Microhabitat requirements of the federally endangered Dalea foliosa, with recommendations on establishment of new populations.

摘要

The microhabitat of the federally endangered Dalea foliosa in Tennessee, USA, was compared to that of its cedar glade congener D. gattingeri, as well as to adjoining habitats absent of both species but appearing suitable for D. foliosa (control site). Compared to D. gattingeri sites, the D. foliosa sites had lower coverage of gravel, higher coverage of herbaceous vegetation, and deeper soils. Both species were present on sites with similar leaf litter and moss coverages. Nostoc commune was absent from D. foliosa populations, but present in most D. gattingeri populations. In terms of soil depth and coverage variables, control sites differed little from D. foliosa sites. The coverage of D. foliosa was negatively correlated with that of associated (neighbouring) species. No appreciable differences in soil fertility were noted among sites. New populations of D. foliosa should be established in areas relatively free of competition, exposed to full or partial sunlight, with soil depths >4 cm, and near washes..