Tree diversity in 30-year chronosequences of cool-humid forests

摘要: Abstract Tree data collected in four inventories of twelve permanent sampling plots during 30 years were analyzed to determine what extent the abundance ubiquitous balsam fir ( Abies balsamea ) drives tree diversity mixed stands Eastern Cape Breton Island, Canada. Dominant deciduous species comprised yellow birch Betula allegheniensis ), sugar maple Acer saccharum and American beech Fagus grandifolia ). richness ranged from 2 6. The Shannon–Wiener index indicated that high proportion decreased H ’) structural evenness J ’). basal area ratio for year over 1 provided an resilience R forest subject natural self-thinning epidemic insect infestations. There was no significant effect admixture on since losses due decline offset within 30-year period largely by hardwood increases. Stand dynamics however, structurally stratified low -values low-diameter trees. indices ’, are recommended assessing naturalness apparent function large trees forests richness.