Sediment losses and gains across a gradient of livestock grazing and plant invasion in a cool, semi-arid grassland, Colorado Plateau, USA
January 1, 2009
Large sediment fluxes can have significant impacts on ecosystems. We measured incoming and outgoing sediment across a gradient of soil disturbance (livestock grazing, plowing) and annual plant invasion for 9 years. Our sites included two currently ungrazed sites: one never grazed by livestock and dominated by perennial grasses/well-developed biocrusts and one not grazed since 1974 and dominated by annual weeds with little biocrusts. We used two currently grazed sites: one dominated by annual weeds and the other dominated by perennial plants, both with little biocrusts. Precipitation was highly variable, with years of average, above-average, and extremely low precipitation. During years with average and above-average precipitation, the disturbed sites consistently produced 2.8 times more sediment than the currently undisturbed sites. The never grazed site always produced the least sediment of all the sites. During the drought years, we observed a 5600-fold increase in sediment production from the most disturbed site (dominated by annual grasses, plowed about 50 years previously and currently grazed by livestock) relative to the never grazed site dominated by perennial grasses and well-developed biocrusts, indicating a non-linear, synergistic response to increasing disturbance types and levels. Comparing sediment losses among the sites, biocrusts were most important in predicting site stability, followed by perennial plant cover. Incoming sediment was similar among the sites, and while inputs were up to 9-fold higher at the most heavily disturbed site during drought years compared to average years, the change during the drought conditions was small relative to the large change seen in the sediment outputs. ?? 2009 Elsevier B.V. All rights reserved.
Citation Information
Publication Year | 2009 |
---|---|
Title | Sediment losses and gains across a gradient of livestock grazing and plant invasion in a cool, semi-arid grassland, Colorado Plateau, USA |
DOI | 10.1016/j.aeolia.2009.03.001 |
Authors | Jayne Belnap, Richard L. Reynolds, Marith C. Reheis, Sue Phillips, Frank Urban, Harland L. Goldstein |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Aeolian Research |
Index ID | 70037427 |
Record Source | USGS Publications Warehouse |
USGS Organization | Southwest Biological Science Center |
Related
Jayne Belnap, Ph.D.
Research Ecologist
Research Ecologist
Email
Phone
Richard L Reynolds
Scientist Emeritus
Scientist Emeritus
Email
Phone
Marith Reheis
Scientist Emeritus
Scientist Emeritus
Email
Phone
Sue Phillips
Center Director
Center Director
Email
Phone
Frank Urban
Email
Phone
Harland Goldstein
Deputy Center Director
Deputy Center Director
Email
Phone
Related
Jayne Belnap, Ph.D.
Research Ecologist
Research Ecologist
Email
Phone
Richard L Reynolds
Scientist Emeritus
Scientist Emeritus
Email
Phone
Marith Reheis
Scientist Emeritus
Scientist Emeritus
Email
Phone
Sue Phillips
Center Director
Center Director
Email
Phone
Frank Urban
Email
Phone
Harland Goldstein
Deputy Center Director
Deputy Center Director
Email
Phone