Bryophytes in East Anglian Orchards

Article

x Fig. 1. A ‘traditional’ orchard in Gloucestershire – sheep-grazed, and with standard trees. Orchards in East Anglia look very different. Robin Stevenson v Orthotrichum stramineum in the Royal orchards at Flitcham, in Norfolk. Robin Stevenson

Orchards, as a habitat, have gained prominence relatively Bryophytes recently, following the proposal to designate them as Biodiversity Action Plan habitats. Robin Stevenson and Jenny Rowntree take a look at the bryophyte flora of in East Anglian these often overlooked corners of the British landscape. orchards he recent proposal to designate used, and was specifically targeted at mosses and orchards as Biodiversity Action lichens, since these were thought to afford shelter Plan (BAP) habitats (Robertson to the major insect pests (Morgan & Marsh, & Wedge, 2008) has resulted in a 1956). (Fig. 3) Consequently, until the use of distinction between ‘traditional’ and Tar Oil ceased in the late 1960s, orchard trees Tcommercial orchards. The former are presented had little or no moss growing on them. Almost as sheep-grazed organic havens for wildlife of all all of the bryophytes found in local East Anglian sorts (Fig. 1) whilst the latter are characterized orchards have thus become established in the last by dwarf-stock varieties grown at very high 40 years. This period coincides with the decline densities with high pesticide input (Fig. 2). of the air pollution that formerly affected the This is, however, a somewhat over-simplified area. view. In the main East Anglian fruit-producing areas East Anglian orchards of Norfolk and Cambridgeshire the ‘tradition’ Many of the orchards in Fenland were is very different from that found, say, in the established as smallholdings in the period just cider orchards of Herefordshire, where sheep after the First World War. The local practice was grazing does indeed occur. In East Anglia, to cultivate the ground under the trees, growing cultivation was mainly for dessert and cooking soft fruit, etc., to provide an income until the apples where, even before the modern demands trees came into crop. Typically, most small of supermarkets, a premium was placed on orchards would grow a variety of cultivars – a producing good quality, undamaged fruit. As a guard against specific problems with any one result, trees were regularly sprayed with a variety variety. These small orchards, unless incorporated of chemicals designed to eliminate disfiguring into larger units, are now no longer financially pests and diseases. Tar Oil was the main chemical viable and have (unless rooted out) often been

10 FieldBryology No99 | Oct09 Article

10 FieldBryology No99 | Oct09 and this seems to depend on how recently they have been actively managed. Long-neglected orchards can easily become overwhelmed by ivy and brambles, leading to low bryodiversity. From our initial surveys, we quickly established that different tree species varied in their attractiveness as a substrate. Plums, for instance are poor hosts to epiphytic bryophytes, compared to apples. Amongst apples, there appeared to be some trees with higher bryophyte species richness, but it has been difficult to draw any real conclusions as the numbers of trees examined were small and the specific cultivars generally unknown. Recording in orchards has been a profitable enterprise, particularly in terms of gleaning neglected or left to go wild, both locally and n Fig. 2. Rows of half-standard trees in a commercial new vice-county records (VCRs). Workers in n Fig. 4 (top). A single, large, old Bramley apple which elsewhere (Potter, 2008). By default, many orchard. Note the sprayed strip under the trees – this Cambridgeshire orchards have added Hypnum is probably close to 100 years old and still producing. alone would disqualify the site as a traditional orchard, Robin Stevenson have now become – in the eyes of some of the cupressiforme var. heseleri (Fig. 6a), Antitrichia even though it is rich in epiphytic bryophytes. Robin n Fig. 5 (bottom). Part of a row of 55-year-old East conservation lobby – ‘traditional’ orchards. curtipendula (Fig. 6b) (Hodgetts et al., 2006), Stevenson Anglian half-standards, bearing good moss cover. There are also many large-scale commercial , Fig. 3. An early view of an ‘infestation’ by moss and Pylaisia polyantha, Sanionia uncinata (Fig. 6c) Robin Stevenson orchards in the area. Some of these have moved lichen! and Orthotrichum obtusifolium (Fig. 6d). completely to growing modern, dwarf-stock Orchards in Norfolk have not been quite so slightly by the need to interplant pollinators; fruit varieties, but many still retain extensive productive in terms of new VCRs, although Roach, 1956). The Royal orchards at Flitcham, plots of older trees. This is particularly true for Hypnum cupressiforme var. heseleri (Blockeel & in Norfolk include large numbers of older trees, Bramley apples where some trees, still in active Stevenson, 2006) and Orthotrichum rupestre are some planted as far back as 1950. These older production, are over 70 years old (Fig. 4). significant additions. trees are very rich in bryophytes (over 40 species Apple and pear trees were typically grown as Further to these novelties, many more second have been recorded), whilst trees less than about half-standards (i.e. trees with trunks approx- and third records have been made of species 30 years old either have very few, or no epiphytic imately 1.4 m tall), to make spraying, picking, such as Pylaisia polyantha, Orthotrichum striatum bryophytes at all. etc., easier. Tree shape has also been modified (Fig. 6e) and Sanionia uncinata. These also occur I (R.W.) decided to record a block of 100 trees over the years (particularly in the case of elsewhere, but seem easier to find in orchards – at Flitcham on a tree-by-tree basis. Initial plots Bramleys), to incorporate changes in cultivation possibly because of the relative ease of access. of my results, in terms of numbers of species per and management practice. With half-standards Interestingly, it seems that some of the new tree, produced an unexpected result: running it is possible to examine the whole bryoflora, species found may be invading from across the diagonally across my sample, half of the trees were including that of the branches, which are North Sea, rather than from elsewhere in the obviously much more species-rich than the other generally inaccessible on standard trees (Fig. 5). UK. half. Enquiries of the then orchard manager, Commercial orchards offer better opportunities Freddy Benefer, quickly established that I had, in The bryoflora of East Anglian orchards to examine the relationships between cultivars fact, inadvertently sampled across two different The ‘traditional’ orchards of East Anglia (i.e. and their epiphyte flora since they tend to cultivars – Cox’s Orange Pippin and Laxton’s mainly small and more or less neglected ones) hold large blocks of single cultivars of known Superb – and the bryophyte diversity differed vary considerably in their bryological interest, age (though the picture can be complicated between the two (Fig. 7).

12 FieldBryology No99 | Oct09 FieldBryology No99 | Oct09 13 and this seems to depend on how recently they have been actively managed. Long-neglected orchards can easily become overwhelmed by ivy and brambles, leading to low bryodiversity. From our initial surveys, we quickly established that different tree species varied in their attractiveness as a substrate. Plums, for instance are poor hosts to epiphytic bryophytes, compared to apples. Amongst apples, there appeared to be some trees with higher bryophyte species richness, but it has been difficult to draw any real conclusions as the numbers of trees examined were small and the specific cultivars generally unknown. Recording in orchards has been a profitable enterprise, particularly in terms of gleaning neglected or left to go wild, both locally and n Fig. 2. Rows of half-standard trees in a commercial new vice-county records (VCRs). Workers in n Fig. 4 (top). A single, large, old Bramley apple which elsewhere (Potter, 2008). By default, many orchard. Note the sprayed strip under the trees – this Cambridgeshire orchards have added Hypnum is probably close to 100 years old and still producing. alone would disqualify the site as a traditional orchard, Robin Stevenson have now become – in the eyes of some of the cupressiforme var. heseleri (Fig. 6a), Antitrichia even though it is rich in epiphytic bryophytes. Robin n Fig. 5 (bottom). Part of a row of 55-year-old East conservation lobby – ‘traditional’ orchards. curtipendula (Fig. 6b) (Hodgetts et al., 2006), Stevenson Anglian half-standards, bearing good moss cover. There are also many large-scale commercial , Fig. 3. An early view of an ‘infestation’ by moss and Pylaisia polyantha, Sanionia uncinata (Fig. 6c) Robin Stevenson orchards in the area. Some of these have moved lichen! and Orthotrichum obtusifolium (Fig. 6d). completely to growing modern, dwarf-stock Orchards in Norfolk have not been quite so slightly by the need to interplant pollinators; fruit varieties, but many still retain extensive productive in terms of new VCRs, although Roach, 1956). The Royal orchards at Flitcham, plots of older trees. This is particularly true for Hypnum cupressiforme var. heseleri (Blockeel & in Norfolk include large numbers of older trees, Bramley apples where some trees, still in active Stevenson, 2006) and Orthotrichum rupestre are some planted as far back as 1950. These older production, are over 70 years old (Fig. 4). significant additions. trees are very rich in bryophytes (over 40 species Apple and pear trees were typically grown as Further to these novelties, many more second have been recorded), whilst trees less than about half-standards (i.e. trees with trunks approx- and third records have been made of species 30 years old either have very few, or no epiphytic imately 1.4 m tall), to make spraying, picking, such as Pylaisia polyantha, Orthotrichum striatum bryophytes at all. etc., easier. Tree shape has also been modified (Fig. 6e) and Sanionia uncinata. These also occur I (R.W.) decided to record a block of 100 trees over the years (particularly in the case of elsewhere, but seem easier to find in orchards – at Flitcham on a tree-by-tree basis. Initial plots Bramleys), to incorporate changes in cultivation possibly because of the relative ease of access. of my results, in terms of numbers of species per and management practice. With half-standards Interestingly, it seems that some of the new tree, produced an unexpected result: running it is possible to examine the whole bryoflora, species found may be invading from across the diagonally across my sample, half of the trees were including that of the branches, which are North Sea, rather than from elsewhere in the obviously much more species-rich than the other generally inaccessible on standard trees (Fig. 5). UK. half. Enquiries of the then orchard manager, Commercial orchards offer better opportunities Freddy Benefer, quickly established that I had, in The bryoflora of East Anglian orchards to examine the relationships between cultivars fact, inadvertently sampled across two different The ‘traditional’ orchards of East Anglia (i.e. and their epiphyte flora since they tend to cultivars – Cox’s Orange Pippin and Laxton’s mainly small and more or less neglected ones) hold large blocks of single cultivars of known Superb – and the bryophyte diversity differed vary considerably in their bryological interest, age (though the picture can be complicated between the two (Fig. 7).

12 FieldBryology No99 | Oct09 FieldBryology No99 | Oct09 13 (a) (b)

Bryopytes in East Anglian orchards

Subsequent sampling in other orchards, where true for lichens – although this requires further I could find other pairs of different cultivars investigation. of the same age, has shown that statistically Systematic recording, in groups of trees significant differences exist between almost all which are equidistantly spaced, also revealed pairs of cultivars. apparent clustering between some species, such These differences between cultivars have as Orthotrichum lyellii and Zygodon spp., i.e. if obvious implications for orchard conservation. they were present on one tree, they seemed to If conservation of overall biodiversity is an issue, be more likely to occur on adjacent trees as then any programmes involving the replanting of well (Fig. 8a). Löbel et al. (2006) observed that (c) ‘old’ apple varieties should also take into account spatial aggregation is more pronounced in their ability to host bryophytes. As yet, we know asexually dispersed species, perhaps due to the nothing about the relative merits of these older heavy, less easily transported, nature of vegeta- (d) cultivars as hosts for epiphytic bryophytes. In tive propagules. However, some species which addition, what is true for bryophytes may also be reproduce sexually also seem to show clustering (Fig. 8b), indicating that spores too may disperse , Fig. 7. Differences in the number of species per tree between 52-year-old Laxton’s Fortune (r) and more efficiently over short distances. Whether Cox’s Orange Pippin (j) apples in the Royal Orchards, these patterns of clustering are ‘real’, or only Flitcham. Robin Stevenson apparent, remains to be tested statistically.

(e)

n Fig. 6. (a) Hypnum cupressiforme var. heseleri just outside Wisbech, found by Mark Hill. (b) Antitrichia curtipendula in an orchard near Wisbech, found by Nick Hodgetts. (c) Sanionia uncinata has been recorded more frequently in orchards than in any other habitat. (d) The Red Data Book species Orthotrichum obtusifolium was an exciting find. (e)Orthotrichum striatum, which is very much a species ‘on the move’ is seen here on an old pear tree. Pears can be as good as apples as hosts for epiphytes. Robin Stevenson

14 FieldBryology No99 | Oct09 FieldBryology No99 | Oct09 15 (a) (b)

Bryopytes in East Anglian orchards

(e)

14 FieldBryology No99 | Oct09 FieldBryology No99 | Oct09 15 Bryopytes in East Anglian orchards Bryopytes in East Anglian orchards

d d d d d d d d d d hedgerows and scrub. This accords well with field or something to do with the different rootstocks within species and how that might affect experience, which suggests that the bryophyte involved? Are patterns of clustering real? What other interacting species and the ecological d d d d d d d d d d communities of elder scrub and sallow carr are can be learnt by looking at the relative position communities they inhabit. In carrying out the d d d d d d d d d d much closer to those of orchards than isolated in which different species grow? How important initial surveys of orchards, we have come across parkland trees. (The parkland model may, of is microclimate, as opposed to cultivar type? an excellent, easy-to-test example of the kind of d d d d d d d d d d course, be more appropriate for other organisms). Gathering data is relatively easy. Making sci- ‘community genetics’ effects that we have been d d d d d d d d d d Data already collected has allowed preliminary entific sense of it is rather more difficult. This is looking for in a number of other plants and estimates to be made of recruitment rates into what J.R. will be doing in collaboration with Mari animals. Different apple cultivars have genetic d d d d d d d d d d orchards, and suggests that floras do increase Walton at the University of Hertfordshire. They differences between each other and these seem (b) d d d d d d d d d d Table 1. Analysis of epiphytic bryophytes by EUNIS v Fig. 9. Leskea polycarpa occurs habitats quite frequently, possibly because d d d d d d d d d d regular spraying helps maintain the Habitat* d d d d d d d d d d sort of high humidity levels normally d 32% of species occur on ‘rock’ habitats [hard found near rivers. Robin Stevenson d d d d d d d d d d rock; soft rock; worked rock; buildings; cliffs; low density buildings] d d d d d d d d d d d 14% occur on ‘soil’ [soil on rock; soil; gravel/ d d d d d d d d d d sand; Cultivated Parks] d 8% on ‘miscellaneous’ [ Decorticated wood; d d d d d d d d d d decaying vegetation] d 45% in ‘woodland’ [parkland; temperate scrub; d d d d d d d d d d shrub heath; fen scrub; hedgerows; deciduous

d d d d d d d d d d woods; conifer woods]

d d d d d d d d d d Of the ‘woodland’ habitat totals: d 13% occur in parkland n Fig. 8. Distribution (d) of Orthotrichum lyellii (a) and d 28% in woodland Cryphaea heteromalla (b) in a block of 100 Cox’s d 58% occur in scrub & hedgerow type habitats apples. d, Trees which have died and have not been replaced; d, individual trees. Robin Stevenson *Habitats with scores of less than 15 were ignored

16 FieldBryology No99 | Oct09 FieldBryology No99 | Oct09 17 Bryopytes in East Anglian orchards Bryopytes in East Anglian orchards

One of the other features of ‘traditional’ for the frequency with which species such as will be conducting more detailed investigations EUNIS habitat – European Nature Information System orchards seems to be that they are more lichen- Leptodictyum riparium and Leskea polycarpa on various aspects of the observations that have (EUNIS) habitat classification is a system developed rich. The regular spraying with fungicides that (Fig. 9) occur. Even Syntrichia latifolia has by the European Environment Agency to facilitate the already been made. The plan now is to compare occurs in commercial orchards disadvantages been found as a canopy epiphyte. The regular harmonized description and collection of data across bryophyte diversity by tree cultivar, location lichens (Bartok, 1999; Henderson, 2008), but pruning which occurs in commercial orchards, Europe through the use of criteria for habitat identification. and age in an effort to determine exactly which presumably offers advantages to bryophytes and which regulates the light regime within the of these factors are important in promoting by reducing competition. The high humidity canopy probably also benefits bryophytes, many over time – even amongst the ‘obligate’ species, bryophyte diversity on apples. Depending on levels maintained by spraying may also account of which are relatively light-demanding. which are supposed to be characteristic of early whether we are able to collect more data, we will (a) The model habitat that Natural England growth stages. use various statistical techniques to analyse the d d d d d d d d d d have suggested to be appropriate for orchards is bryophyte diversity data, and spatial distribution d d d d d d d d d d parkland. Using the data in Bryoatt (Hill et al., Future research analysis to see if sexual and asexual species really 2007) a simple analysis, by EUNIS habitat, of Our experience in orchards has raised many cluster together or not. d d d d d d d d d d the commonest species found (Table 1) shows questions: why do different cultivars differ as hosts In the scientific community, there is in- d d d d d d d d d d the most frequently occurring habitats to be to bryophytes? Is it bark chemistry, bark texture, creasing interest in the role of genetic diversity d d d d d d d d d d hedgerows and scrub. This accords well with field or something to do with the different rootstocks within species and how that might affect experience, which suggests that the bryophyte involved? Are patterns of clustering real? What other interacting species and the ecological d d d d d d d d d d communities of elder scrub and sallow carr are can be learnt by looking at the relative position communities they inhabit. In carrying out the d d d d d d d d d d much closer to those of orchards than isolated in which different species grow? How important initial surveys of orchards, we have come across parkland trees. (The parkland model may, of is microclimate, as opposed to cultivar type? an excellent, easy-to-test example of the kind of d d d d d d d d d d course, be more appropriate for other organisms). Gathering data is relatively easy. Making sci- ‘community genetics’ effects that we have been d d d d d d d d d d Data already collected has allowed preliminary entific sense of it is rather more difficult. This is looking for in a number of other plants and estimates to be made of recruitment rates into what J.R. will be doing in collaboration with Mari animals. Different apple cultivars have genetic d d d d d d d d d d orchards, and suggests that floras do increase Walton at the University of Hertfordshire. They differences between each other and these seem (b) d d d d d d d d d d Table 1. Analysis of epiphytic bryophytes by EUNIS v Fig. 9. Leskea polycarpa occurs habitats quite frequently, possibly because d d d d d d d d d d regular spraying helps maintain the Habitat* d d d d d d d d d d sort of high humidity levels normally d 32% of species occur on ‘rock’ habitats [hard found near rivers. Robin Stevenson d d d d d d d d d d rock; soft rock; worked rock; buildings; cliffs; low density buildings] d d d d d d d d d d d 14% occur on ‘soil’ [soil on rock; soil; gravel/ d d d d d d d d d d sand; Cultivated Parks] d 8% on ‘miscellaneous’ [ Decorticated wood; d d d d d d d d d d decaying vegetation] d 45% in ‘woodland’ [parkland; temperate scrub; d d d d d d d d d d shrub heath; fen scrub; hedgerows; deciduous d d d d d d d d d d woods; conifer woods] d d d d d d d d d d Of the ‘woodland’ habitat totals: d 13% occur in parkland n Fig. 8. Distribution (d) of Orthotrichum lyellii (a) and d 28% in woodland Cryphaea heteromalla (b) in a block of 100 Cox’s d 58% occur in scrub & hedgerow type habitats apples. d, Trees which have died and have not been replaced; d, individual trees. Robin Stevenson *Habitats with scores of less than 15 were ignored

16 FieldBryology No99 | Oct09 FieldBryology No99 | Oct09 17 Bryopytes in East Anglian orchards

to be important in the diversity of epiphytic orchards. They include Peter Goodale, Bob Littlechild, Alec bryophytes found growing on their bark. As Bunting, Jan Stokes and Fred Leach. We are especially grateful to the Sandringham Estate for permitting access, and to the mentioned above, this could be due to differences late Freddy Benefer, the manager of the Royal orchards, who in bark chemistry, which is relatively easy to was unfailingly helpful in sharing his expertise on all matters test, but there could also be other differences relating to orchards and their management, as has been Bob between the tree cultivars that affect bryophyte Lever of the East of England Apples and Orchards Project diversity, which we have not yet thought about. (EEAOP). The EEAOP, and the Cambridge & Peterborough Although environmental factors almost certainly Biodiversity Partnership have funded some of the recording that has taken place in traditional orchards. also affect the growth of epiphytes, the different apple cultivars do seem to be important. The References interactions between cultivar, environment and Bartok, K. (1999). Pesticide usage and epiphytic lichen tree age that we are now proposing to investigate diversity in Romanian orchards. The Lichenologist 31, 21–25. are interesting, as they should tell us how good Blockeel, T.L. & Stevenson, C.R. (2006). Hypnum cupressi- certain cultivars are for associated bryophytes in forme var. heseleri (Ando & Higuchi) M.O.Hill (Bryopsida, different situations. It may be, for example, that Hypnales) in Norfolk. New to the British Isles. Journal of one tree cultivar has high bryophyte diversity in Bryology 28, 190–193. one location, but low diversity in another, and Henderson, A. (2008). Lichens in orchards. In Orchards and this seems to be the case after initial analysis. groves: their history, ecology, culture and archaeology. Edited by I. Rotherham. Landscape Archaeology and Ecology 7, 76–85. There are many possible ways to expand Hill, M.O., Preston, C.D., Bosanquet, S.D.S. & Roy, D.B. this work, looking at different species of fruit (2007). BRYOATT. Attributes of British and Irish Mosses, trees, which we have already begun to do. We Liverworts and Hornworts. Abbots Ripton: Centre for could also look at the invertebrate diversity Ecology and Hydrology. harboured within the bryophytes. As orchard Hodgetts, N.G., Preston, C.D. & Stevenson, C.R. (2006). owners are concerned about pest damage of Antitrichia curtipendula in a Cambridgeshire orchard. Field fruits, this kind of information could also be of Bryology 89, 8–9. value economically as well as for conservation Löbel, S., Snäll, T. & Rydin, H. (2006). Species richness initiatives. By incorporating economic factors patterns and metapopulation processes – evidence from epiphyte communities in boreo-nemoral forests. Ecography into bryophyte diversity studies, we should be 29, 169–182. able to raise publicity about and increase the Morgan, N.G. & Marsh, R.W. (1956). Pests and diseases and value of bryophytes to the general public. their control. In Modern Commercial Fruit Growing. Edited Robin Stevenson by T. Wallace & R.G.W. Bush. London: Country Life Ltd. 111 Wootton Road, King’s Lynn, Norfolk Potter, B. (2008). Old orchards, new possibilities. In Orchards and groves: their history, ecology, culture and archaeology. PE30 4DJ (e [email protected]) Edited by I. Rotherham. Landscape Archaeology and Ecology Jenny Rowntree 7, 101–108. Faculty of Life Sciences, University of Roach, F.A. (1956). Planting systems and tree forms. In Modern Manchester, Michael Smith Building, Manchester Commercial Fruit Growing. Edited by T. Wallace & R.G.W. Bush. London: Country Life Ltd. M13 9PT (e [email protected]) Robertson, H. & Wedge, C. (2008). Traditional orchards and Acknowledgements the UK Biodiversity Action Plan. In Orchards and groves: We would like to thank all of the fruit growers of the area who their history, ecology, culture and archaeology. Edited by I. have patiently answered questions and allowed access to their Rotherham. Landscape Archaeology and Ecology 7, 109–118.

18 FieldBryology No99 | Oct09