Ecology of Carex blanda throughout a woodland/grassland ecotone: a small-scale study of a woodland species in heterogeneous environments

Abstract

Research on a species' distribution and demography across an ecotone provides a population ecology perspective to the study of ecotones. This study focused on the small-scale distribution of a woodland sedge species (Carex blanda) across the heterogeneous environment of a woodland/grassland ecotone in eastern Kansas, USA. Four methods of study were used: observation of naturally occurring plants; a field experiment that focused on the traits of woodland plants when transplanted in woodland, edge, and grassland habitats; a growth chamber experiment where plants from three habitats (woodland, edge, grassland) were grown in high and low light levels; and a herbarium survey of the habitats in which these plants are found in Kansas. In response to different environments, plants showed phenotypic plasticity in morphology and varied in disease incidence. Plants in high light environments were short, broad, produced more seeds, and had lower incidence of rust and smut diseases; those in low light were tall, narrow, produced less seeds, and had disease incidence. Plants growing in the edge habitat, the environment between the high and low light environments, had a mix of morphologies and traits of the other two habitats. Although this species is primarily reported in woodland habitat in eastern North America, results at this study site suggested populations can also persist in open grasslands.