A5084490085- Rangeland and Wildlife Management
- Ecology and Vegetation Dynamics Studies
- Fire effects on ecosystems
- Diabetes and associated disorders
- Pancreatic function and diabetes
- Diabetes Management and Research
- Turfgrass Adaptation and Management
- Rangeland Management and Livestock Ecology
- Botany, Ecology, and Taxonomy Studies
- Diabetes Treatment and Management
- Archaeology and Natural History
- Diet and metabolism studies
- Biocrusts and Microbial Ecology
- Plant and animal studies
- Birth, Development, and Health
- Animal Ecology and Behavior Studies
- Lichen and fungal ecology
- Receptor Mechanisms and Signaling
- Metabolism, Diabetes, and Cancer
- Ruminant Nutrition and Digestive Physiology
- Gestational Diabetes Research and Management
- Primary Care and Health Outcomes
- Pharmacology and Obesity Treatment
- Neuropeptides and Animal Physiology
- Pasture and Agricultural Systems
Forest and Rangeland Ecosystem Science Center
2015-2025
United States Geological Survey
2016-2025
University of San Diego
2018
Corvallis Environmental Center
2004-2017
Agricultural Research Service
2004-2013
Oregon State University
1993-2013
Northwest Watershed Research Center
2013
Rocky Mountain Research (United States)
2013
Rocky Mountain Research Station
2013
Natural Resources Conservation Service
2012
Plant invasions are widely recognized as significant threats to biodiversity conservation worldwide. One way can affect native ecosystems is by changing fuel properties, which in turn fire behavior and, ultimately, alter regime characteristics such frequency, intensity, extent, type, and seasonality of fire. If the changes subsequently promote dominance invaders, then an invasive plant–fire cycle be established. As more ecosystem components interactions altered, restoration preinvasion...
For more than 30 years, the relationship between net primary productivity and species richness has generated intense debate in ecology about processes regulating local diversity. The original view, which is still widely accepted, holds that hump-shaped, with first rising then declining increasing productivity. Although recent meta-analyses questioned generality of hump-shaped patterns, these syntheses have been criticized for failing to account methodological differences among studies. We...
We consider both parametric and nonparametric statistical analyses of survivorship curves removal rates, including assumptions, tests, ecological applications, the difference between censored uncensored survival data. For data, Gehan—Wilcoxon test, longrank likelihood ratio test appropriate are readily available in mainframe computer packages. In cohort analyses, these tests can determine if cohorts different ages have age—specific death rates or over same time period.
Abstract Drylands cover 40% of the global terrestrial surface and provide important ecosystem services. While drylands as a whole are expected to increase in extent aridity coming decades, temperature precipitation forecasts vary by latitude geographic region suggesting different trajectories for tropical, subtropical, temperate drylands. Uncertainty future tropical subtropical is well constrained, whereas soil moisture ecological droughts, which drive vegetation productivity composition,...
(1) Amplitude in the variation of recruitment, survivorship and fecundity was examined for introduced annual grass Bromus tectorum three habitat types eastern Washington (U.S.A.) consecutive generations. A total 18 143 individuals populations varying from 364 to 5322 members per site were mapped repeatedly emergence death with sufficient frequency detect multiple constituent cohorts age fewer than 16 more 200 days. (2) Recruitment usually concentrated late summer autumn, but occurred at any...
In sagebrush ecosystems invasion of annual exotics and expansion piñon (Pinus monophylla Torr. Frem.) juniper (Juniperus occidentalis Hook., J. osteosperma [Torr.] Little) are altering fire regimes resulting in large-scale ecosystem transformations. Management treatments aim to increase resilience disturbance enhance resistance invasive species by reducing woody fuels increasing native perennial herbaceous species. We used Sagebrush Steppe Treatment Evaluation Project data test predictions...
Summary Invasive annual grasses alter fire regimes in shrubland ecosystems of the western USA , threatening ecosystem function and fragmenting habitats necessary for shrub‐obligate species such as greater sage‐grouse. Post‐fire stabilization rehabilitation treatments have been administered to stabilize soils, reduce invasive spread restore or establish sustainable which native are well represented. Long‐term effectiveness these has rarely evaluated. We studied vegetation at 88 sites where...
Summary Ecosystem invasibility is determined by combinations of environmental variables, invader attributes, disturbance regimes, competitive abilities resident species and evolutionary history between residents regimes. Understanding the relative importance each factor critical to limiting future invasions restoring ecosystems. We investigated factors potentially controlling B romus tectorum into A rtemisia tridentata ssp. wyomingensis communities across 75 sites in G reat asin. measured...
Panels of experts from the Society for Range Management and National Research Council proposed that status rangeland ecosystems could be ascertained by evaluating an ecological site's potential to conserve soil resources a series indicators ecosystem processes site stability.Using these recommen- dations as starting point, we developed rapid, qualitative method assessing moment-in-time rangelands.Evaluators rate 17 assess 3 attributes (soil stability, hydrologic function, biotic integrity)...
Thirty-eight patients in diabetic coma from four different centres were treated with a continuous low-dose intravenous infusion of insulin at an average dose 7.2 IU/hr. All recovered rapidly except for one profoundly shocked patient who died. The mean fall plasma glucose was 58% hours after the start insulin. Blood ketone bodies and free fatty acids showed similar response. There no significant difference response according to severity acidosis or previous treatment Hypokalaemia uncommon. In...
The prevalence and features of diabetic retinopathy have been examined in 95 pairs identical twins, 31 concordant for insulin-dependent diabetes (IDD), 27 discordant IDD, 37 non-insulin-dependent (NIDD). Optic fundi were after pupillary dilatation was classified as nil, background, or severe. In the NIDD 35 same category including all but one 15 with duration diabetes. However, situation quite different; only 21 category, 10 co-twins 5 showed a striking difference retinopathy. There no...
Abstract Exotic species dominate many communities; however the functional significance of species’ biogeographic origin remains highly contentious. This debate is fuelled in part by lack globally replicated, systematic data assessing relationship between provenance, function and response to perturbations. We examined abundance native exotic plant at 64 grasslands 13 countries, a subset sites we experimentally tested responses two fundamental drivers invasion, mineral nutrient supplies...
Drylands occur worldwide and are particularly vulnerable to climate change because dryland ecosystems depend directly on soil water availability that may become increasingly limited as temperatures rise. Climate will both impact plant biomass, with resulting indirect feedbacks moisture. Thus, the net of direct effects moisture requires better understanding. We used ecohydrological simulation model SOILWAT at sites from temperate around globe disentangle contributions additional indirect,...