Document: MAR-3-40-36

Understory plant communities of naturally and artificially regenerated forests, southern New Brunswick, Canada.

RAMOVS, B.V.* and M.R.ROBERTS

University of New Brunswick, Fredericton, NB, Canada ¹

Abstract:
Understory vascular plant composition in maturing spruce plantations originating from farmland (oldfield plantations) and harvested land (cutover plantations), is compared to young (27-66 years) and mature (77-100 years) naturally regenerated forests. Abundance (percent cover) of each species was measured using 1m by 1m quadrats. Patterns in species composition was assessed using correspondence analysis. Richness and abundance of species requiring primarily forest or disturbed habitats were compared among treatments. Correspondence analysis explained 41% of variation in the first three axes. Axis 1 (15.9%) partitioned the two plantation types and was characterized by early seral species. Axis 2 (14.1%) divided natural stands according to overstory composition and was characterized by interior forest habitat species. Average richness of forest habitat species was greatest in mature natural stands (R=24), intermediate in young natural stands (R=19) and cutover plantations (R=17), and lowest in oldfield plantations (R=8). Natural stands contained greatest cover and frequency of forest habitat species, while cutover plantations contained greater cover and frequency of disturbed habitat species. Oldfield plantations contained the least cover and frequency of both species types, displaying a community different from the other treatments. Understory composition is substantially altered in oldfield plantations, with little recovery of forest species. Composition of cutover plantations is similar to young natural stands but shows little convergence with mature natural stands. Modification of plantation management is required to maintain levels of understory forest habitat species.

Keywords: understory plant community, natural regeneration, plantations, clearcut harvesting, farmland, disturbance, forest habitat species, biodiversity, correspondence analysis

This abstract is being presented at: 3:30 PM in session:
Poster Session #17: Vegetative Analysis.