Correlations among stand ages and forest strata in mixed-oak forests of southeastern Ohio

摘要: Many models of landscape ecosystem development, as well forest stand dynamics, are based upon spatial and temporal changes in the species composition structure various strata. However, few document interrelationships among strata, or response different strata to alterations natural disturbance regimes. To examine how relationships varied with age, we sampled a chronosequence (five age classes) 21 second-growth (70 149 years old) old-growth (=150 mixed-oak stands from single type within ecological classification system framework for Wayne National Forest. All woody stems were measured by dbh species, classified into these lifeform: (1) canopy (dominant, codominant, intermediate crown classes); (2) saplings (stems 1.37 m tall potential); (3) subcanopy without (4) seedlings < potential). Canonical correspondence analysis (CCA) was used summarize compositional variation each class. correlation then interrelatedness using CCA axis scores. ordinations revealed several trends, primarily that site differences important factors constraining development Although there no significant between sapling strong seedling These canopy, sapling, also strongly correlated their canonical variables, suggesting is responding similar gradients. We suggest regimes study area have been altered, result, compositions southeastern Ohio modifications. Whereas primary landform effect regulating prior European settlement likely pattern surface fires, on frequency geometry fires has diminished fire suppression efforts.