Acer pensylvanicum and Castanea dentata had the greatest number of stems in the TS plot (27% and 23% respectively).
Only three species, Acer pensylvanicum, Tsuga canadensis, and Amelanchier arborea had recruitment into the tree size class on the TS plot (Fig.
QUERCUS SEEDLING ABUNDANCE, ACER PENSYLVANICUM ABUNDANCE, AND LIGHT AVAILABILITY
There was a statistically significant, weak, negative relationship between the basal area of Acer pensylvanicum and canopy closure in both the MLBS plot (Spearman's [rho] = -0.
In particular, Acer pensylvanicum has dramatically increased in abundance in the understory, while the majority of other species have declined.
In 1983-1984, the TS plot may have been successionally more advanced with lower light levels than the MLBS plot, because individual trees had a larger basal area and Acer pensylvanicum (a shade tolerant understory tree) was already more abundant in the TS plot than on the MLBS plot (Tables 1 and 2).
On the other hand, Acer pensylvanicum had increased more than any other species both in numbers and in basal area (Figs.
Seedlings in stand 5 were mostly Acer pensylvanicum, and they were abundant in only one of the five sample years.
These can be less than 5% for Acer rubrum and Tsuga canadensis in New Hampshire (Graber and Leak 1992) and Tilia americana in Wisconsin (Godman and Mattson 1976) and range from 5-70% for Acer pensylvanicum, A.
At 12 random locations ([greater than]10 m from any transect) in the blowdown, we located the nearest five stems each of Betula, Fagus, and Acer pensylvanicum that were over 2 m tall.
Neither Acer pensylvanicum nor Acer rubrum percent cover differed between habitats (Table 2).
In contrast, densities of Fagus and Acer pensylvanicum were low in 1986 but remained relatively constant throughout the study period [ILLUSTRATION FOR FIGURE 1B, D OMITTED].
Betula, Fagus, and Acer pensylvanicum seedlings larger than the median height in 1987 survived better than those smaller than the median (e.
By 1991, the order had changed, due to fast growth of Acer pensylvanicum and Betula [ILLUSTRATION FOR FIGURE 5A OMITTED].
Relative abundance in 1991 of the 1987 "cohort" was greatest in Acer pensylvanicum (94.