Hard Mast Production Before and After the ChestnutBlight Seth J. Diamond (deceased), Robert H. Giles, Jr., and Roy L. Kirkpatrick, Department of Fisheries and Wildlife Sciences, and Gary J. Griffin, Department of Plant Pathology,Physiology,and WeedScience,Virginia PolytechnicInstitute and State University,Blacksburg,VA 24061-0331. ABSTRACT: We estimated hard mastproduction of a Southern Appalachian forestfor two 10 yr intervals: onebeforeand one,35 yr after, the chestnut blightfungus(Cryphonectria parasitica) (Mutt.) Bart, had killed all maturechestnut trees.The basalarea of hard mast-producing treesin thepostblight forest was28% less thanin thepreblight forest. Theestimate of hard mastoutput was34% lessafter thechestnut blight.Postblight production wasless thanpreblightproduction for 8 of l Oyr. During5 of these years, postbli ghtproduction was only5-27% ofpreblight production. Annualpreblightmast production wasrelatively stable,whereas annual postblight production fiuctuated substantially. Ourfindings suggest thattheloss ofmature chestnuts (Castanea dentata)markedlyreducedthe Southern Appalachian forest's carryingcapacity for certainwildlife species. South.J. Appl. For 24(4):196-201. The introduction of the chestnut blight fungus Cryphonectria parasitica(Murr.) Barr(formerlyEndothia) at thebeginning of the 20th centuryproducedan intensiveand extensive vegetational disturbance in Appalachian forests. Numerous studies havedocumented theimpactof the chestnut blighton forestcomposition (Illick 1921, Korstian andStickel1927, Keever1953,Nelson1955,Woods andShanks 1959,Mackey andSivec1973,Stephenson 1974,Karban1978,McCormick andPlatt 1980, Johnson andWare 1982, Stephenson 1986, Arends andMcCormick1987,Day et al. 1988);yettheeffect of thechestnut blightonhardmast production in Appalachian forestshasnot beeninvestigated. The demiseof the Ameri- can chestnut[Castanea dentara (Marsh.) Bork.] at least temporarily eliminated a major sourceof hard mast. Al- though chestnut waslargelyreplaced by oaks(Quercusspp.) andhickories (Carya spp.)(Stephenson 1974,Stephenson et al. 1991,Karban1978,McCormickandPlatt 1980,Day et al. 1988), these speciesmay have mast yields significantly different fromthose of American chestnut. Thehighinterspe- cific andannual variabilityin hardmastproduction recorded for both oaks (Downs and McQuilkin 1944, Tryon and Carvell 1962, Beck 1977) andhickories(Nixon et al. 1980) suggest that the replacementof one hard mast-producing No•: RobertH. Giles, Jr., is the corresponding author,and he can be reachedat Phone (540)231-5910;Fax: (540)231-7580; E-mail: rhgiles @vt.edu. The authors thank theUSDA Forest Service' sCoweeta Hydrologic Labora- tory for collecting and providing datafor this project.This research was supported by the Department of Fisheries andWildlife Sciences, Virginia Polytechnic Institute andState University. Manuscript received September 4, 1997, accepted August31, 1998. Copyright ̧ 2000 by the Societyof American Foresters. species by another does notensure the stability of a forest's hardmastoutput. The objectiveof this study was to estimatepre- and postblight mastproduction for a Southern Appalachian for- est. This information may enhanceunderstanding of the historical andcontemporary relationship betweenSouthern Appalachian wildlife populations andhardmastsupplies and alsomay permitwildlife biologists to determine if effortsto reestablishthe Americanchestnut (Jaynes1978, Hebardet al. 1982) can furnish replacement or mitigating wildhfe benefits. Methods Pre- and postblighthard mastproductionwas estimated for a hardwood forest within control watersheds 14 and 18 in the Coweeta Basin, Macon County, North Carolina. The studyareais in the Blue RidgeProvinces, NantahalaMoun- tains,andwas selected because (1) the forestwastypicalfor the oak-chestnut region (Braun 1950) and (2) quantitative dataonpre-andpostblight forest composition wereavailable (USDA ForestService,CoweetaHydrological Laboratory, 1969, unpublished). The major humandisturbances in the studyareawere light semiannual burningandgrazingfrom 1842to 1900,andlogging between 1900and1923(Dayetal. 1988).The areahasremained largelyundisturbed by people since 1923andis managedby USDA Forest Service' sCoweeta Hydrologic Laboratory. Fora detailed ecological description of the CoweetaBasin,seeSwankandCrossley (1988) During1934,a 1km transect containing twenty-five 0 081 haplotswasestablished from a stream bottom(elevation722 196 SJAF24(4) 2000 Downloaded from https://academic.oup.com/sjaf/article/24/4/196/4793678 by University of Florida - Chiles Info Ctr user on 13 November 2024 m) to a ridgetop (elevation 960 m). Treeslargerthan 1.3 cm dbhweretalliedby species in 2.5 cm dbhclasses by Forest Service personnel. Duringthe 1934inventory, chestnut was still present, but dying from blight. For purposes of timber •nventory, all chestnut treesweretallied includingstanding deadtrees. The plotswerereinventoried 35 yr laterusingthe sameprocedure established in 1934 (USDA ForestService 1969,unpublished). For thisstudy, thebasal areaof eachhard-mast-producing species in 1934 and 1969 was determined. Becauseonly mature trees yieldmast,thebasal areaestimate onlyincluded trees at least 20.3 cm dbh. Annual hard mast output is highly variable for most species (Tryon andCarvell 1962, Beck 1977, Nixon et al. 1980).To account for thisvariability, mastproduction was esnmated for the studyareafor 10 consecutive years.Hard mastproduction wasnotdirectlyrecorded for theplotsin this study. Instead, mast production datafromstudies in forests of s•mdar composition were converted to basal area (kg/m 2) from studies andapplied to the plotsin the Coweeta Basin transect. Beck's (1977:5) production estimates of well-developed acornsby northernred oak (Q. rubra L.), black oak (Q. velutina Lam.), scarletoak (Q. coccineaMuenchh.), white oak(Q. albaL.), andchestnut oak(Q. prinusL.) wereapplied to boththepre- andpostblight plots.Beck'sestimates were selected because his studyarea was closeto the Coweeta Basra,the foresthad similarcomposition, andhad a long- term record(12 yr) of acornproduction.Acorn production esnmates fromthemiddle10 yr of Beck's(1977) study were used. Theaverage dbhof trees in Beck'sarea wasin themid- range of that of the trees in the 1934 and 1969 study. AdJustments in mast production werenotmadefor theslight d•ameter differences. Hickoryseed production wasestimated by applying of the findings of Nixonetal. (1980)thatwererecorded during a 65 yr period.This was the only known long-termstudyof h•ckoryseed production in the formeroak-chestnut associa- tlon.Boththepre-andpostblight inventories of theCoweeta forestrecorded hickoryby genusonly. However,Day et al. (1988)reported thatpignut hickory[C. glabra(Mill.) Sweet] isthedominant hickoryspecies in thisportion of theCoweeta Basin. Hence, onlyNixonet al.'s(1980)pignut hickoryseed production data were used. Because theduration of theNixon et al. (1980)study wasonly6 yr, theseed production datafor the first4 yr wereassumed to be similarto those of thelast4 yr of the 10 yr interval. Estimates of American chestnut seed yieldswereobtained from Diamond(1989:84-90).Theseestimates arebelievedto be the only onesof Americanchestnut seedproduction in forested environments. He used a reasonable combination of chestnut seedyield dataobtained from (1) publications re- portingcommercial chestnut (Castaneaspp.) orchard pro- duction, (2) individuals who harvest chestnutseedsfrom American chestnut orchards in MichiganandWisconsin, (3) measures of the bur cropof a largeoriginalsurvivor of the chestnut blightin Virginia, (4) interviews with peoplewho collected chestnuts in theSouthern Appalachians priorto the blight,and(5) annual chestnut seed harvests fromAmerican chestnut trees thatpresently growin beech-maple forests in Michigan(Table 1). Because Americanchestnut yielddatawereobtained from a variety of sources, we did not estimate Americanchestnut production by calculating meanannual yieldsfromthe five sources.Instead, the context of each data sourcewas used to narrowtherangeof values fromwhichannual yieldestimates couldbe selected (Diamond1989). This process led to the development of three annualproductionestimates---low, moderate, andhigh--thatoccurred at 3 yr intervals. Thefive sources did not providedatasuitable for additional refine- ment.Themoderate production ratewasapplied thefirstyear of the 10 yr interval,followedby high and low rates.This cycle was repeated threecomplete timesduringthe 10 yr interval. The mean and standard error (SE) were estimatedfor the totalproduction for the 10 yr period. Table 1. Notes from Diamond (1989:84-90) on available unpublished information on chestnut mast production. Commercial orchards Estimated age(yr) Kg/tree C. crematagraft Singletree Pennsylvania Pennsylvania C. rnollissirna Georgia Georgia Midwestorchards (C. dentam) Michigan Michigan Wisconsin Michigan Michigan-Wisconsin Appalachians Amherst (Virginia)open-grow (C. dentam) Appalachian elders (NorthCarolinainterviews) Michigan beech-maple forest Tree sizes: 30 cm dbh 61 cm dbh 90 cm dbh 2 0.5 12 6 17 63.5 27 1.87 10 5.2 70 45 130 39 >100 4 11.3 6-45.4 39-45.4 150 120 21.8 1-1.27 6-11.4 9.1-18.1 SJAF 24(4)2000 197 Downloaded from https://academic.oup.com/sjaf/article/24/4/196/4793678 by University of Florida - Chiles Info Ctr user on 13 November 2024 Results Hard Mast-ProducingBasal Area Americanchestnut wasthe dominant species capable of producing hard mastin the studyarea beforethe chestnut blight.It accounted for 58% of thebasin' shard-mast-produc- ing basalarea(nottotalbasalarea;see"Methods")(Table2). Other contributors to the basin'shard mastproducing basal area were chestnutoak (13%), scarletoak (10%), northern red oak (6%), blackoak (5%), hickories(5%), andwhite oak (2%) (Table2). Thesearegeneral statistics for thestudy area and standswere not uniform in speciesnumbersor site conditions. The limited datawere usedto generalize about approximate conditions, usually"potentials," because in any year oneor more species may fail to produce mast. In the postblightforest, the basal area of hard mast- producers declined by 28%, from 16.62to 11.89m2/ha (Table 2). The majorhard mast-producing species that re- placedchestnut werechestnut oak, scarlet oak,northern red oak, and black oak composing 31%, 25%, 18%, and 12%, respectively, of the hard mast-producing basal area. The basal area of hickories (9%) and white oak (5%) did not increase substantially. Red maple (Acer rubrumL.), sour- wood(Oxydendrum arboreum [L.] DC), andyellow-poplar (Liriodendron tulipferaL.) werethemajor,nonmast-produc- ing replacements. It is well knownthatthe annualproduction of forestmast variesgreatly.The treespecies listedaboveonly suggest the type of producers because thereis greatvariationin annual production of mastamong individual trees, eachwith itsown micrositeand susceptibility to frost, storms,insects,and disease andmoisture stress. From oneperspective, theforest structure sets the limits on hardmastproduction. Hard Mast-Production Estimate The hard mast production data (kg/m 2ofbasal area) that were appliedto boththe pre- and postblight forestvaried greatlyamongspecies andyears(Table3). Americanchest- nut wasthe moststableproducer. It hadno mastfailures,and lowproduction years (18.3 kg/m 2ofbasal area) were 48%of high production years (37.7kg/m2). Lackof mast failures waspartiallyattributed to Juneflowering,whicheliminated Table 2. Basalarea of hard mast-producing species* •n a Cowaeta Basin forest before and after chestnut blight epidemic. Species Preblight Postblight ......................... (m2/ha) ................. American chestnut 9.67 0.00 Hickories 0.75 1.11 White oak 0.41 0.56 Chestnut oak 2.21 3.67 Black oak 0.88 1.42 Scarlet oak 1.66 2.96 Northern red oak 1.04 2.17 Total 16.62 11.89 * Trees _>20.3 cm dbh. the opportunity for mastfailuresfrom springfreezesin the Southern Appalachians. In thislimiteddataset,highproduc- tionandlow production years occurred at3 yr intervals. Mast production by hickories waslowestof the seven species in this study, never exceeding 7 kg/m 2ofbasal area forthe10 yr period.White oaksproduced mastcropsgreaterthan30 kg/m 2ofbasal area every other year. High yields tended to occurat 4 yr intervals. Chestnut oakmastproduction did not exceed 0.5kg/m 2 of basal area for7 of the10yr.Bumper crops followedthe same 4 yr cycledisplayed by whiteoaks Black oak wasthe moststableoak mast-producer. Produc- tion never exceeded 27kg/m 2ofbasal area and was less than 1kg/m 2 ofbasal area for3 yr.Scarlet oak mast production was erratic. Annual output ranged between 5 and 75kg/m 2of basalarea.Therewere3 yr of complete mastfailures. North- em red oak produced the largestbumpercropsamongthe seven species, exceeding 300kg/m 2 ofbasal area one year Bumper cropstendedto occur at 5 yr intervals,with two moderate andtwo low-production yearsintervening. Weight may havelittle bearingon the nutritional valueof the mast that is produced. Digestionandmetabolism are affected by substances in themast(e.g.,tannicacid,Chung-MacCoubrey et al. 1997.) Preblight Hard Mast Output Whenthemast production data wereapplied totheprebhght forest (taking basal area of the various mast producing species intoaccount), the annual hardmastoutput for a 10 yr intervalvariedfrom 183.0to 737.8 kg/hawith a meanannual production of 423.7 kg/ha(SE = 59.41) (Table4). Therewas Table 3. Calculatedhard mast productionrates appliedto a Coweata Basinforest beforeand afterthe chestnutblight epidemic American White Chestnut Black Scarlet Northern Year chestnut* Hickories* oak** oakt* oak** oak** red oak** ................................................................ (kg filledseed/m 2of basal areaõ) ............................................................ 1 28 4 119 41 6 17 39 2 38 4 9 1 4 5 0 3 18 1 39 0 1 0 9 4 28 3 3 0 26 75 304 5 38 1 194 86 14 14 27 6 18 7 1 0 1 0 0 7 28 4 31 1 0 0 6 8 38 4 1 0 9 13 74 9 18 1 81 8 14 27 169 10 28 3 2 1 9 10 17 * Based on trees >_20.3 cm dbh. t Calculations based on Diamond (1989:84-90). tt Calculations based on Nixonet al. (1980); first4 yr studyapplied to bothfirstandlast4 yr of 10yr estimate. õ Calculations based on middle10yr of acorn production from Beck (1977). 198 SJAF 24(4)2000 Downloaded from https://academic.oup.com/sjaf/article/24/4/196/4793678 by University of Florida - Chiles Info Ctr user on 13 November 2024 Table4. Estimated hardmastproduct,on for a 10yearintarvalin a CowaetaBasin forastbeforethe chestnutblight epidemic. American White Chestnut Black Scarlet Northern Year chestnut* Hickories t oakt* oak** oak** oak** red oak*t Total ................................................................................... (kg/ha).................................................................................. 1 270 3 49 90 5 28 40 485 2 364 3 4 1 3 9 1 384 3 177 1 16 0 1 0 9 202 4 270 3 1 0 23 125 316 738 5 364 1 80 190 11 24 28 696 6 177 5 1 0 1 0 0 183 7 270 3 13 1 0 0 7 294 8 264 3 1 0 8 22 77 474 9 177 1 33 17 12 45 176 464 10 270 3 1 1 8 17 17 317 * Calculations based on Diamond (1989). t Calculations basedon Nixonet al. (1980); first4 yr of 6 yr studyappliedto bothfirstand last4 yr of 10yr estimate. tt Calculations basedon middle10 yr of acornproduction from Beck (1977). no apparent pattern in annual mastproduction fluctuations. The 2 yr of lowestproduction wereseparated by the 2 yr of highest production. Low production yearsoccurred when poorchestnut mastcrops coincided withmastfailures of at least threeof theoakspecies. Highproduction years occurred when either northern red oak or chestnut oak produced bumper crops. Duringthe10yr interval,American chestnut wasthedominant mast-producer, accounting for 64% of the total hard mastoutput.Americanchestnut contributed be- tween37 and96% of theannual mastoutput andwasthetop producer for 9 of the 10 yr. Northern redoakwassecond to the Americanchestnut (producing 16% of the total output) andwasthetopproducer in year4. Therelative contributions to thetotalhardmastoutputfor theremaining species were 7% for chestnut oak, 6% for scarletoak, 5% for white oak, 2% for blackoak,and 1% for hickories. Therewasonly a single yearin whichoneof these species produced morethan20% of the annual mastoutput (chestnut oakin year5). PostblightHard Mast Output Applicationof the hard mast production data to the postblight forestproduced annualyieldsthat fluctuated be- tween9.5 and924.5kg/haannually (mean = 279.8kg/ha;SE = 97.31) (Table 5). The only production patterndisplayed during the 10 yr intervalwasbetween years2 and7, when2 yr of lowproduction werefollowed by2 yr of highproduction that,in turn, werefollowedby 2 yr of low production. Low production yearsoccurred whenthe mastproduction of at least threeof thefive oakspecies wasless than5 kg/ha.High output years occurred wheneithernorthern redoak•or chest- nutoakproduced theirlargest mastcrop. Northern redoak produced 50%of themast crop during the10yr interval, 47% of whichwasproduced duringyear4, andwasthetopmast producer in years 4, 8, 9, and10.Relative contributions tothe total10 yr mastoutput were18%for chestnut oak,17%for scarletoak, 10% for white oak, 4% for black oak, and 1% for hickories. Preblight vs. PostblightOutput A comparison of totalhardmastproduction in pre-and postblight forests reveals thatthepreblight output wassig- nificantly greater andmorestable thanthepostblight output (Figure1). Total hardmastoutput declined 34% afterthe chestnut blightfroma meanannual output of 423.7 kg/hato 279.8 kg/ha.Postblight production waslessthanpreblight production for 8 of the 10 yr. Duringfive of these years, postblight production wasonly5-27% of preblight produc- tion. The 2 yr that postblight outputexceeded preblight output occurred onlywhen bumper crops werecoincident for northernred oak, scarletoak, and black oak. Preblightmastproduction was relativelystablewith a four-fold differencebetweenthe lowestand highestoutput years.Mast output in thepostblight forestfluctuated mark- edly(Figure1). Therewere4 yr whenmastproduction was Table 5. Estimatedhard mast productionfor a 10 yr interval in a Coweeta Basinforest after the chestnutblight epidemic. White Chestnut Black Scarlet Northern Year Hickories* oak* oakt oak* oakt red oak* Total ................................................................................... (kg/ha).................................................................................. 1 5 67 149 8 49 84 361 2 4 5 2 6 16 0 33 3 1 22 0 1 0 19 42 4 4 2 0 37 223 659 925 5 1 109 315 20 42 58 545 6 8 1 0 1 0 0 10 7 5 17 2 0 0 14 38 8 4 1 0 13 39 160 216 9 1 40 29 19 81 368 542 10 4 1 2 13 30 36 86 * Calculations basedon Nixon et al. (1980);first 4 yr of 6 yr study appliedto both first and last 4 yr of 10 yr estimate. t Calculations basedon middle10yr of acornproduction from Beck (1977). SJAF 24(4)2000 199 Downloaded from https://academic.oup.com/sjaf/article/24/4/196/4793678 by University of Florida - Chiles Info Ctr user on 13 November 2024 lOOO • Pre-blight • • Post-blight • 600 F- • 6oo o •- 400 •' 20o -r o I 2 3 4 5 6 7 6 9 lO YEAR Figure 1. Calculatad total hard mast production for a 10 yr interval in a Cowaata Basin forast bafora and approximataly 35 yr after tha chastnut blight apidamic. less thana 50 kg/haand3 yr whenit wasgreater than500 kg/ ha. There was a 97-fold difference between the lowest and highest output years. Discussion Themajorcauses of decline in thehardmastproduction of thepostblight forest were(1) a reduction in totalbasal areaof hardmast-producing trees, and(2) thelossof a stable, high- volume mast-producer, the American chestnut.Approxi- mately77%of thedecline in thepostblight forest' shardmast output canbedirectly attributed tothe28%reduction in basal areaof capable of producing hardmast. There may have beenchanges in canopydensity,espe- ciallyin thegaps resulting fromloss of chestnut trees. Beck' s (1977) data may reflectproduction from treeswith crown sizessimilarto thoseof the 1969 trees.Thus,usinghis data as a standard may slightlyoverestimate preblight mastpro- duction.Whateverdifferences theremay have been,we do not believethey are of sufficientmagnitude to change our conclusions. The remainingdecrease resulted from the re- placement of Americanchestnut by species (oaksandhicko- ries) with lower hardmastproductivity, bothquantityand quality,thanthe chestnut. The widerfluctuations of annual hard mastproduction in the postblight forestthan in the preblightforestwere entirely due to the replacement of a relativelystable hardmast-producer (American chestnut) by a mix of species thatproduce hardmast crops withconsider- able annualvariabilityand lessfood value. Our findings indicate thatdespite the replacement of Americanchestnut by predominantly hardmast-producing species, the abun- dance, quality, andstability of hardmastcrops havesubstan- tially declinedin Southern Appalachian forestssincethe chestnut blight. Management Implications Hard mastis an integralcomponent of the diet of numer- ouswildlifespecies in theSouthern Appalachians, including white-tailed deer(Odocoileus virginianus Zimmerman), black bear (Ursus americanus Pallas), wild turkey (Meleagris gallopavo Vieillot), gray squirrel (Sciurus carolinensis Gmelin),andruffedgrouse (Bonasa umbellus Lineaus). Hard 200 SJAF 24(4)2000 mastfrolures s•gmficantly reduce product•wty andincrease mortalityfor mostof thesespecies (Segelquist et al. 1969, Nixon et al. 1975,Rogers1976,Eiler et al., 1989,Eloweand Dodge 1989). Our findings indicate thatin recent timebeforethechest- nutblight,totalmastfailuresprobably did not occur.Of the seven majorhardmast-producing species in thisstudy, only the Americanchestnut consistently produced a substantial mast crop. Thiscapacity, coupled withAmerican chestnut' s dominance in the preblight,Southern Appalachian forest, eliminated the potentialfor both mastfailuresandthe low- mastproduction yearsthatarecommon in Southern Appala- chianforests today.Shaw(1971,p. 87) maintained that112 kg/haof hard mast wasadequate forforest wildlife.We found thatthehardmastoutput of thepostblight forest wassubstan- tiallybelowthislevelfor 5 of 10yr whilethemast production estimates for thepreblight forest wereneverlessthan183kg/ ha. Hence, the loss of matureAmericanchestnuts likely significantly reduced the Southern Appalachian forest'scar- ryingcapacity for certain wildlifespecies. Effortsto develop blight-resistant Americanchestnuts (seeJaynes1978) and hypovirulentstrainsof the chestnut blight (Hebard et al. 1982), and to promotetimberharvesting regimesthat con- servechestnut stump sprouts (Griffin 1989)may,therefore, have particular relevance for, and deserve the support of, forestryandwildlife professionals. Literature Cited ARENDS, E., AND J.F.McCoRMICK. 1987.Replacement of oak-chestnut forests in the Great SmokyMountains. P. 305-316 in Proc. of the Central Hardwood For. Conf. VI, R.L. Hay, et al. (eds.).418 p. BECK, D.E. 1977.Twelve-year acorn yield in Southern Appalachian oaks USDA For. Serv. Res. Note SE-244. 8 p. BRAUN, E.L. 1950. Deciduousforestsof easternNorth America. The Blalaston Co., Philadelphia, PA. 596 p. CHUNG-MAcCOUBREY, A.L., A.E. HAGERMAN, ANDR.L. KIRKPATRICK. 1997 Effects oftannins ondigestion and detoxification activity in graysqmrrels (Sciurus carolinensis). Physiol. Zool. 70(3):270-277. DAY, F.P., JR.,D.L. PmLLIPS, AND C.D. MONK.1988. Forestcommunities and patterns. P. 141-149 inForesthydrology andecology atCoweeta. Swank, W.T., andD.A. Crossley, Jr.(eds.).Springer-Verlag, New York. 349 p D•AMOND, S.J.1989.Vegetation, wildlife, andhuman foraging in prehistoric Western Virginia.M.S. Thesis, VirginiaPolytech. Inst.andState Umv, Blacksburg, VA. 239 p. DOWNS, A., ANDW.E. MCQUiLKrN. 1944. Seed production of Southern Appalachian oaks.J. For. 42:913-920. EILER, J.H., W.G. WATHEN, AND M.R. PELTON. 1989.Reproduction in black bears in theSouthern Appalachian Mountains. J.Wildl. Manage. 53:353- 360. ELOWE, K.D., AND W.E. DODGE. 1989.Factors affecting blackbearreproduc- tive success andcubsurvival. J. Wildl. Manage. 53:962-968. GmF•N,G.J. 1989. Incidence of chestnut blight and survivalof American chestnut onforest clearcut andneighboring understory sites. PlantD•s 73:123-127. HEBARD, F.V., G.J. GRIFFIN, ANDJ.R. ELKINS. 1982. Summaryresearch on biologyof hypovirulent and virulentEndothia parasiticaon bhght resistant andblightsusceptible chestnut trees at VirginiaPolytech. Inst andStateUniv. P. 49-67 in Proc.USDA For. Serv.Am. Chestnut Coop Meet., Morgantown, WV. 152p. I•acK, J.S. 1921.Replacement of thechestnut. J. For. 19:105-114. JA•mS,R.A. 1978.Selecting andbreeding blightresistant chestnut treesP 4-6 in Proc.of the Americanchestnut symp.,MacDonald,W.L., et al (eds.). WestVirginiaUniv. Books, Morgantown, WV. 122p. JOHNSON, G.G., AND S. WARE.1982. Post-chestnut forestin the centralBlue Ridgeof Virginia. Castanea 47:329-343. KAR•AN, R. 1978.Changes in anoak-chestnut forest since thechestnut bhght Castanea 43:221-228. Downloaded from https://academic.oup.com/sjaf/article/24/4/196/4793678 by University of Florida - Chiles Info Ctr user on 13 November 2024 KEEVER, C. 1953. Present composition of somestands of the formeroak- chestnut forest in thesouthern BlueRidge Mountains. Ecology 34:44-54. KORSTIAN, C.F., AND P.W. ST•CKEL. 1927.The natural replacement of blight- killed chestnut in hardwood forests of the Northeast. J. Agric. Res. 34:631-48. IVI•cr•Y,H.E., JR., AND N. S•v•c.1973.Thepresent composition of a former oakchestnut forest in theAllegheny Mountains of western Pennsylvania. Ecol. 54: 915-919. McCo•Ic•c, J.F.,• R.B. PL^vr.1980.Recovery of anAppalachian forest following thechestnut blight orCatherine Keever--You were right ! Am. Midl. Natur. 104:264-273. NELSON, T.C. 1955.Chestnut replacement in thesouthern highlands. Ecology 36:352-359. N•XON, C.M., M.W. McC•aN, •/)R.W. DONOHOE. 1975.Effects of hunting - and mast crops ona squirrel population. J.Wildl.Manage. 39:1-25. N•XON, C.M., M.W. McCI•^IN, • L. P. HANSEN. 1980.Six years of hickory seed yields in southeastern Ohio.J. Wildl. Manage. 44:534-539. RO•ERS, L. 1976.Effects of mast andberrycropfailures onsurvival, growth, andreproductive success of blackbears. Trans.N. Am. Wildl. Conf. 41:431-438. SEGELQUIST, C.A., F.D. WARD, AND R.G. LEONARD. 1969.Habitat-deer rela- tions in twoOzarkenclosures. J. Wildl. Manage. 33:511-520. SHAW, S.P.1971.Wildlifeandoakmanagement. P. 284-299in Oaksymp. proc.USDA For. Set.,Northeast. For.Exp. Stn. 161p. STEPHENSON, S.L.1974. Ecological composition ofsome former oak-chestnut communities in westem Virginia.Castanea 39:278-286. STEPHENSON, S.L. 1986.Changes in a formerchestnut-dominated forest after a half century of succession. Am. MidlandNatur.116:173-179. STEPHENSON, S.L., H.S. ADAMS, AND M.L. LIPFORD. 1991. The present distri- bution of chestnut in theupland forestcommunities of Virginia.Bull. Torr. Bot. Club.118(1):24-32. SWANK, W.t., AND D.A. CROSSLEY, JR.(EDS.). 1988.Forest hydrology and ecology atCoteeta.Springer-Verlag, New York.329 p. TRYON, E.H., AND K.L. CARVELL. 1962.Acornproduction anddamage. West VirginiaUniv.Agric.Exp.Sta.Bull.466T,Morgantown, WV. Woo/)s,F.W., AN/) R.E. SHA•KS. 1959.Naturalreplacement of chestnut by otherspecies. Ecology40:340-361. SJAF 24(4)2000 201 Downloaded from https://academic.oup.com/sjaf/article/24/4/196/4793678 by University of Florida - Chiles Info Ctr user on 13 November 2024