Functional groups of rare plants differ in levels of imperilment

Elizabeth J. Farnsworth, Danielle E. Ogurcak
2008 American Journal of Botany  
Comparative examination of a large sample of plant species can reveal important aspects of life history that infl uence the ecology and distribution of taxa and their vulnerability to local extinction. We investigated whether functional groups of 71 rare plant species with contrasting life history traits differed in terms of population losses over time, regional range contraction, and rangewide levels of imperilment. Using town-level occurrence data from herbaria and Natural Heritage Program
more » ... abases, we characterized species ' extents of occurrence as α -hulls encompassing the centroids of New England towns that contained well-documented populations of these rare taxa. Family affi liation was used as a covariate in analyses to reduce phylogenetic bias. Disparate functional groups of plants differed both in proportions of populations lost and declines in range areas over time, with insect-pollinated taxa, upland (vs. wetland) taxa, species with localized seed dispersal modes, and taxa reaching their northern range boundary in New England signifi cantly more imperiled than other functional groups. These techniques permit a broad comparative assessment of the distribution of large numbers of plant taxa, so that we can identify several functional groups that warrant more concerted conservation attention.
doi:10.3732/ajb.0800013 pmid:21632417 fatcat:uv6mnjcnw5bqlojhllscsxlnum