Development of mixed-oak forests in southeastern Ohio: a comparison of second-growth and old-growth forests

摘要: Abstract Traditionally, studies of forest development have independently focused on the compositional and structural differences second-growth old-growth forests. However, few attempted to use current ecosystems as a benchmark with which compare composition, structure, dynamics surrounding matrix sequentially aged In order examine mixed-oak forests we compared stand seventeen relatively undisturbed (70–149 years old) four (at least 150 south-facing ecological landtypes (ELTs) in southeastern Ohio. All living dead trees over 10.0 cm dbh coarse woody debris mid-diameter were inventoried 500-m 2 plots. Saplings seedlings sampled nested 100-m 2-m subplots, respectively. Principal components analysis (PCA) was used support assumption that study sites had similar soils physiography. Overstory species richness greatest younger stands, significantly differed among age classes. Five oaks ( Quercus spp.) dominated overstories all stands. white oak alba L.) canopy importance value (IV) ((relative dominance + relative density)/2) stands; it ranged from 35.5% stands 70–89 old 86.1% 130–149 old, while comprised 46.5% canopies. Pignut hickory Carya glabra (Mill.) Sweet.) IV tended be less than Whereas they almost absent sapling layer (less 5% total densities). The layers classes shade-tolerant species. For example, American beech Fagus grandifolia Ehrh.) density between year (6.3%) at (23.9%). Even though densities saplings low, much greater, suggesting adequate advance regeneration. Few significant structure (e.g. basal area, density, mean diameter, closure) or standing fallen detected Detrended correspondence analyses (DCA) appeared represent gradient increasing age. Although indices attributes proven successful discriminating other regions North America, our results suggest such an index would not work well Canopies by mixture oaks, conjunction majority individuals may best indicators conditions