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United States Department of Agriculture (USDA) 2015

Global Change in Semi-Arid Rangelands : Ecosystem Responses and Management Adaptations

Semi-Arid Rangelands Adaptations

United States Department of Agriculture (USDA) Research, Education & Economics Information System (REEIS)

Titre : Global Change in Semi-Arid Rangelands : Ecosystem Responses and Management Adaptations

Identification : 3018-11000-006-00

Pays : Etats Unis

Durée : Mar 06, 2015 à Dec 31, 2016

Objectif
The semi-arid grasslands of the western Great Plains, mixed-grass prairie and shortgrass steppe, provide a tremendous array of ecosystem services, including livestock forage, a diversity of native plants and animals, resistance to biological invasion, and carbon storage. Global change is expected to dramatically change grasslands and associated ecosystem services, but the nature of its impacts, and the mechanisms underlying those impacts, remain difficult to predict. In water-limited ecosystems, elevated CO2 and warming can have particularly strong and complex effects because, in addition to their direct effects, they alter water availability. Three main objectives will drive our research program over the next five years to understand how these changes might impact the ecosystem services of western rangelands. The first objective is to assess effects of predicted global changes on ecosystem services in a northern mixed-grass prairie. This will be accomplished by determining the effects of temperature, CO2 and precipitation on plant productivity, plant diversity, forage quality, community composition, weed invasion and the ability of native plant communities to recover from disturbance. The biogeochemistry underlying these responses will be studied to improve our understanding of ecosystem responses and to improve algorithms in biogeochemical models like Daycent. We will also evaluate whether and how responses of invasive species differ from those of native species. Our second objective is to develop knowledge and tools that allow rangeland managers to minimize greenhouse gas emissions. We will determine how temperature, CO2 and precipitation influence land-atmosphere exchanges of trace gases and soil carbon (C) storage, and evaluate the relative importance of water, nitrogen (N) and C limitation in regulating C storage. We will use this information plus additional soil C and CO2 flux data from long-term grazing experiments to determine the potential to mitigate greenhouse gas emissions through grazing management, and assess tradeoffs between mitigation and rangeland productivity. The third objective is to develop science-based, region-specific information and technologies for agricultural and natural resource managers that enable climate-smart decision-making and where possible provide assistance to enable land managers to implement those decisions. The work will be conducted as the Northern Plains USDA Climate Change Hub and will be coordinated with NRCS, FS, and other USDA and non-USDA organizations in accordance with guidance found in the USDA Climate Change Hubs Charter, and Terms of Reference

Présentation : USDA

Page publiée le 26 septembre 2015, mise à jour le 13 octobre 2017