Variation in Plant Distributions, Plant Traits and Disease Levels across a Woodland/Grassland Ecotone

The ability of species to establish and persist in multiple habitats is of increasing importance given ecotone shifts following climate change. We examined a sedge (Carex blanda) that primarily occurs in woodlands in Kansas but is reported at low frequency in grasslands. At a Kansas, USA site, we found C. blanda occurred at similar densities across woodland, edge and grassland habitats. Plants differed in morphology: grassland plants were often broader and shorter than woodland plants. We transplanted cloned woodland plants into woodland, edge and grassland habitats. Transplanted plants developed similar height to naturally occurring plants, showing a plastic response. Further, seed number per plant was highest for woodland plants transplanted to grasslands. Both naturally occurring and transplanted plants growing in the grassland also had low disease incidence, suggesting that pathogen presence is affected more by habitat than plant origin. Since light differed greatly among the habitats, we grew cloned plants from each habitat in low and high light in a growth chamber. Regardless of origin, high light plants were broader and shorter than plants growing at low light, again illustrating plasticity. Finally, we examined herbarium records. Ninety percent of Kansas specimens occurred in woodland or edge habitat. Although collection biases are possible, these results suggest a primarily woodland habitat of this species in Kansas. Our results showing “woodland” plants thriving in grasslands illustrates the broad adaptability of this species and raises cautions on simplistic interpretations of habitat distributions.