REGENERATION OF AMERICAN BEECH (FAGUS GRANDIFOLIA EHRH.) IN MICHIGAN: INTERACTIONS OF BEECH BARK DISEASE AND MANAGEMENT PRACTICES. Abstract.

Transcription

1 REGENERATION OF AMERICAN BEECH (FAGUS GRANDIFOLIA EHRH.) IN MICHIGAN: INTERACTIONS OF BEECH BARK DISEASE AND MANAGEMENT PRACTICES Holly A. Petrillo nd John A. Witter School of Nturl Resources nd Environment, University of Michign Astrct Distriution nd origin of Americn eech (Fgus grndifoli Ehrh.) regenertion is eing studied s prt of the Michign Beech Brk Disese Monitoring nd Impct Anlysis System. As overstory sl re of ll species decresed in stnds, the mounts of eech regenertion nd totl regenertion incresed. Both eech regenertion nd regenertion of ll species were more undnt in the Upper Peninsul compred to the Lower Peninsul. The mjority of eech regenertion in Michign ws of origin. Also, more eech regenertion nd totl regenertion were present in mechniclly thinned stnds s compred to unthinned stnds. As overstory eech trees re killed y eech rk disese nd overstory sl re decreses, oth eech regenertion nd totl regenertion will proly increse in ffected stnds. Currently, stnds with eech rk disese hve lower eech regenertion nd totl regenertion; this is likely result of mngement prctices tht hve led to the mintennce of high sl res since mny of these stnds re in stte prks. Structurl nd compositionl chnges in regenertion re expected to e oserved in infected stnds once eech rk disese hs een present for greter length of time, overtking the effects of pst mngement prctices. Introduction nd Literture Review The mjor ojectives of this regenertion study re to: (1) determine loction nd size distriution of eech regenertion nd regenertion of other overstory species in Michign s northern hrdwood stnds, (2) monitor chnges in eech regenertion nd totl regenertion in reltion to eech rk disese, (3) determine origin ( or ) of eech regenertion in Michign nd (4) study influences of mngement prctices on eech regenertion nd totl regenertion. Americn eech cn reproduce either y or vegettively y root s; the extent of ech type hs een little studied (Jones nd Rynl, 1986; Held, 1983; Wrd, 1961). In the sence of disturnce sexul reproduction is thought to e the most common form of reproduction throughout most of its rnge. Asexul reproduction of eech occurs minly in the eech gps of the Smoky Mountins (Russell, 1953) nd in more severe environments in the northern nd western prts of its rnge (Wrd, 1961). Beech s generlly occur when the roots re injured, cusing dventitious uds to form, lthough s cn occur where injury is not evident (Tus nd Houston, 199; Held, 1983). Beech s re more undnt on exposed southfcing slopes where freeze nd thw ctivity cn dmge shllow roots nd stimulte ing (Held, 1983). Although eech s hve high mortlity rtes, they lso hve rpid growth nd there is continul production of new s, ensuring tht the mechnism of sexul ing contriutes significntly to individuls reching the spling stge (Forcier, 1973). Methods The 61 forest stnds used in this study were prt of the Beech Brk Disese Monitoring nd Impct Anlysis System (Thompson nd Witter, 22) (Figure 1). In ech stnd regenertion plots were plced t every other prism point eginning with the first, for totl of 15 regenertion plots per stnd. Plots were 2m X 1m, with the prism point centered on one short edge nd the long sides extending out in the direction of the next prism point. Ech plot ws divided into 4 qudrnts. Within ech regenertion plot, ll trees >9 cm in height nd <12.5 cm in dimeter t rest height (DBH) were identified to species nd tllied y height clss: (1) m, (2) m, (3) m nd (4) >1.8 m. Presence or sence of Americn eech 9 cm in height ws recorded for ech qudrnt, nd overll eech ling density (low, <1%; medium, 1-25%; high, >25%) ws determined for ech regenertion plot sed on the percentge of the plot re covered y Americn eech lings nd then n verge density per stnd ws clculted (Figure 1). Origin ( or ) ws determined for 6 eech stems (four stems per regenertion plot) 9 cm tll within ech stnd. If the regenertion plots did not contin enough individuls, origin ws determined for stems outside the plots ut within the stnd. Origin ws 142

2 Regenertion (stems/ stnd) Lower Peninsul Upper Peninsul Figure 1. Loction of reserch stnds nd regenertion density in Michign. Overll eech ling density (low, <1%; medium, 1-25%; high, >25%) ws determined for ech regenertion plot sed on the percentge of the plot re covered y Americn eech lings nd then n verge density per stnd ws clculted. determined y removing deris from the se of the stem nd serching for lterl roots, which esily distinguished or origins. Results nd Discussion Beech regenertion ws more undnt in stnds tht hd lower overstory sl re, whether from nturl disturnces or nthropogenic fctors. Lower growing seson, higher precipittion, nd sence of eech scle were importnt fctors in explining where high mounts of eech regenertion were found. Stnds locted in close proximity to Lke Michign nd Lke Superior hd the longest growing sesons (Alert et l., 1986). Beech nd ll species regenertion ws more undnt in the Upper Peninsul (UP) compred to the Lower Peninsul (LP) (Figure 2). The stnds with the highest mounts of eech regenertion were long the cost of Lke Superior, nd some were in res tht hd een thinned. Stnds thinned in the lte 198 s nd erly 199 s re likely to hve higher mounts of dvnced regenertion (stems > 1.8m) 1 to 2 yers lter. A comintion of the lkemoderted climte long with the presence of thinning my explin the higher mounts of eech regenertion in these res. Significntly more eech regenertion is present in stnds dominted y sugr mple nd Americn eech or compred to stnds with strong northern red ok (Quercus rur L.) component (ok-eech) (Figure 3). Figure 2. Men mounts of eech regenertion in the Lower nd Upper Peninsuls of Michign. Brs indicte stndrd errors. Different letters indicte men vlues tht re significntly different. Regenertion(stems/ h) Mple-Beech Ok-Beech Figure 3. Men mounts of eech regenertion in two forest types in Michign. Brs indicte stndrd errors. Different letters indicte men vlues tht re significntly different. Amounts of eech regenertion were lowest in the okeech stnds due to their lower productivity nd lower moisture vilility. As BBD progresses throughout Michign, the gps creted y the deth of overstory eech will likely e dominted y eech nd sugr mple regenertion (Forrester nd Runkle, 2; Woods, 2; Brnes et l., 1998; Brnes, 1991). These re the most common species currently present in the understory of the northern hrdwood stnds tht were studied; oth of these species respond positively to cnopy gps. The dense cnopies found in northern hrdwood forests often exclude regenertion of other tree species. Twery nd Ptterson (1984) predicted tht the eech-sugr mple forest type would e very successful fter BBD moves 143

3 through stnd. Houston (1975) found tht while the structure of forests in Mine were very different fter BBD moved through thn efore this disese ws present, eech ws still very importnt component in terms of oth reltive numers of stems nd sl re following disese outrek. Others hve lso extensively studied replcement ptterns of eech nd sugr mple (Hne, 23; Forrester nd Runkle, 2; Poulson nd Pltt, 1996; Runkle, 1981; Woods, 1979). From these studies, it seems likely tht future stnd composition my depend t lest prtilly upon climtic conditions of the re. In southern Michign, self-replcement of eech my e frequent (Forrester nd Runkle, 2; Poulson nd Pltt, 1996) ut in northern Michign where severe climtes re present, reciprocl replcement- in which the presence of overstory eech promotes sugr mple regenertion- my e common (Runkle, 1981; Woods, 1979). ) ) 83% No Scle 82% 17% All Plots 18% 79% Scle 21% Beech reproduction y ws y fr more common in Michign s compred to reproduction y ing, which differs from findings in the estern U.S. nd Wisconsin (White, 1991; Jones nd Rynl, 1986; Held, 1983; Wrd, 1961) (Figure 4). When ing did occur, this type of reproduction ws more common in the Lower Peninsul compred to the Upper Peninsul, gin differing with Wrd s (1961) Wisconsin study (Figure 4). Held (1983) determined tht freeze-thw injury is primry cuse of eech ing. The Lower Peninsul is more vulnerle to lte spring freezes nd frost throughout the growing seson s compred to the Upper Peninsul (Alert et l., 1986); this my explin the high numers of eech s in the Lower Peninsul reltive to the Upper Peninsul. Regenertion y ing ws similr in stnds with nd without BBD (Figure 4). Jones nd Rynl (1986), studying stnds in NY, lso found tht BBD did not seem to hve stimultory effect on production. However, numer of eech s ws lso similr in unthinned nd thinned stnds in Michign, in contrst to findings of White (1991), who determined tht s of severl species, including eech, dominted woody plnt iomss fter hrvesting in Mine (Figure 5). c) 72% Figure 4. Percent of eech stems from nd origins in ) ll reserch stnds in Michign ) stnds with nd without eech scle nd c) the Lower Peninsul (LP) nd Upper Peninsul (UP) of Michign. Regenertion ( stems/ h) LP Unthinned 28% Thinned Figure 5. Men mounts of eech regenertion in unthinned nd thinned stnds in Michign. Brs indicte stndrd errors. Different letters indicte men vlues tht re significntly different. 91% UP 9% 144

4 Acknowledgments We thnk the USDA McIntire-Stennis Progrm, the USDA Forest Service, Michign Deprtment of Nturl Resources Forest, Minerl nd Fire Mngement Division, nd the University of Michign School of Nturl Resources nd Environment for finncil support for this reserch. Literture Cited Alert, D.A., S.R. Denton, nd B.V. Brnes Regionl lndscpe ecosystems of Michign. School of Nturl Resources nd Environment, University of Michign, Ann Aror, MI. (unnumered report). Brnes, B.V., D.R. Zk, S.R. Denton, nd S.H. Spurr Forest Ecology, 4 th ed. John Wiley & Sons, NY. 774 p. Brnes, B.V Ch. 1: Deciduous forests of North Americ. pp In Rohrig, E., nd B. Ulrich (eds.) Ecosystems of the World 7: Temperte Deciduous Forests. Elsevier, Amsterdm. Forcier, L.K Seedling pttern nd popultion dynmics nd the reproductive strtegies of sugrmple, eech, nd yellow irch t Hurd Brook. Ph.D. Disserttion, Yle University, New Hven, CT. Forrester, J.A. nd J.R. Runkle. 2. Mortlity nd replcement ptterns of n old-growth Acer-Fgus woods in the Holden Aroretum, Northestern Ohio. Americn Midlnd Nturlist 144, Hne, E.N. 23. Indirect effects of eech rk disese on sugr mple ling survivl. Cndin Journl of Forest Reserch 33, Held, M.E Pttern of eech regenertion in the est-centrl United Sttes. Bulletin of the Torrey Botnicl Clu 11, Houston, D.R Beech rk disese: The ftermth forests re structured for new outrek. Journl of Forestry 73, Jones, R.H. nd D.J. Rynl Sptil distriution nd development of root s in Fgus grndifoli (Fgcee). Americn Journl of Botny 73, Poulson, T.L. nd W.J. Pltt Replcement ptterns of eech nd sugr mple in Wrren Woods, Michign. Ecology 77, Runkle, J.R Gp regenertion in some oldgrowth forests of the estern United Sttes. Ecology 62, Thompson, E.M., nd J.A. Witter. 22. Michign eech rk disese monitoring nd impct nlysis system: field methods protocol hndook. Mich. Coop. For. Pest Mgmt. Hndk Sch. Nt. Res. And Envir., Univ. Mich., Ann Aror, MI. Tus, C.H. nd D.R. Houston Fgus grndifoli Ehrh. pp In Burns, R.M. nd D.H. Honkl (tech. coords.) Silvics of North Americ: Vol. 2. Hrdwoods. USDA Forest Service Agriculturl Hndook 654. Twery, M.J. nd W.A. Ptterson III Vritions in eech rk disese nd its effects on species composition nd structure of northern hrdwood stnds in New Englnd. Cndin Journl of Forest Reserch 14, Wrd, R.T Some spects of regenertion of the Americn eech. Ecology 42, White, A.S The importnce of different forms of regenertion to secondry succession in Mine hrdwood forest. Bulletin of the Torrey Botnicl Clu 118, Woods, K.D Reciprocl replcement nd the mintennce of codominnce in eech-sugr mple forest. Oikos 33,

5 Evns, Celi A., Lucs, Jennifer A. nd Twery, Mrk J. 25. Beech Brk Disese: Proceedings of the Beech Brk Disese Symposium. Gen. Tech. Rep. NE-331. Newtown Squre PA, US. Deprtment of Agriculture Forest Service, Northern Reserch Sttion. 149 p. Contins invited ppers, short contriutions, strcts, nd working group summries from the Beech Brk Disese Symposium in Srnc Lke, NY, June 16-18, 24. Key Words: Beech Brk Disese, forest structure, wildlife, silviculture nd mngement, genetics, Northestern forests, reserch gend, Cryptococcus fgisug, Nectri coccine vr. fgint, Fgus grndifoli Printed on Recycled Pper