EEB Seminar: November 28th 2013

Dianthus carthusianorum (sheep food)

Yessica Rico will give a talk entitled

Does traditional management by rotational shepherding supports landscape connectivity in fragmented calcareous grassland plants?

at 12:30 in the EEB Lounge

Understanding the mechanisms and patterns of dispersal and gene flow in human-modified landscapes is crucial for effective conservation. In plants, seed dispersal is fundamental for recolonization and recruitment, whereas pollen flow and seed dispersal support gene flow. Calcareous grasslands are one of the most species-rich habitats in Central Europe, but abandonment of traditional management since the 20th Century has caused a dramatic decline of calcareous grassland species. In the Southern Franconian Alb in Germany, the establishment of a landscape management project since 1989 by reintroduction of rotational shepherding in previously abandoned calcareous grasslands showed numerous plant recolonizations, and it has been suggested that sheep acts as the main dispersal vector. To test the effect of rotational shepherding on landscape connectivity, I tested competing models of different assumptions on source patch effects, seed dispersal, and accounting for postdispersal effects. I found that patch colonization rates at the community level (aggregate data for 48 plants) was explained by patch connectivity by rotational shepherding and the diversity of microsite in focal patches related to plant establishment. Landscape connectivity models of individual species showed that even plants without dispersal adaptations to animals responded mainly to connectivity by shepherding. In addition, I investigated the potential effect of shepherding on landscape genetic structure in the calcareous grassland plant Dianthus carthusianorum, whose seeds lack morphological adaptations to dispersal to animals or wind. The genetic data showed a significant pattern of landscape genetic connectivity among grazed patches associated to shepherding routes, while ungrazed patches strongly responded to isolation by geographic distance. Also within individual patches, I found that grazing significantly decreases kinship structure and increases genetic diversity. The ecological and genetic data thus show the potential effect of traditional management by rotational shepherding on landscape connectivity in fragmented calcareous grassland plants.

Yessica Rico

Yessica Rico is currently a Postdoctoral Researcher  at the Natural Resources DNA Profiling and Forensics Centre at Trent University. She did her PhD with Helene Wagner in Ecology and Evolutionary Biology, University of Toronto at Mississauga

Everyone is Welcome to Attend the seminar

Coffee and Cookies right after the talk

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