Successional changes in plant species diversity and coniposition after clearcutting a Southern Appalachian watershed

Water&xi 7, a southwest-fiicing wZi@&EdiIltheCaweetaBasin, weitemNorthCaroliia,USA,wasckarcntin1977. Twenty-four permanent plots were invenmrkd in 1974 before cutting and in 1977,1979,19&t, and 1993 afker clearcutbg. Thisstodyeval~changesinspeciesdiversitydurlnge.srlysucceszn ~onkter -g and cliffinoverstorytree aadgroundnorarespwsetodisMtnmcebycleaccattingandtheir~~~wi~~~~ancesandsubseqnent stand developmem To why specie8 d+$ty, we compu@d Sham~on-Weaverb index of divexsity (R’) aud P&m’s evv index (7). Woody specks diversity rema$ed relatively stable; however, woody species richness &aeased in the cove-hattlwoods and ilaKlwwd-pines, hut llzmaid relatively consult in the mixed~haIdwoods. Althtjltgh nwegetati0~ wasrapidfarestcompositionhaschangeddnoaghsaccession,~qpecies,suchasn~~~ Robiniapseudoacacia,andAcerRcbnan,incnasedinabnndance,whereasQ~velutina,Cmyasmp,andQ.rubm decreased. Ground flora diversity decdhed in the cove-hsrdwoods and mixed-oak hardwoods commuities, but the decreas in the hardwood-pines was not significant. The abundance (s hiomass rn? of ground flora was mnch lower in 1993 than in. 1984,79% less in the cove-hardwoods, 90% less in the mixed-oak hazdwoods, and 79% less in the hardwood-&es. Watenhed7isapparemlyisaeansitionstate~~~yand~successionatspecies abmbce. Barly stlccessionall shade-mtokrant species, such as Erechrites, SWdizgo, Euparorium,‘Pmrinun, and Aster, have declined, whereas late successionat, shade-tokmmt species, soch as pk Gcdium smrguinmia, Uvulaiia, and Vemmmt are not yet well established. -,. -., ~ .-. mo&2 staad ds ;Hehacmsimdwoodyfkna;Dismhcc