Landscape-scale consequences of patch-scale invasion success or failure

Title	Landscape-scale consequences of patch-scale invasion success or failure
Publication Type	Conference Paper
Year of Publication	2002
Authors	Peters DC
Conference Name	US-International Association for Landscape Ecology
Date Published	April 23-26, 200
Conference Location	Lincoln, NE
ARIS Log Number	140892
Abstract	Shrub invasion into perennial grasslands has occurred throughout many arid ecosystems in the US and abroad. Although various factors contributing to invasion have been well studied, there is little understanding of the spatial variation in shrub success into different plant communities. The objective of this study was to examine differential invasion success by the shrub, creosotebush, into grasslands dominated by different species. The study was conducted at the Sevilleta LTER site in central New Mexico, USA, where the landscape consists of a mosaic of patches and ecotones between several grass and shrub species. Sampling was conducted by geo-referencing the location of all shrub plants within patches dominated either by blue grama, a dominant species in the shortgrass steppe, or by black grama, a dominant of the Chihuahuan Desert. Vegetation was sampled within and outside of each shrub patch. Results show that creosotebush-black grama ecotones are diffuse, consisting of a complex mosaic of grasses and shrubs. By contrast, ecotones between creosotebush and blue grama are distinct with very few shrub plants found within patches dominated by blue grama. Consequences of these patch-scale interactions for landscape-scale patterns in shrub invasion and grass resistance are discussed.