CORRELATION BETWEEN ATV TRACKS AND DENSITY OF A RARE PLANT (DROSERA FILIFORMIS) IN A NOVA SCOTIA BOG

摘要

We examined the distribution of Drosera filiformis (thread-leaved sundew) in one of only five bogs in southern Nova Scotia where it is known to occur in Canada, to verify anecdotal observations that the plant grows most abundantly in water-filled rutscreated by all-terrain vehicles (ATVs). The distributions of D. filiformis, ATV tracks, standing water, and a variety of common bog plants were measured using transects of 3 m, 30 m, and > 100 m length. At the > 100 m scale, density of D. filiformis wassignificantly correlated with ATV tracks and standing water or wet peat. At the 30 m scale, 70.7% of quadrats that intercepted an ATV track also contained one or more individuals of D. filiformis; the species was negatively associated with woody plants,but positively associated with Eriophorum virginicum L. (tawny cotton-grass), which also prefers wet depressions. At the 3 m scale, significantly more D. filiformis were counted within water-filled ATV tracks than on the drier, undisturbed Sphagnum around them. Moderate and dispersed ATV traffic, sufficient to depress the peat layer without displacing the Sphagnum, evidently creates microhabitat for D. filiformis.