Three 0.2 - European species of bark beetles not found before by Forestry Commission Plant Health Officers were Orthotomicus longicollis in o~v spruce from Latvia, Phthorophloeus spinulosus in spruce stickers and a Pityokteines species, probably P. curvidens, from Slovakia. Larvae of longhorn beetles found included M onocham us sutor, Semanotus undatus and Saperda car- 0 .4------1------1------*- charias. Adults of the North American wood- 0 0.5 1 1.5 wasp Xeris spectrum were caught in pheromone Log 10 (pupae m~2 + 1),t_1 _2 t traps baited for Dendroctonus spp. at docks in Liverpool and at Newport, Gwent. Figure 2. Relationship between radial stem growth of Scots pine at Tentsmuir and the number B. piniaria of T im W in t e r pupae recorded in winter surveys in the previous two years (t-1 + t-^ (r = -0.527, P<0.01). Radial index is the percent deviation of the observed annual radial incre­ ment from the average (expected) radial increment, T h e im p a c t s o f in s e c t s o n t r e e g r o w t h which is obtained by fitting a standard growth curve to the trend in radial increments with time. Positive values represent relatively wider growth rings. Points are Analysis of ring widths and height measure­ mean values for each year 1956-1989 = 40 trees). (n ments of Scots pine from Tentsmuir Forest, Scotland, have shown that past outbreaks of the pine looper moth, Bupalus piniaria, have had a been used to estimate the potential, or expected, significant impact on tree growth. Analysis of growth in years when increments were influ­ Forestry Commission annual pupal surveys that enced by B. piniaria. Growth loss is calculated were started in 1954 indicates that the popula­ as the percentage difference between observed tion of B. piniaria in Tentsmuir has fluctuated growth and expected growth. in a semi-regular manner. Peak numbers The results show that, after a delay of 1-3 occurred in 1957, 1962, 1969, 1977 and 1984. years, growth increments were reduced for 2-3 Damage caused by these high populations years after each peak in B. piniaria numbers. appears to have been a major cause of year-to- Annual reductions in radial, basal area and vol­ year variation in growth increments of the ume increments amounted to 9-32% of poten­ pines, although the effect on growth is delayed. tial growth, with a total reduction over each Radial, basal area and volume increments are outbreak period of between 17% and 25%. In inversely correlated with the number of B. comparison, the effects on height growth were piniaria pupae recorded in the two seasons small, variable, and only just significant. before that in which tree growth is measured The overall effect of the five outbreaks of B. (Figure 2), and height increments are closely piniaria in Tentsmuir, in the forest compart­ related to pupal numbers three years previ­ ment studied, has been to reduce average tree ously. Best fit models from multiple regression volume at harvest by 4.7-6.5%. The effect is analysis, which incorporate pupal numbers and small because severe growth loss occurred in temperature and rainfall data, explain 42—61% relatively few years and mainly during the later of the variation in increment and confirm the life of the trees when incremental growth was dominant influence of past moth numbers. declining. The trees analysed were only par­ The reduction in growth caused by B. tially defoliated, and never suffered visible piniaria has been calculated by identifying defoliation. Other compartments at Tentsmuir those years in which the effects of the moth experienced higher B. piniaria numbers appear to have been minimal (e.g. Figure 2, (although these were reduced by control opera­ where log10 (pupae nr2+l), t^+t.j is less than tions to prevent the trees from being completely 0.3), and then fitting a growth curve to the mean defoliated) and may have suffered a greater increments for these years. This curve has then reduction in growth. However, tree death follow­

8 ENTOMOLOGY

ing complete defoliation is still the main threat REFERENCE from severe outbreaks of B. piniaria. Defoliation BEVAN, D. and BROWN, R.M. (1978).The pine looper by itself is not usually enough to cause mortality, moth. Forestry Commission Forest Record 119. HMSO, London, pp. 1-13. but the loss of needles weakens trees and renders them susceptible to attack by bark beetles - par­ ticularly pine shoot beetle, Tomicus piniperda and invasion by pathogens. These secondary agents may cause many of the defoliated trees to T h e in f l u e n c e o f f o r e s t s t r u c t u r e o n die (Bevan and Brown, 1978). INSECT DIVERSITY IN BROADLEAVED WOODLAND Experimental studies on the impact of pine shoot moth, Rhyacionia buoliana, on Bishop pine at Wareham Forest, Dorset, and on spruce As part of the Research Division Biodiversity aphids in Hafren Forest, Powys, are continuing. Programme, an Entomology Branch project is Fieldwork at Wareham was completed in 1993 contributing towards identifying those aspects and the data are now being analysed. The study that can enhance insect diversity applicable to at Hafren was established in 1992 to obtain the management of productive forests and improved estimates of the impact of aphids on woodlands. Sitka spruce, particularly in terms of volume It has already been demonstrated from our growth and the length of the tree recovery period trials that insects increase in diversity and following severe attack. The experiment is numbers in response to an increase in size of designed to quantify the combined and indepen­ canopy gaps and to the duration of sunlight. dent effects of green spruce aphid, Elatobium To make the best use of canopy gaps, detailed abietinum, and root aphids, P achypappa and tables have been produced from computer gen­ Pachypapella spp., on the growth of young trees erated graphical plots to identify zones of sun­ in typical plantation conditions. In addition to light duration values according to surrounding immediate direct effects, the data will provide tree height, canopy gap dimensions, orienta­ base-line information to assess the future impact tion, latitude and date. Data have also been of climate change which may well result in collected on near-ground air temperature pro­ increased frequency and severity of aphid out­ files across these zones within canopy gaps on breaks. The site is at 450 m elevation and was cloudless days throughout the year. restocked in 1991 as part of normal forest opera­ A study of the contribution that native trees tions. The previous crop, also Sitka spruce, and shrubs may make towards encouraging achieved a yield class of 14. greater insect diversity in a woodland or forest Impact is being measured by comparing the environment has begun. A pilot survey of growth of trees damaged by aphids with that of aspen Populus ( tremula) carried out with the trees from which aphids are excluded by the appli­ help of parish tree wardens in Hampshire, has cation of foliar or soil insecticides. Treatments are confirmed the present day discontinuous dis­ being applied to replicated series of plots inter­ tribution of this species. Sampling of high den­ mixed in a fully randomised design, with each sity and isolated groups of aspens on different plot consisting of 5 x 5 trees. A further series of sites for insects has commenced with a view to plots in which E. abietinum numbers are raised re-introducing the tree species into forests as artificially to mimic epidemic populations has also part of the move towards encouraging a more been included. A considerable effort is being made diverse ecosystem within plantation monocul­ to record the aphid load experienced by the trees tures. Studies on other components contribut­ over the year in order to establish quantitatively ing to insect diversity, including the retention the relationships between aphid densities, defolia­ of over-mature and dead-wood resources, are tion and growth loss. also being undertaken.

N ig e l S t r a w , N ic k F ie l d in g a n d G il l ia n G r e e n C l iv e C a r t e r a n d T im W in t e r

9 ENVIRONMENTAL RESEARCH

Important developments have been the estab­ Hydrology in the Coalburn catchment in lishment of new experiments on carbon dioxide Kielder. at two of the open-top chamber sites, and the Research on reclamation continues in the updating of the chemical analysis service. branch, particularly in the South Wales coal­ These developments are described in detail field (Morgannwg Forest District) and on mod­ below. Other main areas of work are reclama­ ern landfills. The application of sewage sludge tion of disturbed and derelict land to forestry, to reclamation and other lowland sites also forest hydrology, the effects of trees on sites, remains an area of active work. The effects of and environmental change. trees on sites has been a topic of long-standing After extensive consultation with a large interest in the Branch. New work has been initi­ number of interested parties (other Government ated on this subject as a result of the establish­ departments, the water regulatory authorities, ment of Alice Holt Forest as an Environmental conservation agencies, the water industry, fish­ Change Network site. Environmental Research, ing interests, universities and other research Wildlife and Conservation Research, institutes, etc.) the third edition of the Forests Entomology and Mensuration branches have all and water guidelines was completed and pub­ established new measurements as part of this lished in November 1993. These guidelines are programme. Soil analysis has been undertaken based on research results and practical experi­ at the c. 74 plots of the European Union/United ence; they encourage management practices Nations Economic Commission for Europe which are sensitive to the freshwater and ripar­ (EU/UNECE) national network for monitoring ian environment. Changes to the third edition forest condition and ten, new Level II plots are reflect the findings of recent work on forest being set up under the new EU regulation on drainage and on how the scavenging of acidify­ intensive and continuous surveillance of forest ing pollutants by trees can affect the aquatic, ecosystems. environment. This latter issue is addressed by Advisory work has mainly been for the use of the critical loads approach which has Forestry Authority on environmental issues, now become accepted internationally as the although income has been earned from advisory most appropriate framework for policy formula­ tion on pollutant abatement. Freshwater critical and consultancy work, and from charges for loads maps are now used to identify where chemical analysis. Organisation of meteorologi­ acidification problems might occur, and the cal data has been an increasingly important job, and an automatic weather station is being Forestry Authority will require catchment- based assessment of the threat from acidifica­ installed at Alice Holt. Jobs completed by the tion for some Woodland Grant Scheme applica­ Instrumentation Section include construction of tions. insect samplers, a soil penetrometer, C02 con­ trol equipment, tensile test equipment for fenc­ Freshwater and soil critical loads, and pollu­ ing wire, a device for measuring root pressure tant inputs to woodlands and forests continue and a geared movement device for a tripod to be major areas of work in the Branch. Over mounted dendrometer. the last year attention has focused on Loch Dee and on the Upper Halladale catchments in Scotland, and an important paper was pub­ P e t e r F r e e r -S m it h lished on the pelletised limestone trial under­ taken at Llyn Brianne in mid-Wales (Nisbet, 1993). Attention has also returned to the subject REFERENCE of water-use by forests, with an analysis of low- NISBET, T.R. (1993). The effects of a pelletized flow data being undertaken with the Tweed limestone treatment on drainage water acidity within a River Purification Board, and process studies forest catchment in mid-Wales.Journal of Hydrology, being established with the Institute of 150, 521-539.

10 ENVIRONMENTAL RESEARCH

Figure 3): an average of 6000 samples are C h e m ic a l a n a l y s is s e r v ic e processed each year, some 10% of which are for commercial production forestry. External cus­ tomers include forest management companies, A chemical analysis service was first set up in consultants and private woodland owners. Tree laboratories at Alice Holt Research Station, tissue samples can also be analysed for starch Surrey, in 1965 to provide macronutrient analy­ and soluble carbohydrates - a method devel­ ses of foliar material. The service was designed oped to provide a quantitative measure of food both for use by the Forestry Authority Research stores for several research projects, including Division, and as a basis for prescribing fertiliz­ plant production and the effects of atmospheric ers to Forestry Commission forest districts. pollution. Limited soil analyses were also undertaken, In the past, soil analyses have been limited to principally for research purposes. In the last pH and electrical conductivity. However, new five years, the chemical analysis service has European Union statutory requirements for soil expanded considerably, and a wide range of information under forests has led to the devel­ forestry related materials is now received for opment of facilities and methods for a wide analysis each year. This follows the developing range of analyses. Similarly, water samples need to measure biological and environmental taken from surface waters and from the soil materials quantitatively, for both statutory (using suction cup lysimeters or centrifugation) requirements and basic research. are now routinely analysed, usually for com­ The backbone of the service remains the mon anions and cations, hazen value and tur­ analysis of macronutrients in foliar samples (see bidity.

Tree Tissue Sample

Drying

needle counting grinding/milling

Figure 3. Flow diagram of foliar analysis procedure.

11 ENVIRONMENTAL RESEARCH

Investment in modern analytical equipment Scots pine and beech - had been grown in has been essential to carry out this work. For open-top chambers in either ambient (polluted) determination of nitrogen (as ammonium) and air or filtered air for six seasons. Provisional phosphorus (as orthophosphate) in plant tissue, results indicate that there were no significant continuous flow analysis has been used; a new effects of air quality on height, stem diameter, automated system (Chemlab System 4) was and fresh or dry weights for any of the three used for the first time during 1993 (Plate 3). species at Glendevon. At Chatsworth the result Gerhardt Kjeldatherm digestion and Vapodest was similar, but height growth of both Norway 33 distillation equipment has been purchased spruce and beech had increased in filtered air for determination of soil nitrogen. Since 1978, during 1993. At Headley, Norway spruce and macronutrients potassium, magnesium and cal­ beech grew significantly better in filtered air. cium have been determined by direct current Continuous measurement and analysis of air plasma optical emission spectroscopy using quality at the three sites confirmed that ozone Spectrospan III equipment. This has now been concentrations were highest at Headley. replaced by an inductively coupled plasma Overall, we can conclude from this major, long­ optical emission spectrometer (Plate 4). This term experiment that ambient air quality signifi­ advanced analytical tool can determine all cantly affects the growth of trees in some parts major and minor nutrients simultaneously. In of the U.K. Impacts range from clear adverse addition, inorganic contaminants in water and effects of ozone to subtle beneficial effects of soil will be more easily quantified. sulphur and nitrogen compounds. Follow-up Chromatographic methods of separation and work is now being set up in oak, Sitka spruce quantification are well represented within the and Scots pine stands to identify the response laboratory. Gas chromatography (Hewlett mechanisms occurring at specific forest sites. Packard 5880A) is used to separate volatile With the completion of the air pollution components such as monoterpenes in tree tis­ experiment at Glendevon, the open-top cham­ sue. Ion chromatography using Dionex equip­ bers were converted to investigate the effects of ment is carried out mainly for determination of elevated C 02 and the interaction with nutrition anions and cations, and mono- and di-saccha- on the growth of Sitka spruce. This is a joint rides. Forestry Commission and Edinburgh University Quality assurance has become very important long-term experiment funded by the European in recent years. Methods of analysis have been Union under the research and development pro­ clarified, and all analytical processes detailed in gramme in the field of Environment. In eight standard operating procedures. Certified refer­ open-top chambers the soil was partitioned into ence materials are included in every batch of four equal quadrants with 40 cm moisture-proof samples for foliar analysis. Regular checks of barriers. A 16 tonne tank supplies C02 which is accuracy of the foliar macronutrient analysis introduced at a concentration of 350 ppm above service are made by taking part in interlabora­ background, i.e. on average 700 ppm, through a tory sample exchange exercises run by the computer operated monitoring and feedback International Union of Forestry Research control system (Barton et al, 1993). The volume Organisations/United Nations Economic of air flowing through the chambers is regulated Commission for Europe and the Canadian by motor driven louvre vents linked to a light Forest Service. sensor, to reduce air flow and hence COz usage at night (Durrant et al, 1993). Each tree receives A n d y M o f f a t a n d E r n e s t W a r d water or nutrient solution through an individual drip tube in an irrigation system that regulates total volume received to equal that of incident rainfall. Two quadrants receive water only and A ir p o l l u t io n a n d c a r b o n d io x id e the other two a full strength nutrient solution e n r ic h m e n t : o p e n -t o p c h a m b e r experiments provided at rates calculated to match the growth rate of Sitka spruce. The nutrient treat­ The open-top chamber experiments into the ments are based on those outlined by Ingestad effects of air quality on tree growth were started and Lund (1986) and the control equipment was in 1988 and completed in autumn 1993 with designed and installed by Biotronic. the harvesting of the remaining trees at Tree height and stem diameter was measured Glendevon and Chatsworth. At Headley, the at the time of planting and at the end of the first Scots pine and beech were harvested leaving growing season (October 1993). The data were Norway spruce to grow for one more season. subjected to analysis of variance. In the first Four species - Sitka spruce, Norway spruce, growing season after planting out, nutrition has

12 ENVIRONMENTAL RESEARCH

had a significant effect on the diameter of the enrichment of mature Sitka spruce[Picea sitchensis trees, with nutrient application resulting in (Bong.) Carr.). Plant Cell and Environment, 16, 11 3 9 -1 1 4 8 . increased diameter growth. This difference was larger in ambient C 02 than in elevated C 02. In a DURRANT, D„ LEE, H„ BARTON, C. and JARVIS, P. second experiment, aspect significantly affected (1993).A long-term carbon dioxide enrichment tree height and diameter, with south-facing experiment examining the interaction with nutrition in trees showing increased growth over the first Sitka spruce. Research Information Note 238. Forestry growing season. This illustrates the importance Commission, Edinburgh. of careful experimental design when using INGESTAD, T. and LUND, A.-B. (1986). Theory and small plots or limited numbers of replicates. techniques for steady state mineral nutrition and growth The site at Headley has been equipped with of plants. Scandinavian Journal of Forest Research, 1, the installation of improved fan/filter units pro­ 4 3 9 -4 5 3 . viding increased airflow (Plate5). A new exper­ iment has been initiated (Project712) to investi­ gate the interacting effects of C02, ozone and water supply with a view to predicting changes in tree growth (ash, oak and Scots pine) in post climate-change England.A similar C 02 control system to that described above for Glendevon has been installed providing treatments of ambi­ ent (=350 ppm) and elevated(700 ppm) C 0 2. Ozone addition is also through a computer operated feedback and control system allowing ramping of ozone levels through the morning and afternoon, mirroring diurnal variation. The high ozone treatment (20-100 ppb) is based upon twice the mean concentrations for the 1991 growing season of10 ppb overnight, rising to a maximum of49 ppb during the afternoon. Potted seedlings of all three species have been acclimated to ambient or elevated C02 in a modified polytunnel since January1994. The trees will be transferred to chambers for ozone/C02 fumigation in May1994 and planted in October 1994 when the chambers currently occupied by Norway spruce (see above) are released. Water supply regimes of ambient and full field capacity will be imposed at this stage, resulting in the final experimental design as shown in Figure 4.

D a v e D u r r a n t a n d M a r k B r o a d m e a d o w

REFERENCES Figure 4. The experimental design for the C02, ozone BARTON, C.M.V., LEE, H.S.J. and JARVIS, P.G. (1993). A and water availability treatments for ash, oak and Scots branch bag and C 02 control system for long-term C 02 pine at Headley.

13 FOREST PRODUCTS

Over the past year a significant part of Forest REFERENCE Products’ research has focused on factors influ­ BRAZIER, J.D. and MOBBS, A.D. (1993). The influence of planting distance on structural wood yields of encing the deterioration of timber, both in the unthinned Sitka spruce.Forestry, 66, 333-352. round and in sawn form, particularly as coloni­ sation by sapstain fungi during harvesting and after processing remains a recurring problem for the forest industry. The extent to which mecha­ A PEAT ALTERNATIVE nised harvesting may encourage increased attack by sapstainers is being evaluated and in particular how macro- and micro-environmen­ With the current interest in identifying peat tal factors influence the development of these alternatives, a collaborative venture between fungi. It has also become clear from studies in Forest Products Branch and Forest Enterprise, the sawmill that processed timber becomes New Forest, has evaluated the potential for infected with sapstainers largely through the using bracken as a horticultural medium. actions of invertebrate vectors such as mites Traditionally, bracken was used successfully for and flies, countering the widely held belief that both growing and mulching, although this prac­ degrade of sawn timber originates from propag- tice has been largely discontinued. Trials have ules of bluestain fungi disseminated in air cur­ shown that composting the bracken produces a rents (see below). very versatile horticultural medium and has the added advantage of destroying the carcinogenic As before, the majority of the Branch’s compounds generated by the plant. Following resources has been directed towards commis­ this work, significant quantities of bracken are sioned research on timber properties and the being marketed on a commercial basis. Apart effect of provenance and silvicultural manage­ from the horticultural advantages, using ment on timber quality. The results of a long­ bracken for this purpose would involve regular term study looking at spacing in ‘non-thin’ cutting and harvesting, a recognised method for plantations of Sitka spruce (see below) have controlling this pest species which is an estab­ also recently been published (Brazier and lished and encroaching problem in many wood­ Mobbs, 1993). In essence, this work has lands and on uncultivated farmland. revealed that commercial yields of structural grade timber are likely to be significantly J o a n W e b b e r a n d R o n a P it m a n * reduced if planting intervals between trees of more than two metres are employed, but losses *Forest Enterprise, New Forest in structural performance of timber are particu­ larly marked as planting distances increase from 1.5 to 3 metres. F u n g a l d e g r a d e o f t im b e r Forest Products staff also continue to repre­ sent the Forestry Commission on British Standards committees and play a central role in Preservation of utility poles organising and contributing to the Technical In the case of homegrown pine harvested for Sub-Committee of the Home Grown Timber utility poles, roundwoods are felled and then Advisory Committee. In addition, almost 200 transported to a timber yard where they are enquiries were processed coming from the pub­ debarked and air seasoned in preparation for lic, educational establishments and the forestry pressure treatment with creosote. This season­ industry on a diverse range of subjects includ­ ing period immediately after felling is when ing residues, wood properties, fuel and preser­ many decay basidiomycetes can become estab­ vation. lished. It is the objective of the current project to develop an on-site treatment which will pre­ J o a n W e b b e r vent colonization by these decay fungi.

14 FOREST PRODUCTS

A prime consideration of any forest-based insects. The incidence of infection attributed to treatment is the labour involved in application. bark beetles was confined to periods of beetle Incorporating the treatment into the harvesting emergence whereas infection in logs protected machinery is an obvious way of keeping addi­ from bark beetles occurred throughout the year tional labour to a minimum and at the same and showed much greater variation between time ensuring that treatment is immediate. individual logs, highlighting the importance of Spores of a promising biocontrol treatment, vectors other than bark beetles in the forest Trichoderma harzianum, have been incorpo­ environment. rated into the chain-oil of felling saws with In order to understand the role of micro- encouraging results. Sapstain and decay are arthropods in fungal infection of sawn and reduced in treated material and experiments stacked lumber, a fourteen-week field trial was indicate that application in chain-oil actually established at a sawmill in southern England increases establishment of the Trichoderma during the summer. Defacement of boards sawn compared with treatments where spores are from the sapwood of freshly felled logs of applied in a water suspension. Trials are cur­ Corsican pine [Pinus nigra var. m aritim a) was rently being conducted throughout the year to analysed at two time intervals for fungal sap­ investigate how season affects the success of stain, moulds and basidiomycetes. The boards application by chain-saw. used in the trial were close stacked to reduce Integrated control, the combined use of a bio­ moisture loss and increase the hazard to fungal logical control agent and a compatible chemi­ infection. Individual stacks were constructed in cal, is another area of interest. A field experi­ a nest arrangement which enclosed experimen­ ment run over an eight-month period has tal sterilised board samples contained in plastic indicated that Trichoderma viride can be suc­ tanks and positioned centrally in each stack cessfully applied to pine alongside borate salts. (Plate 6], These experimental boards had previ­ Significant control of decay was observed in the ously been y-irradiated inside the tanks and the experiment whether or not the material was open tank faces then either left uncovered or exposed to rainfall, countering the widely held covered with a very fine (5/rnij nylon mesh view that borates are considered to be too screen to prevent entry of micro-arthropods. In highly leachable for effective outside use. addition, the outer casing timbers in each stack Laboratory studies have continued to yield were dip-treated with either a fungicide, a insights into how biological control operates in broad-spectrum insecticide/acaricide, a com­ the field. A particularly exciting area has bined treatment containing the fungicide and involved the metabolites of T. harzianum and the insecticide/acaricide, or with water which their effect on the interactions between target served as a control. decay fungi. The outcome of interactions At the eight- and fourteen-week inspections between basidiomycetes can be completely basidiomycete infection was minimal in all the reversed in the presence of Trichoderma, indi­ treatments, but the casing boards from the con­ cating that the mould has the potential to trol stacks were severely sapstained and there markedly alter the structure of fungal communi­ was a little superficial mould growth. The ties in wood. fungicide treatment, either alone or in combina­ tion with the insecticide, prevented sapstain or mould development throughout the fourteen- M a g n u s S c h o e m a n , J o a n W e b b e r a n d week trial. Although boards treated with the D a v e D ic k in s o n * insecticide were slightly sapstained and showed 'Department of Biology, Imperial College, London severe moulding after eight weeks, by the end of the fourteen-week trial the degree of sapstain Fungal stain and moulds on unseasoned had increased while the level of mould deface­ tim ber ment was significantly reduced. Treatments Dissemination of sapstain fungi by bark beetles including the fungicide were always effective in is widely reported and accepted, but the extent preventing fungal growth on the wood, while to which both sapstain and mould fungi are the insecticide treatment alone eliminated live transmitted by micro-arthropods onto freshly micro-arthropods and reduced the incidence of felled logs and sawn lumber is rarely consid­ sapstain. Significant numbers of dead micro- ered. In an evaluation of the source of infection arthropods were recorded on these boards and on freshly felled logs stored in the forest, logs their remains were often associated with dis­ protected from bark beetle attack but exposed tocrete zones of sapstain in the wood (Plate 7). other micro-arthropods exhibited similar levels The condition of the irradiated sample of internal sapstain to those exposed to allboards, was evaluated after eight weeks’ expo­

15 FOREST PRODUCTS

sure. Boards which were accessible to arthro­ the screens were heavily moulded. Aerial dis­ pods - that is, placed in open tanks surrounded semination of mould spores to the screens, fol­ by non-insecticide treated casing timbers — lowed by hyphal growth through the screen exhibited a high level of sapstain. When pro­ mesh and sporulation on the inner surfaces, tected from arthropod invasion by a mesh resulted in mould infection of the experimental screen and/or insecticide treatment, sapstain on boards when arthropods are excluded. The the experimental boards was minimal. lower incidence of moulding on experimental However, micro-arthropods were not only boards in open tanks surrounded by non-insec­ implicated as primary vectors of spores of sap­ ticide treated casing timber, and the higher inci­ stain fungi on green sawn lumber (Plate 8), but dence when insecticide was applied confirms the proposition that grazing micro-arthro­ pods significantly reduce surface mould­ ing on the boards. Fungivory by micro­ arthropods, therefore, plays a dual role in the fungal colonisation of green sawn lumber by introducing sapstainers and also contributing to the removal of moulds.

R o d E a t o n a n d M ic h a e l P o w e l l

School of Biological Sciences, University of Portsmouth

Plate 8. Micro-arthropod from sawn lumber (bar equal to 130 pm), also shown at higher magnification (bar equal to 8 pm) with fungal spores (arrowed) on dorsal surface. were also found to graze the moulds and therefore limit the intensity of defacement by these fungi. Mould spores appeared to be largely trans­ mitted into and within the board stacks by air currents and, in the absence of live arthropods on the insecticide-treated casing boards, moulding was severe after eight weeks, but minimal on the other treatments. After fourteen weeks, however, the mould fungi T e s t in g B r it is h - g r o w n t im b e r declined and this was attributed to degradation of the insecticide treatment and re-establish­ ment of the micro-fauna. The low incidence of Strength grading of British-grown oak moulding on the untreated casing timbers, Currently there are no design properties in where the micro-fauna was abundant and BS5268 and no British standard grading rules active, supports the view that fungivory is a for temperate hardwoods. Work is being carried major influence on the intensity of defacement. out at the Building Research Establishment Analysis of the irradiated boards in screened (BRE) on two batches of British-grown oak to tanks where micro-arthropods were excluded enable drafting of a visual grading standard showed significant moulding except when sur­ comprising two or three grades, together with rounded by untreated casing boards. In the lat­ the strength properties for those grades. ter situation, the screens were clean and moulds The first draft of the standard will be applica­ had been removed by grazing micro-arthropods ble to all temperate hardwoods, although in the stack. In the absence of micro-arthropods strength properties will only be given initially

16 FOREST PRODUCTS

for oak in BS5268; the standard is anticipated It is known that the amount of twist in for September 1994. There are also plans to British-grown softwoods, in particular Sitka carry out testing on sweet chestnut in 1995 to spruce, can be reduced by using modified kiln permit mechanical properties to be added for schedules and heavy restraining weights to that species. If the work can be completed in restrict movement during the drying process. time, the grading standard and strength proper­ Indeed, much British-grown timber is already ties will be referenced in the European coming to the market in a suitably straight con­ Standard currently being drafted on the assign­ dition as a result of being dried under restraint. ment of grades and species to strength class. Although this material meets the requirements All visual assessments of the four sides and of BS4978, it cannot be distinguished from sup­ whole lengths of the first batch of oak sections plies dried by conventional air-drying and the are complete as, too, are strength tests to deter­ extent to which current supplies of timber dried mine modulus of elasticity and modulus of rup­ under restraint could subsequently distort in ture on some 450 pieces of oak in three sizes (50 service under cyclic climatic conditions has not x 100 mm, 100 x 200 mm and 150 x 150 mm). been quantified. Inspection of failure sections and data analysis Preliminary results of the research currently are almost complete and provisional grade clas­ being conducted in the Timber Division at BRE sification is progressing. Testing has been car­ have already given a basis for re-assurance. Two sizes of four metre long Sitka spruce battens (47 ried out at moisture contents higher than is typ­ x 150 mm and 47 x 100 mm) were specially ical for oak in structures, and higher than the selected for ‘worst-case’ studies as material 12% moisture content (me) requirements of the likely to twist under the conditions of the inves­ relevant European Standard. The period neces­ tigation. Each batten was cross-cut into two to sary to kiln dry these sections to 12% me would provide end-matched samples which were then have been too lengthy and possibly would have kiln-dried either with or without restraint. After resulted in unacceptable degrade. kilning the amount of twist was measured for Early test results on oak kiln-dried to around each of the respective sizes. Results showed that 35-65% indicated strength properties somewhat on average only 38% of the 47 x 150 mm mater­ ial and 32% of the 47 x 100 mm material com­ lower than expected and this looks likely to be plied with BS4978 when kilned without confirmed by results from the subsequent testing, restraint (Table 1). This compared with 80% including some on freshly sawn ‘green’ timber and 57% compliance respectively for the com­ with an even higher moisture content. When test­ parable battens dried under restraint. The very ing and data analysis is complete, appropriate low values for the unrestrained battens con­ combinations of strength and yield will be deter­ firmed that the quality of material selected for mined to enable decisions on the preferred this investigation was indeed at the poorest end grades to be included in the draft standard. of the quality range.

Drying of Sitka spruce Table 1. Effect of kiln-drying with and without The output of British-grown commercial soft­ restraint on distortion of British-grown Sitka spruce wood is expected to reach four million m3 by (‘worst-case’ sample) 2025. Much of this will be Sitka spruce which Compliance (%) with BS 4978 after can differ in certain characteristics from kiln-drying imported sources of timber. One such difference Batten sizes ------is a somewhat increased tendency to distort, (mm) unrestrained restrained often visible as twist, when the material is dried to ‘in service’ moisture contents. This is particu­ 47 x 150______38______80_ larly associated with faster grown material and 47x 100 32 57 with trees felled at a relatively early age which have a higher proportion of juvenile wood. All material was subsequently subjected to The amount of twist allowed in BS4978 cycled humidity conditions of 65%, 30%, 90% (Softwood Grades for Structural Use) is based and 65% relative humidity, each for approxi­ on measurements made at a maximum timber mately 6-8 weeks. As expected, some increase moisture content of 20%. On this basis, initial in twist occurred after the first two humidity assessments carried out on two parcels of changes but the increases were identical for British grown Sitka spruce battens indicated both methods of kilning. Thus the advantage of that the percentage of battens which complied material dried under restraint was maintained with the British Standard ranged from and any extra induced drying stresses did not 45%-70%; similar results were obtained for emerge as dormant twist on subsequent expo­ imported timber. sure to changes in humidity. Even at the end of

17 FOREST PRODUCTS

the complete cycle, although all battens showed grain, and shrinkage measured from pith to more twist than at the start, the material dried bark. These data are still being analysed in rela­ under restraint maintained its advantage. tion to tree dimensions and site conditions. Research is continuing to confirm these early From all sites, density (Figure 5, opposite Plate indications and to examine the effects of shorter 10) and ring width tended to decrease from pith humidity cycles, shorter kilning schedules at towards bark, while spiral grain (Figure 6, oppo­ higher temperature, and optimising loading site Plate 13) increased. Longitudinal shrinkage weight. Continuing work will include tests on tended to be higher towards the pith, but tangen­ better quality material more representative of tial (Figure 7, opposite Plate 14) and radial shrink­ normal construction grade Sitka spruce and also age showed no clear trends from pith to bark. glue-jointed material. The analyses suggest that basic density, spiral grain and shrinkage (tangential, radial, and lon­

T o n y B r a v e r y , T o n y F e w e l l a n d K e it h M a u n gitudinal) were all influenced by site, at a com­ parable ring number from the pith (Figures 5—7). Building Research Establishment, Garston, Watford Comparing stands with trees of a similar age, there also appeared to be significant differences in bark thickness, sapwood width and early- wood width. However, most of these site differ­ W ood q u a l it y ences could not be related to silvicultural prac­ tice; multiple regressions suggested that only Influence of site and silvicultural practice on ring width and longitudinal shrinkage were sig­ wood quality of oak nificantly correlated with crown dimensions or stocking rate. Between trees within sites there The main aim of this project is to quantify the were considerable differences in density, spiral influence of site and silvicultural practice on grain, and shrinkage; again, these differences wood structure and properties of oak. It is part of were not consistently related to crown dimen­ a larger European Union (EU) funded project sions. These between and within site differences which arose in response to the increasing level of in wood properties suggest there is potential for interest in planting broadleaves in many parts of selection to improve such aspects of wood qual­ the EU, triggered by recent policies encouraging ity, independent of growth rate. farm forestry on previously cultivated land. Between trees, mean ring width was signifi­ Although this type of favourable site can be cantly correlated with weighted density, but at a expected to produce rapid growth, there is little level which is surprisingly low (R2=0.022) in information about the extent to which such the light of the commonly held assumptions growth rates will affect wood quality. For that about the influence of growth rate on density of reason, the present project gives particular oak wood. Density was significantly correlated emphasis to the influence of spacing, crown size with tangential shrinkage, and also with angle and growth rate on wood structure and proper­ of spiral grain. These complex relationships ties. Other EU partners (Scotland, Denmark, and between growth rate, density and other wood Germany) have undertaken similar work on properties, are now being explored in greater beech, ash, sycamore and poplar, each country detail using computer tomography and micro­ contributing material on the different species scopic analyses of growth ring structure. from their own localities to the relevant partners. Early wood vessel dimensions, latewood fibre Samples were collected from ten trees, dimensions, and tissue proportions are being selected from each of 16 sites (six sites from measured for comparison with maximum, mini­ England and Wales, four from Scotland, four mum, and mean density of individual growth Danish and two German), grown at a range of rings determined from computer tomography stocking densities. The original intention was to scans. These analyses should allow further sample from stands of known seed origin and interpretation of the influence of silvicultural silvicultural history, but such material proved management on density (and hence on other impossible to obtain, so stands were selected on wood properties), and suggest the extent to the basis of current site conditions. For each which this relationship can be controlled by tree, measurements included total height, diam­ selection for particular aspects of wood quality eter at breast height, crown dimensions, and between and within stands. branch size and distribution below the spring of the crown. Discs were cut from each tree at D e e A e b is c h e r a n d P a t D e n n e breast height, bark and sapwood thickness recorded, and variations in ring width, early- School of Agricultural and Forest Sciences, wood and latewood proportions, density, spiral University of Wales, Bangor, Gwynedd

18 MENSURATION

The Branch has dealt with a number of advi­ O v e r v i e w sory tasks during the year including: four two- day seminars on the tariff procedure for Forest Enterprise staff and representatives of the pri­ A total of 124 permanent sample plots were vate sector, carried out at the request of South given a full measurement, including thinning Scotland, North and East England, and South where required. Of these plots, ten were and West England Forest Enterprise Regions; a abandoned due to wind damage. A number training course in sample plot methods for five of plots in the Elwy Sitka spruce line thin­ senior forest scientists from China; an increas­ ning experiment were also seriously wind ing number of enquiries on measurement proce­ damaged and this is likely to lead to early dures and yield models requiring field visits closure of this experiment. Twenty-three and data analysis. new permanent sample plots were estab­ The longer-term research programme of the lished covering a range of unthinned Sitka Branch, in particular yield model validation, spruce, mixture and hardwood crops. has continued although advisory and contract Training in sample plot methods was given commitments have inevitably disrupted to contractors and Forest Enterprise district progress. There was major involvement in the staff involved in sample plot measurement Forest Condition Monitoring Survey, and the and a number of collaborative yield studies. Branch continued its representational role on Significant progress has been made on the the European Standards Committee concerned second site yield research project jointly with the preparation of a standard covering funded by the Forestry Commission and the methods of measurement of round timber. A Ministry of Agriculture, Fisheries and Food. collaborative project with the University of Site yield models are being developed for Wales, Bangor, to develop mathematical func­ ash, poplar, sycamore, hybrid larch and tions for tree profiles, and to simulate the effect Norway spruce. Growth measurements have of stem defects on product out-turn, started in been collected from 142 temporary sample November 1993. Three projects dealing with plots on a range of site types for the five aspects of yield, timber quality and carbon stor­ species. Single tree volume functions have age are reported below. been produced for all five species and these are shown in Table 2. Confirmation of major J a n e t M e t h l e y soil group classifications, and improvement of estimates of accumulated temperature and potential soil moisture deficit to take account of altitude, has been necessary for all sample plots included in the study.

Table 2. Parameter estimates of single tree volume functions for ash, poplar,sycamore, hybrid larch and Norway spruce Species Single tree volume function Ash v = - 0.020112 + (0.0000908 x dbh2 x h °-7085) Poplar v = - 0.004298 + (0.0000435 x dbh2 x h °-88°8) Sycamore v = - 0.016828 + (0.0000968 x dbh2 x h °-6660) Hybrid larch v = - 0.014706 + (0.0000833 x dbh2 x h °-7360) Norway spruce v = - 0.015632 + (0.0001099 x dbh2 x h °-6475)

19 MENSURATION

observers. Four log length categories, linked to M o r t a l it y s t u d y in u n t h in n e d S it k a s p r u c e different value products, were identified and c r o p s in S o u t h S c o t la n d R e g io n included in the straightness assessment carried out on the first six metre butt portion of the tree. A Sitka spruce crop of relatively poor qual­ Mensuration Branch was commissioned to ity and a Norway spruce crop of relatively good investigate the mortality assumptions in the quality were assessed for straightness by six unthinned Sitka spruce yield models, and, in trained observers. The assessed trees from both collaboration with Forest Enterprise staff and sites were felled, processed and measured in the contract surveyors, established and measured mill. Preliminary analysis of the data included 171 temporary and permanent sample plots in an investigation of a number of crop quality six Forest Districts. The sample plot data, repre­ scoring systems, which were calculated using senting a range of crop ages, spacings and yield the observed combinations and numbers of dif­ classes, were processed using existing computer ferent log lengths. Initial results have indicated programs to produce stand level estimates of that different crop qualities can be identified the yield model variables. The predictions using straightness assessment scores and that made by the yield models were compared with these are meaningful in terms of product out­ the actual values obtained in sample plots. A turn. Further research is required before the range of tabulation and regression methods was assessment method can be introduced to pro­ employed to test for the presence of bias in pre­ duction forecasting. diction errors. Existing permanent sample plots have also been included in this investigation to determine how representative they are of South Ja n e t M e t h l e y , R o b e r t M a t t h e w s , Scotland conditions. This study has helped to J o h n P r o u d f o o t a n d A d r ia n E l l is progress the longer term validation of the pub­ lished Sitka spruce yield models.

J o in t E n e r g y T e c h n o l o g y S u p p o r t U n it / Ja n e t M e t h l e y , R o b er t M a t t h e w s , Joh n P r o u d fo o t , F o r e s t r y C o m m is s io n p r o je c t o n e n e r g y a n d S t a n A b b o t t , N igel F ea r is an d A d rian E llis CARBON BUDGETS OF WOOD FUEL PRODUCTION

Among the many methods of potentially sus­ T im b e r q u a l it y a s s e s s m e n t f o r p r o d u c t io n tainable energy generation, wood fuel has been FORECASTING receiving increasing attention. Indeed, biomass fuel farming is frequently proposed as a cheap, In April 1993 the HGTAC Technical Sub-com­ low-technology means of producing renewable mittee approved the formation of a Timber energy. For any such bioenergy system to be Quality Steering Group charged with the task of worthwhile, the energy produced must be carrying out a pilot study to investigate the greater than the inputs of non-renewable energy potential for developing a crop quality classifi­ required to establish and operate the scheme. cation system and to demonstrate its relevance Moreover, to be truly sustainable, establishment to sawmill out-turn. The Steering Group mem­ and operation of the bioenergy generation sys­ bers are representatives of sawmillers, private tem must result in negligible net emissions to growers, Forest Enterprise, the Forestry the atmosphere of greenhouse gases, principally Authority and wood science. The study has carbon-based compounds such as carbon diox­ proved to be a major undertaking, requiring ide. In order to confirm that a bioenergy genera­ commitment, cooperation and resources from tion scheme meets these criteria, it is necessary the different sectors of the industry, although to evaluate the energy and carbon budgets of the the bulk of project management and implemen­ proposed system. The Department of Trade and tation has been undertaken by staff from Industry, through the Energy Technology Mensuration Branch and BSW Carlisle. The Support Unit, has collaborated with Steering Group and a sawmillers’ sub-group Mensuration Branch on a research project to agreed that straightness was the most important model the energy and carbon budgets of wood stem characteristic affecting quantity and qual­ fuel production from short rotation coppice. A ity of sawmill out-turn. Straightness was also computer model has been developed which cal­ considered to be the simplest measure of qual­ culates the total energy and carbon benefits and ity that could be studied in the time available, costs of a bioenergy producing system based on and the characteristic that could be assessed the biomass productivity of the crop, a descrip­ with a measure of consistency by different tion of the activities carried out to produce the

20 MENSURATION

Figure 8. Relationship between predicted energy ratio and utilisable biomass productivity for wood fuel production from short rotation coppice. Dashed lines indicate extrapolations based on data for harvesting machines which cannot cope with high biomass yields. Large dot and vertical line: estimate and range for energy ratio, given 30 odt ha ~1 yr ~1, assuming conventional harvesting methods. biofuel, and data on the energy costs of fossil Table 3. Dependence of predicted energy ratio on fuels, materials and machinery. cutting cycle and productive life of coppice crops, It is impossible to make precise statements (the estimates in the grey shaded region are about the energy and carbon budgets of short relatively low, because only a single harvest is rotation coppice crops for the production of obtained from the crop) wood fuel, due to uncertainties in the estima­ tion of certain energy and carbon costs, and Cutting cycle (yr) 1 2 3 4 5 the wide variation in techniques of crop man­ agement, wood harvesting and fuel process­ Productive life (yr) ing. The energy budget of a biofuel system 3 8 7 - - - may be summarised using statistics such as 4 10 - 11 -- the energy ratio defined thus, 5 12 14 - 13 - „ . Total energy benefit 6 13 - - - 16 Energy ratio= ------—------Total energy cost 7 14 18 19 -- 11 17 22 -- 27 which indicates the number of units of energy produced for every unit of non-renewable 13 18 24 27 28 - energy expended in operating the system. For 16 19 - 29 - 32 the biofuel producing system to be worth 17 19 26 - 31 - operating, the energy ratio needs to be signifi­ 25 20 28 32 35 - cantly greater than one. 26 20 --- 37 The computer model was used to investi­ gate the sensitivity of the energy ratio to changes in the methods by which short rota­ from short rotation coppice is estimated to be tion coppice is grown. Table 3 shows the vari­ 30 times greater than the energy expended in ation in the estimated energy ratio with the growing and harvesting the crop, giving an cutting cycle and productive life of the cop­ energy ratio of 30. The fossil-fuel carbon emit­ pice crop, while Figure 8 shows the variation ted in producing one MJ of energy in the form in estimated energy ratio (in megajoules (MJ)) of wood from short rotation coppice is esti­ with the biomass productivity (in oven dried mated to be typically 0.0013 kgC. Because tonnes (ODT)) of the crop. Typically the wood fuel itself is ‘carbon neutral’, this repre­ energy produced in the form of wood chips sents the total emissions of carbon to the

21 MENSURATION

atmosphere as a result of using wood fuel. short rotation coppice crops is required to test These estimates are based on the assumption this assumption. that current methods for growing and harvest­ ing short rotation coppice are sustainable. An R o b e r t M a t t h e w s , N ig e l F e a r is a n d assessment of the full environmental impact of S t a n A b b o t t

22 MYCORRHIZ A RESEARCH UNIT

This Unit was established during 1993 to carry of the working group on systematics and taxon­ out research into aspects of mycorrhizas that omy of arbuscular mycorrhizal fungi within the might be relevant to forestry. It has two staff pan-European COST grouping which has members, whose work continues the mycor- worked to establish the Bank of European rhiza project, formerly carried out within Glomales. This system of culture registration Physiology Branch. and quality assurance in experiments on arbus­ Investigations on ectomycorrhizas have con­ cular mycorrhizal fungi, is based on a database centrated on establishing methods for inocula­ designed and written in the Unit. Data entry is tion of Douglas fir in the nursery with spores of now proceeding, and the bank will shortly be mycorrhizal fungi. Nursery experiments formally launched. Cooperative research is in showed that it was possible to inoculate with progress with laboratories in Brazil, Canada, spores of fungi in the genus Rhizopogon, and Denmark, Finland, France, Germany, India, guidelines for accomplishing such inoculations Ireland, Italy, Kenya, Spain, Switzerland and had been issued. However, continued research The Netherlands, as well as several British insti­ in the nursery failed to reproduce earlier suc­ tutes. In the Finnish work, with Dr M.Vestberg cess. Spores of R hizopogon spp. from the of the Agricultural Research Centre of Finland, Pacific Northwest were inoculated into soil Laukaa, a sealed system for culturing obligately around the roots of seedlings, but mycorrhizas symbiotic mycorrhizal fungi, has been devel­ failed to establish except with naturally-occur­ oped (see Plate 9). A contract with the Food and ring fungi. Agriculture Organization was fulfilled when Dr A European Union research project, in coop­ Walker spent a month in India providing train­ eration with research institutes in France, ing and advice to establish mycorrhiza research Germany, Denmark and Portugal, was started units in two of the Indian Council for Forestry with Silviculture (North) Branch. The project Research and Education institutes. Contracts in examines inoculation of Sitka spruce cuttings the U.K. include an investigation into the myc­ with the fungus Laccaria proximo, and will orrhizal status of a coal-mining spoil heap in investigate the effects of such inoculation on Strathclyde Region. their rooting and future field performance. The Unit Head, Dr Chris Walker, is chairman C h r is W a l k e r

23 PATHOLOGY

A substantial part of the Branch programme is tions to the fungi covered, particularly the concerned with monitoring the health of trees Agaricales, are planned in the near future. across Great Britain. In part this work is done For many years research on the biology of through the Forest Condition Survey, which Fomes root and butt rot, caused by involves annual assessment of the crown den­ Heterobasidion annosum, has been a major part sity of over 8000 forest and plantation trees of the Branch programme. In August, Derek comprising five important species. Assessment Redfern and Jim Pratt attended an International is by comparison with photographs of ideal Union of Forest Research Organizations confer­ trees. The 1993 results showed that a marked ence which was held in Sweden and Finland. two-year decline in the crown condition of They presented papers which re-appraised the Scots pine was reversed and a similar decline in need for stump protection against oak was arrested. There was a continued recov­ Heterobasidion annosum in Britain, and on the ery of beech following a decline in 1991. An use of borates and urea to control stump infec­ additional element in the 1993 survey was a tion by the fungus (Pratt, 1994; Redfern et al., second assessment, conducted with reference to 1994). These topics were particularly appropri­ a local standard rather than an ideal tree. This ate since there is now increased interest in the will permit a more satisfactory comparison with control of the disease in Scandinavia. The dis­ the data produced in many other European ease is well established in the natural forest countries (Redfern et al., 1994). there, and stump protection, which has been A new programme, funded by the practised in British plantations since 1960, has Department of the Environment on contract, generally been considered inappropriate in involves the establishment over a two-year these circumstances. However, large areas of period of a system for monitoring the health of farmland afforested since the last war are now non-woodland trees in England. A report for being thinned for the first time giving rise to 1993 (Gibbs, 1994) was based on ad h o cinvesti­ serious outbreaks of disease. Our knowledge of gations and surveys, but in future these will be the problem, and the particular papers which supplemented by observations made in a net­ were presented on this occasion, aroused great work of plots established in urban and rural interest. areas. Several scientists from abroad spent time Complementary to the above is work con­ working with members of the Branch during the cerned with events aimed at raising awareness year. Dr Stefania Tegli, from the University of of tree health among foresters, arboriculturists Florence, spent the summer working with Clive and the general public. These events are Brasier on the genetic control of cerato-ulmin arranged under the auspices of either the production (cerato-ulmin being the principal Forestry Authority conservancies or Forest wilt toxin of the Dutch elm disease fungus), and Enterprise districts and in 1993 took place at Dr Esperanza Sanchez from the Instituto eleven locations. Steve Gregory of this Branch Nacional de Investigaciones Agrarias in Madrid leads the project and he draws on the services conducted research with John Gibbs on the of other Branch members and of staff in ecology of Seiridium cardinale on Monterey Entomology, Environment and other branches, cypress and with David Lonsdale on the rela­ as appropriate. tionship between the beech scale Cryptococcus The testing and evaluation of the computer fagisuga and its parasitic fungus Verticillium programme ROTTERS, an expert key for the lecanii. Dr Remigijus Ozolincius from the identification of wood rotting fungi in culture Lithuanian Forest Research Institute spent four [Report, 1991) was completed by David Rose months with Derek Redfern working on the during the year. The programme is now being effects of S 0 2 pollution on Norway spruce. made available on a commercial basis to all

interested parties. Upgrades in the form of addi­ J o h n G ib b s

24 PATHOLOGY

REFERENCES A wide range of fungal diseases was GIBBS, J.N. (1994).The health of non-woodland trees in recorded. Early in the season, severe foliage England, 1993. Arboriculture Research and Information infection of hybrid larch and European larch by Note 121-94-PATH. Arboricultural Advisory and Information Service, Famham. Meria laricis occurred at some nurseries. Japanese larch, a species that is normally highly REDFERN, D.B., BOSWELL, R.C. and PROUDFOOT, J. resistant to this disease, was also infected, (1994).Forest condition survey, 1993. Research though not severely, in two cases. As in south­ Information Note 251. Forestry Commission, Edinburgh. ern Britain, willows at many northern localities suffered serious damage from scab disease REDFERN, D.B., PRATT, J.E. and WHITEMAN, A. [Venturia saliciperda) and, in oak, mildew (1994). Stump treatment againstHeterobasidion [Microsphaera alphitoides) was also severe and annosum a : re-appraisal.In: M. JOHANSSON and J. STENLID, eds. Proceedings of the eighth international widespread in the north. A number of cases of conference on root and butt rots. Swedish University of needle browning in Scots pine caused by Agricultural Sciences, Uppsala. 656-661. Lophodermella sulcigena were recorded in late summer and, in spring 1994, another needle PRATT, J.E. (1994). Some experiments with borates and pathogen, Lophodermium seditiosum, was with urea to control stump infection byHeterobasidion responsible for dramatic browning in some annosum in Britain. In: M. JOHANSSON and J. plantations. Several unusual diseases were also STENLID, eds. Proceedings of the eighth international conference on root and butt rots. Swedish University of recorded including Marssonina betulae on Agricultural Sciences, Uppsala. 662-667. birch, Gloeosporidium tiliae and Plectophomella concentrica on lime, and Gloeosporium nervisequum on plane. The last of these, though a common cause of dieback in D is e a s e D ia g n o s t ic a n d A d v is o r y S e r v ic e s southern Britain, is rare in the north. In one of the cases in which M. betu lae was identified, the fungus, which is normally a leaf pathogen, Scotland and northern England was found fruiting on shoot lesions. G. tiliae The year was characterised by a high number was found to be responsible for significant defo­ of enquiries in which climatic damage was liation of lime at three localities; in one believed to have been involved. In spring, instance, this was associated with infection of widespread browning was recorded on petioles as well as leaf blades. P. concentrica conifers in several northern nurseries and, in was also found on lime at three locations. It is a Sitka spruce and Douglas fir, the foliage injury common cause of canker and minor dieback in was frequently accompanied by dieback of elm but it is less well known on lime. Following shoot tips. The precise cause of these symp­ the unusual record of Pseudonectria rous- toms remains unknown but they may have seliana in last year’s Report, another case of been induced by a combination of wind and dieback in box caused by this fungus has been low temperature. Unusually severe spring diagnosed. Browning and dieback in yew were weather was also probably responsible for investigated on a number of occasions. Though some cases of damage to young broadleaves. At the cause of damage was not clearly established one exposed site in southern Scotland, oak and in any of these cases, one fungus was consis­ birch suffered substantial dieback, and went tently found on symptomatic needles and on to produce feeble shoots with exceptionally shoots. Its precise identity and possible role in small leaves. In the oak, the leaves also exhib­ the damage are still under investigation. ited a marked reddish discoloration. Autumn frosts caused browning of Sitka spruce in sev­ S t e v e G r e g o r y , G r a c e M a c A s k il l , eral plantations in southern Scotland and D e r e k R e d f e r n a n d J im P r a t t northern England. In a nursery fertilizer trial in northern England, Sitka spruce seedlings Wales and southern England that had received high nitrogen treatments sus­ tained foliage browning and shoot dieback that The generally cool and damp spring gave rise to was also probably attributable to autumn frost. a number of leaf and shoot diseases. Most The shoot injuries were extended by Botrytis noticeable were scab diseases - Venturia inae- infection in many cases. In late summer, a qualis on apple species, particularly some culti- north-easterly gale led to salt-spray damage to vars of crab apple, and Venturia saliciperda on the foliage of trees on the southern shore of the willows, particularly Golden willow [Salix alba Forth estuary. Reports suggest that this damage var. vitellina). Damage to flowering cherries by extended along the North Sea coast as far blossom wilt, caused by the fungus M onilinia south as Northumberland. [=Sclerotinia) laxa, was particularly severe in

25 PATHOLOGY

the south of England. The cultivax Prunus both species across Europe, North America and ‘Saxgentii’ was most commonly involved and south-west and central Asia (Brasier, 1990). The often suffered severe dieback. Wilting leaves on survey across China in 1987 [Report, 1988) indi­ a 22-year-old rowan in the grounds of Alice cated that China was probably not the source of Holt Research Station, Surrey, were found to be the disease. This led to the hypothesis that infected with Monilinia aucupariae. This is either introduction from the Himalayas, a major apparently the first British record for this fun­ unsurveyed region with unique elm and bark gus. beetle species, or one or more unusual evolu­ During the summer a number of cases of leaf tionary events may have been involved in its spot, followed by reddening or yellowing of origins (Brasier, 1990). affected leaves and premature defoliation, were During September and October 1993 a further reported on wild cherry. The causal fungus, research survey was carried out in parts of Blumeriella jaapii, has not been recorded by Himachal Pradesh, western Himalayas, with the this Service before and only a handful of assistance of the Forest Research Institute (FRI), records are known from other sources. It was Dehra Dun (Plate 10). No wilt disease symptoms somewhat of a surprise, therefore, to receive were seen on elms in the area, but typical beetle eight records in this year including two from feeding wounds (the point of entry of Dutch elm south Scotland and one from Northern Ireland. disease) were found on some trees of Ulmus In addition there were further reports of cherry wallichiana. In addition, a Dutch elm disease­ leaf scorch, caused by the fungus like O phiostom a was obtained from bark Apiognomonia erythrostoma, first reported last around scolytid beetle breeding galleries on U. year [Report, 1993). The year was also notable wallichiana at high altitude in two Himalayan for the number of reported cases of root killing valleys. by Phytophthora. Species affected included This is the first report of an apparently wild cherry, sweet chestnut, lime, sycamore, endemic form of Dutch elm disease fungus. The yew, Douglas fir, noble fir, larch and cedar. Himalayan fungus appears to be a separate Only two species were positively identified - P. species from O. ulmi and O. novo-ulm i (Plate cinnam om i on Douglas fir and sweet chestnut 11), but shares a number of important biological and P. citricola on yew. Phytophthora root dis­ properties with O. novo-ulm i, including the ease of alder is covered later in this report. production of high levels of cerato-ulmin, the Oak mildew, caused by Microsphaera alphi- principal protein toxin implicated in the dis­ toides, was widespread and exceptionally ease. Its discovery promises to shed new light severe in some parts of England making some on their origins. One possibility is that it is trees almost white in appearance. A severe leaf unconnected with this century’s two pan­ spot on sycamore in early September was iden­ demics, and is of solely ancient affinity to O. tified as being caused by the fungus P hleospora ulmi and O. novo-ulmr, in this case, the aceris (=pseu doplatan), ia fungus only recorded Himalayan fungus may present a further threat once before in this area (in 1955) but on three to the elms of the Northern Hemisphere. occasions more recently in Scotland and north­ Another is that it may be a recent evolutionary ern England (R eport, 1973, 1981, 1987). precursor of O. novo-ulmi. A third, suggested by the preliminary results of sexual crosses, is that D a v id R o s e , B o b S t r o u t s a n d J o a n R o s e the Himalayan O phiostom a may have hybridised with O. ulmi to give rise to O. novo- ulmi via a secondary speciation event [cf. Brasier, 1990). Indeed, if more than one hybrid A n e n d em ic D u t c h e l m d is e a s e f u n g u s in genotype was favoured by selection, or if the t h e H im a l a y a s Himalayan fungus was introduced separately into Europe and North America to give rise to Two highly destructive pandemics of Dutch elm the EAN and NAN in independent hybridisa­ disease have occurred in the Northern tion events, such hybridisation could account Hemisphere in this century, the first caused by for the many unexplained differences between Ophiostoma ulmi, and the current pandemic by EAN and NAN O. novo-ulm i(see Brasier, 1991). the more aggressive O. novo-ulmi. However, The discovery of an endemic form of the dis­ Dutch elm disease was unknown before 1900, ease may also open up new opportunities for its and the origins of both fungi are a mystery. A biological control elsewhere in the world. series of Forestry Commission sample surveys Detailed studies on the behavioural, physiologi­ aimed at elucidating the origins of the disease cal and molecular properties of the Himalayan have established the recent history of spread of fungus are now in progress. Investigations of the

26 PATHOLOGY

ecology and population biology of the disease infection obtained in English elm was identical system in the Himalayas are planned in collabo­ to U. pumila, but external symptoms of wilting ration with scientists at FRI, Dehra Dun, with a and leaf yellowing were always observed. The view to establishing the biological constraints minimum spore threshold resulting in any on the disease under natural conditions. infection in the three species was 500, 1000 and

5000 spores for U. pumila, English and C l iv e B r a s ie r Commelin elm respectively.

Apparently, the immunity of U. pumila to REFERENCES Dutch elm disease does not necessarily pre­ BRASIER, C.M. (1990). China and the origins of Dutch clude successful entry by O. novo-ulmi or its elm disease: an appraisal.Plant Pathology, 39, 5 -1 6 . partial establishment in the xylem. However, despite its more moderate level of resistance, BRASIER, C.M. (1991). O.novo-ulm sp. i nov., causative agent of current Dutch elm disease pandemics. Commelin elm may have an active resistance Mycopathologia, 115, 151-161. mechanism expressed in the bark surrounding the beetle feeding groove, perhaps derived from

its U. glabra parentage. The existence of such a mechanism requires investigation, since it D ifferential r e s is t a n c e o f e l m s t o might be exploitable for use in resistance breed­ INFECTION VIA BEETLE FEEDING WOUNDS ing.

J o a n W e b b e r a n d C l iv e B r a s ie r Studies on resistance to Dutch elm disease have concentrated almost exclusively on the spread REFERENCES of the fungus once it is within the xylem ves­ WEBBER, J.F. and KIRBY, S.G. (1983). Host feeding pref­ sels. However, initial infection commonly erence of Scolytus scolytus. In: D.A. BURDEKIN, ed. occurs via wounds (known as feeding grooves] Research on Dutch elm disease in Europe. Forestry made by the bark beetle vectors. Elms are resis­ Commission Bulletin 60. HMSO, London, pp. 47—49. tant both to beetle feeding (Webber and Kirby, 1983) and to penetration of the fungus into the WEBBER, J.F. (1987). Influence of the d2 factor on sur­ vival and infection by the Dutch elm disease pathogen, xylem via such feeding wounds (Webber, 1987) Ophiostoma ulmi. Plant Pathology, 36, 531-538. but these aspects of resistance have remained largely unexploited in elm breeding. Previous studies simulating natural insect transmission via artificial feeding grooves have An u n u s u a l P hytophthora associated with shown that a minimum 1000 spores of NAN O. DISEASE OF COMMON ALDER novo-ulmi are required to infect English elm,

Ulmus procera (Webber, 1987). Using similar tests, three elm species with different levels of During the summer of 1993 we investigated two resistance to the spread of O. novo-ulmi within cases of damage to common alder, Alnus gluti- the xylem - U. procera (moderately suscepti­ nosa, which involved the characteristic symp­ ble), Commelin [Ulmus glabra x U. carpinifolia, toms of Phytophthora root disease - death of moderately resistant) and U. pumila (immune) - bark on roots and at the stem base accompanied were compared. The wounds were inoculated by a tarry exudate (Plate 12). At one site, near with spore concentrations of O. novo-ulmi rang­ Droitwich in the west Midlands, some 20 ing from 50 to 100 000. They were then scored affected trees were distributed along the banks for persistence of the fungus in the feeding of a small stream. At the other, near a nature groove and for xylem infection one month after reserve in Kent, two affected trees were found. inoculation. Although U. pumila is highly resis­ Here damage to alder from other causes was tant to wilt disease, entry of the fungus into the probably also present. Following the dissemina­ xylem via the feeding wounds was readily tion of a press release by the nature reserve achieved. With 10 000 spores, infection authorities, a number of additional reports of occurred successfully in 70% of tests and was diseased alder were received, and on investiga­ always associated with strong internal symp­ tion Phytophthora symptoms were found at a toms of tylosis and streaking. However, no further site. This involved young (five years external symptoms of wilt were ever visible. In old) trees in Gwent that had been planted on contrast, entry was strongly restricted on the land formerly used for the production of hardy moderately wilt-resistant Commelin elm; 10 000 ornamental nursery stock. spores resulted in only 30% infection, but some Isolation attempts were made from necrotic external symptoms did develop. The level of bark tissue and from soil at the base of affected

27 PATHOLOGY

trees at all three locations. An unusual for our trials by the Belgian Instituut voor Phytophthora was isolated from the west Bosbouw en Wildbeheer, where they were bred Midlands and Gwent sites. It shows a close sim­ and where disease resistance screening has ilarity to P. cam bivora, a known pathogen of already been carried out. Further screening in hardwoods in Britain, in terms of the morphol­ the U.K. is advisable because of the possible ogy and size of sporangia and gametangia (asex­ existence of more aggressive variants of the ual and sexual spores). However, it also exhibits fungi and bacteria that cause the major poplar important differences from this species. diseases. The diseases of greatest concern in Whereas colonies of P. cam bivora are normally both countries are bacterial canker, rust and fast growing with dense woolly aerial Marssonina leaf spot, of which bacterial canker, mycelium, those of the alder fungus are slow caused by Xanthomonas populi is the most growing and ‘flat-frosty’ in appearance. They damaging in roundwood crops. sector readily, suggesting a genetic instability. The first year’s results of screening for resis­ Whereas P. cam bivora colonies grow well at tance to bacterial canker have been obtained for 30°C, the alder fungus fails to grow at this tem­ the first batch of 29 new clones received from perature. Also, whereas P. cam bivora is classi­ Belgium. The test was done using a leaf-sear cally heterothallic, requiring its two mating inoculation technique which has been standard­ types for gametangial production, the alder fun­ ised throughout most of Europe, and which gus produces gametangia and oospores pro­ requires 3—4 years for full assessment following fusely in single culture, and is therefore intrin­ inoculation. For comparison with the test sically homothallic. clones, six reference clones of known perfor­ Research is in progress on the biological mance in Belgian trials were also tested. The affinities and pathological potential of this selected results in Table 4 show the ranking of Phytophthora. A programme of fieldwork is also these reference clones, together with seven of required as little is known about the pathology the new clones, which are identified by code of common alder and we need to know whether numbers. These seven clones have all been pro­ these cases represent the norm or are a depar­ posed for possible registration in Belgium. One ture from it. additional Belgian clone has also been thus pro­ posed, but results for its first year’s screening are still awaited. It is interesting to note that J o h n G i b b s , R o b e r t S t r o u t s , J o a n R o s e a n d five of the seven clones are of very high resis­ C l iv e B r a s ie r tance to English isolates of the canker pathogen. The rather poor performance of the registered clone ‘Ghoy’, ranked 29th out of 35, is of some

S c r e e n in g o f p o p l a r c l o n e s f o r d is e a s e concern, although it must be emphasised that the final data, which will be obtained in 1995 or RESISTANCE 1996, may show a different result. This longer- term testing is likely to differentiate more With the current interest in poplars for use in strongly between clones which recover from roundwood and biomass crops, a number of initial infection and those which develop peren- new clones of enhanced growth potential are nating cankers. being evaluated for disease resistance in the U.K. These clones have been kindly supplied D a v id L o n s d a l e a n d J o a n R o s e

28 Plate 1. The self-contained, ultra low volume applicationPlate 6. Freshly sawn close-stacked pine lumber system developed by Entomology Branch for controlledconstructed in a nest arrangement, just before the droplet application of pesticides to forests. addition of plastic tanks containing sterilised board samples to the central part of the stack.

Plate 2. View of the spray rig in action during an Plateopera­ 7. Dead fungus fly surrounded by an area of tion to control pine beauty moth in Scotland.sapstain on the surface of a casing timber previously dip-treated with an insecticide. This suggests spores of staining fungi are regularly transferred onto sawn lumber by arthropod vectors.

Plate 3. Continuous flow systems for analysis of nitrogen and phosphorus.

Plate 4. Inductively coupled plasma spectrometer for Plate 5. The Headley open-top chamber site. analysis of major and minor nutrients. Plate 9. The sealed bag system, developed for growing Plate 10. Mixed Picea-Ulmus obligate symbionts free from contaminating organisms, wallichiana-Aesculusforest in the being used to produce pure cultures of arbuscularupper Kullu Valley area, northern mycorrhizal fungi. The potted plants in the bagsHimachal can be Pradesh, Himalayas. seen placed close to each other without dangerInset: of a surviving large U. cross-contamination. wallichiana in a heavily degrad­ ed forest area.

Plate 11. Representative cultures of the recentlyPlate 13. Delegates of the 1993 IUFRO Wind and wind discovered Himalayan Dutch elm disease fungus (arelated - c) damage to trees conference preparing to board O. novo-ulmi(d,e) and a culture O. of ulmi(f). a cruise of Kielderwater at the end of the field visit.

Plate 12. Phytophthora Plate 14. A long-eared owl chick just recently out of the symptoms at the base nest. A new project is investigating the ecology of this of common alder. species in coniferous forest. PATHOLOGY

Table 4. Ranking of some of the poplar clones assessed for resistance to bacterial canker in 1993 RankingClone Parental Status in testing Mean (1-35) origin canker index (0-5 scale) 1 71.015/1 § D xT New clone under test 0.966 f 2 71.009/1 § D xT New clone under test 1.000 t 3 Beaupre * T xD Registered ’UNAL’ clone 1.004 f 4 71.009/2 § D xT New clone under test 1.016 f 5 60.038/6 § T xD New clone under test 1.174 f 6 69.039/4 § T xD New clone under test 1.376 f 16 Donk *** D xT Unregistered older clone 2.268 t t 19 Boelare ** T xD Registered ‘UNAL’ clone 2.382 t 29 Ghoy ** (D x N) x N Registered ‘UNAL’ clone 2.786 t t 30 S.681-84 § D xN New clone under test 2.856 t t 31 S.683-24 § DxN New clone under test 2.865 t t 34 Regenerata **** D xN Unregistered older clone 3.114 t t 35 Androscoggin **** M xT Unregistered older clone 3.821 t t § Proposed for registration in Belgium t Mean value for five different bacterial isolates from England t t Mean value for two different bacterial isolates from England Asterisks denote reference clones of known performance in Belgian trials as follows: * highly resistant, ** moderately resistant, *** relatively susceptible, **** very susceptible Abbreviations for species of Populus used as parents: D = deltoides, T = trichocarpa, N = nigra, M = maximowiczii

29 PLANT PRODUCTION

Plant Production Branch is a team of five scien­ at 1-5°C for 3-6 weeks, referred to as tists with responsibilities divided between prechilling. A similar method termed invigora­ statutory matters related to the Forest tion incubates moist seeds at 15 or 20°C for Reproductive Material regulations, such as seed periods up to two weeks. Both methods testing and advisory work, and scientific increase the rate of germination of seeds at opti­ research to improve woody plant propagation. mal temperatures, and prechilling widens the In June 1993 the work of the branch was sub­ range of temperatures over which Sitka spruce jected to external scrutiny by a Visiting Group. seeds germinate. But the effect of invigoration Its report applauded the quality of the current on germination at sub-optimal temperatures is programme and recognised the ‘considerable unknown. This is important information synergy which exists between the testing, advi­ because Sitka spruce seeds are sown in the sory and research roles of the branch’. This spring when U.K. soil temperatures are sub- linkage is crucial to the development of relevant optimal (often 5-10°C). research programmes. Moist Sitka spruce seeds were incubated for Two notable achievements were the winning periods between 0 and 23 weeks at 5°C of a three year, European Union sponsored pro­ (prechill) or 10, 20 or 30°C (invigoration treat­ ject, in collaboration with five other countries, ments) then moved to germination conditions at on temperate broadleaved tree seed dormancy, 10°C for up to 42 days. Data showing maximum and a one year Overseas Development germination (%) reached by the end of the test Administration contract on seed pretreatment of are presented in Table 5. tropical legumes. The Branch hosted visitors from across the world, from Australia to Zimbabwe. In particu­ Table 5. Germination (%) achieved by the end of a 42 day test at 10°C. Means are based on lar, Dr Ciccarese from Italy collaborated on sev­ 4 x 100 seeds eral months’ research comparing the pretreat­ ment and germination of temperate and Treatment Temperature duration (weeks) mediterranean pines. And Mr Balcha from temperature Ethiopia spent several weeks learning seed test­ ing techniques and investigating germination 0 2 5 6 14 18 23 and viability assessments on the seeds of native 30°C (invigoration) 4 23 19 0 0 0 Ethiopian trees. 20°C (invigoration) 11 19 24 35 17 1 10°C (invigoration) 0 1 1 28 39 79 P e t e r G o s l in g 5°C (prechill) 2 3 26 90 98 93 Untreated 1

S eed a n d n u r s e r y r e s e a r c h Only 1% of the control (untreated) seeds ger­ minated at 10°C, while treated seeds reached The effects o/5°C (prechill) or 10, 20 or 30°C 98% (5°C), 79% (10°C), 35% (20°C) and 23% (invigoration) on dormant Sitka spruce seed(30°C). The best treatment was the 5°C germination. (prechill). Even the longest invigoration treat­ Sitka spruce seeds [Picea sitchensis (Bong.) ments did not bring about those benefits but Carr.), like many temperate conifer seeds, this was probably due to the increasing number exhibit shallow or conditional dormancy. They of seeds killed by fungi during such treatments. only germinate slowly and over a narrow range of temperatures. A common way to overcome this type of dormancy is to incubate moist seeds S t e v e J o n e s a n d P e t e r G o s l in g

30 PLANT PRODUCTION

Imbibition by cherry (Prunus avium) stones These results show that although the endocarp Wild cherry is an increasingly important delays the rate of water uptake by the seed, a broadleaved species for lowland planting, but two day soak is all that is required to achieve current nursery practices give erratic germina­ full imbibition of cherry seed. tion. Cherry stones are deeply dormant and In a further study it was shown that soaking require pregermination treatments for 12 or in water, before stones are transferred to the more weeks. Recommendations range from stratification medium, was not necessary since incubating moist stones at about 20°C for two a comparison of moisture content of seed in weeks followed by 12 weeks at 4°C (Gordon stones either soaked in water or placed in moist and Rowe, 1982), to a sequence of warm fol­ peat and sand showed an identical pattern of lowed by cold treatments (Suszka, 1976). The water uptake (Table 6). first stage of pretreatment involves soaking seed in water for a period of time, since seed R ic h a r d J in k s a n d J a n e B r e a r l e y must be fully imbibed to respond to the pre- treatment temperature regime. However cherry seeds are surrounded by a hard endocarp Table 6. Seed moisture content (%) which may significantly delay the rate of imbi­ Time (h) bition. A study was carried out to determine the length of time required for seed in intact Treatment 0 24 48 72 stones to become fully imbibed, and to investi­ Water soak 6 23 41 41 gate the effects of the endocarp on water entry into stones. Peat: sand 6 27 37 41 The process of imbibition by whole stones was followed by determining the change in REFERENCES moisture content of whole stones, and the con­ GORDON, A.G., and ROWE, D.C.F. (1982).Seed manual stituent endocarps and seeds over time during for ornamental trees and shrubs. Forestry Commission soaking. Results showed that the process of Bulletin 59. HMSO, London. water uptake was rapid with stone moisture content increasing from about 10% to nearly SUSZKA, B. (1976). Increase of germinative capacity of mazzard cherryPrunus ( avium L.) seeds through the 25% after 48 hours of soaking (Figure 9). The induction of secondary dormancy.Arboretum Kornickie, endocarp reached its maximum moisture con­ 21, 257-270. tent of 23% after only five hours, while seed moisture content began increasing after about Pretreatment of multipurpose tropical legume two hours and then increased at a more steady tree seeds rate, reaching about 33% after 48 hours. This Current recommendations for breaking hard pattern of change in moisture content with time seed coated dormancy in multipurpose tropical indicates that the endocarp becomes rapidly legume trees are never reliable and often inef­ saturated and then water continues to pass fective. Hence valuable seed is wasted and through the endocarp to the enclosed seed. plant supply is rarely sufficient. The Overseas Removal of the endocarp before soaking Development Administration is funding a sys­ resulted in seed moisture content reaching its tematic investigation of tropical legume tree maximum after 24 hours compared with 48 seed pretreatment and germination. hours for seed soaked inside intact stones. Leucaena leucocephala is one of the most widely planted multipurpose tropical legume trees and there is a lot of scientific, technical and anecdotal literature on the germination and pretreatment of this species. However, it appears that optimal germination conditions have yet to be established and even within recent literature there remain numerous funda­ mental anomalies and contradictions including some authors who maintain that pretreatment is unnecessary! Figure 10 shows the results of an experiment to determine the optimum germination condi­ Figure 9. The change in moisture content with tionstime of of L. leucocephala seeds which were intact stones, the endocarp, and Prunus seed avium of either untreated or pretreated by chipping with stones. a scalpel. One obvious feature is that germina-

31 PLANT PRODUCTION

germination occurred. At temperatures of 15-35°C inclusive the germination of chipped seeds reached ca. 80% and was consistently 60% higher than untreated seeds. It can be concluded, firstly, that a chipping pretreatment does stimulate the germination of L. leucocephala and, secondly, that laboratory seed tests could be carried out over a relatively wide range of temperatures because the germi­ nation capacity of untreated and chipped seeds is not significantly affected at constant incuba­ tion temperatures in the range 15-35°C.

P e t e r G o s l in g , Y v o n n e S a m u e l a n d S t e v e J o n e s Figure 10. Germination capacity at different temperatures of untreated and chipped Leucaena leucocephala. O f f ic ia l S eed T e s t in g S t a t io n tion was completely prevented at 10°C and In 1993-94, we tested 180 Forestry Commission 40°C, but was otherwise extremely consistent seed lots, 233 lots from the Oxford Forestry between 15 and 35°C. An interesting contrast Institute, and 73 seed lots from seed merchants between the ungerminated seeds remaining at and nursery managers. 10°C and 40°C was that seeds at the former ger­ A contract to perform additional tests for the mination temperature remained alive but those Oxford Forestry Institute was carried out with at the higher temperature had been killed. help from a biology graduate on a temporary Another obvious feature is that chipped contract. seeds germinated significantly better than untreated seeds at all temperatures at which Y v o n n e S a m u e l a n d P e t e r G o s l in g

32 SILVICULTURE (NORTH)

undertook a contract for Forest Enterprise, pro­ O v e r v ie w viding revised windiness scores for all their forests in upland Britain, calculated using a geo­ graphical information system. Following a review of the branch structure in James Simpson organised a European Union the Division, we were joined in October 1993 by (EU) sponsored workshop on The establishment Helen McKay, Bruce Nicoll, Colin McEvoy, of farm woodlands in conjunction with col­ David Clark and Joyce Harrower from leagues from Institut National de la Recherche Physiology Branch. We have worked closely Agronomique in France. The workshop was with them in the past, especially on aspects of attended by researchers from throughout the EU plant stock quality and root development, and and provided recommendations on topics in look forward to developing integrated pro­ this field requiring future research. grammes that will build on their physiological Besides these aspects, staff were involved in a expertise and our silvicultural skills. range of research initiatives related to the Windthrow has long been recognised as a Government’s sustainable forestry programme, major constraint on British silviculture, particu­ including natural regeneration, nutritional impli­ larly on the shallow-rooting acid soils of north­ cations of whole-tree harvesting, farm woodlands ern and western Britain. Research into the silvi­ and community forestry. Research into the devel­ cultural, physical, physiological and ecological opment of site-specific silvicultural regimes and aspects of windthrow has understandably been systems is essential if multipurpose forest man­ a major component of our work. 1993 saw a agement is to become a reality. number of important developments in this field. Firstly, a major and very successful interna­ B il l M a s o n tional conference on Wind and wind-related damage to trees was held in July at Heriot-Watt University under the auspices of the International Union of Forestry Research P hysiological q u a l it y o f p l a n t in g st o c k Organizations (Plate 13). The organising com­ mittee was chaired by Chris Quine, and staff Two years’ experiments investigating survival from the Northern Research Station were major and growth of directly planted bare-root stock contributors to and organisers of the five day have shown major species differences in out- meeting. The meeting attracted international planting performance. Sitka spruce of Queen interest with over 100 people attending. Charlotte Islands origin could be planted over Speakers from Europe, Australasia and North the widest period (November to March) with America provided a very valuable account of good survival and growth, whereas survivals of research and its application. greater than 80% with Douglas fir were Earlier in the year, two Research Information achieved only when planted in February and Notes were published representing the first sub­ March. Both Corsican and Scots pine had poor stantial updating of the Windthrow Hazard survival when planted immediately after lifting Classification since the early 1980s. The modifi­ in October; survival improved as lifting was cations give a more accurate estimate of the delayed, reaching 95% in mid-November. Pine windiness scores for a particular site. In prac­ survival fluctuated during November and tice, these modifications appear to reduce the December but was >85% throughout January, amount of forest area in the highest risk classifi­ February and March. The pattern of survival for cation (WHC VI). Because of the investment and Sitka spruce, Douglas fir, Scots pine and planning implication of these changes, we held Corsican pine was closely related to the condi­ a one day briefing for members of the Timber tion of their fine roots, which was assessed by Growers Association in October 1993 and electrolyte leakage.

33 SILVICULTURE (NORTH)

The response of both hybrid and Japanese larch to direct planting was different to that of the ever­ I n f l u e n c e o f fertilization o n f o r e s t green conifers. Freshly lifted larch had two dis­ PERFORMANCE OF SlTKA SPRUCE PLANTING tinct times (one in autumn and one in spring) STOCK when >80% survival was achieved; there was poor survival (50-60%) in mid-winter. These fluc­ tuations were closely related to seasonal changes Nursery regimes in larch root growth potential but not to elec­ A large number of Sitka spruce plants are pro­ trolyte leakage — in mid-winter the roots were in duced using precision sowing and undercutting excellent condition but did not elongate even techniques rather than traditional methods of when given good conditions for growth. The broadcast sowing and transplanting. Undercut autumn lifting window was narrow and varied stock is associated with better physiological from year to year, whereas survival of >80% was condition and root:shoot ratios than transplants achieved throughout March. The results from of the same age (Deanset al., 1989; McKay and these experiments were combined with those Mason, 1991). Recent experiments at the Forest from cold-storage experiments to make recom­ Enterprise nursery at Wykeham have demon­ mendations on the best management strategies for strated that the process of undercutting is asso­ larch: direct planting of larch lifted during the last ciated with a reduction in the nitrogen content twoweeks in October and during March, and cold of foliage even when trees are given high rates storage of stock lifted between November and of fertilizer to compensate for root regeneration mid-March with planting in early April. (Figure 11). To ensure that trees achieve size Seasonal trends in the physiological condi­ specifications and high nutritional status, nurs­ tion of oak, ash, beech and Norway maple have eries now repeat top dressings with compound been examined by measuring root growth fertilizer to redress nitrogen, phosphorus and potential, electrolyte leakage from the fine (<2 potassium deficiency. In some cases high fertil­ mm diameter) and tap roots, root and shoot izer input regimes are not appropriate due to moisture content, shoot water potential, and tol­ environmental or managerial concerns, particu­ erance to frost, desiccation and rough-handling. larly where there is a risk of losses to ground­ In general, the species showed the same pat­ water. It is therefore important to specify opti­ terns of electrolyte leakage and stress tolerance mum fertilization regimes for crop growth and as conifers (decreasing electrolyte leakage dur­ subsequent forest performance. Experiments ing October to December before stabilizing at a suggest that rates of fertilizer equivalent150 to low over-winter level, and increasing stress tol­ kg nitrogen ha-1 yi-1 are optimum for plant erance during autumn with maximum tolerance growth in the nursery (Figure12), while higher during winter). There were marked and consis­ inputs are unlikely to be justified in height tent differences among the species. Ash, for growth terms. example, had the lowest fine root electrolyte leakage. Both ash and oak had much greater Forest performance shoot water potentials during winter (30 and 20 The influence of nutrition on forest perfor­ bars respectively) than maple and beech (<5 mance of Sitka spruce transplants has been bars). This work has been funded by the extensively researched by Benzianet al. (1974). Department of the Environment. The main findings from her work suggested that Morphological and physiological differences optimum nutrition was not important to sur­ among seedlings of four native Scots pine origins vival but did benefit subsequent height growth (Loch Maree, Glengarry/Glen Moriston, Glen of trees. Recent outplanting experiments with Affric, and Abernethy), from a British seed orchard Sitka spruce undercuts given different nutri­ and of a provenance from middle Sweden were tional regimes in the nursery did not show a examined. Several consistent differences have been consistent response (Table7). Foliage nutrient noted. The plants from seed orchard seed were analysis has suggested that trees achieve simi­ largest but had the poorest root:shoot ratio. The lar, satisfactory, nutrient concentrations after Loch Maree provenance seems to allocate the great­ one growing season despite contrasting nutri­ est proportion of its biomass to fine roots and nee­ tional status at planting (Table 8). The implica­ dles and the smallest proportion to the stem and tion of these findings is that foliar nitrogen sta­ woody roots. Plants raised from Swedish seed are tus may be less critical for planting stock slightly more root frost hardy. This work has been establishment than other aspects of plant qual­ funded by the Scottish Forestry Trust. ity. Physiological assessments of frost hardiness and root electrolyte leakage did not indicate any H e l e n M c K a y , C o l in M c E v o y a n d M ik e P e r k e s differences between trees grown with different

34 SILVICULTURE (NORTH)

Undercutting date Undercutting date I i

200 kgN

100 kgN

50 kgN

co n tro l

i i O N Date (month 1990 and 1991)

Figure 11. Foliar nitrogen concentrations of Sitka spruce undercuts with different nitrogen regimes.

Date (month 1990) Figure 12. Height growth of Queen Charlotte Islands Sitka spruce 1u1 undercuts in response to different top dressings.

levels of nutrition. However, high rates of fertil­ REFERENCES BENZIAN, B., BROWN, R.M. and FREEMAN, S.C.R. izer top dressing may even be detrimental to (1974). Effect of late-season top-dressings of nitrogen forest performance where root:shoot ratios are (and potassium) applied to conifer transplants in the adversely affected. nursery on their survival and growth on British forest sites. Forestry, 45, 151-184. Jo h n M org an an d B ob H owes

35 SILVICULTURE (NORTH)

Table 7. Survival and first year increment of Sitka spruce undercuts planted with different nutritional status Treatment (quantity of Experimental site (1992 planting season) fertilizer applied in nursery, kg N ha~1) Brecon 39 North Yorks Moors 67 Moray 26 Survival (%) Control - 0 97 97 94 50 96 91 99 100 97 97 98 200 94 98 98 LSD @ 5% ns 5.0 ns Height increment (cm) Control - 0 13.2 5.7 8.2 50 9.2 4.9 4.8 100 7.5 6.0 5.3 200 12.3 9.1 5.5 LSD @ 5% 3.3 2.2 1.6

Table 8. Foliar nitrogen concentrations at the end of the first growing season Experimental site (1992 planting season) Initial nitrogen level (% oven Treatment dry weight) Brecon North Yorks Moors Moray Control 0.97 * 2.49 2.82 2.74 50 N 1.33 ** 2.35 2.86 2.75 100 N 1.74 ** 2.11 2.77 2.68 200 N 2.17*** 2.18 2.70 2.81 LSD @ 5% 0.26 0.22 ns ns Deficient levels for nursery stock Marginal levels for nursery stock *** Satisfactory levels for nursery stock

DEANS, J.D., MASON, W.L., CANNELL, M.G.R., growth (Coutts and Nicoll, 1991). This behav­ SHARPE, A.L. and SHEPPARD, L.J. (1989). Growing iour combined with an ability to turn down­ regimes for bare-root stock of Sitka spruce, Douglas fir and Scots pine. I: Morphology at the end of the nursery ward in response to certain surface conditions phase.Forestry, 62, Supplement, 53-60. (Coutts and Nicoll, 1993) allows these roots to track beneath the soil surface. The better nutri­ McKAY, H.M. and MASON, W.L. (1991). Physiological ent supply and aeration near the soil surface let indicators of tolerance to cold storage in Sitka spruce surface roots thicken faster than other deeper and Douglas fir seedlings.Canadian Journal of Forestry roots and, as a result, they develop into the Research, 17, 7 8 7 -7 9 3 . tree’s main structural roots. These are important for tree stability, but can cause damage in urban areas when growing under pavements or other structures. S u r f a c e r o o t development o f u r b a n tr ee s Experiments are now under way to find the basic patterns of root development in four Previous work on conifer species showed that species of broadleaved trees. This work is roots originating from the upper part of tree root funded by a Department of Environment con­ systems have an innate tendency for upward tract, and is directed towards understanding the

36 SILVICULTURE (NORTH)

development of surface roots in amenity areas. sium nutrient status of trees (Harrison and The direction of growth and allocation of bio­ Helliwell, 1979; Dighton and Harrison, 1983; mass between main lateral roots is being inves­ Jones, et al., 1987; Jones and Poskitt, 1991). This tigated using seedlings and transplants of technique is based on the rate of uptake of a Norway maple, wild cherry, hawthorn and sil­ labelled element (phosphorus, nitrogen, or ver birch. Trees are grown both in controlled rubidium as an analogue for potassium) from conditions and also outdoors in large containers solution by excised roots. The technique inte­ that allow relatively unrestricted root develop­ grates plant and soil conditions, and could be ment. Basic patterns of growth are determined potentially more effective than foliar analyses by excavation and measurement of coordinates for predicting nutrient deficiencies and hence using methods developed on conifers. Analysis fertilizer response. of diameters will provide information for these A fertilizer experiment was established in species on whether biomass is allocated pre­ south Wales in 1991 to investigate which nutri­ dominantly to a few large surface roots or to a ent (nitrogen, phosphorus or potassium), or larger number of small roots. Such differences combination of nutrients, was most effective in would be useful in selecting trees for planting promoting growth in a late thicket stage Sitka in urban areas. Other experiments will identify spruce crop planted in 1968. This allowed a the responses of roots to barriers in the soil. comparison of the root bioassay technique with Barriers are sometimes used in an attempt to standard foliar analysis. Samples of top whorl avoid the damage caused by surface roots to foliage were collected and analysed using stan­ pavements. These experiments will examine if dard procedures (Taylor, 1991) in autumn 1990. roots can be permanently deflected or if they Root samples were collected in May 1991 for return to their original growth direction after root bioassay assessment. Fertilizer applications negotiating a barrier. Work in both parts of this of nitrogen, phosphorus and potassium were study is at an early stage, but an initial assess­ made to the plots in a factorial design in July ment indicates large differences in root system 1991. Both the foliar and root sampling assess­ development between species. ments were carried out one and two years after the initial assessments, and basal area growth B r u c e N ic o l l was assessed annually. The foliar concentrations prior to fertilizer REFERENCES application indicated marginal to deficient COUTTS, M.P. and NICOLL, B.C. (1991). Orientation of the lateral roots of trees. I: Upward growth of surface nitrogen levels, deficient phosphorus levels and roots and deflection near the soil surface.New potassium levels well above the marginal Phytologist, 119, 227-234. threshold. Threshold values were those identi­ fied for younger crops (Binns et al., 1980). From COUTTS, M.P. and NICOLL, B.C. (1993). Orientation of these foliar analyses a growth response to phos­ the lateral roots of trees. II: Hydrotropic and gravitropic phorus and possibly nitrogen would have been responses of lateral roots of Sitka spruce grown in air at predicted. Results from the root bioassay indi­ different humidities.New Phytologist, 124, 277-201. cated very strong uptake of both phosphorus and potassium, with a relatively low uptake for nitrogen (Jones and Poskitt, 1991), suggesting a A COMPARATIVE STUDY OF TWO METHODS FOR growth response to both phosphorus and potas­ PREDICTING FERTILIZER RESPONSE sium might have been expected, while one to nitrogen would seem unlikely. Foliar sampling after fertilizer application Where significant growth responses can be showed a significant increase in nitrogen levels obtained, the application of fertilizer late in a with nitrogen fertilizer application, in both forest rotation can be economically attractive. 1991 and 1992. Phosphorus and potassium lev­ However, past research has shown that it is dif­ els only showed a significant response to, ficult to predict where crops more than 15 years respectively, the phosphorus and potassium fer­ old will respond to fertilizers. This is especially tilizer in 1992. By comparison, the root bioassay true for Sitka spruce crops, where it has proved results showed significant reductions in uptake difficult to establish any relationship between as a result of all fertilizer applications (nitrogen, foliar nutrient concentrations and growth phosphorus and potassium) in 1992, although responses to fertilizer applications in pole-stage in 1993 this effect was only significant in the crops (McIntosh, 1984). case of phosphorus. A root bioassay technique has been devel­ oped at the Institute of Terrestrial Ecology for Analysis of basal area increment during 1992 assessing the nitrogen, phosphorus and potas­ and 1993 shows that the only element to which

37 SILVICULTURE (NORTH)

there has been a positive growth response has Seven FE forest districts were included in the been phosphorus. There is no indication of study with the highest mean level of regenera­ either a response to the other two elements ortion (60% of full stocking) being found at sites an interaction between the elements. in the Forest of Ae, Dumfries and Galloway In conclusion, neither foliar analysis nor the Region. In general, greater densities of seedlings root bioassay technique have proved reliable were recorded on sites with peat and peaty gley guides as to which fertilizer to apply in a 26- soils. This trend was also associated with the year-old Sitka spruce crop. rate of site re-invasion by vegetation. Grasses and rushes were found to be particularly com­ J a n e t D u t c h a n d N e v il l e D a n b y petitive to young seedlings, and their presence greatly reduced the final density of established REFERENCES regeneration. Mosses appeared to provide a very BINNS, W.O., MAYHEAD, G.J. and MACKENZIE, J.M. good medium for seed germination on moist (1980).Nutrient deficiencies of conifers in British forests. sites which were not prone to droughting. The Forestry Commission Leaflet 76. HMSO, London. reduced vigour of vegetation on high elevation DIGHTON, J. and HARRISON, A.F. (1983). Phosphorus sites (>250m a.s.l.) also provided a better oppor­ nutrition of lodgepole pine and Sitka spruce stands as tunity for Sitka spruce seedling establishment. indicated by a root bioassay.Forestry, 56, 33-43. The influence of good seed years was evident throughout. Particularly high seedling densities HARRISON, A.F. and HELLIWELL, D.R. (1979). A bioassay for comparing phosphorus availability in soils. were evident on sites which had been supplied Journal of Applied Ecology, 16, 495-505. with abundant seed at a time when the ground conditions were receptive to seed germination JONES, H.E., HARRISON, A.F. and DIGHTON, J. (1987). and seedling establishment. If, as suggested by A 86 Rb bioassay to determine the potassium status of the literature (e.g. Isaac, 1940; Scarratt, 1966), trees.New Phytologist, 107, 695-708. Sitka spruce seed remains viable for only one

JONES, H.E. and POSKITT, J.M. (1991).A preliminary year, then the timing of felling of trees in rela­ assessment of the nutrient status of Sitka spruce in an tion to the seed production cycle appeared criti­ area affected by bent top in the south Wales coalfield. cal to successful promotion of natural regenera­ Contract report, project no. T01062B5. Institute of tion. Ecology, Grange-over-Sands. Unpublished. The results of this study will enable future

McINTOSH, R. (1984).Fertiliser experiments in monitoring work to concentrate in more detail established conifer stands. Forestry Commission Forest on the most relevant factors such as vegetation Record 127. HMSO, London. competition, seed production cycles, and soil and site conditions. The work has also provided TAYLOR, C.M. A. (1991).Forest fertilisation in Britain. a very useful stimulus to the consideration of Forestry Commission Bulletin 95. HMSO, London. managing natural regeneration in a deliberate and planned way. A workshop to discuss the management of Sitka spruce natural regenera­ N a t u r a l regeneration o f S it k a s p r u c e tion within Forest Enterprise is now being arranged.

The majority of Sitka spruce stands are cur­ C h r is N i x o n , P e t e r O l iv e r a n d C o l in E d w a r d s rently managed under a patch clear-felling silvi­ cultural system which relies upon artificial REFERENCES regeneration. However, heavy seed years can ISAAC, L.A. (1940).Life of seed on the forest floor. result in the occurrence of very dense natural Research Note 31. United States Department of regeneration on receptive sites. This creates a Agriculture Forestry Service. number of problems for forest managers in plan­ ning the restocking of forest areas. SCARRATT, J.B. (1966).Germination, early growth and The deliberate fostering of Sitka spruce nat­ survival of Sitka spruce seedlings. Ph.D. Thesis, University of North Wales, Bangor. ural regeneration would offer an opportunity not only to reduce the costs of restocking but also to increase the diversity of the forest. In order to help identify the site and crop factors THE AGE STRUCTURE OF THE NATIVE PINEWOODS which influence the success of Sitka spruce nat­ o f S c o t l a n d ural regeneration on the characteristic site types of the Border country, a survey of 47 sites was carried out during the summer of 1993, on con­ Pine dominated forests, once widely distributed tract to Forest Enterprise (FE). across the Scottish Highlands, are now reduced

38 SILVICULTURE (NORTH)

The mean tree age at the three study sites was 185 years with a range from 27-323 years. At Glen Loy, three distinct age classes were appar­ ent (Figure 13), while at Glengarry the majority of trees were found to be within a range of 160-210 years (Figure 14). The Loch Arkaig woodlands also had a compact age range of 149-271 years (Figure 15). All three woodlands lacked young trees as a result of restricted regeneration over the last 100 years. The struc­ ture of the mature trees was semi-irregular in nature with the oldest trees being scattered throughout areas of younger individuals, sug­ gesting that previous regeneration had occurred in relatively small pockets rather than as a result of catastrophic wind or fire damage. The range of tree ages present in the three pinewoods was similar to that found in the three Mar Lodge pinewoods. The distribution of tree ages seen in each woodland appears to be largely a function of variations in the exploita­ tion and management history of each area rather than inherent site-based variation. The study has illustrated the fundamental changes in the structure of the native pinewoods brought about by man’s intervention and exploitation. In some cases, the lack of young trees may put the regenerative capacity of the woodlands in doubt unless, in future, management acts to address the problems asso­ ciated with the lack of regeneration. Further work is needed to study the seed viability, and the periodicity of seed production of the older trees to help to assess the urgency of the situa­ tion. More detailed and wider ranging studies are still needed. An increased understanding of the structure and dynamics of these woods will to remnant populations. In order to manage and make it possible to manage and extend the extend these woodlands we need more informa­ existing remnant woodlands in an ecologically tion about their natural composition and struc­ appropriate manner, thereby helping to satisfy ture. A study was carried out during the sum­ the objectives of the Forestry Authority’s guide­ mer of 1993 of the age structure of three lines for the management of the native pinewoods in west Scotland at Glengarry, Glen pinewoods. Loy and Loch Arkaig (Highland Region). All three study sites were representative of the C h r is N ix o n , T im G o u c h e r a n d C o l in E d w a r d s south-western biochemical region of the native pinewoods, thereby complementing earlier REFERENCE work carried out within the east central region NIXON, C.J. and CAMERON, E. (1994) A pilot study on at the Mar Lodge Estate in Deeside (Report, the age structure and viability of the Mar Lodge 1993; Nixon and Cameron, 1994). pinewoods. Scottish Forestry, 48(1), 22-27.

39 SILVICULTURE (SOUTH)

strategy to ensure the conservation of the O v e r v ie w genetic variability of the species. Measuring and recording of notable trees has been continued largely through support for the Silviculture of broadleaves Tree Register of the British Isles, and a revision Handbook 9, Growing broadleaves for timber by of Champion trees has been prepared for publi­ Gary Kerr and Julian Evans, was published dur­ cation as a Technical Paper. ing the year and launched by the Forestry Authority on the occasion of the Centre of Weed control Excellence award ceremony at Workmans Wood near Birdlip, Gloucestershire. The heavy load of advisory work on forest weed Experiments on the silviculture of walnut control has continued. A revised version of were written up by Gary Kerr and published in Field Book 8, The use of herbicides in the Forestry. forest, has been finalised and presented for pub­ lication. In the meantime, Research Information Poplars and short rotation coppice Note 246 (Edwards et al., 1994) has been released, giving an up-to-date listing of cur­ A well attended conference was held at the rently approved herbicide products. National Agriculture Centre at Stoneleigh enti­ tled Poplar - a profitable farm and woodland Avon Vegetation Research contract crop, and selected papers from the conference were published in the Quarterly Journal of Further experiments investigating the effective­ Forestry (Tabbush, 1993a). Poplar research con­ ness of herbicides to control forest and nursery centrated on the European Union contract weeds were carried out, under contract, by working towards European site yield predic­ David Clay and Fiona Dixon of Avon Vegetation tions for poplar as an alternative use for land Research, with joint funding from The Forestry surplus to agricultural requirements. Four new Authority and Forest Enterprise. clonal trials were set up to include 60 new As part of the search for more effective foliar- clones received from Belgium since 1990, and a acting herbicides for forest nurseries, crop toler­ set of Dutch and Italian clones which are being ance was evaluated by testing the effect of seven planted in similar experiments in the other herbicides at three doses and two application European countries. dates on birch, Japanese larch and Sitka spruce. A final report on an Energy Technology Simulated rain was applied to half the pots 24 Support Unit (ETSU) contract, Coppiced trees hours after spraying to assess potential for root as energy crops, was presented to ETSU and uptake. Fluroglycofen-ethyl and pyridate were published by them (Tabbush, 1993b). New generally safe except on birch at the first appli­ experiments were established under two new cation date. Desmetryn, metamitron and thifen- contracts: Initial spacing (ETSU) and The effects sulfuron-methyl were generally safe on larch. of sewage sludge (Southern Water Services). Post-spraying rain increased the toxicity of cyanazine on all species, but reduced that of Arboreta and dendrology desmetryn. The hunt for native black poplar trees (Populus Heather can be a serious problem on some nigra subsp. betulifolia) has been pursued nurseries; candidate herbicides were evaluated through the press and radio, and 1046 trees ver­ for pre- and post-emergence control. Pre-emer­ ified so far. A Research Information Note has gence applications of chlorthal dimethyl, been published (White, 1994). A collection of napropamide, oxadiazon and propyzamide were authentic native black poplar accessions is effective at low doses. Metazachlor gave promis­ being established at two forest sites (one in ing results as a post-emergence treatment. South Wales and one in Norfolk), as part of a Previous work has shown the effectiveness of

40 SILVICULTURE (SOUTH)

imazapyr for control of Rhododendron pon- TABBUSH, P.M. (1993b).Coppiced trees as energy ticum. Further experiments have shown that crops. Energy Technology Support Unit B 1291. translocation of herbicide from sprayed shoots Department of Trade and Industry, London. is quite rapid but root exudation of imazapyr WHITE, J.E.J. (1994).Black poplar: the most endangered and transfer to adjacent plants was not detected. native timber tree in Britain. Research Information Note Where the foliage of sprayed bushes was cut off 239. Forestry Commission, Edinburgh. two or more days after spraying there was no regrowth from cut stumps. Where untreated R. ponticum or spruce trees were grown in the same pots as treated plants there was no evi­ R e s e a r c h a n d demonstration in t h e dence of imazapyr damage. N a t io n a l F o r e s t Cycloxydim was shown in the 1992 work to be very effective for the control of wavy hair The Branch is establishing three large-scale grass (Deschampsia flexuosa). This was con­ demonstration and research woodlands in the firmed in a new experiment where it gave con­ National Forest, in consultation with the trol superior to fluazifop-butyl or glyphosate on National Forest Team, and with part-funding plants grown under different moisture regimes. from the Department of the Environment. The aims of these woodlands are: Arboriculture and urban forestry • to demonstrate cost effective techniques of The Arboriculture Advisory and Information woodland creation; and Service became free-standing with finance through the Tree Advice Trust and was • to investigate alternative methods of estab­ launched by Lord Strathclyde in March 1993. lishing a range of multiple-use woodlands. The demonstration plot concept has devel­ The sites have been selected to represent the oped through the success of the demonstrations type of land that is likely to be planted within at Wednesbury (in association with the Black the National Forest. The largest site extends to Country Urban Forestry Unit), and at Thames 13 hectares (ha) of newly restored spoil at the Chase and the Forest of Mercia in association former Desford colliery in Leicestershire. The with the community forest teams. This year, a other two sites comprise eight ha of good qual­ 19 hectare demonstration was planted on col­ ity arable land at Barton-under-Needwood, liery spoil in association with Nottinghamshire Staffordshire, and 11 ha of low grade pasture County Council. near Swadlincote, Derbyshire. Each woodland A final report was presented to the combines a number of demonstration areas, Department of the Environment (DoE) on the showing a range of establishment systems, with Arboriculture V contract, and on the basis of research experiments investigating topics such this a new contract has been obtained, in part to as mixtures, direct seeding, spacing and species pursue the idea of a plant quality index. The trials. Figures 16, 17 and 18 (with plates) show work on planting stock has been written up by planting plans for the three areas. Incorporated Gary Kerr for publication in Forestry. in the three demonstration woodlands are five DoE funded work on the use of steel rods to ha of open space, water features, existing copses assess soil aeration has been published by and hedgerow, all of which are being actively Simon Hodge in three peer-reviewed journals managed. and as an Arboriculture Research Note (ARN). Conference presentations were made in the U.K. Successful establishment on newly restored and U.S.A. and more than 50 enquiries received colliery spoil from around the world. Similarly, DoE funded One of the major challenges is to establish trees work on compressed-air soil injection and stem on the newly restored colliery spoil at Desford. nutrient injection has been published in The Detailed site analysis revealed several obstacles Arboriculture Journal and in three ARNs. to successful woodland establishment. The mound of colliery spoil was covered with P a u l T a b b u s h between 15 and 40 cm of topsoil which was unstable on some of the steeper slopes; the spoil r e fe r e n c es was also very compacted. In addition, a very EDWARDS, C., MORGAN, J. and WILLOUGHBY, I. high level of pyrites was found in the colliery (1994).Approved herbicides for use in forestry. Research spoil, which on contact with air would result in Information Note 246. Forestry Commission, Edinburgh. extreme soil acidity. These problems are being alleviated by the addition of coarse lime, to TABBUSH, P.M. (1993a). Poplar husbandry.Quarterly Journal of Forestry, 87, 203-205. ensure controlled buffering of acidity, and con­

41 SILVICULTURE (SOUTH)

tour ripping to alleviate compaction and species to obtain information on how this range improve soil stability on slopes. of species performs on a difficult site. The A range of tolerant species has been grouped experiment has also been replicated on the good for planting depending on site conditions. On arable site and the poor quality grazing site, to the north facing slope a mixture of mainly oak compare the performance of these species on (Quercus spp.) and birch (Betula pendula) was sites of varying quality. planted; on more drought stressed areas grey alder (Alnus incana), Corsican pine (Pinus nigra Direct sowing of tree seed var. m aritim a) and silver maple (Acer sacchar- Direct sowing of tree seed as a low cost method inum) were planted. To broaden our under­ of establishing trees on former agricultural land standing of species choice on difficult sites, two has recently generated a lot of interest. The species trials have been established to investi­ methods currently being used involve the direct gate exotic and native species. The former sowing of tree seed at high densities at the same includes 17 species which have potential on time as an agricultural crop such as linseed or any combination of dry, acid or compacted sites oilseed rape. The seedlings are protected by the and are considered robust; examples of these agricultural crop which is removed during or at include Robinia pseudoacacia, Ginkgo biloba the end of the first growing season to allow the and Catalpa speciosa. Other elements of the trees to grow on. Similar systems can be traced robust establishment package were: high stock­ back to recommendations made by John Evelyn ing density (between 3100 and 4500 stems per in his classic work Sylva, or a discourse of for­ hectare) to ensure that woodland conditions are est trees, first published in the seventeenth cen­ established as quickly as possible; fertilizer tury. The main potential benefit of the system is application; careful planting using high quality that it uses techniques which are familiar to stock; and effective weed control. farmers, but this must be balanced against the unpredictability of emergence of dormant tree Creation of new native woodland seed and the difficulties in controlling arable On each of the three sites a large area of new weeds near young tree seedlings. Two experi­ native woodlands has been established using ments have been established, to examine the the design principles outlined in Forestry direct sowing of oak and Scots pine (Pinus Commission Bulletin 112 Creating new native sylvestris) tree seed and subsequent vegetation w oodlands (Rodwell and Patterson, 1994). The management strategies, on the colliery spoil and aim is to plant native trees and shrubs based on the good quality arable site. the composition of semi-natural woodlands on The areas contain much that is relevant to the similar sites within the framework of the expansion of forestry in lowland Britain and National Vegetation Classification (Rodwell, have already attracted large numbers of visitors 1991). Different methods of establishment have since planting began in January 1994. been used to form woodlands on similar sites with the objective of comparing the costs of G a r y K e r r , S im o n H o d g e , Ia n C o l l ie r each system with the structure and form of the a n d N ic k R y l a n c e resulting woodlands. r e f e r e n c e s Growing trees for profit RODWELL, J.S. (ed.) (1991).British plant communities, Vol. 1: Woodlands and scrub. Cambridge University The subject of the eight ha demonstration area at Press, Cambridge. the Barton-under-Needwood site is Silviculture for profit, which shows how to maximise the RODWELL, J.S. and PATTERSON, G. (1994).Creating economic return from forestry on good arable new native woodlands. Forestry Commission Bulletin land. The area contains: poplars (grown at one 112. HMSO, London. and three metre spacings for chips and pulp, and eight metre spacings for veneer) with or without understorey plantings; pure fast growing conifers such as Corsican pine and Norway spruce (Picea S u r v e y o f n a t u r a l colonization abies); Norway spruce and ash (Fraxinus excel­ sior) in different types of mixture; and pure ash Natural colonization is the process of woodland and sycamore (Acerpseudoplatanus). creation on previously unwooded sites by nat­ ural dispersal of seeds. It has long been recog­ Growth of native tree species nised as a method of establishment and a recent An experiment on the Desford colliery site com­ survey within the West Midlands Borough of pares the survival and growth of 17 native tree Sandwell has shown that 35% of the woodland

42 SILVICULTURE (SOUTH)

present arose in this way. Although it is proba­ quadrats with this type of sward were colonised bly the closest method to a natural succession to an acceptable level (Figure 20). that can be achieved it is very unpredictable and it is difficult to control either the speed of the process or the character of the woodland which develops. A survey of natural coloniza­ tion was carried out in 1993 to associate site characteristics with the presence of seedlings and help managers identify sites where natural colonization is likely to be successful. The survey covered a total of 47 sites which had been abandoned for between 10 and 41 years, situated in Avon, south Staffordshire and the West Midlands. Sites varied between one and seven hectares (ha) in size, and sufficient 4 x 4 m quadrats were assessed at each to cover 2.1% of the area. The following characteristics were assessed within each quadrat: numbers Figure 20. The effect of vegetation type on number of and mean height of each woody species present; quadrats colonised in a survey of abandoned urban predominant vegetation type (e.g. weak grass sites. sward, herbs); nature of the substrate (e.g. col­ liery spoil, top soil, rubble); texture of the sub­ strate (e.g. clay, sand); penetrability; damage; Eight different substrates were recognised; and aspect. The species of parent trees sur­ top soil was the most frequent and pulverised rounding the site were also recorded. fuel ash the least. There was a strong positive association between the presence of coloniza­ Species tion and either sub-soil or small-sized soil-less substrates such as gravel, ballast and clinker, In all, 25 species were found as seedlings but where approximately 50% of quadrats were their frequencies and abundances varied con­ colonised. In contrast there was a negative asso­ siderably. The species which were found at the ciation with pulverised fuel ash where no greatest number of sites - hawthorn (25), wil­ seedlings were found. low (22), birch (17), oak (17) and ash (12) - Texture of the substrate also had an influence were generally the most abundant with the on the occurrence of colonization. There were largest total numbers of seedlings in the order: significant negative correlations between the ash (705), birch (673), willow (515), hawthorn presence of seedlings and either sand or imper­ (398), and oak (104). Some species, such as vious substrates such as rock and concrete. In alder and beech, were present as parents but not contrast the presence of seedlings was posi­ found as seedlings, whereas others such as dog­ tively correlated with loam and clay. wood and wayfaring tree were found as The relationships between colonization and seedlings but not seen as parents. The distribu­ other factors are less clear. Too little damage tion of colonising species differed between the was observed to allow useful analysis. There three areas (Figure 19, with plates). In relatively was some evidence which suggested that sites rural Avon, 17 species were recorded, with ash of low penetrability (high compaction) were less and hawthorn dominating, but in south readily colonised than those where penetrabil­ Staffordshire and the West Midlands, 13 and 11 ity was high. Although most quadrats were flat, species were found respectively with birch and aspect did have some effect; north and west fac­ willow the predominant species. ing slopes tended to be most frequently colonised. Distribution For woody colonization to occur there must The type of vegetation had a marked effect on be a suitable seed supply, and species with poor the occurrence of colonising seedlings. The powers of dispersal are least likely to colonise most common vegetation type was a densely urban sites. The survey found the frequency of matted grass sward, and only 14% of these were colonization of most species to be closely colonised to an acceptable woodland standard linked to the presence of parent trees and site (defined as a 4 x 4 m plot containing at least conditions conducive to the germination and four trees of any size or two trees >1 m). Weak, establishment of woody seedlings. In the open sward was the vegetation type most fre­ absence of ground vegetation, fertile, moist sites quently associated with seedlings and 33% of will be colonised most quickly and by the

43 SILVICULTURE (SOUTH)

widest range of species. However, these sites woody colonization cannot establish either. are also most favourable to rank ground vegeta­ Woody colonization is most likely on sites that tion. Rapid invasion of coarse grasses and other are sufficiently infertile and moisture stressed vegetation prevents seed from making contact to prevent the rapid dominance of rank vegeta­ with the mineral soil and provides competition tion, but not so stressed as to prevent the estab­ for moisture and light with seed that does ger­ lishment of woody seedlings. minate. In contrast, on the most impoverished sites little ground vegetation develops, but moisture and nutrient stress are so great that S im o n H odge a n d R a lp h H akm er

44 Figure 5. Changes in basic density of oak wood (g cm3) measured from pith to bark. Points are means of ten trees from each stand.

Figure 23. Schematic of the layout of drain and boreholes in the drainage demonstration at Kielder Forest.

Figure 6.Angle of spiral grain measured on vertically split oak discs using an angle gauge (positive or negative direction of grain angle has been ignored). Points are means of ten trees.

Figure 24. Increased depth of the water- table (cm) following drainage for a week with 30 mm rainfall.

Figure 7. Tangential shrinkage (mm) in oak following oven drying of green oak, variation at three positions across a disc. Points are means of ten trees. Figure 16.Research and demonstration in the National Forest: Church Gresiey site.

1. New netvr woodlands • AH/FM 2. Community woodland speciesm 3. Direcl seeding • 4. Nalive species trial ~ 5. New native woodlands • OK/B 6. Reclamation woodlandm OK/BI / m GA/SM 8. m CH 9. m w. Hop ID. Short rotation coppicem Pop/Will Hedgerow Unplanled

Figure 17. Research and demonstration in the National Forest: Desford Lakes site.

gcat willow, wayfaring1 ree hazel, elm. cherry sycamore, holly apple f elc maple Avon

West Midhinds

Figure 18. Research and demonstration in the National Forest: Barton-under-Needwood site. goa: wil'ow South Staffordshire Figure 19. Species mix of colonisation in the three regions. TREE IMPROVEMENT

Increasing proportions of time and resource O v e r v i e w are being spent on contract research, now amounting to almost 25%. The Branch is involved in two major contracts, namely the A number of significant changes took place MAFF/FC project on genetic improvement of within the Branch during the 12 months under broadleaves for farm forestry and secondly a report. At the start of the year, David Rook was European Union (EU) funded project on Fast appointed Chief Research Officer (North) at the growing northern conifers. The latter involves Northern Research Station. Alan Fletcher took the evaluation of Douglas fir families from the over as Head of Branch, but his previous posi­ Pacific North-West of America in collaboration tion was not filled so a reorganisation of project with colleagues in France, Belgium and Italy. A responsibilities was needed. Dr Christine second part of this contract concerns flowering Cahalan, who was responsible for the Ministry and seed production in larch and Sitka spruce. of Agriculture, Fisheries and Food/Forestry A further EU project involves selection and Commission (MAFF/FC) funded project on propagation for increased production of aescin genetic improvement of broadleaves for farm in horse chestnut (HCH) in conjunction with forestry, resigned to take up a post at the research teams in Germany and Italy. Three University College of North Wales. Dr Ned populations of HCH have been sampled in the Cundall has been appointed as a replacement to U.K. and the chemical level in the nuts complete the five-year project and to initiate analysed. This shows that there are significant new work on improvement in broadleaves. between-tree differences in the concentrations The current and previous reductions in staff of aescin. Attempts will now be made to estab­ have meant the reprioritising of projects and lish the high yielding individuals in clonal species. There has been a slowly decreasing banks and cutting hedges. effort on provenance of conifer species and a A three week workshop for four scientists closure programme for older and fringe species from the Chinese Academy of Forestry was held has been initiated. Efforts on conifer prove­ in spring 1994 as part of the Overseas nances are now concentrated on the main Development Agency project on the improve­ International Union of Forestry Research ment of Japanese larch and other larch hybrids. Organizations’ experiments with Sitka spruce, This proved to be very successful and the Douglas fir, grand fir, noble fir and Pacific silver Chinese scientists will continue the improve­ fir. As regards broadleaves, new provenance ment programme in China during 1994. experiments have been planted with Quercus The University of Edinburgh instituted a new robur, Q. p etraea and Q. rubra. M.Sc. course in Tree Improvement during Flowering in the major commercial species 1993/94. This involved a considerable lecture was light in spring 1993 which lessened the workload for several members of the Branch, demand for registration of new seed stands. This who are also involved in supervising and assist­ Branch is now responsible for the inspection and ing with dissertations. registration of poplar stool beds, involving a sub­ The Branch was host for the annual meeting stantial work load in summer 1993. The database of the Nordic Tree Breeders. Two topics were for all Forest Reproductive Material was com­ discussed - progeny testing and breeding strate­ pleted and the List of basic material in abbrevi­ gies. Twenty papers were presented on these ated, bound form was published for the first time. topics and the proceedings of the meeting have This includes seed stands, seed orchards and been published. poplar stool beds, and will be updated and re­ The breeding of Sitka spruce is still the largest printed annually. The Register of Native single project but, with the increasing emphasis on Pinewood Seed Collection Areas was also broadleaves and contracts, the time being devoted updated and a similar list was published. to the species is diminishing. Nevertheless,

45 TREE IMPROVEMENT

following on from a review of the breeding The B-glucuronidase reporter gene has been strategy, a general breeding population was inserted into embryogenic cell lines by identified using an index selection method (see Agrobacterium tumefaciens mediated gene below). Because of competition for resources, delivery and into mature zygotic embryos by the next phase in the project on breeding of particle bombardment. This gene has been used Sitka spruce will not begin for another 12 to optimise the conditions needed for transfor­ months. mation to be successful in the two delivery sys­ The biochemical work of the Branch has tems. Success of the delivery system was mea­ developed with work starting on the use of the sured by assay of the products of the transient random amplified polymorphic DNA technique expression of this gene. to characterise (fingerprint) the clones in the The npt-II gene has also been inserted into Sitka spruce breeding population. The technique embryogenic cell lines using the Agrobacterium will be extended to identification of poplar and delivery system. This gene confers resistance to willow clones. Studies in a Sitka spruce seed aminoglycoside antibiotics such as kanamycin orchard using isozyme genetic markers, as sulphate. The Agrobacterium treated cell lines reported later, have shown that a very high per­ have been grown on a medium containing the centage of outcrossing is being achieved. antibiotic, and putative transformed cell lines In 1991 the Forestry Commission placed a have been established from those cells that were research grant with Nottingham University to formed. Experiments are now in progress to fund work on the possibilities of producing regenerate whole plants from these cell lines. transgenic plants of Sitka spruce. Although the The whole plants will be analyzed at the molec­ project encountered problems in the early days, ular level for the presence and expression of the these have largely been overcome to the extent inserted gene. that the B-glucuronidase reporter gene has been The genes inserted into the Sitka spruce successfully inserted into embryogenic cell embryogenic tissue to date will not confer any lines of Sitka spruce (see below). benefit to the whole plants developed from it. They have been used to optimise the delivery

A l a n F l e t c h e r system and to allow selection of transformed cells. The system that has been developed will allow genes for beneficial characters such as herbicide or insect resistance to be inserted into D e v e l o p in g transformation s y s t e m sf o r somatic embryogenic tissue and expressed in S it k a s p r u c e the growing tree.

P a s c a l D r a k e This project was initiated to develop systems for introducing foreign genes into Sitka spruce with the ultimate aim of producing genetically transformed plants. Development of such a sys­ T h e u se o f is o z y m e g e n e t ic m a r k e r s t o tem requires the investigation of a range of tech­ e s t im a t e t h e r a t e o f outcrossing in a S it k a niques, such as the establishment of the plant SPRUCE SEED ORCHARD IN SCOTLAND material in the correct condition for transforma­ tion, insertion of the genes, establishment and testing of completely transformed cell lines, and Seed orchards are the means by which the end regeneration of transformed whole plants from product of a breeding programme is produced the cell lines. for commercial use. In order to function effec­ A system has been developed where somatic tively outcrossing rates must be high, as selfing embryogenic cell lines can be initiated from leads to an increased proportion of empty seeds mature zygotic embryos. The frequency of initi­ as well as to inbreeding depression. To max­ ation of cell lines is low but at rates comparable imise the opportunity for outcrossing, conven­ to other conifer species that have been investi­ tional seed orchards generally comprise large gated. Plantlets have been generated from the numbers of superior clones with wide separa­ embryogenic cell lines by maturation and ger­ tion between ramets of each clone. Such a mination of the immature embryos. The rapid design is expected to produce a seed crop rate of growth of the embryogenic cell lines and which reflects both the genetic superiority and the ability to obtain whole plants from them the broad genetic base of the parental clones. offers an ideal system for obtaining completely However, despite such efforts to optimise transformed plants following the insertion of design, factors outwith the control of the tree the selected foreign gene. breeder, such as variation between clones in the

46 TREE IMPROVEMENT

timing and intensity of their male and female results indicate that, of the seeds which germi­ flowering, may prevent the seed orchard from nated, a negligible proportion were the product functioning effectively. There is, therefore, a of selfing during the 1990 season. These high need for quantitative information on flowering estimates of outcrossing rates were probably and outcrossing rates in our seed orchards. partly due to the prolific and synchronous Isozyme markers are ideally suited to the flowering of all ramets of all the clones. A sea­ study of outcrossing rates. Isozymes are the son in which there was poorer flowering might multiple molecular forms of proteins, enzymat­ have produced a very different result. ically active and catalysing the same reaction. Variant enzymes produced by different alleles J o a n C o t t r e l l at the same locus are termed allozymes. Stains which produce a non-diffusible, chromogenic precipitate at the site of enzyme activity are used to locate the multiple forms of enzymes B r e e d in g genetically im p r o v e d D o u g l a s f ir with common catalytic activity after they have been resolved by means of electrophoresis in a Douglas fir is a species with a great potential in solid matrix. The inheritance of the isozymes western Europe. As part of a collaborative pro­ makes them suitable markers for studying mat­ ject, partially funded under the European ing systems. In conifers, it is possible to iden­ Union/AAIR programme, the genetic testing of tify the genotype of the mother clone by analy­ superior phenotypes selected by the United sis of the haploid gametophyte in the seed and, States Forest Service in natural stands in by further analysis of the associated diploid Washington and Oregon has begun in Britain embryo, to determine the paternal contribution and France. The general objective of the pro­ to the embryo. Using this information it is pos­ gramme is to identify superior Douglas fir sible to obtain an estimate of the outcrossing clones, for vigour and form, which can be rate in the seed orchard. included in both pan-European and U.K. based Isozyme markers were used to study the out- breeding populations. crossing rate in a grafted seed orchard at Plants of 250 open-pollinated families, col­ Ledmore, Perthshire during 1990, six years lected from candidate trees growing in origins after planting. A survey of flowering in the within the state of Washington known to be orchard during that year showed that all the well adapted to this country, will be estab­ clones flowered, with 95% of the ramets of lished over three forest sites and one farm field each clone producing female cones and 95% of site (FFS). A further 70 families of Oregon ori­ the ramets producing male cones. Most clones gins, constituting a sub-sample of more com­ produced more than 50 male and 50 female prehensive testing work in France, will also be cones per ramet. Female flowers were receptive established on the same sites. at the same time in nearly all the clones, and The first 160 open-pollinated families from pollen shedding peaked a few days before the Cowlitz and Snoqualmie (Washington origins) female flowers were at their most receptive. were planted in Huntly, Marches, and South Gametophytes and embryos were separated, East Wales Forest Districts and in a specially ground in extraction buffer, applied to commer­ selected FFS near to the Northern Research cially prepared cellulose acetate plates and Station in the spring of 1994. The balance of subjected to electrophoresis. The plates were families from Skagit (Washington), Mapelton, stained for the following isozyme systems; glu- Gold Beach and Powers (Oregon) will be tamate-oxaloacetate transaminase (GOT), gluta­ planted in the spring of 1995. mate dehydrogenase (GDH), phosphoglucose Intensive measurements from the FFS over isomerase (PGI) and phosphoglucomutase the first three years will be correlated with later (PGM). GOT and GDH were polymorphic at one assessments in forest-based experiments to locus and PGI and PGM each produced two investigate whether selection could be made at loci which were polymorphic. Single locus an earlier age in the more uniform and fertile estimates of outcrossing rates ranged from 0.94 FFS. If this proves possible, the cost of future to 1.00 and did not differ significantly from 1. forest progeny tests could be reduced consider­ The multilocus estimate, based on data from ably by screening out poorer families based on the six polymorphic loci was 0.98. The propor­ early test results. tion of empty seeds and the percentage of seeds The opportunity will be taken to compare which failed to germinate were not recorded, so family performance for vigour and stem form these estimates of outcrossing are based solely amongst Britain, France and the United States. on seeds which successfully germinated. These If the same families are found to be superior,

47 TREE IMPROVEMENT

then improved seed can be imported into Number of sites Britain from the more advanced clonal seed The number of sites over which a progeny test orchards already established in the U.S.A. The was replicated varied from eight in 1967 to first data to be correlated between Britain and three in 1977. In this exercise the number of the U.S.A. will become available in 1997. sites analysed was limited to a maximum of three although often only two survived to 15 S t e v e L e e years and beyond. If 15-year data were available from more than three sites, attempts were made to select one site from Wales, one from the Borders and one from North Scotland, i.e. typi­ cal Sitka spruce growing areas. M u l t i-t r a it s e l e c t io n o f S it k a sp r u c e CLONES FOR THE GENERAL BREEDING Variation in site quality POPULATION The family heritability calculated at each test site was used to weight family mean trait value. Introduction Thus in the combined analysis of data from a Breeding value estimation of Sitka spruce number of sites, those with a high family heri­ [Picea sitchensis (Bong.) Carr) plus-trees, tability (e.g. 0.8) would be given greater weight based on measurement of half-sib progeny inthan a variable site with low heritability (e.g. comparative trials, began regularly 1967 in 0.4). This is roughly equivalent to the ‘best lin­ and continued until 1993. A review of the ear predictor’ equation adopted by White and Sitka spruce breeding strategy showed that theHodge (1989, Equation 5.3) which serves to time was opportune to identify all the clones weight observations in proportion to the ratio of that will constitute the F0 general breeding additive to phenotypic variance. It also relates population and move forward into the next to the multi-site index selection suggested by generation of breeding and selection. Burdon (1979).

Composition of the general breeding Weighted performance data and standard population indices A complete re-analysis of all progeny tests Data from all years were combined into one planted between 1967 and 1977 for 15-year or large data set. This involved weighting family greater (up to 22-year) diameter, wood density mean performance relative to the overall mean and stem form (combination of stem straight­ Queen Charlotte Islands control. Standard para­ ness and branching quality; see Lee, 1992) led meter estimates for family mean heritability and to the ranking of all plus-trees in test using a phenotypic and genotypic correlations were cal­ selection index. From this, a breeding popula­ culated by averaging values across years. In this tion of the top 240 index-ranked plus-trees has way a standard index was created (Table 9). been constructed. Re-selection for the breeding population based on index value was restricted to those Table 9. Standard family mean heritabilities and tests greater than 15 years old, since this is the phenotypic and genetic correlations used in the earliest age at which selection for wood den­ index calculations sity can be carried out. Other high index- ranked plus-trees, subsequently identified fol­ Diameter Density Stem form lowing 15-year assessment of diameter, wood Heritabilities 0.70 0.80 0.70 density and stem form in progeny tests planted after 1977, will enter as bottom- Phenotypic ranked clones in the Fj breeding population. correlatons Analysis of the data available for the index Diameter 1.00 calculation was not straightforward due to the Density 0.58 1.00 complicated nature of the half-sib tests estab­ Stem form 0.11 0.04 1.00 lished. Factors which had to be considered in Genetic the analysis of the data included: varying correlations number of sites by year; variation in quality of Diameter 1.00 site both within and across years; and use of Density 0.66 1.00 weighted performance data and standard indices (Cotterill and Dean,1990). Stem form 0.04 0.00 1.00

48 TREE IMPROVEMENT

Moving into the next generation this way more breeding effort will be spent on The 240 top-rated clones have been divided those clones believed to be of greatest breeding into four sub-lines of equal index value and an value as suggested by Lindgren (1986) and amended form of assortative mating will now be White et al. (1993). employed in the next generation. Each sub-line Controlled pollinations within the first of the has been further divided into thirds; all clones sub-lines is programmed to begin in spring in the top third will be employed in five 1995. crosses; the middle third in three crosses; and the bottom third in two crosses (Figure 21). In S t e v e L e e

REFERENCES BURDON (1979). Generalisation of multi-trait selection indices using information from several sites.New Top 33% Zealand Journal of Forest Science, 9(2), 145-152.

5 crosses COTTERILL, P.P. and DEAN, C.A. (1990).Successful tree / clone breeding with in d ex selection. CSIRO, Australia.

20 clones LEE, S.J. (1992). Likely increases in volume and revenue from planting genetically improved Sitka spruce.In: D.A. ROOK, ed. Super Sitka for the 90s. Forestry Commission Bulletin 103. HMSO, London. Middle 33% LINDGREN, D. (1986). How should breeders respond to 3 crosses breeding values?In: Proceedings oflUFRO conference / clone on tree breeding theory, progeny testing and seed orchards. October 13-17. Williamsburg, Virginia. 20 clones WHITE, T.L. and HODGE, G.R. (1989).Predicting breeding values with applications in forest tree Bottom 33% improvement. Klewer Academic Publishers, The Netherlands. 2 crosses / clone WHITE, T.L., HODGE, G.D. and POWELL, G.L. (1993) An advanced-generation tree improvement plan for slash pine in the southeastern United States.Silvae Genetica, 20 clones 42(6), 359-371.

60 clones

Figure 21. Sub-line structure of the Sitka spruce general breeding population.

49 WILDLIFE AND CONSERVATION RESEARCH

The Branch was reorganised in mid-year. Staff at Wildlife and Conservation Research Branch Arctium minus Ardentinny and the Northern Research Station Hypochoeris radicata were amalgamated with Site Studies (North) to form Wildlife Ecology Branch. The Wildlife and D+H H Conservation Research Branch remains at Alice Juncus articulatus Holt. Torillis japonica A successful one day conference, T he biol­ Veronica chamaedrys ogy, impact and management of Muntjac deer, D+H H organised jointly with the British Deer Society Glechoma hederacea and Forest Enterprise, was held at New Hall, Picris echioides Cambridge in October 1993. This was the first ■ Plantago lanceolata conference devoted entirely to the status of D+H H N Senecio jacobea muntjac deer in the U.K. The proceedings will be published in 1994. Cirsium vulgaris; Conyza canadensis; Galium verum In Thetford, the joint English Nature and ogLci Holcus lanatus; Poa annua Forestry Commission red squirrel conservation D+H H N Reseda lutea; Urtica dioica study has been remarkably successful, with red squirrels appearing in the designated conserva­ Arrhenatherum elatius tion area in reasonable numbers. The conserva­ Convolvulus arvensis El Mosses tion strategies of supplementary feeding, grey D+H H squirrel removal, squirrel releasing and habitat design are all being evaluated. Rubus fruticosus The application for approval for grey squirrel Sedum acre poisoning in red squirrel areas was not granted until February 1994, which prevented the D+H H N planned trials in summer 1993. D+H - deer and hare H - hare N - neither A major review of damage by mammals was published in 1993 which highlighted areas in Figure 22. Preliminary results on the effect of browsing need of further research, one important topic by deer and hares on the cover of different ground flora species in Thetford Forest, East Anglia. Changes in rel­ being the long-term effects of browsing by deer ative cover of ground flora species in response to graz­ on tree growth and timber quality. This year an ing by hares, or deer and hares in combination. Each experiment was established to investigate the species has been scored as being more abundant, long-term responses of eight tree species to intermediate or less abundant under each grazing browsing by roe deer. The experiment will pro­ regime, and then grouped with the other species show­ vide a better understanding of to what extent ing a similar response. growth loss and deformity relate to early damage and how much they differ between tree species. As deer populations continue to increase concern is growing about the effects of browsing G r e y s q u ir r e l d a m a g e p r e d ic t io n : in d e x on forest vegetation structure and diversity. A TRAPPING monitoring experiment is revealing how the succession of ground flora on a restocked site is modified by the effects of browsing by hares A collaborative study involving The Forestry and deer (Figure 22). The experiment will pro­ Authority Research Division, Queen Mary and vide evidence of the loss of diversity and Westfield College (London University), and changes in structure that arise from the impact Forest Enterprise is in progress to formulate a of browsing mammals. damage risk prediction index. The aim is to

50 WILDLIFE AND CONSERVATION RESEARCH

help forest managers target warfarin control of continued for a further five years to validate the grey squirrels more cost-effectively. The ratio­ index. nale, based on previous research studies, is as

follows: the severity of grey squirrel damage to H a r r y P e p p e r , J a c k ie D a g n a l l a n d J o h n G u r n e l l broadleaved woodland is positively associated with the number of squirrels, particularly young animals, present during the main damage period of April to July. This, in turn, is directly V e g e t a t i o n m a n a g e m e n t ( l o w l a n d s ) related to the availability of tree seed in the autumn. If seed supplies are abundant, overwin­ One of the objectives of managing forest edges, ter survival and the spring recruitment of young such as roadsides and rides, is to provide a vari­ are high. A good measure of seed availability is ety of habitat conditions across a structurally the trappability of grey squirrels in baited live graded edge or ecotone. Successional processes, capture traps. High trappability indicates food if unhindered, result in the eventual dominance scarcity, low numbers during the damage of scrub and woodland. Intervention is needed to period and therefore a low damage risk. Low halt this process. Intervention is commonly by trappability indicates food abundance, high mechanical cutting of herb and scrub belts, numbers of both adults and juveniles during the although alternative techniques such as scarifica­ damage period, and a high damage risk. tion, to create bare ground for recolonisation, The study started in 1990 in three Forest may also be considered. A series of experiments Enterprise districts in southern England and have been set up, in collaboration with Forest was extended to seven districts in 1994. A stan­ Enterprise, at Llandovery and Northamptonshire dardised trapping procedure using multi-cap­ Forest Districts, to examine how these operations ture traps was carried out in January/February influence vegetation succession. Detailed moni­ in two selected woodlands within each forest toring programmes using permanently marked district. Additional information, on the breed­ quadrats have been undertaken at each site. ing condition of trapped animals and seed avail­ These studies have shown that plant species ability at the time of trapping, has also been diversity may be increased in the short term by obtained and will be incorporated into the scarification of the ride or roadside vegetation, index. Follow-up surveys of bark-stripping with many species regenerating from buried damage have been carried out at some sites. seed. Severe scarification can lead to colonisa­ Differences in numbers of captures among sites tion by common non-woodland species of low and years have been found (Table 10), with gen­ conservation status, and it is suggested that erally good trapping success in 1993 and 1994, light scarification of irregularly spaced patches intermediate in 1992 and no captures in 1990. of vegetation may be preferable. The results for 1991 were affected by a heavy Cutting without removal of cuttings may lead fall of snow causing the trapping to be discon­ to a build-up of nutrients in the long term, with tinued early. The damage assessment and a consequent suppression of some plant species breeding data will be analyzed in 1994 and the by others which are more competitive and able precise index formulated. The study will be to exploit high soil nutrient conditions. No evi­

Table 10. Number of grey squirrels captured (n) and number of sites where traps were laid (s, each site with six traps) in different forest districts over a five year period 1990 1991 1992 1993 1994 Forest District n s n s n s n s n s West Downs 0 2 15 2 7 2 32 2 44 2 South Downs 0 2 0 2 1 2 7 2 1 2 Wilts & Avon 0 6 7 4 8 3 20 4 17 5 Dorset 5 4 1 1 21 4 37 4 Cornwall & S. Devon 2 4 2 4 6 3 - - Somerset & N. Devon 2 4 1 7 26 3 8 4 Dean 3 2 0 2 8 3 Totals 0 10 31 20 23 21 112 20 115 20

51 WILDLIFE AND CONSERVATION RESEARCH

dence of this is so far available from these stud­ tions beneath the bramble. The loss of a ies, although the non-removal of cut plant mate­ shrubby fringe at forest edges, often comprising rial does have a mulching effect, with physical goat willow [Salix caprea), ash [Fraxinus excel­ smothering of smaller herbaceous species. sior), and smaller shrubs such as blackthorn There is also evidence that the expected veg­ [Prunus spinosa), can greatly reduce their value etation succession on many forest edges is inter­ for wildlife. rupted by the actions of vertebrate herbivores, Monitoring of vegetation change following especially deer. Where deer pressure is high, windthrow of a lowland pine plantation has there may be little or no woody regeneration continued over three years, in parallel with along forest roadsides or at ride margins. mapping studies of fallen and standing dead Research studies of vegetation succession on wood. This has shown small, but discernible, edges have incorporated fenced exclosure plots, changes to the relative abundances of plant in order to assess better the impact of deer, rab­ species, but little indication of recovery of the bits, and other small mammals. These have original pre-afforestation heathland plant com­ demonstrated clear effects on natural regenera­ munity. The detailed recording of the fate of the tion of broadleaved trees and shrubs, leading to dead-wood resource may provide a useful gross changes in vegetation structure. The insight into the dynamics of decay and coloni­ removal of valuable invertebrate food-plants, sation of this vital component of natural forest such as bramble (Rubus fruticosus agg.), may ecosystems. Monitoring continues. have indirect effects on the abundance of other species such as violet [V iola spp.), which have been found to flourish in the bare ground condi­ R ic h a r d F e r r is -K a a n

52 WILDLIFE ECOLOGY

Wildlife Ecology Branch was formed on 1 adequately to the demands of multiple-use October 1993 by joining Site Studies (North) forestry. By focusing attention on forest ecosys­ Branch with the Northern Research Station and tems we shall be better able to develop sustain­ Ardentinny members of Wildlife and able practices and have a sound basis for Conservation Research Branch. Dr Philip wildlife conservation and other aspects of forest Ratcliffe, Head of Wildlife and Conservation planning. This new approach should also bene­ Research Branch, was seconded to Headquarters fit the educational and recreational uses of for most of the year, a move that has since been forests. made permanent. This has curtailed progress Development of the classification has pro­ with the Biodiversity Project Team formed dur­ gressed to the stage where all the proposed ing summer 1993. components are in place. Ecological Site The then Site Studies (North) Branch Classification (ESC) uses many of the ideas of received a Visiting Group in July 1993. Support the British Columbian Biogeoclimatic was received for the two themes reviewed, Ecosystem Classification (BEC), but has also drainage and ecological site classification. The been able to benefit from major recent publica­ series of six ‘Z’ drainage demonstrations will tions in plant ecology and forest soils within continue and be completed in 1996. So far the western Europe (Rameau et al., 1989, 1993; fieldwork for three has been completed and Brethes et al., 1992). Much effort has also been analysis of the results is in progress. given to integrating ESC with the National Commissioned research on the flora of Vegetation Classification of Britain (Rodwell, recently established broadleaved woodlands in 1991). upland Britain provided important information ESC can be applied at various scales: at the for the major publication Creating new native national level, for regions or Forestry Authority w oodlands (Rodwell and Patterson, 1994). conservancies, for forests, or at the subcompart­ Carnivore ecology work continued at Cowal ment level. The classification is being tested in Forest District with the range and habitat use of a series of case studies using forest design plan ten foxes being studied by radio telemetry. The areas. The first such study has suggested that study of sympatric populations of foxes and there is a value in recognising a larger, broad­ wildcats could not proceed at this locality brush, mapping unit at a hierarchical level because too few wildcats were found. above that of the traditional soil type/phase unit We are continuing to give financial and/or normally found in pieces of one to several technical support to outside research on hectares. This larger unit may extend to one goshawks, capercaillies and songbirds in hundred or several hundred hectare pieces, and conifer forests. encompass soil variation equivalent (in the new classification) to several site types. The larger unit has been provisionally termed a landscape G r a h a m P y a t t site unit. Mapping of such large units is much REFERENCE faster and therefore cheaper than traditional site RODWELL, J.S. and PATTERSON, G.S. (1994).Creating mapping. Greater detail can be added for loca­ new native woodlands. Forestry Commission Bulletin tions of special interest, such as forthcoming 112. HMSO, London. felling coupes or other areas of intensive man­ agement. ESC is essentially three-dimensional with the variables being climate, soil moisture regime Ec o l o g ic a l S it e C lassification and soil nutrient regime. Britain is divided into eight climatic zones according to a combination There is a need for an ecologically based site of wetness and warmth factors. Two of the classification if forest managers are to respond zones are above the tree line. Further division

53 WILDLIFE ECOLOGY

into subzones based on the same two factors would be appropriate at regional and forest lev­ C l a y s o il s els. A third climatic factor, oceanicity, can be introduced to represent climatic trends not The ‘Z’ drainage demonstration on a clayey peaty already covered. Within each climatic zone or gley at Kielder Forest (Report, 1991, 1992, 1993) subzone, variation in soil quality is depicted by has been completed (Figure 23, opposite Plate 11). a grid made up of eight classes of soil moisture The relationship between water-table depth regime and six classes of soil nutrient regime. in each borehole and weekly rainfall was mod­ Site diagnosis consists therefore of assessing elled by linear regression, separately for the the climatic zone/subzone, from appropriate year before drainage and the year after drainage. maps, and locating the site in question on the From the models the difference in water-table soil quality grid. This can be done by one or depth due to drainage for an average week with more methods. The traditional approach 30 mm rainfall is illustrated in Figure 24 (oppo­ through soil type/phase is considered insuffi­ site Plate 11). At a distance 2.5 m downslope of ciently precise, but would be an obvious start. the ditch the change in water-table depth was An additional or alternative approach would be 16 cm. At 5 m downslope the change was 7 cm, through ground vegetation where sufficient and at 10 or 20 m downslope it was 3 cm. A exists (all species are now considered to have similar pattern of change was found using a some indicator value). An assessment of the more complex model developed by Rennolls et form of humus (e.g. mull, moder, mor) is a third al. (1980). The smallness of the drainage effect alternative, particularly where ground vegeta­ was not unexpected in such a clayey soil. tion is lacking. Although the effect on mean water-table It is intended that silvicultural and other depth is small, drainage also speeds up the rate interpretations would be linked to climatic of fluctuation, thereby reducing the length of zone/subzone and the respective soil quality periods of flooding of roots. Since roots can sur­ grid. Each of the 48 cells of the grid could be vive short periods of flooding (Coutts and considered as a potentially different site type (if Philipson, 1978), the increased depth of the sites of all qualities occur in the subzone), but woody root system may exceed the change in prescriptions would be made for groups of cells water-table depth. Current tree-pulling work as appropriate in a particular context. As a sim­ will investigate this possibility. ple example, drainage prescriptions would be linked to classes of soil moisture regime irrespec­ D u n c a n R a y tive of nutrient regime, subdivided as at present by soil texture classes. The climatic zonation REFERENCES would, however, provide a useful refinement in COUTTS, M.P. and PHILIPSON, J.J. (1978). Tolerance of respect of the risk of soil erosion in the drains. tree roots to waterlogging. 1: Survival of Sitka spruce and lodgepole pine.New Phytologist, 80, 63-69.

G r a h a m P y a t t RENNOLLS, K„ CARNELL, R. and TEE, V. (1980). A descriptive model of the relationship between rainfall REFERENCES and soil water table.Journal of Hydrology, 47,103-114. BRETHES, A., BRUN, J.J., JABIOL, B„ PONGE, J.F. and TOUT AIN, F. (1992).Humus form reference base: excerpts from Referentiel Pelologique. Association Francaise pour l’Etude du Sol, Paris. D eep p e a ts

RAMEAU, J.C., MANSION, D. and DUME, G. (1989). The experiment at Rumster Forest, Caithness on Flore forestiere Francaise: guide ecologique illustre. Vol the soil and hydrological effects of afforesting 1: Plaines et collines. Institut pour le Developpement blanket peat (R eport, 1989, 1990) has been run­ Forestier, Paris. ning for five years. The height of the ground surface along a transect across each treatment RAMEAU, J.C., MANSION, D. and DUME, G. (1993).Flore plot has been measured twice each year relative forestiere Francaise: guide ecologique illustre. Vol 2: to a benchmark (the top of a metal rod ham­ Montagnes. Insdtut pour le Developpement Forestier, mered through the three metres of peat into the Paris. mineral substrate). The annual rate of subsi­ dence has decreased over the period. The RODWELL, J.S., ed. (1991).British plant communities I: unploughed, unplanted control treatment has Woodlands and scrub. Cambridge University Press, subsided by 4 cm over the five years. This can Cambridge. be ascribed to the effect of the deep ditch

54 WILDLIFE ECOLOGY

around the perimeter of the 42 x 20 m plots which lowered the water-table by 6 cm in the F e r t il it y o f s ik a d eer in S c o t l a n d first year. The ploughed and planted treatments have subsided by 11 cm. The extra subsidence is probably due to the intensive drainage of the furrow ploughing - which, in combination with Knowledge of fertility is necessary for the man­ the perimeter ditch, lowered the water-table by agement of sika deer populations, in the manner 14 cm in the first year — rather than to any dry­ pioneered by the Red Deer Management Package. ing effect of the trees. Depth markers installed at 25 cm intervals down to 1.5 m depth have Female reproductive tracts and jaw bones were collected between 1984 and 1991, mainly revealed that subsidence of the surface is due by Forestry Commission Rangers during normal not only to shrinkage of the drained surface non-selective culling, from most Scottish popu­ layer, but also to compression of the peat at lations including: Shin in the north; Torrachilty, greater depth. Inchnacardoch and Farigaig in the Great Glen area; Kintyre in the west; and Peeblesshire in the R u s s e l l A n d e r s o n south. Pregnancy was determined by the pres­ ence of an embryo or a developed ovarian cor­ pus luteum. Age was determined by tooth erup­ tion and wear and animals classified as calf, V e g e t a t io n yearling or adult. Sika female fertility was

The joint project with Scottish Natural Heritage on the wildlife benefits of birch in second gen­ n= 97 344 69 309 276 1235 eration Sitka spruce forests continued with commissioned surveys of the invertebrate fauna associated with different sizes of birch clumps in restocks of different ages. Over 100 species of Lepidoptera were recorded and there was a trend of increasing diversity from the older, more pure spruce towards younger spruce with a higher proportion of birch. Calf Yearling Adult The effects of cultivation on ground vegeta­ tion in upland conifer forests were studied in H SHSika three long-running silvicultural experiments in north Scotland. Vegetation surveys were com­ Red missioned and the results compared with records from before planting. Cultivation Figure 25. Fertility of woodland sika and red deer in appears to have an indirect effect on vegetation Scotland. through the improvement in crop performance, which in turn causes a reduction in ground flora diversity and a shift towards more shade n= 6 8 51 241361 11 9 36 6 5 26 145 28 21 12 29 tolerant species. There were no discernible effects of different methods of cultivation. In collaboration with Wildlife and Conservation Research Branch at Alice Holt we have prepared two project plans concerned with biodiversity. The first concerns the effects of stand manipulations on the biodiversity of plantations. The second attempts to develop a methodology for the depiction, measurement and monitoring of stand-level biodiversity in unmanaged and near-natural forests. In this we hope to collaborate with other European coun­ ^ Calf tries. The overall theme is to compare the biodi­ m Yearling versity of managed and natural forests. E H Adult

J o n a t h a n H u m p h r e y Figure 26. Fertility of sika deer in Scotland.

55 WILDLIFE ECOLOGY

related to age as a measure of reproductive per­ ing and breeding areas. It will also add another formance and compared with that of woodland piece to the jigsaw of the ecology of owl com­ red deer, data from Ratcliffe (1987). munities in coniferous forests. Sika were more productive than red deer in During the late winter and early breeding sea­ all age classes (Figure 25). Most Scottish sika son all four species of owl in upland Britain populations exhibited some calf pregnancies feed largely on small mammals, particularly (Figure 26) but for red deer, at 0.6%, they were field voles (Figure 27). Field voles are abundant rare (Figure 25). Sika yearling fertility varied lit­ on restocked areas that develop grassy vegeta­ tle, being above 70% for all populations (Figure tion (Petty, 1992; Petty and Peace, 1993). In 26). In contrast, red populations varied greatly, Kielder Forest around 1000 ha are being from 0% in Glen Crippesdale to 90% in restocked each year which, over a 12-15 year Galloway (Ratcliffe, 1987), resulting in mean period, provide a vast resource for field voles yearling fertility about half that of sika. Adults and their predators. of both species performed at a high level in the In upland areas devoted to sheep rearing, amenable forest environment (Figure 25). long-eared owls traditionally bred in shelter- belts and this habit persisted when many areas

A n d r e w C h a d w ic k were afforested. Village’s (1981 and 1992) study on long-eared owls in Eskdalemuir provides the REFERENCE only information for first-generation forests. As RATCLIFFE, P.R. (1987).The management of red deer in forests mature many nest sites in retained shel- the commercial forests of Scotland related to population terbelts are abandoned and the status of long­ dynamics and habitat changes. Ph.D. thesis. University eared owls then becomes obscure. of London, London. Work on raptor communities in Kielder Forest suggested that, prior to extensive restruc­ turing of the forest, long-eared owls were con­ B ir d s fined to the forest/moorland edge. Here they bred mainly in old crow nests and hunted over adjacent open ground. During the late 1980s, Ecology of long-eared owls in coniferous long-eared owls started colonizing the interior forests of the forest and are now breeding successfully This new project started in Kielder Forest in where tawny owl density is highest (Petty, 1993. It aims to provide information for forest unpubl. data). Therefore, one aim of the project managers and ecologists on the value of second- is to study how tawny and long-eared owls dif­ generation forest for long-eared owls (see Plate fer in their foraging ecology. This will be 14), and how forest habitats might be manipu­ achieved by radio tracking both species in adja­ lated to provide the right configuration of hunt- cent territories. A Ph.D. student, funded by the Hawk and Owl Trust, will start work on this aspect in 1994.

S t e v e P e t t y

REFERENCES PETTY, S.J. (1992).Ecology of the tawny owl, Strix aluco, in the coniferous forests of Northumberland and Argyll. Ph.D. thesis. The Open University, Milton Keynes.

PETTY, S.J. and PEACE, A.J. (1993). Temporal and spatial fluctuations in field vole abundance in a predator/prey study.In: Report on forest research, 1992. HMSO, London, pp. 40—42.

VILLAGE, A. (1981). The diet and breeding of long-eared owls in relation to vole numbers.Bird Study, 28, 2 1 5 -2 2 4 . Figure 27. Diet (percentage frequency) of tawny owl (TO), barn owl (BO), long-eared owl (LEO) and short­VILLAGE, A. (1992). Asio owls and kestrels in recently eared owl (SEO) during the breeding season planted and thicket plantations.In: C.A. GALBRAITH, I. (March-July), determined from pellet analysis in TAYLOR and S. PERCIVAL, eds. The ecology and Kielder Forest. Sample sizes of prey items are: = TO conservation of European owls. Joint Nature 2324, BO = 976, LEO = 157, SEO = 68. Conservation Committee, Peterborough. 56 WILDLIFE ECOLOGY

Golden eagle ranging behaviour in relation toThree sets of prey transects have been walked land cover in different habitats. The numbers of encounters Since July 1991, the Forestry Authority has with potential prey or carrion have been few, commissioned the Royal Society for the but the relative value of these habitats, in terms Protection of Birds to study the ranging behav­ of prey, is becoming clearer. iour of territorial golden eagles in Argyll using Information on the reproductive success of radio telemetry. The aims are to determine the golden eagles has been collected and is being size of the eagle territories and to identify any analysed in relation to the Macaulay Land Use preferred areas or habitats within those territo­ Research Institute Land Cover Map for Scotland ries. The study also examines the relationship using a geographical information system. between eagle productivity and land cover. To The project has two more years to run. date, ten birds have been fitted with transmit­ ters and tracked. M ic h a e l M c G r a d y a n d J u s t in G r a n t Royal Society for the Protection of Birds

57 COMMUNICATIONS

Both research stations continue to attract sev­ eral hundred visitors each year. Student groups L ib r a r y a n d I n f o r m a t io n S e r v ic e are welcomed from forestry, woodland manage­ ment and environmental science courses at uni­ The Library at Alice Holt Lodge has seen con­ versities and agricultural colleges. Visitors from tinued demand for its services by Research professional and vocational interest groups Division staff, the rest of the Forestry included members of the National Small Commission and outside users. The weekly cur­ Woods’ Association, the Royal Institution, the rent awareness listing on electronic mail gener­ Timber Growers’ Association and the ated over 4600 requests from the Department of Edinburgh Branch of Rotary International. A Forestry, The Forestry Authority and Forest two-day training course was held at Alice Holt Enterprise. A new information technology area for MAFF Plant Health and Seeds Inspectors. has been created in one of the reading rooms. It Staff at the Northern Research Station organised provides a convenient and central area for and hosted a number of national and interna­ access to the CD-ROMs and to the Library cata­ tional conferences and seminars. Overseas visi­ logues on adjacent terminals, which are now tors included senior government forestry offi­ linked to the Alice Holt local area network. cials, foresters and forest scientists from Personal visits to the Library were received Albania, China, Finland, France, India, from about 180 individuals and groups who Indonesia, Malawi, New Zealand, Poland, made use of the range of our stock and the data­ Romania, Slovakia, South Africa and bases available on CD-ROM. Zimbabwe. The Library at the Northern Research Station has seen improvements to its reference collec­ J o h n P a r k e r tion in the past year and further additions are planned. During the year, Mrs Margaret Plews took over the day-to-day responsibility for the R e s e a r c h A d v is o r yS e r v ic e NRS Library from Mrs Cathie Mcllwhan.

C a t h e r in e O l d h a m Following the introduction of charging for research advice, an Oracle database for han­ dling advisory information was designed and P h o t o g r a p h y set up for access over the Alice Holt local area network. Since April 1993, information from all enquiries has been entered by individual The Photographic Officer at the Northern branches. The objectives of the database are (a) Research Station has continued to provide a to provide summary data and statistics for the much needed service for the Station and plans effective management of the Research Advisory are in hand to increase the computer graphics Service on a Divisional basis; and (b) to pro­ output facility at that location. vide a facility for central invoicing. The Graphics Officer at Alice Holt success­ During the year over 3000 enquiries were fully completed a computer training course, as a completed by research advisers. Of these, 21% consequence of which the output of computer- were from The Forestry Authority, 13% from generated graphics for presentations and publi­ Forest Enterprise, 19% from private individu­ cations has increased. A computer-aided design als, 10% from private forestry, and the remain­ facility is now available. der were split between categories such as local The Forestry Authority exhibit at the Royal authorities and education. Show was designed and produced jointly by Photography Section and Artisan of Bristol, and M a r t in J u k e s was awarded the Silver Medal.

58 COMMUNICATIONS

The photographic library has expanded its Technical Papers service to external publishers. Security mounts 1 Black grouse and forestry: habitat have been introduced to protect transparencies requirements and management (£3). and ensure no improper use. 2 Deterioration of fine tree roots during cold storage in two contrasting winters G e o r g e G a t e (£3). 3 Forest nursery herbicides (£3). 4 The carbon content of trees (£3). P ublications Miscellaneous The Section began the year with a new adminis­ Research Advisory Service leaflet (free). trative support team; the staff settled in quickly and have made significant contributions to the Research Information Notes rolling programme of system reviews. They 230 Revised windiness scores for the have maintained a high standard of service to windthrow hazard classification: the our customers throughout the year, particularly revised scoring method. in the prompt fulfilment of orders. 231 The effects of revised windiness scores Fewer than usual new priced publications on the calculations and distribution of were issued during the year, which meant that windthrow hazard classes. less income was generated than had been expected. Output in the unpriced Research 232 Grey squirrel control using modified Information Note series returned to normal with hoppers. 17 new titles issued. 233 Rhododendron control by imazapyr. The year saw the launch of a new series, 234 Root growth in Sitka spruce grown in Technical Papers, which superseded the filtered and unfiltered air. Occasional Paper series. This series will cover a 235 Red squirrel supplementary food hopper. broad spectrum of research findings of interest 236 Forest condition 1992. to other scientists, as well as to technical and professional staff in the forestry industry. 237 Using household surveys to estimate First steps have been taken to improve our forest visitor numbers. publications promotion and marketing strategy, 238 A long-term carbon dioxide enrichment with the setting up of a review group. experiment examining the interaction The following titles were published during with nutrition in Sitka spruce. the year ending 31 March 1994: 239 Black poplar: the most endangered native timber tree in Britain. Report 240 The marketing of British grown Report on forest research 1992 (£16). hardwood as dimension stock. 241 The conservation management of Bulletins deadwood in forests. 109 The value of birch in upland forests for 242 Setting up tree planting and woodland nature conservation (£5.95). demonstrations. 112 Creating new native woodlands (£8.95). 243 The quality of Sitka spruce at the time of planting. Guidelines 245 Sitka spruce genetic gain trials. Forests & water (3rd edtn) (£5.75). 246 Approved herbicides for use in forestry Field Books (1994). 9 Classification and presentation of 247 Fertilization regimes to produce different softwood sawlogs (2nd edtn) (£2). size classes of cell-grown birch. 13 Invertebrate animals as indicators of acidity in upland streams (£11.95). K a t h y D a v ie s

59 STATISTICS AND COMPUTING (NORTH)

The local area network is now linked to Alice been tried. A relatively simple method is to treat Holt Research Station, allowing e-mail and file zero and non-zero values separately. Ideally, transfer between Northern Research Station both zero and non-zero values should be (NRS) and Alice Holt. Various improvements included in the same analysis, with a plausible have been made to network security. Links are model linking the two. This work underpins also established with the Forestry Commission Pathology Section projects on Prevention of wide area network and work continues on iron­ Fomes root and butt rot on first rotation sites and ing out teething problems. Chemical control of Fomes root and butt rot Programs have been written to simplify data­ A Genstat program was written to obtain the base interrogation. The main databases have outcrossing rate in a Sitka spruce seed orchard been reorganised to make it easier to handle by maximum likelihood estimation, given the problems on one database without affecting oth­ pollen and maternal allele contributions to the ers. A Plan of Operations database has been pro­ embryo at several loci in a random sample of duced for outstations. To support these activi­ seed. (See also the report from Tree ties, training courses in the Oracle database Improvement Branch.) management system have been mounted in- Multiple regression was used to relate the house for NRS and outstation staff, and these average daily tatter rate of cotton flags to the will be repeated and extended as necessary. aspect, elevation and topographic profile of The tatter flag work for Silviculture (North) 1100 sites. Branch continued; all stages of the handling Work has begun on dynamic modelling of and processing of tatter flag data are now com­ tree stability; this will continue in the medium puterised. term and will contribute to the output of the Stability Project Team. W a y n e B l a c k b u r n Further courses have taken place during the year on experimental design, elementary mathe­ Innovative methods to address non-standard matical techniques, and the use of statistical problems continue to be developed. Areas of packages. This is an on-going activity, designed tree stumps colonised by Heterobasidion anno­ to reinforce the trend towards researchers doing sum do not follow any well-known distribution their own basic statistical analysis. and there are typically many zero values. Several methods for analysing such data have Ia n W h it e a n d Ia n M a r t in

60 STATISTICS AND COMPUTING (SOUTH)

The work of the Branch is divided into four main areas: statistical consultancy, process D a t a c o l l e c t i o n modelling, computing and programming. With the exception of modelling, the branch A revolution in the approach to data collection activities relate mainly to service work, but has been made with the advent of hand held opportunities are also taken to earn income MS-DOS1 micro-computers. Object-oriented through approved contracts. Some branches programming techniques have been used to cre­ which employ tour-of-duty forest officers still ate a versatile data collection program used for look for a full data analysis service. Others, a variety of data collection tasks. The object is a staffed mainly by scientists, carry out their own form, and the user is able to move freely around computing and require help only with design the form, filling in data and editing it as and interpretation problems. In the statistics required, as if it were a paper form. area, the final analysis of the open top chamber As each field is accessed, its name appears at experiments was completed this year and over the top of the screen. Any warning messages 130 other experiments were analysed for relating to the field are shown at the bottom of Silviculture and Environmental Research the screen. The program displays a row identi­ Branches. fier on the left of the screen so that users always Alice Holt and Northern Research Station know where they are on the form. (NRS) computer systems were linked via the The data are validated as they are entered. Forestry Commission (FC) wide area network Entry of individual fields can be restricted to during the year and access to the Joint certain characters and ranges, while consistency Academic Network (JANET) is available via the checks can be made against other data entered. NRS connection to Edinburgh University. A The program has a facility for checking the cur­ modem link to the local network has been rent data against previously recorded values. added, new menus implemented and network The user is queried if an entry is significantly cards fitted to PCs. New computing strategy and different from the previous data or if an excep­ security documents were produced. tional assessment has been made. An archiving system has been created for use The program uses picklists for filling fields on the UNIX system, and project costing soft­ such as the surveyor’s name, thus ensuring con­ ware written to record staff time and calculate sistent entry of information. Picklists are also costs. Following an audit of the FC, a number of used as menus. changes to production forecasting programs An on-line context-sensitive help facility is were required. The program has been modified built into the program. At any stage during data in time for the 1995 FC forecast. collection, the user can call up this help with a A contract to create a new nursery sampling single keystroke. Information will be displayed system and data capturing facility was com­ about the current field. The help contains an pleted and has been used in this year’s Forest explanation of the information required and a Enterprise nursery stock take. Modelling work definition of the codes allowed as input for the on carbon allocation within the tree and stem field. Further help is available on the use of the respiration has continued in collaboration with program: moving about the screen; field editing Edinburgh University and partners from else­ capabilities, and so on. where in Europe. The program has been written using Turbo Pascal2 (version 6.0) and the Object Professional3 D a v id M o b b s

1 MS-DOS is a registered trademark of Microsoft Corporation. 2 Turbo Pascal is a registered trademark or Borland Interantional Inc. 3 Object Professional is a trademark of TurboPower Software.

61 STATISTICS AND COMPUTING (SOUTH)

library routines. It was developed on a desktop PC and is generally used on hand held MS-DOS Table 11. Coefficients of variation (CV) in stem units such as the Micro Palm4 PC5000 and mass at 70 years when input parameters were varied in the Forestry Commission growth model. PC3000 units and the Husky5 FS/2. Only one parameter was varied at a time and The program is used in several projects includ­ variation in the input parameter had a CV of 10% ing the annual Forest Condition Monitoring between trees or 10% between stands. Survey (Pathology (North)) and the computerisa­ tion of the production of timber load despatch Parameter Between tree Between stand notes (Forest Enterprise, Wales). variation (CV1) variation (CV) Crown angle 5.2 1.0 Jo h n H a l l a n d L esley H a l s a ll Light extinction coefficient 18.4 13.6 Light saturated S e n s it iv it y a n a l y s is o f a n in d iv id u a l t r e e gross photosynthesis MODEL rate 3.9 2.6 Light-use efficiency 41.3 26.5 As part of a project with other research groups Note: across Europe, the Forestry Commission model 1 CV = (s.d. x 100)/mean has been used to simulate a stand of Scots pine in Finland, using Finnish site conditions and thesis rate may be more important further south. weather data. We varied a number of inputs to The effect of each parameter was greater on the model including crown angle (degrees) the individual trees than on the whole stand (Table light extinction coefficient (m2 ground area m-2 11) because competition between neighbouring leaf area) the light-saturated photosynthetic rate trees amplified the parameter’s effect. Such (g C02 m-2 leaf area h_1) and the efficiency of amplification complicates the way we should light-use (g C 02 J-1). scale up from measurements on single trees to There were 16 trees in the simulated stand the whole stand, so the study has implications and they were identical at planting except for for interpreting experiments as well as for tree the parameter being varied. When this was improvement research. crown angle, for example, the 16 trees were allocated angles randomly from a normal distri­ A n t h o n y L u d lo w a n d T im o t h y R a n d le bution with a coefficient of variation (CV) of 10% (standard deviation = 10% of the mean). The trees grew from 0 to 70 years and the stem T h e seed germination a n a l y s is p r o g r a m mass at age 70 had a CV of 5.2% (Table 11). In other words, a 10% variation in crown angle of individual trees produced a 5.2% variation in The seed germination program automates the stem mass at 70 years. basic analysis required for standard seed germi­ When the mean crown angle of the whole nation data sets. stand was varied with a CV of 10%, the mean Analysis of variance (ANOVA) is performed stem mass of the stands varied by only 1%. In to examine any difference between treatments other words, a wide crown angle makes a tree a for germination rate, maximum germination good competitor, but a clonal stand of wide­ reached and for seed viability. There is an angled trees would do no better than a narrow option to graph the germination profiles over angled stand at the same spacing, because they time when the number of treatments is within intercept similar amounts of light per hectare reasonable limits. In addition to the ANOVA after canopy closure. output, summary files are produced to provide Table 11 shows that the light extinction coeffi­ basic summary information and to format data cient and efficiency of light use had a large effect for graphing with a spreadsheet. Various other on final stem mass, while light-saturated rate of features are built in, including error checking photosynthesis had little effect. Under Finnish procedures and identification. conditions, needles were light saturated for very To use the program, a Fortran program is run little of the year but the light saturated photosyn- which prompts the user for the name of the data file, and then creates basic file management information, before automatically calling the Micro Palm is a registered trademark of Micro Palm main Genstat program. Computers Inc. 5 Husky is a trademark of Husky Computers Limited. Jo n a t h a n T ay lo r

62 PUBLICATIONS BY RESEARCH DIVISION STAFF

APPENDIX 1

ANDERSON, A.R., [ADAMSON, J.K.,1 PYATT, intermediate Clusia minor L. growing in D.G. and HORNUNG, M. (1993). pH, alu- Trinidad. O ecologia, 95(3), 444—453. minium and calcium concentrations of streams draining acidic soils on calcareous BRASIER, C.M. (1993). Ceratocystis or till at Kershope, Cumbria. Journal o f Ophiostoma? The status of Ceratocystis and Hydrology, 149(1-4), 27-37. Ophiostoma species on Quercus. In: N. LUISI, P.PERARIO, and A. VANNINIA, eds. [AUSTARA, O.] and CARTER, C.I. (1993). On Recent advances in studies on oak decline. the distribution and biology of Aphrastasia pp.241-245. p ectin atae (Cholodkovsky 1888) in Norway. In: P. KINDLMANN and A.F.G. DIXON, eds. BRASIER, C.M. (1993). Phytophthora cin- Critical issues in aphid biology: proceedings nam om i as a contributory factor in European of the 4th International symposium on oak declines. In: N. LUISI, P. LERARIO and aphids, pp. 21-24. A. VANNINI, eds. Recent advances in studies on oak decline, pp. 49-57. BALDWIN, E. (1993). Leader breakage in upland spruce plantations. Scottish Forestry, BRASIER, C.M. (1993). The genetic system as a 47(2), 25-29. fungal taxonomic tool: gene flow, molecular variation and sibling species in the Ophiostoma [BAMBRIDGE, L.,] HARMER, R. [and piceae-Ophiostoma ulmi complex and its taxo­ MACLEOD, R.) (1993). Root growth in Sitka nomic and ecological significance. In: M.J. spruce grown in filtered and unfiltered air. WINGFIELD, K.A. SEIFERT and J.F. WEBBER, Research Information Note234. Forestry eds. Ceratocystis and Ophiostoma: taxonomy, Commission, Edinburgh. ecology and pathogenicity. (American Phytopathological Society), pp. 77-92. [BATES, M.R., BUCK, K.W. and] BRASIER, C.M. (1993). Molecular relationships between BRASIER, C.M. and KIRK, S.A. (1993). Sibling Ophiostoma ulmi and the NAN and EAN species within Ophiostoma piceae. races of O. novo-ulm i determined by restric­ Mycological Research, 97(7), 811-816. tion fragment length polymorphisms of BRASIER, C.M. [and STEPHENS, T.M.] (1993). nuclear DNA. Mycological Research, 97(4), Temperature-growth responses distinguish 449-455. the OPC and OPH sibling species within [BATES, M.R., BUCK, K.W. and] BRASIER, Ophiostoma piceae. Mycological Research, C.M. (1993). Molecular relationships of the 97(12), 1416-1418. mitochondrial DNA of Ophiostoma ulmi and BRASIER, C.M., [BATES, M.R., CHARTER, the NAN and EAN races of O. novo-ulm i N.W. and BUCK, K.W.] (1993). DNA poly­ determined by restriction fragment length morphism, perithecial size, and molecular polymorphisms. Mycological Research, 97(9), aspects of d-factors in Ophiostoma ulmi and 1093-1100. O. novo-ulmi. In: M.B. STICKLEN and J.- [BODMER, R.E., FANG, T.G., MOYA, I.L. and] SHERALD, eds. Dutch elm disease research: GILL, R.M.A. (1994). Managing wildlife to cellular and molecular approaches, pp. conserve Amazonian forests: population biol­ 308-321. ogy and economic considerations of game BRASIER, C.M., [HAMM, P.B. and HANSEN, hunting. Riological Conservation, 67, 29-35. E.M.] (1993). Cultural characters, protein pat­ [BORLAND, A.M., GRIFFITHS, H.,] BROAD- terns and unusual mating behaviour of MEADOW, M.S.J., [FORDHAM, M.C. and Phytophthora gonapodyides isolates from MAXWELL, C.] (1993). Short-term changes in Britain and North America. Mycological carbon-isotope discrimination in the C3-CAM R esearch, 97(11), 1287-1298.

63 PUBLICATIONS BY RESEARCH DIVISION STAFF - APPENDIX 1

BRASIER, C.M., [ROBREDO, F. and FERRAZ, DOBSON, M.C. and MOFFAT, A.J. (1993). J.F.P.] (1993). Evidence for Phytophthora cin- Should trees be planted on capped landfills? n am om i involvement in Iberian oak decline. Waste Planning, 7, 30-32. Plant Pathology, 42, 140-145. DOBSON, M.C. and MOFFAT, A.J. (1993). Trees [BRAZIER, J.D. and] MOBBS, I.D. (1993). The and desiccation of clays (letter). Waste influence of planting distance on structural Planning, 8, 32. wood yields of unthinned Sitka spruce. Forestry, 66(4), 333-352. DOBSON, M.C. and MOFFAT, A.J. (1994). Landfill and trees: are the two compatible? BROADMEADOW, M.S.J. [and GRIFFITHS, H.] Environmental Manager’s Journal, 2(2), (1993). Carbon isotope discrimination and 31-34. the coupling of CO2 fluxes within canopies. In: J.R. EHLERINGER, G.D. FARQUHAR and DURRANT, D.W.H., BARTON C.V.M., LEE, A.E. HALL, eds. Stable isotopes and plant H.S.J. and JARVIS, P.G. (1994). Long-term carbon/water relations. C02 enrichment experiment examining the interaction with nutrition in Sitka spruce BROADMEADOW, M.S.J. [and GRIFFITHS, H.] (P icea sitchensis Bong. Carr.). In: Biological (1993). Genotypic variation in Plantago indicators of climate change. Royal Society m ajor in response to elevated C 02. Journal o f of Edinburgh, Edinburgh. Experimental Botany, 44 (Supplement), 15. DURRANT, D.W.H., LEE. H.S.J., BARTON, [BROEKHUIZEN, N„] EVANS, H.F. [and HAS­ C.V.M. and JARVIS, P.G. (1993). Long term SELL, M.P.] (1993). Site characteristics and C02 enrichment experiment examining the the population dynamics of the pine looper intraction with nutrition in Sitka spruce moth. Journal of Animal Ecology, 62(3), [Picea sitchensis Bong. Carr.). In: Abstracts 511-518. book for ecophysiology and genetics of trees [CANNELL, M.G.R., DEWAR, R.C. and] PYATT, and forests in a changing environment. D.G. (1993). Conifer plantations on drained IUFRO conference, Viterbo, Italy, May 1993. peatlands in Britain: a net gain or loss of car­ p. 38. bon? Forestry, 66(4), 353-369. DURRANT, D.W.H., LEE, H.S.J., BARTON, CARTER, C.I. (1993). A rare pine aphid estab­ C.V.M. and JARVIS, P.G. (1993). A long-term lished in Cornwall. Zoological Cornwall and carbon dioxide enrichment experiment the Isles of Scilly, 2, 4. examining the interaction with nutrition in Sitka spruce. Research Information Note 238. CARTER, C.I. (1993). Aspen and its insect fauna Forestry Commission, Edinburgh. (brief item). Native Woodlands Discussion Group Newsletter, 18, 47. EDWARDS, C., MORGAN, J.L. and WILLOUGHBY, I. (1994). Approved herbi­ CARTER, C.I. [and DANIELSSON, R.] (1993). cides for use in forestry. Research New and additional records of gall-forming Information Note 246. Forestry Commission, aphids of the family Pemphigidae in Britain. Edinburgh. The Entomologist, 112(2), 99-104. EDWARDS, C., TRACY, D. and MORGAN, J.L. COUTTS, M.P. and NICOLL, B.C. (1993). (1993). Rhododendron control by imazapyr. Orientation of the lateral roots of trees. 2: Research Information Note 233. Forestry Hydrotropic and gravitropic responses of lat­ Commission, Edinburgh. eral roots of Sitka spruce grown in air at dif­ ferent humidities. New Phytologist, 124, EVANS, J. (1993). Long-term experimentation in 277-281. forestry and site change. Invited paper at Rothamsted 150th Anniversary Conference, [DAVIS, H. and] MOFFAT, A.J. (1992). Trees July 1993. and woodland on restored soils. In: Sixth ADAS national land restoration seminar. EVANS, J. [and HIBBERD, B.G.] (1993). Shell- Wolverhampton, West Midlands, 12 October WWF tree plantation review. Study 9: 1992. pp.15-22. Operations. [DIXON, A.F.G., WELLINGS, P.W.,] CARTER, EVANS, J. [and WOOD, P.J.] (1993). The p lace C.I. and NICHOLS, J.F.A. (1993). The role of of plantations in sustainable tropical forestry. food quality and competition in shaping the Invited paper at the 14th Commonwealth seasonal cycle in the reproductive activity of Forestry Conference, Kuala Lumpur, the sycamore aphid. O ecologia, 95(1), 89-92. Malaysia, September 1993.

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EVANS, J. (compiler) (1992). Ten years of impacts on forestry. In: M.G.R. CANNELL forestry research: an account of the work of and C.E.R. PITCAIRN, eds. Impacts of the the Forestry Research Co-ordination mild winters and hot summers in the United Committee, 1982 to 1992. Forestry Kingdom in 1988-1990. pp. 33-35. Commission, Edinburgh. GILL, R.M.A. (1990). The Global Environment EVANS, J., [MORRIS, A.R. and MASSON, P.] Monitoring System: monitoring the status of (1993). Sustainability of pulpwood planta­ European and North American cervids. tions in the Usutu forest, Swaziland. Invited UNEP, Nairobi, Kenya. United Nations case study, 14th Commonwealth Forestry Environment Programme and University of Conference, Kuala Lumpur, Malaysia, Cambridge, Department of Zoology, Large September 1993. Animal Research Group. (GEMS Information Series 8). [FENNING, T.M., GARTLAND, K.M.A. and] BRASIER, C.M. (1993). Micropropagation and [GUILLAUMIN, J-J., MOHAMMED, C., regeneration of English elmUlmus procera ANSELMI, N., COURTECUISSE, R.,] GRE­ Salisbury. Journal of Experimental Botany, GORY, S.C., [HOLDENRIEDER, O., INTINI, 44(264),1211-1217. M., LUNG, B„ MARXMULLER, H., MORRI­ FERRIS-KAAN, R., LONSDALE, D. and WIN­ SON, D., RISHBETH, J., TERMORSHUIZEN, TER, T.G. (1993). The conservation manage­ A.J., TIRRO, A. and VAN DAM, B.] (1993). ment of deadwood in forests. Research Geographical distribution and ecology of the A rm illaria species in western Europe. Information Note 241. Forestry Commission, European Journal of Forest Pathology, Edinburgh. 23(6-7),321-341. FORREST, G.I. (1994). Biochemical markers in tree improvement programmes. Forestry [GURNELL, J. and] PEPPER, H.W. (1993). A crit­ Abstracts, 55(2),123-153. ical look at conserving the British red squir­ rel Sciurus vulgaris. Mammal Review, GARDINER, B.A. (1994). Wind and wind forces 23(3-4),127-137. in a plantation spruce forest. Boundary-layer Meteorology, 67,161-186. HARMER, R. (1993). Branching in young clonal oak. Annales des Sciences Forestieres, GARDINER, B.A. (1994). Windthrow special: Genetics of oaks: proceedings of the first mechanics and management. Timber Grower, meeting of the IUFRO working party 130, 22. S2.02-22, Arboretum National des Barres, France, 2-6 September 1991. 50, Suppl.l, GIBBS, J.N. (1993). Impacts of the terrestrial envi­ 399s-402s. ronment: forest and amenity trees. In: M.G.R. CANNELL and C.E.R. PITCAIRN, eds. Im pacts HARMER, R. and NIXON, C.J. (1993). The nat­ of the mild winters and hot summers in the ural regeneration of native woodlands.Native United Kingdom in 1988-1990. pp. 96-98. Woodlands Discussion Group Newsletter, 18, GIBBS, J.N. (1993). Saving salt and the earth: 32-34. research has proven that over-use of de-icing HODGE, S.J. (1993). Setting up tree planting salt destroys trees, but have highway authori­ and woodland demonstrations. Research ties taken this on board? Surveyor, 7, October Information Note 242. Forestry Commission, 1993,14-15. Edinburgh.

GIBBS, J.N. (1993). The biology of HODGE, S.J. (1993). The effect of stem nutrient Ophiostomatoid fungi causing sapstain in injection and compressed air soil injection on trees and freshly cut logs.In: M.J. WING­ the performance of established amenity trees. FIELD, K.A. SEIFERT and J.F. WEBBER, eds. Arboricultural Journal, 17(3),287-300. Ceratocystis and Ophiostoma: taxonomy, ecology, and pathogenicity, pp. 153-160. HODGE, S.J. (1993). Trees to fuel the urban for­ est. Horticulture Week, 213(16),23—24, 26-27. GIBBS, J.N. (1994). De-icing salt damage to trees: the current position. Arboriculture HODGE, S.J. (1993). Treeshelters: the first years Research Note 119-94-PATH. Arboricultural and where we are today.Association of Advisory and Information Service, Farnham, Professional Foresters Newsletter, June 1993, Surrey. 55-59. GIBBS, J.N. [and CANNELL, M.G.R.] (1993). HODGE, S.J. (1993). Trials of organic backfill Impacts on the terrestrial environment: amendments on trunk road sites.

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Arboriculture Research Note 114-93-ARB. Arboriculture Research Note 116-93-PATH. Arboricultural Advisory and Information Arboricultural Advisory and Information Service, Farnham, Surrey. Service, Farnham, Surrey. HODGE, S.J. (1993). Using steel rods to assess LONSDALE, D. (1993). Choosing the time of

aeration in urban soils.Arboriculture year to prune trees. Arboriculture Research Research Note 115-93-ARB. Arboricultural Note 117-93-PATH. Arboricultural Advisory Advisory and Information Service, Farnham, and Arboriculture Information Service, Surrey. Farnham, Surrey.

HODGE, S.J. and BOSWELL, R.C. (1993). A LUCAS, M., DURRANT, D.W.H., LEE. H.S.J. study of the relationship between site condi­ and JARVIS, P.G. (1993). Long-term CO2 tions and urban tree growth. Journal of enrichment experiment examining the inter­ Arboriculture, 19(6), 358—367. action with nutrition in Sitka spruce (Picea HODGE, S.J. and KNOTT, K. (1993). A practical sitchensis Bong. Carr.). Journal of guide to the use of steel rods for the assess­ Experimental Botany, 44, (Supplement), 17. ment of aeration in urban soils. Journal of MASON, W.L. (1993). The challenge to silvicul­ Arboriculture, 19(5), 289-294. turists: rethinking options in northern HODGE, S.J., BOSWELL, R.C. and KNOTT, K. Britain. Timber Grower, 128, 24-25. (1993). Development of the steel rod tech­ MASON, W.L. (1993). The ecology, genetics and nique for the assessment of aeration in urban silviculture of aspen in Scotland. Native soils. Journal of Arboriculture, 19(5), Woodlands Discussion Group Newsletter, 18, 281-288. 45—46. HOLLINGSWORTH, M.K. and MASON, W.L. (1993). Vegetative propagation of native MATTHEWS, R.W. (1992). Role of carbon bud­ geting in assessing the environmental costs aspen: an update. Native Woodlands and benefits of forestry schemes. In: G.E. Discussion Group Newsletter, 18, 34-36. RICHARDS, ed. Wood: energy and the envi­

[INGLEBY, K.,] WALKER, C. [and MASON, ronment. Proceedings of a workshop held in P.A.] (1994). Acaulospora excavata sp. nov: Harrogate, England, 9-10 September 1992. an endomycorrhizal fungus from Cote pp. 21-27. d’Ivoire. Mycotaxon, 50, 99-105. MATTHEWS, R.W. [and ROBINSON, R.L.] JONES, S.K., [BERGSTEN, U. and] GOSLING, (1993). Biomass from energy: progress in P.G. (1993). A comparison of 5°C and 15°C computer modelling of energy and carbon as dormancy breakage treatments for Sitka budgets for wood fuel production from short spruce seeds (Picea sitchensis). In: D.G.W. rotation coppice. In: Short rotation coppice: EDWARDS, ed. Dormancy and barriers to growing for profit. National Agricultural germination: Proceedings of the International Conference, 24 March 1993. Royal Agricul­ Symposium IUFRO Project Group P2.04-00 tural Society of England and The Wood (Seed Problems), Victoria, British Columbia, Energy Development Group. Canada, 23-26 April 1991. pp. 51-55. MAYLE, B.A. (1992). Fallow under scrutiny: the KERR, G. (1993). Establishment and provenance third largest species of deer in Britain is now of walnut in Britain. Forestry, 66(4), 381-393. the subject of a major research project which, KERR, G. (1993). New visions for broadleaves. it is hoped, will lead to guidelines for its

Timber Grower, 128, 27. management. Timber Grower, 124, 20.

KERR, G. (1993). Robust woodland establish­ MAYLE, B.A. (1993). Bat activity in a mixed ment. Quarterly Journal of Forestry, 87(4), lowland woodland in relationship to insect

302-304. prey availability. In: G. ROBERTS, ed. The KERR, G. and EVANS, H.F. (1993). Beech in Isle of Wight bat detector workshop report. treeshelters. Quarterly Journal of Forestry, Bat Conservation Trust, pp. 29-30. 87(2), 107-115. McKAY, H.M. (1993). Deterioration of fine tree LEE, S.J. (1994). Sitka spruce genetic gain trials. roots during cold storage in two contrasting Research Information Note 245. Forestry winters. Technical Paper 2. Forestry Commission, Edinburgh. Commission, Edinburgh. LONSDALE, D. (1993). A comparison of ‘target’ McKAY, H.M. (1994). The quality of Sitka

pruning, versus flush cuts and stub pruning.spruce at the time of planting. Research

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Information Note 243. Forestry Commission, catchment in SW Scotland.In: Foundation Edinburgh. for Water Research, ed.Proceedings of the Loch Dee symposium: acidification, forestry McKAY, H.M., GARDINER, B.A., MASON, and fisheries management in upland W .L., NELSON, D.G. and Galloway. Gatehouse of Fleet, Dumfries and HOLLINGSWORTH, M.K. (1993). The gravi­ Galloway, Scotland,8-9 December1992. pp. tational forces generated by dropping plants 123-136. and the response of Sitka spruce seedlings to dropping. Canadian Journal of Forest NIXON, C.J. (1994). Effectiveness of treeshel- R esearch, 23, 2443-2451. ters in upland Britain.Quarterly Journal of Forestry, 88(1), 55-62. MOFFAT, A.J. (1993). Silvan sludge: more sewage sludge will be used on the land as NIXON, C.J. [and CAMERON, E.) (1994). A sea disposal is phased out; its application as pilot study on the age structure and viability a forest fertiliser. Landscape Design, 219, of the Mar Lodge pinewoods. Scottish 24-27. Forestry, 48(1), 22-27.

MOFFAT, A.J. (1994). Sewage sludge as a fer­ PATTERSON, G.S. (1993). The value of birch tilizer in amenity and reclamation planti­ in upland forests for wildlife conservation. ngs. Arboriculture Research Note76-94- Forestry Commission Bulletin 109. HMSO, SSS. Arboricultural Advisory and London. Information Service, Farnham, Surrey. PATTERSON, G.S. [and MORRISON, B.R.S.] MOFFAT, A.J. [and SHAW, P.J.A.] (1993). (1993). Invertebrate animals as indicators of Establishment of trees on mixtures of pul­ acidity in upland streams. Forestry verized fuel ash and gypsum. 1: Tree perfor­ Commission Field Book 13. HMSO, London. mance. Land Degradation and PEPPER, H.W. (1993). Red squirrel supplemen­ Rehabilitation, 4(2), 87-97. tary food hopper. Research Information Note MOFFAT, A.J., [ARMSTRONG, A.T. and COL- 235. Forestry Commission, Edinburgh. LYER, E.L.] (1994). Site preparation for tree PEPPER, H.W. [and STOCKER, D.) (1993). Grey establishment on lowland clay soils. squirrel control using modified hoppers. Quarterly Journal of Forestry, 88(1), 35-41. Research Information Note232. Forestry MORGAN, J.L. and MASON, W.L. (1993). Commission, Edinburgh. Vegetative propagation of conifers in Great PETTY, S.J. and PEACE, A.J. (1993). Temporal Britain. In: C.M. KOOISTRA, ed. and spatial fluctuations in field vole abun­ Proceedings of the 12th Annual Forestry dance in a predator/prey study.In: Report Nursery Association of Rritish Columbia on forest research 1992. HMSO, London, pp. m eeting. Penticton, British Columbia, 40-42. Canada, 28 September-1 October 1992. pp.- 23-28. PRATT, J.E. (1993). Some experiments with borates and with urea to control stump MORGAN, J.L. (1994). Fertilization regimes to infection by H .annosum in Britain. In: M. produce different size classes of cell-grown JOHANSSON and J. STENLID, eds. birch. Research Information Note 247. Proceedings of the eighth international con­ Forestry Commission, Edinburgh. ference on root and butt rots. Uppsala, Sweden and Finland, 1993. IUFRO MORGAN, J.L. (1994). Forest nurseries herbi­ S2.06-01. pp. 662-667. cide update. Forestry and British Timber, 23(2), 35. PYATT, D.G. (1993). Multi-purpose forestry on peatland. Biodiversity and Conservation, NISBET, T.R. (1993). The effects of a pelletised 2(5), 548-555. limestone treatment on drainage water acid­ ity within a forest catchment in mid-Wales. QUINE, C.P. (1994). Windthrow special: classi­ Paper presented at the International sympo­ fied information. Timber Grower, 130, 23 and sium on forest hydrology, Canberra, 25. Australia, 22-26 November 1993. Journal o f QUINE, C.P. and WHITE, I.M.S. (1993). H ydrology, 150(2-4), 521-539. Revised windiness scores for the windthrow NISBET, T.R., [FOWLER, D. and SMITH, R.I.] hazard classification: the revised scoring (1993). The effect of conifer afforestation on m ethod. Research Information Note230. stream water acidity within the Loch Dee Forestry Commission, Edinburgh.

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QUINE, C.P. and WRIGHT, J.A. (1993). The [SEIFERT, K.A.,] WEBBER, J.F. [and WING­ effects of revised windiness scores on the cal­ FIELD, M.J.] (1993). Methods for studying culation and distribution of windthrow haz­ species of O phiostom a and Ceratocystis. In: ard classes. Research Information Note 231. M.J.WINGFIELD, K.A. SEIFERT and J.F. Forestry Commission, Edinburgh. WEBBER, eds. Ceratocystis and Ophiostoma: taxonomy, ecology, and pathogenicity. [RAHMAN, M.A., MILLAR, C.S. and] GIBBS, American Phytopathological Society, J.N. (1994). Shoot dieback of lodgepole pine Minnesota, pp. 255-259. in Scotland caused by Ramichloridium pini. European Journal of Forest Pathology, 24(1), [SHAW, P.J.A. and] MOFFAT, A.J. (1993). 40—47. Establishment of trees on mixtures of pulver­ ized fuel ash and gypsum. 2: Nutrition and RATCLIFFE, P.R. (1993). Biodiversity in trace elements. Land Degradation and Britain’s forests. Forestry Commission, Rehabilitation, 4(3), 123-129. Edinburgh. [SOUTH, D.B., MITCHELL, R.J., ZUTTER, B.R., RATCLIFFE, P.R. and MAYLE, B.A. (1994). An BALNEAVES, J.M., BARBER, B.L.,] objective approach to roe deer management. NELSON,D.G. [and ZWOLINSKI, J.B.] (1993). Deer, 9(3), 151-152. Integration of nursery practices and vegeta­ tion management: economic and biological RAY, D. (1993). Forests and water guidelines potential for improving regeneration. update. Forestry and British Timber, 22(11), Canadian Journal of Forest Research, 23(10), 21-22, 24. 2083-2092. RAY, D. (1994). The Forests and water guide­ STROUTS, R.G. [and PATCH, D.] (1994). lines and riparian management. In: I. GLIM- Fireblight of ornamental trees and shrubs. MERVEEN and A. RICHIE, eds. Proceedings Arboriculture Research Note 118-94- of river woodlands conference at Melrose. PATH.Arboricultural Advisory and Institute of Chartered Foresters and British Information Service, Farnham, Surrey. Ecological Society, pp. 13-15. TABBUSH, P.M. (1993). Coppiced trees as REDFERN, D.B. (1993). Climatic injury as a energy crops: final report. ETSU B 1291. problem of introduced species in northern Department of Trade and Industry, Energy Britain. In: R. JALKANEN, T. AALTO and M- Technology Support Unit. L. LAHTI, eds. Forest pathological research TABBUSH, P.M. (1993). Poplar husbandry. In: in northern forests with special reference to Poplar: a profitable farm and woodland crop. abiotic stress factors. Finnish Forest Research National Agricultural Conference, 25 March Institute Paper 451. pp. 44—49. 1993. Royal Agricultural Society of England, REDFERN, D.B. (1993). The effect of wood The Wood Energy Development Group and moisture on infection of Sitka spruce stumps The Poplar Working Group. by basidiospores of Heterobasidion annosum. TABBUSH, P.M. (1993). Poplar husbandry. European Journal of Forest Pathology, 23(4), Quarterly Journal of Forestry, 87(3), 203-205. 218-235. [TAYLOR, M.A., DAVIES, H.V., SMITH, S.B., REDFERN, D.B. (1993). Monitoring in the ABRUZZESE, A. and] GOSLING, P.G. (1993). United Kingdom. Proceedings from the meet­ Cold-induced changes in gene expression ing of the SNS ad hoc group on monitoring during dormancy breakage in seeds of forest damage. As, Norway, 26-28 April Douglas fir (Pseudotsuga menziesii). Journal 1993. Aktuelt fra Skogforsk, 2-93, 18-19. o f Plant Physiology, 142(1), 120-123.

REDFERN, D.B., BOSWELL, R.C. and PROUD­ WALKER, C., [GIANINAZZI-PEARSON, V. and FOOT, J.C. (1993). Forest condition 1992. MARION-ESPINASSE, H.] (1993). Scutellospora Research Information Note 236. Forestry castanea, a newly described arbuscular mycor­ Commission, Edinburgh. rhizal fungus. Cryptogamie Mycologie, 14(4), 279-286. RILEY, M. and NIXON, C.J. (1993). 50 year results from an oak spacing trial in south [WANG, G.M., STRIBLEY, D.P., TINKER, P.B. and] WALKER, C. (1993). Effects of pH on Scotland. Scottish Forestry, 47(3), 79-82. arbuscular mycorrhiza. 1: Field observations [RODWELL, J.S. and] PATTERSON, G.S. (1994). on the long-term liming experiments at Creating new native woodlands. Forestry Rothamsted and Woburn. New Phytologist, Commission Bulletin 112. HMSO, London. 124,465-472.

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WARD, E. and DEANS, J.D. (1993). A simple 3-5 April 1992. Institute of Chartered method for the routine extraction and quan­ Foresters, pp.96-102. tification of non-structural sugars in tree tis­ sues. Forestry, 66(2), 171-180. WILLIAMSON, D.R., MASON, W.L., MORGAN, J.L. [and CLAY, D.V.] (1993). Forest nursery WEBBER, J.F. (1993). D factors and their poten­ herbicides. Technical Paper3. Forestry tial for controlling Dutch elm disease. In: Commission, Edinburgh. M.B.STICKLEN and J.L. SHERALD, eds. Dutch elm disease research: cellular and [WINGFIELD, M.J., SEIFERT, K.A. and] WEB­ molecular approaches, pp. 322-332. BER, J.F. (eds) (1993). Ceratocystis and WHITE, J.E.J. (1993). Black poplar: the most Ophiostoma: taxonomy, ecology and patho­ endangered native timber tree in Britain. genicity. American Phytopathological Research Information Note239. Forestry Society, Minnesota. Commission, Edinburgh. WINTER, T.G. (1993). Deadwood: is it a threat [WILCOX, W.F., SCOTT, P.H., HAMM, P.B., to commercial forestry? In: K.J. KIRBY and KENNEDY, D.M., DUNCAN, J.M.,] BRASIER, C.M.DRAKE, eds. Dead wood matters: the C.M. [and HANSEN, E.M.] (1993). Identity of ecology and conservation of saproxylic inver­ a Phytophthora species attacking raspberry in tebrates in Britain. English Nature Science7. Europe and North America. Mycological English Nature, Peterborough. B esearch, 97(7), 818-831.

WILLIAMSON, D.R. (1993). Forestry WRIGHT, J.A. and QUINE, C.P. (1993). The use Commission research on farm woodland of a Geographical Information System to establishment.In: D.A.GREIG, ed. Farm and investigate storm damage to trees at small scale forestry. Proceedings of an ICF Wykeham Forest, North Yorkshire.Scottish discussion meeting, University of Reading, Forestry, 47(4), 166-174.

69 RESEARCH DIVISION ORGANISATION

APPENDIX 2

t - with section at Alice Holt * - with section at Northern Research Station

70 RESEARCH DIVISION BRANCHES AND THEIR PROJECT GROUPS1

APPENDIX 3

Project leader(s) at Project leader(s) at 31 March 1994 31 March 1994

Entomology Site yield R.W. Matthews, Advisory and T.G. Winter P.C. Jokiel taxonomic Yield modelling R.W. Matthews Beech bark disease D. Wainhouse Biodiversity C.I. Carter Mycorrhiza Research Unit Dendroctonus micans N.J. Fielding, D. Development of C. Walker Wainhouse rooting patterns Elatobium abietinum C.I. Carter Mycorrhizas C. Walker H ylastes and H ylobius S.G. Heritage, R. Moore Impact N.A. Straw Pathology Panolis flammea S.G. Heritage Damage monitoring J.N. Gibbs, S.C. Gregory Stress D. Wainhouse and risk assessmentD.B. Redfem, R.G. Strouts Environmental Research Disease diagnosis D.B. Redfern, D.R. Rose, Air pollution M.S.J. Broadmeadow, R.G. Strouts D.W.H. Durrant, Dutch elm disease C.M. Brasier P.H. Freer-Smith Fomes root rot B.J.W. Greig, J.E. Pratt, A.J. Moffat D.B. Redfern Chemical analysis E. Ward Oak dieback B.J.W. Greig Effects of trees on sites A.J. Moffat, T.R. Nisbet Poplar diseases D. Lonsdale Forestry and M.S.J. Broadmeadow, Stem decays D. Lonsdale environmental P.H. Freer-Smith, change D.A. Waddell Plant Production Hydrology: water T.R. Nisbet Nursery research R.L. Jinks quality Seed research P.G. Gosling, S.K. Jones Instrumentation T.R. Nisbet Seed testing P.G. Gosling, Lowland production A.J. Moffat Y.K. Samuel forestry Reclamation A.J. Moffat Silviculture (North) Forest Products Crofter forestry A.L. Sharpe Preservation J.F. Webber Farm and community J. Simpson Quality and value J.F. Webber forestry enhancement Nurseries and J.L. Morgan Wood and timber J.F. Webber establishment properties Nutrition and site yield J.C. Dutch Planting stock quality H.M. McKay Mensuration Reclamation (north) M. Riley Advisory services J.M. Methley Root growth and form B. Nicoll Measurement studies J.M. Methley Species and long-term W.L. Mason Sample plots J.M. Methley, experiments J.C. Proudfoot Stability B.A. Gardiner, C.P. Quine Stand structure and C.J. Nixon 1 ‘Advisory’ is distinguished as a separate project group in certain branches, but is an activity in all of them. natural regeneration

71 RESEARCH DIVISION BRANCHES AND THEIR PROJECT GROUPS - APPENDIX 3

Project leader(s) at Project leader(s) at 31 M arch 1994 31 M arch 1994

Stability B.A. Gardiner, Micropropagation A. John C.P. Quine Origin C.J.A. Samuel Stand structure and C.J. Nixon Production: clone W. Brown natural regeneration banks and orchards Rejuvenation A. John Silviculture (South) Testing progeny S.J. Lee and clones Ecology of native R. Harmer broadleaves Wildlife and Conservation Research Establishment and G. Kerr stand silviculture Roe and fallow B.A. Mayle Farm woodlands, I. Willoughby deer; bats short rotation The impact of R.M.A. Gill mammals on coppice & weed forest vegetation control Squirrels, rabbits and H.W. Pepper Poplars P.M. Tabbush tree protection Species and arboreta J.E.J. White Stand manipulation R. Ferris-Kaan Urban and community S.J. Hodge and vegetation forestry management Statistics and Computing (South) W ildlife Ecology Forest growth A.R. Ludlow Birds S.J. Petty process modelling Carnivores A.H. Chadwick Clay soils D. Ray Tree Improvement Deep peats A.R. Anderson Biochemical variation G.I. Forrest, J. Cottrell Ecological site D.G. Pyatt Biometrical studies C.J.A. Samuel classification Flowering J.J. Philipson Loamy gleys A.R. Anderson Forest reproductive A.M. Fletcher, Red and sika deer A.H. Chadwick materials regulations C.J.A. Samuel Streams and riparian J.W. Humphrey Improvement and C.M. Cahalan vegetation propagation of farm Vegetation J.W. Humphrey forestry broadleaves management

72 NET EXPENDITURE OF RESEARCH DIVISION 1993/94

APPENDIX 4

£000 Branch (a) Expenditure Net value of Commissioned Expenditure by Branch in-house research (d) attributable direct (b) services less to Branch those provided (c) Entomology 677 133 26 836 Environmental Research 509 160 75 744 Forest Products 87 17 246 350 Mensuration 360 47 - 407 Pathology 568 133 58 759 Physiology 269 57 9 335 Plant Production 116 56 - 172 Silviculture (North) 1978 -41 4 1941 Silviculture (South) 1222 93 28 1343 Tree Improvement 1106 214 10 1330 Wildlife and Conservation Research 475 91 88 654 Wildlife Ecology 181 90 - 271 Communications 556 -192 - 364 Stats & Computing (North) 292 -194 - 98 Stats & Computing (South) 607 -479 - 128 Engineering Services 185 -185 - - Total 9188 - 544 9732

Notes: (a) Ordered as in the text of this Report. (b) All directly incurred expenditure on wages and salaries, pension provisions, travelling and subsistence, materials, equipment, etc., plus office overheads of the Division of £2.023m plus Forestry Commission headquarters overheads for common services of £0.494m, net of income of £1.139m for contract services provided to outside parties. (c) Figures show net effect of charges for services received (principally research information, engineering workshops and statistics and computing) less charges for services provided by the specific branch to other branches. (d) Work commissioned at other government institutes, universities, etc.

73 CONTRACT WORK DONE BY RESEARCH DIVISION

APPENDIX 5

British Coal Opencast coal spoil reclamation Amenity tree health monitoring in England Demonstration and research in the New National Forest Department of the Environment Development of plant quality index for - Arb VI broadleaved trees Minimising pavement damage from street trees Production of manual on decay and safety in trees Department of the Environment Potential for woodland establishment on landfill sites Department of Trade and Industry Coppiced trees as energy crops (Energy Technology Support Initial spacing in short rotation Unit) coppice Department of Transport Alternatives to peat Backfill studies EU Forest condition surveys Interdisciplinary research for poplar improvement Tree seed dormancy EU/AFOCEL Northern conifers in fast growing conditions - a step towards an adequate wood supply for industry EU/Imperial College Chemical control of bluestain EU/Institute of Virology and Transgenic poplar Environmental Microbiology EU/Irish Forestry Service Wind stability EU/Macaulay Land Use Agroforestry Research Institute EU/Madaus AG European A esculus cultivation system EU/University of Edinburgh The likely impact of rising C 02 and temperature on European forests FAO Establishment of Mycorrhiza research programmes Kemforschungszentrum Spruce root stock (Germany) Lothian Regional Council Transplant performance MacFarlane Smith Animal repellent studies Ministry of Agriculture, Provenance testing Fisheries & Food Vegetative propagation Yield assessments

74 CONTRACT WORK DONE BY RESEARCH DIVISION - APPENDIX 5

Niko Chemical Co Ltd Animal repellent studies ODA Nutritional aspects of Chinese fir Tropical legume seed pretreatment ODA/ECTF China larch tree breeding project Pilkington Trust Control of Ophiostoma novo-ulmi by the'd-factor’ Scottish Enterprise Condition of large planting stock Scottish Forestry Trust, Physiology of native Scots pine via TGUK Private woodlands squirrel questionnaire 1991 Sierra UK Fertilization of birch Southern Water Services Short rotation coppice/sewage sludge Strathclyde Greenbelt Co Mycorrhizas in spoil heaps Species choice on reclamation sites Use of sewage sludge

75 RESEARCH CONTRACTS AWARDED BY RESEARCH DIVISION

APPENDIX 6

Avon Vegetation Research Herbicide evaluation Building Research Dimensional stability of Sitka spruce Establishment Effects of water storage on strength and porosity of timber Modelling strength properties of Sitka spruce Modelling wood characteristics Testing British grown hardwoods for British standards Testing British grown softwoods for European standards Dundee Institute of Technology Genetic engineering of English elm Environmental Management Introduction and establishment of Consultants Ltd understorey vegetation in woodlands Forest Insect Surveys and ITE Invertebrate fauna of birch in spruce forests George Peterken Dead wood New native woodlands Imperial College, London Biological control of decay in utility poles Greenwood preservative treatments Potential of entomopathogenic nematodes for control of restocking pests Institute of Hydrology Effects of afforestation on water resources Institute of Terrestrial Ecology Capercaillie breeding ecology National Rivers Authority Effects of forestry on surface water (Welsh Region) acidification Royal Society for the Golden eagle ranging behaviour Protection of Birds Tweed Foundation Fauna of a small stream University College of North Crown development and timber Wales, Bangor quality Effect of provenance and silviculture on timber quality of oak University College of Wales, Biology of Ramichloridium dieback of Aberystwyth lodgepole pine University of Aberdeen Biocontrol of Heterobasidion annosum in Sitka spruce stumps University of East Anglia Windspeed prediction in complex terrain University of Lancaster The physiological impact of long-term exposure of trees to elevated C 02

76 RESEARCH CONTRACTS AWARDED BY RESEARCH DIVISION - APPENDIX 6

University of Nottingham Development of transformation systems for Sitka spruce University of Portsmouth Management of bluestain in sawn timber University of Wales, Cardiff Conifer seed as a food for vertebrates

77 STAFF EMPLOYED IN RESEARCH DIVISION AT 31 MARCH 1994

APPENDIX 7

Health and Safety Section R e s e a r c h D iv is io n M. R. Jukes, C.Biol., M.I.Biol., Head of Section Office Services Section Director D. A. Burdekin, B.A., Mrs C. A. Evans, Head of Section Dip. Ag. Sci., M.I.C. For. Miss F. J. Parsells [Alice Holt) E. W. Perrins Mrs T. M. Smalley Chief Research Officer D. Rook, B.Sc., F.I.C. Mrs A. Smith (North) For. (Northern Research Mrs D. Steel Station) Personnel Section M. G. Wheeler, Head of Section Head of the Northern Research Station. General Miss L. J. Caless responsibility for research north of the Mrs P. C. Fawcett Mersey/Humber line and in Wales, with spe­ Mrs P. A. Iremonger cific responsibilities for silviculture and for Miss J. R. Lacey environmental and wildlife research in the Mrs S. E. Robson uplands, and throughout Britain for research in tree improvement. Typing Section Mrs J. Shipp, Head of Section Chief Research Officer J. Evans, B.Sc., Ph.D., Mrs J. M. Bell (South) D.Sc., F.I.C. For. [Alice Mrs B. E. Dickinson Holt) Mrs C. A. Holmes Mrs H. R. Payne General responsibility for research south of theMrs M. C. Peacock Mersey/Humber line, with specific responsibil­ Mrs S. G. Stiles ity for silviculture and for environmental and Mrs P. J. Wright wildlife research in the lowlands, and through­ out Britain for research in pathology, entomol­ Communications Branch ogy, plant production, instrumentation and E. J. Parker, Ph.D., C. Biol., M.I. Biol., Head of technical aspects of legislation relating to plant Branch health. Library and Information Section Miss C. A. Oldham, B.A., M.A., Dip. Lib., A.L.A., Head of Section and Librarian S t a f f b a s e d a t A l ic e H o l t L o d g e Mrs E. M. Harland, M.A., Dip. Lib., Assistant Librarian Mrs D. Whitehead Administration Branch Photography Section K. N. Charles, F.M.S., Personnel and G. L. Gate, Head of Section Administration Officer, Head of Branch G. R. Brearley[Northern Research Station) Finance Section Miss M. Trusler R. Murray, Head of Section J. Williams Miss J. M. Atkins Publications Section P. A. Filewood Ms K. A. Davies, Head of Section D. M. Payne Miss M. J. Froud Ms S. J. Worman Miss M. Taylor

78 STAFF ENGAGED IN RESEARCH DIVISION AT 31 MARCH 1994 - APPENDIX 7

Entomology Branch(with section at Northern R. G. Strouts Research Station) M. L. Sutherland, B.Sc., M.Sc., Ph.D. H. F. Evans, B.Sc., D.Phil., F.R.E.S., Head of Miss M. Trusler Branch R. Ashburner, B.Sc. Plant Production Branch C. I. Carter, M.Sc., C. Biol., M.I.Biol., F.R.E.S. P. G. Gosling, B.Sc., Ph.D., Head of Branch N. J. Fielding (Ludlow) A. S. Gardiner Mrs G. Green, B.Sc. R. L. Jinks, B.Sc., Ph.D., Mrs W. Groves S. K. Jones, C. Biol., M.I. Biol., M.I.Hort. Mrs J. F. A. Johnson, B.Sc., M. Phil., C. Biol., Mrs Y. K. Samuel, B.A. M.I.Biol., F.R.E.S. N. A. Straw, B.Sc., Ph.D., F.R.E.S. Silviculture (South) Branch Mrs C. A. Tilbury, B.Sc. P. M. Tabbush, B.Sc., M.I.C. For., Head of D. Wainhouse, M.Sc., Ph.D., F.R.E.S. Branch T. G. Winter, F.R.E.S. J. L. Budd I. Collier (M idlands) Environmental Research Branch D. Elgy P. H. Freer-Smith, B.Sc., Ph.D., Head of Branch A. R. Hall A. T. Armstrong, M.I.C. For. R. Harmer, B.Sc., Ph.D. Mrs S. E. Benham D. A. Hendrie (Thetford) M. S, J. Broadmeadow, B.Sc., Ph.D. S. J. Hodge, B.Sc., M.Sc., M.I.C. For. P. G. Crow G. Kerr, B.Sc., M.I.C. For. M. C. Dobson, B.Sc., Ph.D. S. Minton (Exeter) D. W. H. Durrant, B.A. R. A. Nickerson T. R. Hutchings D. G. Rogers (Exeter) A. J. Moffat, B.Sc., Ph.D. N. Rylance T. R. Nisbet, B.Sc., Ph.D. P. de Silva Mrs J. E. Stonard D. West (Thetford) Mrs D. A. Waddell J. E. J. White (Westonbirt) E. Ward, B.Sc., M.Sc., C.Chem., M.R.S.C. I. Willoughby, B.Sc. Miss C. Woods Mrs A. Yeomans Instrumentation (South) Section T. R. Nisbet, B.Sc., Ph.D., Head of Section Statistics and Computing (South) Branch I. D. Mobbs, C.Stat., Head of Branch Forest Products Branch R. C. Boswell, B.Sc., M.I.S. J. F. Webber, B.Sc., Ph.D., Head of Branch Mrs C.A.V. Foden Mrs C. M. Lishman G. J. Hall, B.Sc., B.A. Miss L. M. Halsall, B.Sc. Mensuration Branch S. D. Hibbs, B.Sc. Mrs J. M. Methley, B.Sc., Head of Branch Miss T. J. Houston, B.Sc., M.I.S. S. R. Abbott A. R. Ludlow, B.Sc., Ph.D. N. Fearis, B.Sc. Mrs P.F. Newell P. C. Jokiel, B.Sc. A. J. Peace, B.Sc. R. W. Matthews, B.Sc., M.Sc. Mrs L.P. Pearce J. C. Proudfoot T. Porter, B.Sc. Mrs S.A. Stephens T. J. Randle, B.Sc. Miss B. J. Smyth, B.Sc. Pathology Branch(with section at Northern J. Taylor, B.Sc. Research Station) J. N. Gibbs, M.A., Ph.D., Sc. D., Head of Branch Tree Improvement Section (of branch at Miss F. Baldwin Northern Research Station) C. M. Brasier, B.Sc., Ph.D., D.Sc. C. M. Cahalan, B.Sc., M.Sc., Ph.D., B. J. W. Greig, M.I.C. For. Mrs C. A. Baker Mrs S. A. Kirk M. R. Plowman, B.Sc., M.Sc. M. A. Lipscombe Wildlife and Conservation Research Branch D. Lonsdale, B.Sc., Ph.D. D. R. Rose, B.A. H.W. Pepper, Acting Head of Branch Mrs J. Rose R. Ferris-Kaan, B.Sc., Ph.D.

79 STAFF ENGAGED IN RESEARCH DIVISION AT 31 MARCH 1994 - APPENDIX 7

R. M. A. Gill, B.Sc. R. E. J. Howes (Wykeham, North Yorkshire) Mrs B. A. Mayle, M.Sc. C. D. Jones, B.Sc. (Talybont-on-Usk) Miss C. Woods A. L. Mackie, M.I.C. For. A. W. MacLeod (Newton, Grampian) C. McEvoy, B.A. H.M. McKay, B.Sc., Ph.D. t a f f b a s e d a t o r t h e r n e s e a r c h t a t io n S N R S J. D. McNeill (in charge of outstations) J. L. Morgan, B.Sc., Ph.D. Administration B.C. Nicoll, B.Sc. M. Abrahams, Head of Section C. J. Nixon, B.Sc., M.I.C. For. Mrs J. Atkinson C. P. Quine, M.A., M.Sc., M.I.C. For. N. Campbell M. J. Ridley (Kielder, Northumberland) G. Cockerell M. Riley Mrs M. Farm A. L. Sharpe (Newton, Grampian) Miss E. Hall J. M. S. Simpson, B.Sc. Mrs H. Hirst D. R. Tracy (Cairnbaan by Lochgilphead) Mrs M. Holmes D. M. Watterson (Mabie, Dumfriesshire) Mrs K. Hutchinson Mrs L. Legge Statistics and Computing (North) Branch Mrs C. Mcllwhan I. W. Martin, B.Sc., M.Sc., Head of Branch Mrs M. Plews R. W. Blackburn, B.Sc. Mrs M. Rendall A. D. Milner, B.Sc., Ph.D. Mrs R. Shields I. M. S. White, B.Sc., M.Sc. Mrs S. Walker Entomology Section (of branch at Alice Holt) Tree Improvement Branch(with section at S. G. Heritage, C.Biol., M.I. Biol, Head of Alice Holt) Section A. M. Fletcher, B.Sc., Ph.D., Head of Branch A. C. Hendry, B.Sc., Miss C. M. M. Baldwin D. Johnson, B.Sc. (Mabie, Dumfriesshire) W. Brown R. Moore, B.Sc., Ph.D. J. Cottrell, B.Sc., Ph.D. C. E. S. Fleming (Newton, Grampian) Mycorrhiza Research Unit G. I. Forrest, B.Sc., M.Sc., Ph.D. C. Walker, B.A., Ph.D., Head of Unit A. John, B.Sc., Ph.D. Miss A.C. Broome, B.Sc. S. J. Lee, B.Sc., M.I.C. For. J. S. McIntyre Pathology Section (of branch at Alice Holt) Mrs M. O’Donnell D. B. Redfern, B.Sc., Ph.D., M.I.C. For., Head of S. Osborne, B.Sc. Section J. J. Philipson, B.A., Ph.D. S. C. Gregory, M.A., Ph.D. C. J. A. Samuel, B.Sc., Ph.D. Miss G. A. MacAskill R. J. Sykes (Shobdon, Hereford) J. E. Pratt G. C. Webb (Shobdon, Hereford) Silviculture (North) Branch Wildlife Ecology Branch W. L. Mason, B.A., B.Sc., M.I.C. For., Head of Branch D.G. Pyatt, B.A., B.Sc., Ph.D., M.I. Soil Sci., D. Anderson Acting Head of Branch J. Boluski [Lairg, Highland) A.R. Anderson P. Cairns (Cairnhaan by Lochgilphead) A.H. Chadwick (Ardentinny, Argyll) N. P. Danby (Talybont-on-Usk) J.W. Humphrey, B.Sc., Ph.D. J. Davidson, B.A., M.I.C. For. (IVewfon, S.J. Petty, Ph.D. (Ardentinny, Argyll) Grampian) D. Ray, B.Sc. J. Dick (Wykeham, North Yorkshire) J. C. Dutch, B.Sc., Ph.D. C. Edwards I n d u s t r ia l s t a f f B. A. Gardiner, B.Sc., Ph.D., F.R. Met.S. P. W. Gough (Kielder, Northumberland) A. J. Harrison, B.Sc. The total number of industrial employees in M. K. Hollingsworth Research Division at 31 March 1994 was 93.5.

80 STAFF ENGAGED IN RESEARCH DIVISION AT 31 MARCH 1994 - APPENDIX 7

S. K. Jones, Plant Production Branch, Alice S t a f f m o v e m e n t s Holt, to SSO R. Murray, Finance, Alice Holt, to SEO New appointments D. R. Rose, Pathology Branch, Alice Holt, to FOI Mrs J. Rose, Pathology Branch, Alice Holt, to SO Dr M. S. J. Broadmeadow, HSO, Environmental Research Branch, Alice Holt (3-year Period Transfers out: Appointment) M. Allen, FOIII, from Silviculture (South) Miss C. A. Broome, ASO, Mycorrhiza Research Unit, Northern Research Station Branch, Arley to West Midlands Conservancy (Delamere) Dr E. P. Cundall, SSO, Tree Improvement Branch, Alice Holt A. Hall, FOIII, from Silviculture (South) Branch, Alice Holt to Ministry of Defence Dr J. W. Humphrey, SSO, Wildlife Ecology Branch, Northern Research Station J. Lumley, Grade 7, from Alice Holt to Crown Prosecution Service T. R. Hutchings, ASO, Environmental Research Branch, Alice Holt N. Smith, FOIII, from Silviculture (South) Branch, Exeter to Wye and Avon Dr R. Moore, HSO, Entomology Branch, Conservancy Northern Research Station Detached duty: Trcmsfers in: P. R. Ratcliffe, Grade 7, from Wildlife Ecology K. N. Charles, Grade 7, from Headquarters to Branch, Northern Research Station to Administration, Alice Holt Headquarters A. H. Dowell, FOIII, from Forestry Authority J. M. S. Simpson, FOII, from Silviculture Wales to Silviculture (South) Branch, Alice (North) Branch, Northern Research Station to Holt Headquarters S. Minton, FOIII, from Wiltshire and Avon Forest District to Silviculture (South) Branch, Special unpaid leave: Exeter N. C. Rylance, FOIII, from Forest Enterprise D. Patch, Grade 7, (3 years) North Yorkshire Moors Forest District to Silviculture (South) Branch, Arley Resignations: Dr C. Cahalan, SSO, Tree Improvement Branch, Promotions: Alice Holt W. Brown, Tree Improvement Branch, Northern Research Station, to FOI Retirements: Dr J. E. Cottrell, Tree Improvement Branch, T. C. Booth, Grade 6, Chief Research Officer Northern Research Station, to HSO (North), Northern Research Station Dr B. A. Gardiner, Silviculture (North) Branch, Dr M. P. Coutts, Grade 6, Physiology, Northern Northern Research Station, to Grade 7 Research Station

81 ADDRESSES OF RESEARCH LOCATIONS

APPENDIX 8

M a in c e n tr e s

The Forestry Authority Research Division The Forestry Authority Some staff engaged in research Alice Holt Lodge Northern Research Station are stationed at: Wrecclesham Roslin Forestry Commission Farnham, Surrey Midlothian Headquarters GU104LH EH25 9SY 231 Corstorphine Road Tel: 01420 22255 Tel: 031 445 2176 Edinburgh EH 12 7AT Fax: 01420 23653 Fax: 031 445 5124 Tel: 031 334 0303 Fax: 031 334 3047

Research outstations Ardentinny Wildlife Ecology HeadleySilviculture (S) Ludlow Entom ology Forestry Authority Forestry Authority Forestry Authority Wildlife Ecology Branch Headley Research Nursery Entomology Office Ardentinny Headley Park Whitcliffe Dunoon Bordon Ludlow Argyll Hampshire Shropshire PA23 8TS All mail via Alice Holt Lodge SY8 2HD Tel: 036 981 253 Tel: 0420 473466 Tel: 0584 878322

Bush Silviculture (N) KielderSilviculture (N) an d MabieSilviculture (N) an d Forestry Authority Entom ology Entom ology Northern Research Station Forestry Authority Forestry Authority Roslin Research Office Research Office Midlothian EH 259SY Kielder Mabie Tel: 031 445 2176 by Hexham Troqueer Northumberland Dumfries CairnbaanSilviculture (N) NE481H F DG2 8HB Forestry Authority Tel: 0434 250235 Tel: 0387 52267 Research Office Cairnbaan Lairg Silviculture (N) Midlands Silviculture (S) Lochgilphead Forestry Authority Forestry Authority Argyll Research Office Research Office PA31 8SQ Ord Croft Woodside Tel: 0546 602304 Lairg Arley Sutherland Coventry ExeterSilviculture (S) IV27 4AZ Warwickshire Forestry Authority Tel: 0549 402150 CV7 8GH Research Office Tel: 0676 41668 Bullers Hill Kennford Exeter Devon EX6 7XR Tel: 0392 832687

82 ADDRESSES OF RESEARCH LOCATIONS - APPENDIX 8

Newton Silviculture (N) and Talybont-on-Usk Silviculture (N) Westonbirt Silviculture (S) Tree Improvement Forestry Authority Forestry Commission Forestry Authority Research Office Westonbirt Arboretum Research Office Cefn Gethiniog Tetbury Newton Nursery Talybont-on-Usk Gloucestershire GL8 8QS Elgin Brecon Tel: 0666 88220 Morayshire Powys LD3 7YN IV30 3XR Tel: 0874 87444 Wykeham Silviculture (N) Tel: 0343 543165 Forestry Authority Thetford Silviculture (S) Research Office Shobdon Tree Improvement Forestry Authority Wykeham, Scarborough Forestry Authority Research Office N. Yorks Y 013 9HQ Research Division Santon Downham Tel: 0723 862031 Uphampton Brandon Shobdon, Leominster Suffolk IP27 OTJ Hereford HR6 9PB Tel: 0842 810271 Tel: 056 881 8881

83 84 INDEX

Adelges cooleyi 7 cerato-ulmin 24, 26 advice 5, 7, 10, 19, 25-6, 30, 41, 58 chemical analysis 10, 11-12 Advisory Committee on Forest Research 3 cherry 7, 25-6 aescin 45 wild 26, 31, 37 A garicus spp. 24 chestnut age structure 38-9 horse 45 Agrobacterium tumefaciens 2, 46 sweet 17, 26 alder 26, 27-8, 43 chromatography 12 grey 42 Cinara spp. 7 Apiognomonia erythrostoma 26 climate 7, 9, 10, 17, 25-6, 53—4 apple 25 coalfields, collieries 10, 23, 41-2 ash 3, 7, 13, 18, 19, 34, 42, 43, 52 colonization, natural 42—4 aspect 13, 43 community forests 3, 33, 41 aspen 9 computing 1, 9, 12-13, 18, 20-1, 23, 24, 58, 60-2 Bank of European Glomales 23 conservation 50-2 basidiomycetes 14, 15 coppicing, short rotation 20-2, 40 beech 3, 7, 12, 18, 24, 34, 43 crown density 24 beetles, bark 15, 27 Cryptococcus fagisuga 24 bioassay technique 37-8 cypress, Monterey 24 biodiversity 51, 53, 55 damage 43 insect 3,5,9 climatic 25-6 . bioenergy generation 20-2 fungal 25-8 biofuel energy, 20-2, 40 insect 2, 5-9 biological control 15, 26 mammal 50-1 biotechnology 2 salt 25 birch 3, 25, 40, 42, 43, 55 dead-wood 9, 52 silver 37 decay 14-15 birds 53, 56-7 deer 3, 50, 52, 55-6 blackthorn 52 defoliation 7, 8-9 Blumeriella jaapii 26 demonstration plots 41, 42 borate salts 15 Dendroctonus micans 5-6 Botrytis infection 25 Deschampsia flexuosa 41 box 25 dieback 25 bracken 14 Dimilin 6 bramble 52 Diprion pini 7 breeding strategies 45-6, 48-9 diseases 1, 9, 24-9 Bupalus piniaria 2, 8-9 DNA technique 46 dogwood 43 Caliroa spp. 7 drainage 10, 53, 54, 55; see also water canker, bacterial 25, 28-9 ‘Z’ 53, 54 carbon drying, timber 17-18 allocation 61 Dutch elm disease 24, 26-7 budgets 20-1 dioxide, effects of 1, 2, 10, 12-13, 20-2 eagles, golden 57 storage 19 Ecological Site Classification (ESC) 53-4 Catalpa speciosa 42 ecology, wildlife 53—7 cedar 26 Elatobium abietinum 2, 7, 9

85 INDEX

elm 25, 26—7 predators 5-6 energy, biofuel 20-2, 40 vectors 14, 27 Entomophthora spp. 7 instrumentation 10 environmental research 1, 10, 11, 22; see also invigoration 30 ecology; pollutants Ips spp. 8 establishment 41-2 irradiation 15-16 on agricultural land 1,3; see also farm isozymes 46-7 forestry on colliery spoil 41-2 kiln-drying 17 on upland sites 1 Euproctis chrysorrhoea 7 Laccaria proximo 23 landfill sites 10 farm forestry 1, 3, 18, 33, 40, 42, 45, 47 larch 25, 26, 45 fertilizers 11, 34-6, 37-8, 42 hybrid 19, 25, 34, 45 fir spp. 7, 26, 45 Japanese 25, 34, 40, 45 Douglas 7, 23, 25, 26, 33, 45, 48 legume trees 30, 31-2 foliar analysis 1, 11-12, 37-8 Lepidoptera spp. 55 Food and Agriculture Organization 23 Leucaena leucocephala 31-2 Forest Condition Survey 24 library 58 Forest Reproductive Materials (FRM) regula­ lime 7, 25, 26 tions 30, 45 Lophodermella sulcigena 25 Forestry Research Coordination Committee Lopbodermium seditiosum 25 (FRCC) 3 Lymexylon navale 7 foxes 53 fuel, biomass wood 20-2 Malacosoma neustria 1 fungi 7, 14-16, 23, 24, 25-8, 30 maple fungicides 15 Norway 34, 37 fungivory 16 silver 42 Marssonina betulae 25 genetic mensuration, measurement 18, 19—22, 40; see improvement 45, 46, 47-8 also statistics markers 2, 46—7 biological 11 transformation 2, 46 environmental 10, 11 germination 30-2, 62 Meria laricis 25 Ginkgo biloba 42 micro-arthropods 15-16 Gloeosporidium tiliae 25 micro-computers 61-2 Gloeosporium nervisequum 25 Microsphaera alphitoides 25, 26 Glomales, Bank of European 23 M onilinia spp. 25, 26 graphics 58 Monochamus sutor 8 growth, tree 2, 8-9, 12-13, 18 moths 2, 6-9 mycorrhizas 23 hares 50 harvesting 14 National Forest 41-2 machinery 15 National Vegetation Classification (NVC) 42, 53 hawthorn 37, 43 natural colonization 42-4 hazel 7 natural regeneration 7, 33, 38, 39, 51—2 heather 40 nurseries 1, 34, 61 herbicides 40—1, 42, 46 nutrients 1,11-12, 37-8, 41, 51 heritability 48 nutrition 12-13, 34-6 Heterobasidion annosum 24, 60 Himalayas 26—7 oak 3, 7, 12-13, 16-18, 24-6, 34, 42-3, 45 humidity 17-18 open-top chambers 1, 2, 10, 12—13, 61 Hylobius abietis 5 Operophtera brumata 7 O phiostom aspp. 26 improvement, tree 1, 45—9 Orthotomicus longicollis 8 insecticides 6-7, 9, 15 outcrossing 46-7, 60 insects 1,3, 5-9, 46 overmaturity 9 pests 2, 5-9 owls 56

86 INDEX

ozone 1, 2, 12, 13 Saperda carcharias 8 sawfly, large pine 7 Pachypapella spp. 9 saws 15 P ach y p ap pspp. a 9 scarification 51 Panolis flammea 6-7 Sclerotinia laxa 25 pathogens 1, 9, 24-9 seed 3, 38, 39, 43, 51 peat 54-5 collection areas 45 Phleaspora aceris 26 direct sowing 42 photography 58-9 dormancy 30 Phthorophloeus spinulosus 8 imbibition by 31 Phyllobius pyri 7 pretreatment 30, 31 Phytophthora spp. 26, 27-8 testing 30, 32 pine 7, 30, 38-9, 52 seedlings 34, 38, 42, 43 bishop 9 Seiridium cardinale 24 Corsican 7, 15, 33, 42 Semanotus undatus 8 lodgepole 6, 7 sensitivity analysis 62 Scots 2, 7-8, 12-13, 24-5, 33-4, 38-9, 42, 62 sewage sludge 10, 40 pine wood nematode 5 site Pityokteines curvidens 8 classification 3 plane 25 influence of 18 planting stock 33-6, 41 soil Platypus cylindrus 7 acidity 41-2 Plectophomella concentrica 25 aeration 41 pollutants 1, 10, 11, 12-13, 24 analysis 10, 11-12 poplar 3, 18-19, 28-9, 40, 42, 45-6 injection 41 prechilling 30 variation 53—4 progeny testing 45, 47, 48-9 spacing 2, 14, 18, 40 provenance 45, 47 spectro-span equipment 1, 12 Pseudonectria rousseliana 25 spraying, by helicopter 6-7 publications 40, 59, 63-9 spruce Norway 7, 12, 13, 19, 20, 24, 42 quality Sitka 2, 5, 7, 9, 12, 14, 17-20, 23, 25, 30, air 12-13 33-8, 40-1, 45-6, 48-9, 55, 60 assurance 12 spruce bark aphid 7 soil 53-4 squirrels 3, 50-1 timber 2, 14, 18, 19, 20 stability 36, 42, 60 standards 16-17, 19 rabbits 52 statistics 60-2; see also mensuration reclamation 10; see also coalfields stem defects 19 regeneration, natural 7, 33, 38, 39, 51-2 straightness assessment 20 research directions 1 strength, timber 2, 16-18 restocking 38 stress 3, 5 R hizophagus grandis 5-6 stump protection 24, 60 R hizopogon spp. 23 substrates 43 Rhododendron ponticum 41 sycamore 3, 18, 19, 26, 42 Rhyacionia buoliana 2, 9 Robinia pseudoacacia 42 tatter flags 60 root thinning 19 bioassay technique 37-8 Tom icus piniperda 7, 9 development 36-7 Tomostethus nigritus 7 electrolyte leakage 33, 34 training 19 flooding 54 Trichoderma spp. 15 growth potential 34 twist 17-18 shoot ratio 34-5 undercutting 34-6 surface 36-7 utility poles 14 R osaceae spp. 7 ROTTERS 24 vegetation 43—4, 54, 55 rowan 26 management 51—2

87 INDEX

Venturia spp. 25 willow 3, 25, 43, 46, 52 Verticillium lecanii 24 windthrow 2-3, 7, 19, 33, 52 violet 52 hazard classification 2, 33 voles, field 56 Xanthomonas populi 28 walnut 40 Xeris spectrum 8 water 10, 13; see also drainage analysis 11-12 yew 25, 26 imbibition 31 yields 14 wayfaring tree 43 model validation 19, 20 weed control 40-1, 42, 46 site 19, 40 wildcats 53 wildlife 50-7 ‘Z’ drainage 53, 54

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