Author
Peters, Debra | |
YAO, JIN - New Mexico State University |
Submitted to: Ecosphere
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 12/21/2011 Publication Date: 3/30/2012 Citation: Peters, D.C., Yao, J. 2012. Long-term experimental loss of foundation species: consequences for dynamics at ecotones across heterogeneous landscapes. Ecosphere. 3(3): Article 27. Interpretive Summary: Our objective was to use long-term data (>13 years) to examine patterns in dominance and community composition following the experimental removal of one of three foundation species at an arid - semiarid biome transition zone. Dominant species removals from 3m x 4 m plots were conducted annually in communities with a single dominant species, and in ecotonal communities with two dominant species across two types of ecotones (semiarid grassland- arid grassland, arid grassland-arid shrubland). Responses depended on characteristics of the recovering species and micro-environmental conditions that affected their recruitment and survival rather than legacies of the foundation species removed. Widespread loss of foundation species is expected to result in an increase in landscape-scale vulnerability to environmental drivers that will depend the ability of species to respond and the micro-environmental conditions of the site rather than the identity of the species that was lost. Technical Abstract: Long-term (> 13 years) patterns in dominance and community composition were examined following the experimental removal of one of three foundation species at an arid - semiarid biome transition zone. Objectives were to identify key processes influencing these patterns, and to predict future landscape-scale dynamics following mortality of different foundation species. Dominant species removals from 3m x 4 m plots were conducted annually in communities with a single dominant species, and in ecotonal communities with two dominant species across two types of ecotones (semiarid grassland- arid grassland, arid grassland-arid shrubland). Canopy cover by species was estimated annually on control and removal plots. In general, responses depended on characteristics of the recovering species and micro-environmental conditions that affected their recruitment and survival rather than legacies of the foundation species removed. For ecotonal communities, resident co-dominant species increased to dominance following the loss of a foundation species with little change in community composition. In mono-dominated communities, dominant species loss resulted in a shift to species that are currently sub-dominants of the same functional type as the species that was removed. Widespread loss of foundation species is expected to result in an increase in landscape-scale vulnerability to environmental drivers. The extent and magnitude of this change in vulnerability will depend the ability of species to respond and the micro-environmental conditions of the site rather than the identity of the species that was lost. |