دورية
Linkages Between Riparian Characteristics, Ungulate Grazing, and Geomorphology and Nutrient Cycling in Montane Grassland Streams
| العنوان: | Linkages Between Riparian Characteristics, Ungulate Grazing, and Geomorphology and Nutrient Cycling in Montane Grassland Streams |
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| المؤلفون: | Van Horn, David J., White, Carleton S., Martinez, Edward A., Hernandez, Christina, Merrill, Joshua P., Parmenter, Robert R., Dahm, Clifford N. |
| المصدر: | Rangeland Ecology and Management; September 2012, Vol. 65 Issue: 5 p475-485, 11p |
| مستخلص: | Catchment characteristics and disturbances control the conditions and processes found in stream ecosystems. We examined nutrient cycling linkages between riparian soils and adjacent streams and the impacts of the removal of ungulate grazing on these ecosystems and processes at six grazing exclosure sites in the Valles Caldera National Preserve, NM, USA. The exclusion of native and domestic ungulate grazers for 3 yr significantly increased the riparian aboveground biomass of standing vegetation (273 ± 155 in grazed vs. 400 ± 178 g . m-2in exclosures) and litter (58 ± 75 in grazed vs. 110 ± 76 g . m-2in exclosures) (P = 0.003 and 0.006, respectively). Except for an increase in total soil phosphorous (P) at three of the six sites, soil nutrient values were minimally affected by grazing after five growing seasons. Within the six sites studied, no connection was found between 0–15-cm depth soils, which were P-limited based on stoichiometric ratios, and stream nutrient availability or limitation, which were nitrogen limited. Stream geomorphology was not significantly altered by 5 yr of grazing exclusion. The elimination of grazing suppressed instream nutrient processing with significantly longer NH4uptake lengths (P = 0.003). These results suggest the exclusion of ungulate grazing impacts terrestrial characteristics (increased standing vegetative biomass) that are linked to ecosystem services provided by adjacent aquatic ecosystems (reduced N-uptake). Management plans should carefully balance the positive effect of grazing on stream nutrient processing and retention reported here with the well-documented grazing-related loss of other ecosystem services such as decreased fish and aquatic invertebrate habitat and effects on water-quality parameters such as turbidity and water temperature. |
| قاعدة البيانات: | Supplemental Index |
Full Text Finder | تدمد: | 15507424 15515028 |
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| DOI: | 10.2111/REM-D-10-00170.1 |