Grazing effect on diversity of annual plant communities in a semi-arid rangeland: interactions with small-scale spatial and temporal variation in primary productivity

Published source details Osem Y., Perevolotsky A. & Kigel J. (2002) Grazing effect on diversity of annual plant communities in a semi-arid rangeland: interactions with small-scale spatial and temporal variation in primary productivity. Journal of Ecology, 90, 936-946.
Share Tweet Email

This study is summarised as evidence for the following.

	Action	Category
	Other biodiversity: Exclude grazers Action Link

Other biodiversity: Exclude grazers

A replicated, controlled study in 1996–1999 in rangelands in Israel (same study as (19)) found more species of plants in plots from which grazers were excluded, in two of four sites, but fewer species in one site. More plants and more plant biomass were found in plots from which grazers were excluded. Plants: More plant species were found in ungrazed plots, in two of four sites (5–12 vs 5–9 species/quadrat), but fewer were found in one site (6–13 vs 9–15). Total plant biomass was higher in ungrazed plots (10–490 vs 10–155 g/m²), and there were more plants in ungrazed plots in three of four sites (28–134 vs 28–94 plants/quadrat). There were more plants and plant species in grazed sites in less productive areas, but not in more productive areas. The abundance of common species increased with productivity in ungrazed plots, but not in grazed plots, in less productive sites. There was no difference for rare and abundant species. In more productive sites, the abundance of rare plants increased with productivity in grazed, but not ungrazed sites. There were no differences between grazed and ungrazed sites for common or abundant species. Methods: Four sites (one considerably more productive than the others) were established in 1993, each with a 10 x 10 m fenced plot to exclude sheep. Plants were surveyed in April 1996–1999, when vegetation was at a peak.