In order to look for significant differences between the frequency of occurrence of A. altissima along the perimeter and in stands of different ages and plots of different aspect the chi-squared test was used.
Smaller understory A. altissima stems are more abundant than canopy trees and abundance decreases for each larger size class (Table 1).
The frequency (number of transect plots with A, altissima divided by the total number of transect plots) of A. altissima throughout the woodlot is 13.5%.
The number of stems and basal area of A. altissima were negatively correlated with distance from the woodlot edge (p [less than or equal to] 0.01) (Table 3, Fig.
The range of ages of the cored trees suggested that A. altissima has gradually established itself within the canopy over the last 20 to 60 years.
Annual survivorship from 2001 to 2002 for all A. altissima found in the O1, O2, and S2 plots combined was 41.9%.
The oldest A. altissima in the woodlot appears to be the 59-year-old canopy tree in the S2 macroplot.
The two secondary growth stands were once fields, habitats easily colonized by pioneer species like A. altissima (Rabe and Bassuk 1984; Miller 1990; Facelli and Pickett 1991; DeMars and Runkle 1992; Kowarik 1995; Knapp and Canham 2000).
Even though the secondary growth stands were probably where A. altissima first invaded the woodlot, they do not differ from the old growth stand in terms of A.
While presence of A. altissima did not differ between the secondary and old growth stands, it did differ between woodlot perimeter and interior.
While A. altissima can occur both along the woodlot perimeter and within the interior, the number of stems of A.