Haynes, K. J. and J. T. Cronin. 2006. Interpatch movement and edge effects: the role of behavioral responses to the landscape matrix. Oikos 113: 43-54.
ABSTRACT
Few studies have examined how the composition of the matrix, intervening habitat between suitable patches, influences movement behavior. We examined movement characteristics of the planthopper Prokelisia crocea in host-plant habitat (prairie cordgrass, Spartina pectinata) and two matrix habitats (mudflat and monoculture stands of exotic smooth brome, Bromus intermis) , known to result in different rates of inter-patch dispersal. Movement behavior was strongly influenced by matrix composition. Planthoppers dispersed through the mudflat matrix 10 times faster than through cordgrass or brome (as measured by median net displacement rate), initiating movement quickly and moving in a linear fashion with high velocity. In addition, a study examining movement behavior at patch edges revealed that edge permeability is matrix dependent. While the cordgrass-mudflat edge is relatively impermeable to emigration, planthoppers drift freely out of cordgrass patches bordered by brome. The low permeability of the cordgrass-mudflat edge may explain why planthoppers accumulate against the edges of cordgrass patches embedded in mudflat but not brome. Also, the low permeability of mudflat edges may retain planthoppers on these patches and explain why these patches maintain higher population densities and are at lower risk for extinction. The higher connectivity of local clusters of cordgrass patches embedded in the brome matrix may result from slow, circuitous movement through the matrix promoting high patch encounter rates. The high permeability of cordgrass patches to emigration loss created for patches embedded in a matrix composed of exotic smooth brome is predicted to decrease the stability of planthopper metapopulations.
Keywords: Connectivity · edge effects · dispersal · metapopulation · movement behavior
