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Corvallis, OR, United States

Knapp C.N.,University of Alaska Fairbanks | Fernandez-Gimenez M.E.,Colorado State University | Briske D.D.,Texas A&M University | Bestelmeyer B.T.,Research ecologist | Wu X.B.,Texas A&M University
Rangeland Ecology and Management | Year: 2011

State-and-transition models (STMs) are being developed for many areas in the United States and represent an important tool for assessing and managing public and private rangelands. Substantial resources have been invested in model development, yet minimal efforts have been made to evaluate the utility of STMs for rangeland assessment and management. We interviewed 47 rangeland professionals, equally divided between managers and researchers, in four ecoregions to determine their perceptions of the purpose, development, and strengths and weaknesses of STMs to assess the status of the STM framework. Our analysis identified three primary perspectives regarding the purpose of STMs: a decision-making tool for land managers, a means to represent the complex dynamics of rangeland ecosystems, and an effective communication tool. These diverse views of STM purposes were associated with differing perspectives concerning model development that identified five major issues in need of further development and refinement: 1) the relative importance of management practices and ecological processes in driving transitions, 2) the criteria used to define thresholds, 3) the appropriate level of model complexity, 4) the respective roles of expert knowledge and ecological data in model development, and 5) processes for model review and revision. We recommend greater dialogue among researchers and managers to further clarify STM terminology and develop standard protocols for model development and validation. Mechanisms are critically needed to assure peer review and revision of existing models so that STMs are continually updated to reflect current understanding of rangeland dynamics. © Society for Range Management. Source


Keane R.E.,Rocky Research | Loehman R.A.,Research ecologist | Holsinger L.M.,Rocky Research
USDA Forest Service - General Technical Report RMRS-GTR | Year: 2011

Fire management faces important emergent issues in the coming years such as climate change, fire exclusion impacts, and wildland-urban development, so new, innovative means are needed to address these challenges. Field studies, while preferable and reliable, will be problematic because of the large time and space scales involved. Therefore, landscape simulation modeling will have more of a role in wildland fire management as field studies become untenable. This report details the design and algorithms of a complex, spatially explicit landscape fire and vegetation model called FireBGCv2. FireBGCv2 is a C++ computer program that incorporates several types of stand dynamics models into a landscape simulation platform. FireBGCv2 is intended as a research tool. Descriptions of FireBGCv2 code, sample input files, and sample output are included in this report, but this report is not intended as a user's manual because the inherent complexity and wide scope of FireBGCv2 makes it unwieldy and difficult to use without extensive training. The primary purpose of this report is to document FireBGCv2 in adequate detail to interpret simulation results. Source


Reeves J.L.,Research ecologist | Derner J.D.,U.S. Department of Agriculture | Sanderson M.A.,Research ecologist | Kronberg S.L.,Research Animal Scientist | And 5 more authors.
Rangelands | Year: 2015

On the Ground Ranching is a challenging and sometimes risky business, with cattle production (and associated enterprise income) largely being dependent on seasonal weather patterns and corresponding forage production. To help reduce this risk, the USDA-Agricultural Research Service performed a multistate study of seasonal weather effects on cattle production across the Northern Great Plains (Wyoming, North Dakota, and Montana). Cool, wet springs and longer, cooler growing seasons increased cattle production across the Northern Great Plains. Knowledge of these seasonal weather influences on cattle production is important for management decision making, but practical application of this knowledge remains problematic. Increased enterprise flexibility to deal with variable forage production can be achieved by using seasonal weather forecasts, as well as reducing base cow-calf herd numbers to less than 100% of typical ranch carrying capacity. Yearlings or seasonal contract grazing can then be used to increase grazing to use additional forage in good years. Recently launched USDA Regional Climate Hubs will deliver science-based knowledge, practical information, management and conservation strategies, and decision tools to ranchers that will help them adapt to weather variability and changing climatic conditions. © 2015 The Society for Range Management. Source


Hanley T.A.,Research wildlife biologist | Bormann B.T.,Forestry science Laboratory | Barnard J.C.,Research ecologist | Nay S.M.,Forestry science Laboratory
USDA Forest Service - Research Paper PNW-RP | Year: 2013

Aboveground growth rates of seedlings of bunchberry (Cornus canadensis L.), oval-leaf blueberry (Vaccinium ovalifolium Sm.), salmonberry (Rubus spectabilis Pursh), devilsclub (Oplopanax horridus (Sm.) Miq.), and western hemlock (Ts uga heterophylla (Raf.) Sarg.) were compared in a study of their responses to an artifcial light gradient in an Oregon greenhouse and in a study of response to overstory and soil type in a field manipulation experiment in southeast Alaska. Seedlings of all five species were grown independently under nine intensities of light for 156 days, and their oven-dry weight of new leaves and twigs was measured and expressed as a percentage of their maximum growth observed under all light treatments. Results indicated strongly differential responses to light, with bunchberry responding most strongly to very low intensities and western hemlock requiring mid to high intensities of light to reach its maximum growth rate. The same five species were planted in plastic grow pots placed in the ground under overstory canopies of red alder (Alnus rubra Bong.) and dense, young-growth western hemlock for one annual growing season (May through August). Soils were artificial and of two contrasting types, one strongly mineral and the other mineral mixed with organic matter. Measures of total aboveground production of new leaves and twigs (oven-dry grams per plant) indicated differential responses among the species and significant differences in canopy and soil treatments for all species except bunchberry. Statistically significant (P < 0.05) interactions of canopy by soil (alder canopy and "mixed" soil producing greatest growth) were observed in oval-leaf blueberry and salmonberry, both of which also had a significant main effect of soil (mixed > mineral). The canopy main effect (alder canopy > conifer canopy) was significant for all species except bunchberry. Overall, light availability was a strong ecological factor in both studies, but responses to light differed among species. Knowledge of such differential responses is important for designing silviculture treatments for multiple benefits. Source

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