Grazing Density Effects on Cover, Species Composition, and Nitrogen Fixation of Biological Soil Crust in an Inner Mongolia Steppe
Citation
Liu, H., Han, X., Li, L., Huang, J., Liu, H., & Li, X. (2009). Grazing density effects on cover, species composition, and nitrogen fixation of biological soil crust in an inner Mongolia steppe. Rangeland Ecology & Management, 62(4), 321-327.Publisher
Society for Range ManagementJournal
Rangeland Ecology & ManagementDOI
10.2111/08-179.1Additional Links
https://rangelands.org/Abstract
Biological soil crusts (BSCs) are important in many arid and semiarid ecosystems for their abilities to fix atmospheric nitrogen (N) and stabilize surface soil. Grazing disturbance has a profound influence on abundance, species composition, and ecological functioning of BSCs. To elucidate the effects of grazing on BSCs in Inner Mongolia grasslands, an investigation was conducted in a typical steppe that had previously been subjected to long-term grazing with six grazing densities (control: 0 sheep ? ha21, very light: 4 sheep?ha21, light: 8 sheep?ha21, medium: 12 sheep?ha21, heavy: 16 sheep?ha21, and very heavy: 20 sheep?ha21). Cover, species composition, potential N-fixing activity, and potential N input of BSC indicate that long-term grazing significantly reduced the importance of BSC in N input and soil stabilization. Such reductions were highly related to grazing density. Very light grazing had no significant effect on the role of BSC in soil stabilization, but resulted in a 13.3% reduction in BSC N input potential. Heavy and very heavy grazing led to a decrease of potential N input by one order of magnitude, and a decline of BSC function via a shift from high coverage of an attached group-dominated BSC community to a low coverage of a vagrant group-dominated community. Constraining grazing level to a very light density—and to a lesser extent, a light grazing density—is likely a preferred practice for conserving BSC and the ecological services it provides in N fixation and soil stabilization.Type
textArticle
Language
enISSN
0022-409Xae974a485f413a2113503eed53cd6c53
10.2111/08-179.1