Clonal diversity in an expanding community of arctic Salix spp. and a model for recruitment modes of arctic plants

Background/Question/Methods   Rapid climate change in arctic environments is leading to a widespread expansion in woody deciduous shrub populations. However, little is known about the reproductive, dispersal, and establishment mechanisms associated with shrub expansion. It is assumed that harsh environmental conditions impose limitations on plant sexual reproduction in the Arctic, such that population survival and expansion is predominately a function of clonal recruitment. Clonal diversity in an expanding community of Salix Spp. was sampled using molecular genetic markers.

Results/Conclusions   We present microsatellite data suggesting the prevalence of recruitment by seed. Further, we present a conceptual model describing modes of recruitment in relation to the abiotic environment. While there is currently little information on timing, duration and cues leading to recruitment in arctic plants, climate change may be alleviating abiotic stress so that resources are available for more frequent recruitment by seed. Such changes have dramatic implications for ecosystem structure and functioning, including species composition, wildlife habitat, biogeochemical cycling, and surface energy balance.