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Title: Remote sensing and ecosystem simulation modeling of the intermountain sagebrush-steppe, with implications for global climate change

Three papers are presented that focus on remote sensing and ecosystem simulation modeling of the Intermountain Northwest sagebrush-steppe ecosystem. The first utilizes Advanced Very High Resolution Radiometer data to derive seasonal greenness indices of three pre-dominant vegetation communities in south-central WashingtoN. Temporal signatures were statistically separated, and used to create a classification for the three communities by integrating Normalized Difference Vegetation Indices over the growing season. The classification accuracy was 75% when compared to 53 ground-truthed sites, but was less accurate (62%) in a more topographically variable region. The second paper develops a logic for treating the intermountain sagebrush-steepe as a mosaic of distinct, hydrologically partitioned vegetation communities, and identifies critical ecophysiological considerations for process modeling of arid ecosystems. Soil water and nutrient dynamics of an ecosystem process model were modified to simulate productivity and seasonal water use patterns in Artemisia, Agropyron, and Bromus communities for the same study site. 60 year simulations maintained steady state vegetation productivity while predicting soil moisture content for 65 dates in 1992 with R[sup 2] values ranging from 0.93 to 0.98. In the third paper, the model was used to derive projections of the response of the ecosystem to natural and general circulation modelmore » (GCM)-predicted climate variability. Simulations predicted the adaptability of a less productive, invasive grass community (Bromus) to climate change, while a native sagebrush (Artemisia) community does not survive the increased temperatures of the GCM climates. High humidity deficits and greater maintenance respiration costs associated with increased temperatures limit the ability of the sagebrush community to support a relatively high biomass, and substantial increases in soil water storage and subsurface outflow occur was the vegetation senesces.« less
Authors:
Publication Date:
OSTI Identifier:
5437778
Resource Type:
Miscellaneous
Resource Relation:
Other Information: Thesis (Ph.D.)
Publisher:
Missoula, MT (United States); Univ. of Montana
Research Org:
Montana Univ., Missoula, MT (United States). Dept. of Zoology
Country of Publication:
United States
Language:
English
Subject:
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.; CLIMATIC CHANGE; BIOLOGICAL EFFECTS; GLOBAL ASPECTS; SAVANNAS; POPULATION DYNAMICS; ARID LANDS; MATHEMATICAL MODELS; ECOSYSTEMS; TERRESTRIAL ECOSYSTEMS 560400* -- Other Environmental Pollutant Effects