FENCEROW AND FOREST EDGE ARCHITECTURE IN EASTERN ONTARIO FARMLAND

In landscapes of fragmented forest, fencerows and similar linear patch es of vegetation may provide movement corridors for woodland plants if they connect matching habitats. This will be expected where fencerow architecture has developed as a structural or functional extension of woodland, and thus offers low resistance to plant movement. A comparis on was made of several architectural components of fencerows and fores t edges to determine whether fencerows extend forest remnants structur ally into the surrounding agricultural matrix. Horizontal foliage dens ity and foliage profile diversity were greater in fencerows than in fo rest edges. Main contributors to the difference detected between edge types were greater frequencies of vines, trees and grasses in fencerow s. Large trees were clustered at fencerow centres, but showed a polyno dal distribution across forest edges. In fencerows, greater tree stem diameter and stem and branch frequencies resulted in infrequent and sm aller sub-canopy gaps there relative to those in forest edges. Several individual elements (shrub density, the size and condition of coarse woody debris, rock size) were not detectably different between edge ty pes, but the combination of these elements contributed to significantl y greater architectural diversity in fencerows. The spatial distributi on of architectural elements across edge widths indicated qualitative differences between edge types, It is concluded that habitat qualities that result from the architectural differences between fencerows and forest edges may constrain plant movement along fencerow corridors bet ween isolated forest patches.