Spatial Interaction Webs in Ozark Glades

This research takes a metacommunity approach to understanding variation in the diversity and abundance of species that interact with focal plant species, and a demographic approach to understand the effects of those interactors on the persistence and population growth of that focal plant species.   Our study system, Ozark dolomite glades, represents an ideal system in which to study metacommunity interaction webs.  Glades are small but variable (0.5-50 ha) openings within forested ecosystems where the soil layer is thin due to surface rocks, and herbaceous plants and their associated fauna dominate the plant community.  Glade flora are typically similar to grassland and prairie species, but many are endemic to glades.  Glade fauna include mammals, birds, and arthropods typical of Midwestern grasslands, as well as some species that are glacial relicts more typical of the desert-like conditions of the southwest, such as scorpions, tarantulas, and Collared lizards (Crotophytus collaris).  As herbaceous ‘islands’ within a forested ‘sea’, glades are sometimes isolated from each other by great distances, but often exist as regional complexes (metacommunities) where individual glades vary in size and distance from each other.  In addition to providing an excellent natural system in which to explore interaction webs in metacommunities, glade ecosystems are the focus of an intensive restoration effort following the encroachment of cedar trees due to fire suppression.  As such, our studies on the role of space in species interactions will provide a framework on which to base these restoration efforts. 

This research is a collaboration with my colleague (and wife) Tiffany Knight (currently a postdoctoral associate at the University of Florida , and soon to be a postdoc at NCEAS).  Although preliminary, so far we have found that in both larger glades and in glades that are closely linked to other glades, the diversity and abundance of competitors, herbivores, and pollinators is higher than in smaller and more isolated glades.  In addition, we have found that insectivorous lizards in these grasslands can sometimes have large effects on their grasshopper prey which may cascade to plants. 

Grasshopper in Glade

Missouri Evening Primrose

Glade Metacommunity