Herbivore-plant interactions and desertification in arid lands

Authors: WHITFORD, WALTER - New Mexico State University; STEINBERGER, YOSEF - Bar-Ilan University

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 10/15/2010
Publication Date: 11/15/2010
Citation: Whitford, W.G., Steinberger, Y. 2010. Herbivore-plant interactions and desertification in arid lands. In: Seckback, J., Dubinsky, Z., editors. All Flesh is Grass. Springer-Verlag Publishing. p. 239-256.

Interpretive Summary: Most studies that have examined effects of animals-plant interactions on desertification or the contribution of animal-plant interactions were conducted in arid and semi-arid regions, where desertification began approximately 1.5-2 centuries ago, coincident with the introduction of the livestock industry. In these landscapes portions of theses ecosystems are in a state of change while other portions are stable. In these environments, animal-plant interactions may be direct, e.g., removal of plant leaf tissue by grazing, or indirect, e.g., seed dispersal and soil modification. In degrading or relatively stable ecosystems, grazing can contribute to changing plant species composition or modifying the form of dominant plant species. Animals are frequently agents of seed dispersal, which may be critical for the expansion of native shrubs into areas where they were absent earlier. Animals that modify soil may affect the distribution of critical resources 9water and nutrients), which has bee identified as one of the most important consequences of desertification. This book chapter provides a synthesis of studies that have addressed animal-plant interactions and desertification.

Technical Abstract: Arid lands around the world have experienced or are currently experiencing degradation that is known as desertification. Animal-plant interactions that have an effect on desertification are among the most important function of animals in arid ecosystems. Desertification has been defined as land degradation in arid and semiarid areas that is the result of various factors, including climate variation and human activities. The interactions between animals and plants affect desertification arid environments in a number of ways. These interactions may exacerbate desertification processes or contribute to the stability of desertified ecosystems. Some animal-plant interactions are direct, e.g., herbivory, while others are indirect, e.g., seed dispersal and soil modification. Animal-plant interactions that contribute to changes in the structure of plant communities or the spread of alien plant species may enhance some degradation processes such as soil erosion or contribute to soil stability and resistance to degradation.