Effects of Disturbance on Vascular Plants and Biocrusts in Sagebrush Steppe

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Semi-arid sagebrush ecosystems experience chronic disturbances through grazing, invasive grasses, and acute disturbance of fire. Biocrusts, a community of cyanobacteria, mosses, and lichens, develop on soil surfaces and contribute to the land’s resistance to invasive plants. 

There are groups of biocrusts and plants, based on their shapes, sizes, and life spans, but post-disturbance responses of these groups have not been previously studied simultaneously. To better understand the resilience of these groups, USGS scientists examined the cover of plants and biocrusts 12-23 years post-fire within big sagebrush communities across the northern Great Basin. Biocrusts decreased in cover with less disturbance when compared with perennial herbaceous plants but differed in sensitivities. Tall mosses were less sensitive to disturbance compared with lichens. Cover of perennial grasses, annual forbs, and short mosses increased in cover with intermediate levels of disturbance. Results suggest that disturbance intensity may have a greater impact on plant and biocrust resilience than abiotic factors.

 

Condon, L.A., Pyke, D.A., 2018, Resiliency of biological soil crusts and vascular plants varies among morphogroups with disturbance intensity: Plant and Soil, v. 433, no. 1-2, p. 271–287, https://doi.org/10.1007/s11104-018-3838-8

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