Instability of development and fractal architecture in dryland plants as an index of grazing pressure

Journal of Arid Environments
By: , and 

Links

Abstract

Developmental instability has been used to monitor the well-being of natural populations exposed to physical, chemical and biological stressors. Here, we use developmental instability to assess the impact of grazing on Chrysothamnus greenii and Seriphidium novumshrubs, and Oryzopsis hymenoidesgrass, common in the arid intermountain west of the U.S.A. Statistical noise in allometric relations was used as an indicator of developmental instability arising from grazing-induced stress. Unpalatable species that are not grazed (Chrysothamnus greenii) or species that are dormant during the winter–spring grazing period (Oryzopsis hymenoides) show lower allometric variability under high grazing pressure. Palatable species (Seriphidium novum) exhibit high developmental instability under low and high grazing pressure. Grazing pressure imposed by presumably co-adapted wild herbivores enhances developmental stability in species habituated to moderate grazing, likeOryzopsis hymenoides, but stresses plants such as Chrysothamnus greenii that prefer disturbed environments. These grazing effects are probably due to the impact grazing has on competitive relationships and not to the direct action of the herbivore on the plants.

Publication type Article
Publication Subtype Journal Article
Title Instability of development and fractal architecture in dryland plants as an index of grazing pressure
Series title Journal of Arid Environments
DOI 10.1006/jare.1997.0317
Volume 38
Issue 1
Year Published 1998
Language English
Publisher Elselvier
Contributing office(s) Western Fisheries Research Center
Description 14
First page 63
Last page 76
Google Analytic Metrics Metrics page
Additional publication details