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Home , Gaultheria, Gaultheria shallon

Ttre biolory of Canadian weeds. lO2. slnllon Pursh.

Lauchlan Fraserl, Roy Ti;rkingtonl, and C. P. Chanwayz rBotany Depafiment, tJniversity of , Vancouver, Bftish Columbia, Canada VAT 124; ind,Oepartment of'Forest Sciences, IJniversity of Hitish blunibia, Vancouver, British Columbia,'Canada V6T 124. Fcceived 21 luly 1992, accepted 24 Match 1993.

Fraser, L., Turkington, R. and Chanway, C. P. 1993. The biologr of Caladian weeds. lD. Gaukhefit shallon Pursh. Can. J. Sci. 73:- L233-1247. Pursh., salal (), is a densely growing perennial evergreen occurring only from the panhandle of along the entire toast of British Columbia'to southern ; it is of native origin. Salal grows on a wide range of soil types and textures, and is abundant in open habitats near the.coast particularly on rocky knoils and atoir! Utuffs. It is a persistent, pervasive woody perennial an0]1 a serious competitor with coniferous rp."i"r. The plant produces numerous but the most significant and effective form of colonization is through n"g"tutin" spread. Several are recommended for control ofthe the wee.d but it is both resistanl and resiiient to many herbicides. This contribution summarizes the known biological data for this species.

Key words: Gaultheria shallon, salal, evergreen shrub, weed biology' competition

Fraser, L., Turkington, R. et Chanway, C. P. 193. Biologie des mauraises_herbes du Canada. 102. Cntlfheria slullannrrstr. Can. f . pUnf Sci. 73: 1233-1247 . Gaultheria shnllnn Pursh., le salal @ricacees)' est un arbrisseau p6renne, touffu, )r feuilles persistantes, que I'on ne retrouve, dans son habitat d'origine' que sur la cdte du Pacifique, de la bande cOtidre sud (le "Manche-de-po0le'.') de I'Alaska ir la Colombie- Britannique et jusqu'au iud de la Californie. Il pousse sur un vaste assortiment de types et de textures de sols. I est a-bondant dans les habitats ouvertJprds de la cOte, en particulier sur les buttes rocheuses grosse et le long des escarpements. C'est une vivace ligneuses, persistante et envahissante, qui cr6e une concurrdnce ao* conifb.es. La production grainidre est abondante, mais la plante se propage-surtout par voie v6g6tative. Plusieurs herbicides sont recommandds, mais la plante r6siste d de nombreuses pr6parationJ. Le m6moire rdcapitule les donn6es biologiques connues concernant cette espece. For personal use only. Mots cl6s: Gaultherta shallnn, salal, arbrisseau d feuilles persistantes, biologie des mauvaises herbes, concurrence

1. Name rhizomatous-like structures spreading from a Gaultheriq shallon Pursh. - salal (Scoggan central point. Stem 0.5-2.5 m high, creeping 1978), shatlon (Conners 1967), lemon to upright, smooth, but may become scored (Anonymous 1970); genus, with age. Twigs green when young, pilose to Ericaceae, Heath or Heather Family, (Hitch- hirsutq and often glandular. Mature rwigs red cock and Cronquist 1973), Ericac6es. or brown. Buds 1.0-1.5 cm long' usually green but sometimes tinged red, ovoid and 2. Description and Account of Variation acute-tipped. Leaves alternate and petiolate; (a) A sparse to densely growing perennial, persistent, leathery and shiny; ovate to ovate- evergreen shrub (Fig. 1) ranging from nearly e[iptic, 3-10 cm x 3-5 cm, sharply semllate; prostrate to erect. Gaultheria shnllon forms margins often finely toothed. Petioles 2-4 mm an extensive shallow root system with very long. 5-15 in terminal and sub- Can. J. Plant Sci. Downloaded from www.nrcresearchpress.com by University of British Columbia on 05/21/19 fine roots rcJ-2.0 mm in diameter) and terminal bracteate that appear one-sided because pedicels are deflexed; qn Can. J. Plant Sci. 73: 1233-1247 (Oct. 1993) racemes usually 5-12 long. reddish, 1233 tz34 CANADIAN JOURNAL OF PI.ANT SCIENCE For personal use only.

Fig. l. Gaultheria shallon Pursh. (a) single (b) stamen (c) (d) mature plant.

Can. J. Plant Sci. Downloaded from www.nrcresearchpress.com by University of British Columbia on 05/21/19 6-10 cm long and prominent. Calyx lobes Corolla white or pinkish, urn-shaped, with triangular to lanceolate, glandular-pilose and five short recurved lobes, glandular, and red in color, usually U3 to U2length of sticky, 6-ll mm. Stamens 10; filaments corolla, but often increasing in size with age. basally expanded; anthers with four slender GAU LTII ERIA SII,{IZON PURSH. r235

apical awns, opening by terminal pores; following clear-cut logging (Germain 1985; superior ovary, multiple seeds. Fruit a Weernan et al. 1990; Messier 1991). Harmful depressed capsule 6-10 mm thick, purplish- effects from salal on their neighbours vary black, -like because of the thickening from reduced growth to chlorosis of the of the calyx at its base, fleshy, pubescent needles and mortality of seedlings. (Szczawinski 1962; Hitchcock and Cronquist Considering that in coastal British Columbia 1973). The chromosome base number is 11; salal is dominant in at least 10 000 ha of the chromosome somatic number is 88 cedar-hemlock forests (Barker et al. 1987; (Taylor and MacBryde 1977). Weetman et al. 1990), and slightly fewer hectares ofDouglas-fir forests (Nuszdorfer et (b) feature of salal The most distinguishing al. 1991), the economic loss to the forest green is its large leaves which are ovate, shiny industry is potentially very high. Presently, for approximately and leathery. Leaves live the added expenditure of site preparation and persist as long as 6 yr (Koch 2-4 yr but can for management on salal-dominated sites is sub- 1983; Haeussler and Coates 1986). Another stantial (C. Fox, personal communication)' In hairy, dark distinguishing feature is the addition, salal can grow so rapidly that most purplish . Fruits persist for several plantable sites may become occupied and (between and months after maturation August nearly impossible to clear manually. October); eventually they dry up and drop off in December. However, some fruits can Beneficial Salal forms a very large longer. @) - remain on the plant considerably rooting system with many fine roots and miqueliana Takeda is similar to Gaultheria associated microorganisms (mycorrhizae and Asia, and the salal but is found only in east rhizophere bacteria) in only a few years westernmost Aleutian Islands (Scoggan following clearcutting. Therefore, salal with 1978). Gaultheria miqueliana racemes maintaini nutrients in the system that would these to about 5 mm, rarely over six flowers, otherwise have been leached and lost' Further- white Gaultheria shall.on and with fruit. more, the roots may act to reduce soil erosion uP 8 mm racemes are many-flowered, to on recently disturbed sites and contribute to purplish black fruit. long, and the organic matter content of the soil (Sabhasri (c) Variability of morphology has been 1961). The leaves of salal also contribute to

For personal use only. reported for G. shqllon in the size and shape the organic matter content of the soil, as well of , stem and . However, no as cycling nutrients back into the soil. When subspecies or varieties have been described salai is abundant, the leaflitter is very large (Hitchcock and Cronquist 1973). The presence and may serve as a mulch, thus reducing eva- of altitudinal ecotypes is possible but not potranspiration. This trait is particularly probable (Pojar 1974). useful in dry habitats. Gaultheria shallonhas also been recommended for coastal sand dune 3. Economic Importance stabilization (Brown and Hafenrichtet 1962). (a) Detimental - Gaultheia shalbn is a The young leaves, twigs andberries ofsalal persistent and pervasive plant and is consi- are an important food source for many ani- dered a serious competitor with coniferous mals, in particular, for black-tailed deer, species, particularly Douglas-fir (Pseudo- which is the major big game species of the tsuga menziesil) on semi-xeric sites in low- Pacific Northwest (McTaggart-Cowan 1945; elevation coastal British Columbia (Tan et Singleton 1976; Crouch 1979; Jones and al. 1977; Stanek et al. 19'79; Price et al' Bunnell 1984; Chambers 1988). Other animals 1986). On wetter sites. G. shallon competes which feed on salal include ruffed ' grouse and other birds (Martin et al. Can. J. Plant Sci. Downloaded from www.nrcresearchpress.com by University of British Columbia on 05/21/19 with young planted seedlings of western red blue cedar (Thuja plicata), western hemlock 1951 ; King 1969; Zwickel and Bendell 1972; (Tsuga heterophylla), Pacific silver fir (z4bies Viereck and Little 1972; King and Bendell amabilis) and Sitka spruce () 1982), black bears, (Bailey r236 CANADIAN JOURNAL OF PLANT SCIENCE

1966; Singleton 1976), mountain beaver 1975). The berry was prepared many ways (Banfield 1974), and, small mammals (e.g. red but the main form was as a dried fruit for squirrel (Dimock et al. L974). will also winter food. As well, native Indians smoked eat young, tender salal leaves which has the leaves with kinnikinnick (Arctostaphylos recently led to their introduction into salal- uva-ursi) and used it for medicinal purposes dominated areas. (Gunther 1945). Salal is a very atfactive plant used by land- scapers and florists. Florists use the leaves as 4. Geographical Distribution a foliage supplement (trade name "lemon Gaultheia shnllon occus from the panhandle leaves") for cut flower arrangements (Anony- of Alaska (56"N) along the entire British mous 1970). Salal is also grown commercially Columbia coast continuing to southern in greenhouses. In 1980 salal had an annual California (34.5"N) (Fig. 2). All recorded retail value of approximately $2 million in BC populations in BC occur west of the Coast (Hunt 1980). Mountains except for a single isolated popu- Salal berries are nutritious and plentifrrl and lation along the east shore of southern were known to be a staple food source for the Kootenay Lake (Szczawinski 1962; Calder native peoples of British Columbia (Turner and Taylor 1968). Gaultheria shallon has

BRIT]SH COLUMBIA

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For personal use only. o roo 200

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l3 Can. J. Plant Sci. Downloaded from www.nrcresearchpress.com by University of British Columbia on 05/21/19 Fig. 2. The distribution of Gaultheria shallon in British Columbia (adapted from Szczawinski (1962), Haeussler et al. (1990), and Hult6n (1968). The shaded area indicates the general distribution, while the individual points represent the locations where herbarium samples weie collected. GAULTHERIA SI'{IZON PURSH. 1237

been introduced to England, but is found least 10% full photosynthetically active radia- nowhere else in the world. tion (PAR), less than 10% of PAR will result Gaultheria shallon is found mainly at lower in the formation of shade leaves. southern range it can be elevations. [n its Substratum - Gaultheria shnllon grows on found up approximately 800 m (Lyons @) to a wide range of soil types and textures inclu- 1952), north salal rarely exceeds in the ding peat, glacial till, sand dunes, and shallow 100-200 m elevation. rocky soils. [t is most commonly found on Podzols, often with deep mor humus forms, 5. Habitat but is also found on Folisolic, Brunisolic and (a) rgquirements Salal is restricted Climatic organic soils (Klinka etal. 1979). Moist sandy humid to perhumid coastal- climate with to a or peaty soil is the best medium for cultiva- mild temperatures, little snow, and unfrozen tion. It does not grow well in alkaline soil con- soils in winter. It is abundant on open habitats ditions (Anonymous 1970). Salal exhibits particularly on rocky knolls and near the coast vigorous upright growth in shaded conditions, along bluffs (Calder and Taylor 1968), where good soil and plenty of moisture (Anonymous gale winds. Salal it can withstand force 1970). However, if the soil is poor salal often (Paul Bavis, personal is sensitive to frost produces a low mat-forming habit. Salal can (1961) communication). Sabhasri observed often be found growing in old stumps and that a short period of freezing temperature in decaying wood, and will also grow epiphytic- the middle of May killed nearly all germi- ally on living in extremely humid nants. Although salal can grow under dense climates (Anonymous 1970). Sabhasri (1961) forest canopies 0.3% full sunlight, the in has demonstrated that salal can survive and vigour, growth rate and flowering of salal grow on soils of low fertility, but the addi- increases as the light intensify increases tion of nutrients produces a definite growth (Sabhasri 1961; Stanek 1979; Koch et al. response. 1983: Messier et al. 1989: Bunnell 1990; Messier 1993). However, best growth is in (c) Communities in which the species occurs partial shade rather than in full sunlight - Using the biogeoclimatic classification for (Anonymous 1970; Dimock et al. 1974; Koch British Columbia (Krajina 1965), G. shallon 1983). occurs predominantly in the Coastal Western For personal use only. Characteristic of many trees, , and Hemlock and the Douglas-fir zones, i.e. herbaceous salal leaf morphology lowland coniferous coastal forests. In the differs dramatically under different light Douglas-frr zone, the species with which salal intensities. Sun leaves develop in bright light, usually grows are Pseudotsuga menziesii vat. whereas shade leaves develop under low light menziesii, Abies amabilis, Thuja plicata, levels. Sun leaves characteristically have Mahonia nervosa, Vaccinium parvifulium, prostrate stems and small, thick blades. Shade Rosa gymnocarpa, Pteridium aquilinum, leaves are found on taller, more erect plants Rubus ursinus, mollis, with larger but thinner blades. Smith (1991) Kinbergia oregana, Hylocomium splendens found that sun leaves had a mean specif,rc leaf and Phytidiadelphus tiquetrus (Nuszdorfer et t; area less than 90 .-' g - and shade leaves al. 1991). The species with which salal were greater than 90 cmz g-1 . At 1 .8 % full usually grows in the Coastal Western Hem- sunlight (80% canopy cover), leaves were lock zone are shown (Table 1). almost three times larger in area than they were in a clearing (Messier et al. 1989). 6. History Under deep shade (0.3% tull sunlight), Gaultheria shallon is of native origin through-

Can. J. Plant Sci. Downloaded from www.nrcresearchpress.com by University of British Columbia on 05/21/19 Messier et al. (1989) reported that leaves were out its present range. Salal is the Coastal similar in size to those in the clearing, but Indian name for the plant. When David only half the dry weight. Smith (1991) Douglas landed in in 1825, Haskin reported that sun leaves of salal require at (1934; cited in Szczawinskr 1962) reported 1238 CANADIAN JOURNAL OF PLANT SCIENCE

Table 1' Zonal vegetation ofsubzones ofthe Coastal Western Hemlock biogeoclimatic zone (adapted from Pojar et al. (1991)). vh, very wet hypermaritime; xrn, very dry maritime; dm, drymaritime; mm, moisi maritime; vm, very wet maritime. Gauhheia shalbn is not present in the wh (wet hypermaritime), wm (wet maritime), ds (dry submaritime), ms (moist submaritime), and ws (wet submaritime) subzones. Percent cover classes, a - O.l-lV;, 6 - 2-57o, c - 6-10%, d - ll-25Vo, e - 26-997o Botanical name vh xm dm mm vm Common name Gaultherfu shallnn b dd salal Abies amabilis dd amabilis fir b vine maple Achlys tiphylla b b- vanilla-leaf Blechnum spicatum deer fern C hamae cypari s nootl(otensis b- yellow-cedar Chimaphila umbellnta i a a- prince's pine Coptis aspleniifulia a fern{eaved goldthread Cornus canadensis b -;; bunchberry Hylocominm spledens d d cbb step moss Listera cordata a -aa heart-leaved twayblade Mahonia nervosa 1 -a dull Oregon grape Maianthemum dilatanm a : false lily-of-the-valley Menziesia ferruginea b a ; false azalea Picea sitchensis b ? Sitka spruce P lagiothe cium undulaum a ; o a b flat moss b b sword fern Pseudotsuga mcnziesii e d Pteridium aquilinum b b bracken fern Rhytidiafulphus loreus ; ; lanky moss Rubus pedarus : : five{eaved bramble Rubus ursinus a : trailing blackberry Scapania bolanderi b ? Thuja plicata d c d d western redcedar Tiarella trifuliata a threeleaved foamflower Tsuga heterophylla d o e western hemlock Vaccinium alaskaense b o d Alaskan blueberry Vaccinium ovalifolium a ? a b oval-leafed blueberry For personal use only.

that "he was so impressed by the sight of salal mother shoot under sparse canopies, whereas he could scarcdly see anything else. daughter shoots were farther away from Throughout all his journey in the west, the the oldest shoots under closed canopies. salal was one of Douglas' favorites and he Salal accumulates considerable biomass in a held great hopes of introducing it into growing season, but mainly through the England, and making of it a cultivated fruit. " expansion of leading to the produc- tion of new shoots, not through significant 7. Growth and Development increase in the height of pre-existing shoots (a) Morphology - Gqultheria shallon has (Sabhasri 1961). slow initial growth for approximately the frrst Salal's ability to respond to a continuum of 2 yr, but once it is established it spreads understory light conditions by producing vegetatively very rapidly by means of rhi- either sun leaves or shade laves (Messier et al. zomes (Messier 1991). The length and com- 1989; Smith 1991) is important to its survival. plexity of the rhizomes of an iniividual salal Under dense stands salal can persist by plant in an area dominated by salal has not forming shade leaves; in clearings or in been Can. J. Plant Sci. Downloaded from www.nrcresearchpress.com by University of British Columbia on 05/21/19 determined but Koch (1983) found new openings of otherwise dense stands, salal shoots up to 2 m from the parent plant. forms sun leaves. Another important adaptive Bunnell (1990) observed a strong tendency for characteristic to capture light is stem elonga- daughter shoots to be clumped around the tion which responds to high red light levels GAU LTHERA SI'{LLON PURSH. 1239

(Sabhasri 1961; Vales 1986) occurring in level tested (24.24 pmol m-2 s-r; lSabhasri red dense stands (Messier et al. 1989). 1961). Maximum growth occurs under Leaves of G. shallon have a thin epicuticu- light (Sabhasri 1961). Bunnell (1990) reported lar layer that consists mostly of triterpenes, that the cost of flowering was shared across is and always contains ursolic acid; this material connected shoots of a plant, showing there also had traces of external flavonoid agyl- physiological integration between ramets. cones, namely galangin-3-methyl ether (Wollenweber and Kohorst 1984). Salasoo (d) Phmobgy - The maximal growth of salal (1981, 1988) determined the patterns of (roots, rhizomes, shoots and leaves) is alkane distribution in the epicuticular wax of between late April and August, peaking in G. shalLon and detected rimuene. The wax early June. Vegetative buds burst in early was 28% hydrocarbon- April (Sabhasri 1961). Flowering can occur The pollen tetrad diameter of Gaultheriq anvtime between March and July depending calculated by Hebda (1978) on th" (Dimock etal.1974).In Alaska, shallon has been "."u from a sample size of 100 tetrads collected flowering occurs between March and June in Burns Bog, Delta, BC. The mean tetrad (Viereck and Little 1972). Near Vancouver, diameter is 46.97 pm, with a range of BC, Pojar (1974) reported flowering between 4l-53 pm and a standard deviation of 2.50. 12 June and 4 July. In state, Hebda (1978) postulated that small tetrads flowering begins in the 3rd week of June. (41-44.5 pm) indicate growth of salal in dry Fruits ripen between August and October and conditions, intermediate tetrads (44'6-49.5 remain on the stem until December (Dimock pm) imply dry to intermediate habitats or fire, et al. 1974). and large tenads (49.6-53 pm) reflect wet sites. (e) Mycorrhizae Largent et al. (1980) (b) shoots may - Perennation - Individual reported that G. shnllon can be associated survive for 10-15 yr, but leaves are rarely with three different kinds of mycorrhizae: older than 4 yr before senescence (Haeussler arbutoid, ericoid, and ectomycorrhizae. bear leaves and Coates 1986). Shoots will Three different fungal species have been iden- (Koch only during the first few years 1983). tified, one is Oidiodendron griseum Robak potential continue Rhizomes have the to and the taxonomic position of the other two is suffrcient For personal use only. vegetatively if there reproducing species are being studied (Xiao and Berch (gaps and light through the forest overstory t9gZ). fnis is the first report of O. griseum- sunflecks) for shoot growth. Bunnell (1990) as an ericoid mycorrhizal fungus of rhizomes in found extensive mats of salal Gaultheria. conifer stands between 80 and 110 yr old, were even when aboveground salal densities 8. Reproduction low. During winter, salal is virnrally dormant Floral biology Gaultheria shallon frost @) - and is very sensitive to frozen soils and flowers are pollinated by insects, primarily (Sabhasri 1961). bumblebees and flies (Pojar 1974). The fruit (c) Physiological dqta - Salal is at least a is a many-seeded capsule, and each inflores- moderately shade-tolerant species (Sabhasri cence has 5-15 capsules' However, Bunnell 1961; Koch 1983) but its photosynthetic and (1990) found that salal will flower only when respiration characteristics are consistent with two conditions are met: on vigorous stems a shade-intolerant plant species (Sabhasri greater than 4 yr old, and at a mean crown 1961). For an actively growing plant it was iompleteness (a measure of forest canopy found that at low light intensities (6.06 ptmol closure) less than 3OVo. Hebda (1982) found - t) less than Can. J. Plant Sci. Downloaded from www.nrcresearchpress.com by University of British Columbia on 05/21/19 * -t s respiration was greater than photo- that Gaultheria shallon contributed synthesis. Photosynthetic activity and - 2% of thepollen and spore rain in areas domi- ling growth significantly increased with nated by salal, indicating how little salal increased light intensities up to the maximum flowers. nn CANADIAN JOURNAL OF PLANT SCIENCE @) Seed production and dispersal - The roots and stem bases. However, among the fruits of salal remain on the stem until 54 naturally growing plants that Bunnell December and those seeds remainins are (1990) examined, no evidence of stem viable for up to I yr following ripEning layering was found; rhizomes were the only (Dimock etal. 1974). Fruits have an aterag- means of producing new shoots. Bunnell of 126 seeds each. When conditions are (1990) forced stems into the organic mat and suitable for flowering, heavy crops of fruit examined them I yr later to find that they had are produced on a regular basis (Haeussler et grown adventitious roots, and concluded that al. 1990). Seeds are dispersed mainly by the layering must also occur naturally. He found, animals which feed upon the fruit: black-tailed while monitoring the colonization of salal, deer, Roosevelt elk, mountain beaver, ruffed that85% ofthe space occupied by salal after grouse, blue grouse, and other small 9 yr of growth was occupied during the first mammals and birds (Halverson 1986). 3 yr. Bunnell also observed that the vegeta- tive reproduction of ramets was negatively (c) Vinbiliry of seeds and germinntion- Seeds associated with age (rz : 0.95) and that no can remain viable for several years in cold, new shoots were produced after an individual dry storage, but the viability of seeds under ramet reached 9 yr of age. Seed production natural conditions is generally much reduced may be significant in the initial colonization (Dimocket al.1974), Sabhasri (1961) stored of a newly disturbed area (e.g. windthrow, seeds at 4.4'C for I yr and found a decline clearcut), but considering that a plant must be in germination from 3I to 2l%. Seeds do not at least 4 yr old before it will flower, and that require chilling (Haeussler et al. 1990) or most colonization of an area occurs within the stratification (McKeever 1938) to induce first 3 yr, the vast majority of colonization germination. Successful germination requires occurs through vegetative spread. Bunnell moist, acidic sites under partiat ihade (1990) found no seed production, only vegeta- (Dimock etal. 1974) and light for 8 h or more tive spread, at a mean crown completeness per day is essential (McKeever 1938). In Ereater than 3O%. Washington, germination rates of 27-35% from fresh seed under lighted conditions were 9. Hybrids reported (Sabhasri Gaultheia shallon does not naturally hybri- For personal use only. 1961; Dimock etal.1g74). In British Columbia, Messier (personal com- dize with any other species (Pojar 1974). munication) obtained germination rates of However, an artificial hvbrid between approximately 60% under the same G. shnllon and, Pernenya muironatahas been conditions. produced in England (Dimock et al. 1974). Despite the large quantity of seeds produced and the many seeds which germinate, seedling 10. Population Dynamics survival is very low (Haeussler et al. 1990). The rate of increase of salal populations Sabhasri (1961) found that in Wesrern depends largely on the stage of succession of Washington, seedling establishment is most the area. Messier (1991) proposed a general successful in the understory of young growth model based on the work of Messier Douglas-fir stands. (1991), Messier and Kimmins (1991), Messier et al. (1989), Vogt et al. (1997), and Vales (d)_Vegetative reproduction The most sig- (1986) (Fig. 3) of the development of salal nificant - and effective form of colonization is over a 60-yr period following a major distur- thqough vegetative spread, both in open bance (e.g. clear-cutting and slashburning) of habitats and in deep shade. Once salai is old-growth western red cedar and western Can. J. Plant Sci. Downloaded from www.nrcresearchpress.com by University of British Columbia on 05/21/19 present on a site, further expansion is almost hemlock forests on northern Vancouver exclusively by vegetative means (Sabhasri Island. The development of the live hne-root, 1961; Koch 1983; McGee 1988; Messier leaf, stem and rhizome biomass of salal has 1991) including layering and suckering from three different stages. Stage one is between GAULTHERI A ST'{LZON PURSH. t24l Salal biomass (1OOO kg/ha) to 'Lcaf Nsw-rhiZOme Flnc-rcot - Stcm ltrgr t-l ltry. 2 fLef 3- - - - l-

/)

o t6 t0 46 otd-grorth iorrrt Yeara etter clear'cuttlng rnd burnlng

Fig. 3. Hypothetical development of fine-root, leaf, stem and rhizome abundance of C'aultheria shallon the clear-cutting and burning of old-growth forests of western redcedar on-er a OO-yi -hemlockperiod following and westein on no.thern (taken from Messier (1991)).

1 and 15 yr and is characterized by a rapid Bunnell et al. 1990; Messier et al' 1990; growth rate of rhizomes and fine-roots, in par- Messier 1991). The competitive influence of ticular, between 8 and 15 yr. Stage two, salal on the seedlings of Douglas-frr' western is believed to be For personal use only. approximately between 16 and 45 yr, begins hemlock, and Sitka spruce with a rapid decline in salal live fine-root much stronger than on western red cedar and biomass followed by a more gradual decrease lodgepole pine (Bunnell et al. 1990). Com- in leaf and stem biomass. The decline of the petition is most severe during the early stages population is caused by shading due to an of stand development (Long 1977) but may increase in the overstory tree canopy. There continue through the rotation, in particular, are no data for rhizome biomass in the 10- if the canopy is open enough to allow a well- to 60-yr period, but it is believed to be high developed understory of salal to persist (Messier 1991). The f,tnal stage, occurring (Stanek et al. 1979). from 46 yr until the next major disturbance, Young stands of Douglas-fir on sub-xeric (Tan is the virnral exclusion of salal by the dense sites are limited by soil water potential overstory canopy. However, it is not com- etal. 1977). At low values of soil water poten- pletely excluded and can quickly re-establish tial, the reduction in stomatal conductance is following a disturbance. greater for Douglas-fir than for salal, Much research effort has been focused on indicating that salal transpiration would the competitive interactions of salal and account for a higher proportion of total stand (Tan 1978). Price et al. Can. J. Plant Sci. Downloaded from www.nrcresearchpress.com by University of British Columbia on 05/21/19 coniferous tree species in low-elevation transpiration et al. coastal British columbia forests (Tan et al. (1986), found that the removal of the salal 1978; Black et al. 1980; Price et al. 1986; understory of thinned 32-yt-old Douglas-fir Weetman et al. 1989a; Klinka et al. 1989; significantly increased rates of photosynthesis 1242 CANADIAN JOURNAL OF PLANT SCIENCE

and tree growth due to an increase in the 11. Response to Herbicides and Other soil water potential. Other researchers have Chemicals proposed that salal may be competing for In general salal is both resistant and resilient nutrients in the Douglas-fir forests (Stanek et to many herbicides. The most successful her- al. 1979; Haeussler and Coates 1986). bicide in controlling salal is triclopyr ester There is evidence to suggest that salal may (Garlon). Applying triclopyr ester at 4 kg a.i. also competitive be in moist ecosystemi ha-' reduced salal cover by 78% @arker (Weetman et al. 1989b; Messier 1991). Two 1988). Combining diesel with triclopyr ester hypotheses have been proposed to account for effectively controlled salal for three seasons this. First, is the resource exploitation in a Douglas-fir salal ecosystem on the south- hypothesis. Weetman et al. (19894,b) have east coast of Vancouver Island (Dunsworth shown that on northern Vancouver Island 1986). In an experiment conducted in a dry western red cedar and western hemlock cedar-hemlock ecosystem, 4 kg a.i. ha-r cutovers that are dominated with salal are triclopyr ester in diesel oil at 100 L ha-l in nutrient deficient. Germain (1985) and early spring or late sufilmer reduced salal Messier (1991) found that salal can have an cover by 60-90%. When using mineral oil as impact on the nutrient budget for conifers. the carrier instead of diesel oil, salal cover Gaultheria shnllon forms three symbiotic was reduced by only 40% (Haeussler et al. fungal associations: ericoid-, arbuioid- and 1e90). ecto-mycorrhizae (Largent et al. l9g0), Stewart (1974b) tested 10 herbicides mixed whereas western red cedar and western hem- in diesel-oil carriers. Salal plants were lock only form one fungal association each: sprayed on I April, when flower buds were endomycorrhizae and ectomycorrhizae, swelling and vegetative buds were dormant. respectively. Therefore, G. shallonmight be Silvex, dichlorprop, 2,4,5-T, and dicamba more efficient at extracting nutrients such as produced at least 80% topkill and a 50% nitrogen and phosphorus at low pH, and reduction in salal cover with silvex showine accessing nutrients in complex organic forms the best control. Salal is resistant to thesi (Xiao, Cade-Menum and Berch, personal same herbicides when applied in water, or communication). Parke et al. (1983) suggest applied later in the growing season (Grat- that dense salal can lower soil temperatures kowski 1970; Stewart 1974a). For personal use only. causing reduced conifer growth by inhibiting Other herbicides which are less effective root growth and mycorrhizal infection. The but have been reported to cause slight damage second hypothesis involves the possible to salal are glyphosate and 2,4-D (Conard allelopathic properties of salal. Del Mbral and and Emmingham 1984). Results from hexazi- Cates (1971) did not f,rnd convincinq evidence none applications are variable; Newton and for allelopathy in salal, but Rose eiA. (tg8:) Knight (1981) and Boateng and Herring have shown that allelochemicals in salal (1990) found it to be ineffective at controlling litter may inhibit seedling growth. It has salal. However, Wellman and Harrison been suggested that salal may have an (1987) reported thar an April ground appli- rgranular allelopathic effect through the production of cation of 2 kg a.i. ha - hexazinone tannins and phenolic acids (de Montigny, resulted in control of salal. Two years after personal communication). application, salal biomass on the Gaukheria shallon can be classified as a treated areas was about half that on the stress-tolerator with a low R (the level of untreated areas. resource below which the population is unable In all ofthe herbicidal tests to control salal, to maintain itself) (Messier l99l). Evidence little is known about how the below-ground

Can. J. Plant Sci. Downloaded from www.nrcresearchpress.com by University of British Columbia on 05/21/19 that salal has a low R is its abilitv to maintain plant portion responds. D'Anjou (cited by a higher stomatal conductance than Douslas- Haeussler et al (1990)) showed that although fir under a low soil water potential (Tin et aboveground patts of salal were well co"n- al. 1978). trolled by triclopyr ester, living roots (dry GAA LTH ERIA SHILLON PURSH. t243

comprised 89Vo of that in weight basis) still Table 2. The percentage of total number of leaves untreated controls, indicating that roots infected by commonly observed fungal taxa on 1240 leaf continue to survive despite substantial foliar discs of Gaultheria shallon Punh. (adapted from Petrini control. et al. (1980)). Acremonium sp. 2.4 12. Responses to other Human Manipulations Geniculosporium sP. 8.4 et Massee 3.6 Several studies have reported that salal will Leptothyium berberidis Cooke Nodulisporium sP. 2.4 and vigour following rapidly increase in cover Peziculn sp. 6.4 the removal or reduction ofthe forest canopy Phialophora spp. 7.2 (Sabhasri 1961; Inng and Turner 1975;lnng Phomapsis sp. 4.8 1977; Stanek etal.1979; Black et al. 1980; Phyllosticta pyrolae Ellis et Everh. 34.7 vaccinii Earle 5.6 Koch 1983; Gholz et al. 1985; Price et al. Phyllosticta Ramularia sp. 4.8 al. 1986; Vales and Bunnell 1988; Messier et Septogloeum sp. 4.4 1989). Messier (1991) found that salal re- Signoidea sp. 1.2 establishes relatively quickly below ground Xylaria hypoxylon (L. ex Fr') 2.0 following clear-cut logging and slashburning, Grev. anamorph but the aboveground portion does not grow as rapidly and may take many years to become southern Vancouver Island, B. Green (per- dominant. sonal communication) has speculated that Prescribed burning and logging can heavy soil scarification (i.e. removing the increase the growth of salal if the burn is light. organic layer) on dry sites causes mortality Fire stimulates resprouting from roots and of salal rhizomes due to desiccation. stem bases (Sabhasri 1961). Only severe burns that penetrate sufficiently deep to kill the roots can reduce salal cover. Vihanek 1.3. Responses to Parasites (1985) reported that on dry sites on eastern Salal is infected by numerous fungal parasites. Vancouver Island high severity burns The most common and serious is the leaf spot decreased salal cover by 80% compared to fungus (Mycosphaerella gaultheriae) adjacent unburned areas; whereas low to (Conners 1967; Haeussler et al. 1990). In a moderate burns decreased coverby oriy 4A%. study conducted in western Oregon, Petrini For personal use only. Fertilizer application, particularly nitrogen- et al. (1982) isolated 13 different species of rich fertilizer. increases both above and endophytic fungi (Table 2). The most frequent below-ground growth of salal (Sabhasri 1961; was Phyllosticta'pyolne Ellis et Everh. which Anonymous 1970). However, in forest occurred on 34jVo of the observed leaves. stands, applications of fertilizer that result in They found that the frequency of endophyte an increased tree canopy density may cause infections diminishes with decreasing habitat a decline in the vigour and cover of the salal moisture. Furthermore, rates of overall infec- understory due to shading (Long an Turner tion were higher in samples taken from 1975; Stanek et al. 1979). densely wooded sites than in samples taken Salal readily forms new plants from cuttings from more open sites. Other fungi reported of the stem and roots (Sabhasri 1961), so it on salal are Asterella gaultheriae, Bulgaria can be expected that any form of soil distur- melastoma, I'achnella gaultherine, Lepto- bance that causes mechanical damage to the sphaeria gaultheri.ae, Phacidiwn gaultherine, plant, but that does not physically remove it Phyllosticta gaultheriae, and Poria ferrea from the site, will stimulate resprouting. (Conners 1967). Linderman and Zeitoun However, it has been reported by Muller (1977) found Phytophthora cinnamomi

Can. J. Plant Sci. Downloaded from www.nrcresearchpress.com by University of British Columbia on 05/21/19 (1989, cited in Haeussler et al. (1990) that Rands, a very widespread fungus, occurring heavy scarification on areas on southern on nursery-grown salal. Apothecia of Valden- Vancouver lsland has resulted in very slow sinia heterodom Peyr. (Sclerotiniaceae), have reinvasion of salal. Based on trials on been found on fallen G. shallon leaves 1244 CANADIAN JOURNAL OF PLANT SCIENCE

(Redhead 1974). Salal is known to have at Chambers, M. f988. Deer in British Columbia least one higher plant parasite, Boschniakia BC. Min. Environ., Fish Wildl. Br., Inf. and hookeri Walp. (Olsen and Olsen 1981; Kuijt Education Section, Victoria, BC. and Toth 1985), a perennial root parasite. It Conners, l. L. 1967. An annotated index of plant is not known to what degree the parasite diseases in Canada and fungi recorded on plants in Alaska, Canada and Greeland. actually damages salal. Canadian Depart- ment of Agriculture, Ottawa, ON. Publ. 1251. 38lp. ACKNOWLEDGMENTS Conard, S. G. and Emmingham, W. H. 1984. Herbicides This work was funded by a Natural Sciences and for brush and fem control on forest sites in western Engineering Research Council/Industry grant to Oregon and Washington. Special Publ. Res. C.P.C. and R.T. as part of the SCHIRP study. 8, For. Lab., Oregon State University, Corvallis. OR. Anonymous, 1970. Gaultheria shallon Prrsh. Crouch, G. L. 1979. Food habits of black-tailed Davidsonia l:29-31. deer on forest habitats in the Pacific Northwest. Pages 53-59 rn Wallmo, O. C. and Schoen, Bailey, A. W. 1966. Forest associations and J. W. eds. Proceedings of a Conference on Sitka Black- secondary plant succession in the southern Oregon tailed Deer. USDA Forest Service, Alaska Coast Range. Ph.D. thesis. Oregon State Univer- Region, sity, Corvallis, OR. Juneau, AK. Del Moral, R. 1971. Banfield, A. W. F. lW4. The mammals of R. and Cates, G. Allelopathic potential of the dominant vegeta- Canada. University Toronto Press, Toronto, ON. tion of western Washington. Ecology 52: Barker, J. E. 19E8. Control of salal with Garlon 1030-r037. (1988 update). Expert Committee on Weeds. Dimock [, E. J., Johnston, W. F. and Stein, Research report. p. 194. Western Canada Section W. l. ty74, Gautheria L., wintergreen. 1n S. C. Meeting. Winnipeg, MB. Schopmeyer, ed. Seeds of woody plants of the Barker, J. E., Weetman, G. F. and Fournier. United States. Agric. Hand. 450. USDA For. Ser., R. M. 1987. Growth and nutrition of sitka spruce, Washington, DC. western hemlock and western red cedar followins Dunsworth, B. G. 1986. Salal removal fertilization of coastal cedar/hemlock sites. Westeri and its impact on crop tree performance. Expert Forest Products. Vancouver, BC. 14 pp. Committee on Weeds. Research rcport, pp. 197. Black, T. A., Tan, C. S. and Nnyamah, U. J. Western Canada Section Meeting. Saskatoon, SK. 1980. Transpiration rate of Douglas-fir trees in Germain, A. 1985. Fertilization of stagnated Sitka For personal use only. thinned and unthinned stands. Can. J. Soil Sci. 60: spruce plantations on northem Vancouver 62s-63r. Island. M.Sc thesis. Boateng, University of British Columbia, J. O. and Herring, L. 1990. Vancouver, BC. preparation: Site Chemical. Pages 164-178 in Gholz, H. L., Hawk, G. M., Campbell, A., D. P. Lavender, Parish. R. C. A. Johnson. Cromack, JR., K. andBrown, A. T. 19E5. Early G. Montgomery, Vyse, and A. R. Willis, eds. vegetative recovery and element cycles on a clear- Regenerating British Columbia's forests. Univer- cut watershed in western Oregon. Can. J. For. Res. sity of British Columbia Press, Vancouver, B.C. 15: 400-409. Brown, R. L. and Hafenrichter, A. L. 1962. Gratkowski, H.1y70. Foliage sprays fail on salal. Stabilizing sand dunes on the Pacific coast with West. Soc. Weed Sci. Res. Prog. Rep. 1970: 18. woody plants. USDA, Washington, DC. Misc. Gunther, E. 1945. Ethnobotany of Western Publ. 892, 18 pp Washington, University of Washing Press, Seattle, Bunnell, R. L. 1990. 1990. Reproduction of salal wA. (Gaultheria shallon) under forest canopy. Can. J. Haeussler, S. and Coates, D. 19E5. Autecological For. Res. 20: 91-100. characteristics of selected species that compete with p. Bunnell, F. L., McCann, R. K. Lindop, and conifers in B. C. : a literahue review. Land Manage. Messier, C. 1990. Salal - a competitor? A field Rep. No. 33 BC. Ministry of Forests, Victoria, guide. Ministry of Forest and l,ands, Victoria, BC. BC. Can. J. Plant Sci. Downloaded from www.nrcresearchpress.com by University of British Columbia on 05/21/19 Calder, J. A. and Taylor, R. L. 1968. Flora of Haeussler, S., Coates, D. and Mather, J. 1990. the Queen Charlotte Islands. Part 1. Svstematics Autecology of common plants in British Columbia: of the vascular plants. Queen's Printerj Canadian a literature review. FRDA report #158, Victoria, Department of Agriculture, Ottawa, ON. BC. GAULTHENA ST'{LLON PURSH. 1245

Halverson, N. M. (ed). 1986. Major indicator and pyrolaceous plants in nortttern Califomia' Can. shrubs and herbs on national forests of western J. Bot.5E: 2n+2279. Oregon and southwestem Washington. USDA For. Linderman. R. G. and Zeitoun, F. 1977. Serv., Pacific NW Region. Pytophthora cirvmmomi causing root rot and wilt of Hebda, R. J. 1978. Size, productivity, and nursery-grown native westem azalea and salal. Plant paleoecological implications of ericaceous pollen Dis. Rep. 61: 1045-1048. from Burns Bog, southern Fraser River Delta, Irog, J. N. 1yl7. Trends in plant species diversity British Columbia. Can. J. Bot. 57: 1712-1717. associated with development in a series of Pseudat- Hebda, R. J. 1982. Late-glacial and postglacial suga menziesii / Gaulthcria shallon stands. Northwst vegetation history at Bear Cove Bog, northeast Sci.5l: 119-130. Vancouver Island, British Columbia. Can. J. Bot. Ipng, J. N. and Turner, J. 1975. Aboveground 6l:3172-3192. biomass of understory and overstory in an age Hitchcock, C. L. and Cronquist, A. 1973. Flora sequence offour Douglas-fir stands, J. Appl. Ecol' of the Pacific Northwest. University of Washington 12: 179-188. Press. Seattle. WA. Lyons, C. P. 199. Trees, shrubs and flowers to Hultdne E. 196E. Flora of Alaska and neigh- know in British Columbia. J. M. Dent and Sons Ltd' bouring Territories: A manual of vascular plants. Vancouver, BC. Stanford University Press, Stanford, CT. Martin, A. C., ZIiM\ H. S. and Nelson' A. L. Hunt, R. S. 1980 Rhytismataceae on salal leaves. 1951. American wildlife and plants. McGraw-Hill Mycotaxonomy ll:. 233-240. Inc., New York, NY. Jones, G. W. and Bunnell' F. L. 19M. Response McG€e, A. B. 19E8. Effects of prescribed buming ofblack-tailed deer to winters ofdifferent severity on vegetation and natural tree regeneration in nlature on northern Vancouver Island. Pages 385-396 in cedar-hemlock forests in the Pacific Rim National W. R. Meehan, T. R. Merrell, Jr., and T. A. Park. B.S.F. thesis. University of British Columbia' Hanley, eds. Proceedings of a Symposium on Vancouver. BC. Fish and Wildlife Relationships in Old-Growth McKeever, D; G. 1938. The effect of various Res. Biol. Morehead City, Forests. Am. Inst. Fish. methods of treaftnent on the germination of seeds of NC. some plants valuable for game and erosion purposes. suflrmer foods of King, R. D. 1969. Spring and M.Sc. thesis, University of Idaho, Moscow, ID. grouse Wildl. ruffed on Vancouver Island. J. McTaggart-Cowan' I. l!)45. The ecological rela- Manage. 33:. 440-442. tionships of the food of the Columbia black-tailed King, R. D. and Bendell, J. F. 1982 Foods deer. Odocoileus hemionus columbianus selected grotse (Dendragapus obscurw by blue (Richardson), in tlre Coast Forest Region of soutlprn For personal use only. Can. J. Zool. 60: 3268-3281. fuIiginpsis). Vancouver Island, British Columbia. Ecol' Monogr. Klinka, K., Nuszdorfer, F. C. and Skoda' L. 15:110-139. 1979. Biogeoclimatic units ofcentral and southern Mesier, C. 1991. Factors timiting early conifer Vancouver Island. BC Min. For., Victoria, BC' golvth in salal{ominated cutovers on nortlpm Van- Klinka, K., Carter, R. E., Feller, M. C. and couver Island, British Columbia. Ph.D. thesis. Wang, 1989. Relations between site index, Q. of British Columbia, Vancouver, BC. salal, plant communities, and sites in coastal University Messier. C. 1993. Effects of neutral shade and douglas-fir ecosystems. Northwest Sci. 63(1): 19-28. growing media on growth, biomass allocation, and Koch, J. M. 1963. Salal plant structure, growth and ablty of Gaultheria shnllott- Can' J' Bot. allometric relationships under several forest stand conrpetitive 70:2271-2276. densities in south coastal British Columbia, B.S.F. Messier, C., Honer, T. W. and Kimmins' J. P. thesis, University of British Columbia, Vancouver, 1989. Photosynthetic photon flux density, red:far- BC. minimum light requirements for sur- Kmjina, V. J. 1965. Biogeoclimatic zones and clas- red ratio, and western red sification of British Columbia. Ecol. West. N. Am. vival of Gaultheria shnllon in l: l-17. cedar/western hemlock stands in coastal British Kuijt, J. and Toth, R. 19E5. Structure of the Columbia. Can. J For. Res. 19: 1470-1477. and host-parasite interphace of Boschniakia hooken Messier, C., Kimmins, J. P., Bunnell, F. L. Can. J. Plant Sci. Downloaded from www.nrcresearchpress.com by University of British Columbia on 05/21/19 Walpers (Orobanchaceae). Acta Bot. Neerl. 34: McCann, R.K. 1990. Understanding salal as a 257-270. competitor. .In Vegetation management: An Largent, D. L., Sugihara, N. and Wishner' C. integlated approach. Proc. ofthe fourth annual BC 1980. Occurrence of mycorrhizae on ericaceous Veg. Manag. Workshop. Victoria, BC' 1246 CANADIAN JOURNAL OF PLANT SCIENCE

Messier, C. and Kimmins, J. P. fgl. Above- Salasoo, I. f988. Epicuticular wax hydrocarbons and below-ground vegetation recovery in recently of Ericaceae in the Pacific Northwest of U.S.A. clear-cut and burned sites dominated bv Gauttheria Biochem. Syst, Ecol. 16: 619-622. shallon in coastal British Columbia. For. Ecol. Scoggan, H. J. f978. The flora ofCanada. Part Man. 46: 275-294. 4. National Museum of Canatla, Ottawa, ON. Newton, M. and Knight, D. E. p8f. Handbook Singleton, J. 1976. Food habits ofwild of weed and insect control chemicals for forest in British Columbia: Bioliography and plant syn- resource managers. Timber Press. Beaverton. opsis. BC Ministry of the Environment, Terres- oR. trial Studies Branch, Victoria, BC. Nuszdorfer, F. C., Klinka, K. and Demarchi, Smith, N. J. 1991. Sun and shade leaves: clues D. A. f991. Coastal Douglas-fu zone. Ecosystems to how salal (Gaaltheria slwllon) responds to over- of British Columbia. D. Meidinger, and J. pojar, story stand density. Can. J. For. Res. 21: 300-305. eds. In Research Branch, Ministry of Forestry, Stanek, W., Beddows, D. and State, D. 1979. Victoria, BC. Fertilization and thinning effects on a Douglas-fir Olsen, S. and Olsen, I. D. f981. Observations ecosystem at Shawnigan Lake on Vancouver on the biology of Boschniakia hookei (Oroban- Island: some observations on salal and bracken fern chaceae). Nord. J. Bot. 1: 585-594. undergrowth. Rep. BC-R-I, Canadian Forestry larke' J. L., Linderman R. G. and Trappe, Service, Victoria, BC. J. N. 1983. Effects of forest litter on mvcorrhizal Stewart, R. E. 1974a. Foliage sprays for site development and growth of Douglis-fir and preparation and release from six coastal brush spe- western red cedar seedlings. Can. J. For. Res. 13: cies. Report PNW-172. USDA For. Ser. Portland, 6ffi-67r. oR. Petrini, O., Stone, J. and Carroll. F. E. 19E2. Stewart, R. E. 1974b. Budbreak sprays for site Endophytic fungi in evergreen shrubs in western preparation and release from six coastal brush spe- Oregon: a preliminary study. Can. J. Bot. 60: cies, Repon PNW-176. USDA For. Ser. Portland. 789-796. oR. Pojar, J. 1974. Ttrc relation of the repro- Szczawinski, A. C. 1962. The heather family ductive biology of plants to the structure and (Ericaceae) of British Columbia, BC Provincial firnction of four plant communities. ph.D. thesis. Museum, Victoria, BC. Handb. No. 19. University of British Columbia, Vancouver. Tan, C. S., Black, T. A. and Nnyamah, J. U. BC. 1977. Characteristics of stomatal diffusion Pojar, J., Klinka, K. and Demarchi, D. A. resistance in a Douglas-fir forest exposed to soil

For personal use only. 1991. Coastal western henrlock zone. In D. water deficits. Can. J. For. Res. 7: 595-604. Meidinger and J. Pojar, eds. Ecosystems of British Tan, C. S., Black, T. A. and Nnyamah, J. U. Columbia. Research Branch, Ministry of Forestry, 197E. A simple diffrrsion model of transportation Victoria, BC. applied to a thinned Douglas-fir stand. Ecology 59: hice, D. T., Black, T. A. and Kelliher, F. M. t22r-r229. 1986. Effects of salal understory removal on Taylor, R. L. and MacBryde,B. 1977. Vascular photosynthetic rate and stomatal ionductance of plants of British Columbia: A descriptive resource young Douglas-fir trees. Can. J. For. Res. 16: inventory. The University of British Columbia %-97. Press, Vancouver, BC. Redhead, S. ln 4. Epistolae mycologic ae Iy . VaI- Turner, N. J. f975. Food plants of British densinia heterodozoxa Peyr. (Sclerotiniaceae). Columbia Indians. Handbook No. 34, BC, Provin- Syesis 7: 235-238. cial Museum, Victoria, BC. Rose, S. L., Perry, D. A. Pilz, D. and Schoene- Vales, D. J. 1986. Fwrctional relationships between berger, M. M. 1983. Allelopathic effects of litter salal understory and overstory. M.Sc. thesis. on the growth and colonization of mycorrhizal University of British Columbia, Vancouver, BC. tungi J. Chem. Ecol. 9: lt53-1162. Vales, D. J. and Bunnell, F. L. 1988. Relation- Sabhasri, S. 1961. An ecological study of salal ships between transmission of solar radiation and (Gaultheria shallon). Ph.D. thesis, University forest stand characteristics. Agric. For. Meteorol. Can. J. Plant Sci. Downloaded from www.nrcresearchpress.com by University of British Columbia on 05/21/19 Washington, Seattle. WA. 43:201-223. Salasoo, I. 1981. Alkane distribution in epicutic- Viereck, L. A. and Little, E. L. 1972. Alaska ular wax ofsome evergreen Ericaceae. Can. J. Bot. trees and shrubs. Agric. Hand. 410. USDA For. 59:1189-1191. Ser., Washington, DC. GAT] LTHENA SI'{LLON PURSH. t247

Vihanek, R. E. 1985. The effects of slashburning Weetman, G. F., Fournier, R. M., Schnborbus- Post-burn on the growth and nutrition of young Douglas-fir Pmozzo, E. and Barker, J. 1990. plantations in some dry, salal dominated nitrogen and phosphorous availability in coastal ecosystems. M.Sc. thesis, University of British British Columbia cedar/hemlock forests and the use Columbia. Vancouver. BC. of fertilization and salal eradication to restore Vogt, K. A., Vqgt, D. J., Moore, E. E.' Fatuga' productivity. lz S.P. Gessel, ed' Sustainedproduc- B. A., Redlin, M. R. andEdmons, R. L. 19E7. tivity of forest lands. Proc. 7th North Amer. For. Conifer and angiosperm fine-root biomass in rela- Soils Conf. Friesen Press, Vancouver, BC. Granular tion to stand age and site productivity in Douglas- Wellman, R. and Harrison, C. 19E7. fir forests. J. Ecol. 75: 857-870. hexazinone site prep. Expert Committee on Weeds. Weetman, G. F., Fournier, R., Barker, J., Research report, p. 207. Western Canada Section Schnorbus-Panozzo, E. and Germain, A. 19E9a. Meeting, Victoria, BC. Novel Foliar analysis and response of fertilized chlorotic Wollenweber, E. and Kohorst, G. 1984. and Sitka spruce plantations on salal-dominated cedar- epicuticular leaf flavonoids from Kalmia hemlock cutovers on Vancouver Island. Can. For. Gaultheri.a (Ericaceae). Z. Naturforsch 39c: Res., 12: 1501-1511. 7t0-713. Weetman, G. F., Fournier, R., Barker, J. and Xiao, G. and Berch, S. M. 192. Ericoid mycor- Schnorbus-Panozzo, E. 19E9b. Foliar analysis rhizal fungi of Gaultheria shallon. Mycologia and response of fertilized chlorotic western hem- 84(3): 470-471. lock and western red cedar reproduction on salal- Zwickel, F. C., and Bendell, J. F. 1972. Obser- dominatd cedar-hemlock cutovers on Vancouver vations on food habits of incubating female blue Island. Can. For. Res. l2z 1512-1520. grouse. Condor 74: 493-494. For personal use only. Can. J. Plant Sci. Downloaded from www.nrcresearchpress.com by University of British Columbia on 05/21/19