|Lauenroth, W. - COLORADO STATE UNIV|
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: March 1, 2007
Publication Date: September 1, 2008
Citation: Peters, D.C., Lauenroth, W.K. 2008. Simulation of disturbances and recovery in shortgrass steppe plant communities. In: Lauenroth, W.K, and Burke, I.C., editors. Ecology of the Shortgrass Steppe: A long-term perspective. Oxford, NY: Oxford Press. p. 119-131. Interpretive Summary: We developed a gap dynamics simulation model to examine key processes affecting dynamics of shortgrass steppe communities following disturbance. The model is similar to those developed for forests, but focuses on belowground interactions among plants. The model (STEPPE) was used to examine the recovery of communities following disturbances of different sizes and soil textures. We found that seed dispersal is a key process limiting the recovery of the dominant plant species, blue grama, for all disturbance sizes. Soil properties, in particular, silt content constrain seedling establishemnt and recovery of blue grama.
Technical Abstract: The objective of this chapter was to evaluate the importance of gap dynamics concepts of succession for understanding shortgrass plant community recovery following disturbances. A gap dynamics approach focuses on individual plants, and the interactions between disturbance characteristics and plant life history traits in explaining successional patterns. We developed a gap dynamics model for shortgrass steppe plant communities (STEPPE) based upon the conceptual and modeling framework provided by forest models, modifying it to represent Great Plains grasslands. We used STEPPE in several capacities: (1) to synthesize and integrate existing knowledge to improve our understanding of recovery processes following disturbance; (2) to identify key processes limiting recovery; and (3) to predict long- term recovery dynamics for different climate and disturbance characteristics, in particular soil texture and disturbance size. Our analyses show that seed dispersal is a key process limiting recovery of the dominant species, blue grama, across a range of disturbance sizes. Our simulation results also indicate the importance of soil properties, especially silt content, to recovery rates of blue grama, and the greater importance of seedling establishment compared to seedling growth; however these hypotheses have yet to be tested in the field.