Physical Sciences and Mathematics | Open Access Articles

The Value Of Native Plants And Local Production In An Era Of Global Agriculture, Oren Shelef, Peter J. Weisberg, Frederick D. Provenza

Wildland Resources Faculty Publications

For addressing potential food shortages, a fundamental tradeoff exists between investing more resources to increasing productivity of existing crops, as opposed to increasing crop diversity by incorporating more species. We explore ways to use local plants as food resources and the potential to promote food diversity and agricultural resilience. We discuss how use of local plants and the practice of local agriculture can contribute to ongoing adaptability in times of global change. Most food crops are now produced, transported, and consumed long distances from their homelands of origin. At the same time, research and practices are directed primarily at improving …

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Phenology Largely Explains Taller Grass At Successful Nests In Greater Sage-Grouse, Joseph T. Smith, Jason D. Tack, Kevin Doherty, Brady W. Allred, Jeremy D. Maestas, Lorelle I. Berkeley, Seth J. Dettenmaier, Terry A. Messmer, David E. Naugle

Wildland Resources Faculty Publications

Much interest lies in the identification of manageable habitat variables that affect key vital rates for species of concern. For ground-nesting birds, vegetation surrounding the nest may play an important role in mediating nest success by providing concealment from predators. Height of grasses surrounding the nest is thought to be a driver of nest survival in greater sage-grouse (Centrocercus urophasianus; sage-grouse), a species that has experienced widespread population declines throughout their range. However, a growing body of the literature has found that widely used field methods can produce misleading inference on the relationship between grass height and nest success. Specifically, …

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Uv Screening In Native And Non-Native Plant Species In The Tropical Alpine: Implications For Climate Change-Driven Migration Of Species To Higher Elevations, Paul W. Barnes, Ronald J. Ryel, Stephan D. Flint

Wildland Resources Faculty Publications

Ongoing changes in Earth’s climate are shifting the elevation ranges of many plant species with non-native species often experiencing greater expansion into higher elevations than native species. These climate change-induced shifts in distributions inevitably expose plants to novel biotic and abiotic environments, including altered solar ultraviolet (UV)-B (280–315 nm) radiation regimes. Do the greater migration potentials of non-native species into higher elevations imply that they have more effective UV-protective mechanisms than native species? In this study, we surveyed leaf epidermal UV-A transmittance (TUVA) in a diversity of plant species representing different growth forms to test whether native and non-native species …

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Relative Selection Strength: Quantifying Effectsize In Habitat- And Step-Selection Inference, Tal Avgar, Subhash R. Lele, Jonah L. Keim, Mark S. Boyce

Wildland Resources Faculty Publications

Habitat-selection analysis lacks an appropriate measure of the ecological significance of the statistical estimates-a practical interpretation of the magnitude of the selection coefficients. There is a need for a standard approach that allows relating the strength of selection to a change in habitat conditions across space, a quantification of the estimated effect size that can be compared both within and across studies. We offer a solution, based on the epidemiological risk ratio, which we term the relative selection strength (RSS). For a "used-available" design with an exponential selection function, the RSS provides an appropriate interpretation of the magnitude of the …

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The Relationship Between Species Richness And Ecosystem Variability Is Shaped By The Mechanism Of Coexistence, Andrew T. Tredennick, Peter B. Adler, Frederick R. Adler

Wildland Resources Faculty Publications

Theory relating species richness to ecosystem variability typically ignores the potential for environmental variability to promote species coexistence. Failure to account for fluctuation-dependent coexistence may explain deviations from the expected negative diversity–ecosystem variability relationship, and limits our ability to predict the consequences of increases in environmental variability. We use a consumer-resource model to explore how coexistence via the temporal storage effect and relative nonlinearity affects ecosystem variability. We show that a positive, rather than negative, diversity–ecosystem variability relationship is possible when ecosystem function is sampled across a natural gradient in environmental variability and diversity. We also show how fluctuation-dependent coexistence …

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Landscape-Level Wolf Space Use Is Correlated With Prey Abundance, Ease Of Mobility And The Distribution Of Prey Habitat, Andrew M. Kittle, Morgan Anderson, Tal Avgar, James A. Baker, Glen S. Brown, Jevon Hagens, Ed Iwachewski, Scott Moffatt, Anna Mosser, Brent R. Patterson, Douglas E. B. Reid, Arthur R. Rodgers, Jen Shuter, Garrett M. Street, Ian D. Thompson, Lucas M. Vander Vennen, John M. Fryxell

Wildland Resources Faculty Publications

Predator space use influences ecosystem dynamics, and a fundamental goal assumed for a foraging predator is to maximize encounter rate with prey. This can be achieved by disproportionately utilizing areas of high prey density or, where prey are mobile and therefore spatially unpredictable, utilizing patches of their prey's preferred resources. A third, potentially complementary strategy is to increase mobility by using linear features like roads and/or frozen waterways. Here, we used novel population-level predator utilization distributions (termed "localized density distributions") in a single-predator (Wolf), two-prey (moose and caribou) system to evaluate these space-use hypotheses. The study was conducted in contrasting …

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Estimating Utilization Distributions From Fitted Step-Selectionfunctions, Johannes Signer, John Fieberg, Tal Avgar

Wildland Resources Faculty Publications

Habitat-selection analyses are often used to link environmental covariates, measured within some spatial domain of assumed availability, to animal location data that are assumed to be independent. Step-selection functions (SSFs) relax this independence assumption, by using a conditional model that explicitly acknowledges the spatiotemporal dynamics of the availability domain and hence the temporal dependence among successive locations. However, it is not clear how to produce an SSF-based map of the expected utilization distribution. Here, we used SSFs to analyze virtual animal movement data generated at a fine spatiotemporal scale and then rarefied to emulate realistic telemetry data. We then compared …

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Shrub Communities, Spatial Patterns, And Shrub-Mediated Tree Mortality Following Reintroduced Fire In Yosemite National Park, California, Usa, James A. Lutz, Tucker J. Furniss, Sara J. Germain, Kendall M. L. Becker, Erika M. Blomdahl, Sean M. A. Jeronimo, C. Alina Cansler, James A. Freund, Mark E. Swanson, Andrew J. Larson

Wildland Resources Faculty Publications

Shrubs contribute to the forest fuel load; their distribution is important to tree mortality and regeneration, and vertebrate occupancy. We used a method new to fire ecology—extensive continuous mapping of trees and shrub patches within a single large (25.6 ha) study site—to identify changes in shrub area, biomass, and spatial pattern due to fire reintroduction by a backfire following a century of fire exclusion in lower montane forests of the Sierra Nevada, California, USA. We examined whether trees in close proximity to shrubs prior to fire experienced higher mortality rates than trees in areas without shrubs. We calculated shrub biomass …

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Patterns In Greater Sage-Grouse Population Dynamics Correspond With Public Grazing Records At Broad Scales, Adrian P. Monroe, Cameron L. Aldridge, Timothy J. Assal, Kari E. Veblen, David A. Pyke, Michael L. Casazza

Wildland Resources Faculty Publications

Human land use, such as livestock grazing, can have profound yet varied effects on wildlife interacting within common ecosystems, yet our understanding of land-use effects is often generalized from short-term, local studies that may not correspond with trends at broader scales. Here we used public land records to characterize livestock grazing across Wyoming, USA, and we used Greater Sage-grouse (Centrocercus urophasianus) as a model organism to evaluate responses to livestock management. With annual counts of male Sage-grouse from 743 leks (breeding display sites) during 2004-2014, we modeled population trends in response to grazing level (represented by a relative grazing index) …

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Climate Drives Fire Synchrony But Local Factors Control Fire Regime Change In Northern Mexico, Larissa L. Yocom Kent, Peter Z. Fule, J. Brown, E. Cerano, E. Cornejo-Oviedo, C. Cortés Montaño, S. A. Drury, D. A. Falk, J. Meunier, H. M. Poulos, C. N. Skinner, S. L. Stephens, J. Villanueva-Diaz

Wildland Resources Faculty Publications

The occurrence of wildfire is influenced by a suite of factors ranging from “top-down” influences (e.g., climate) to “bottom-up” localized influences (e.g., ignitions, fuels, and land use). We carried out the first broad-scale assessment of wildland fire patterns in northern Mexico to assess the relative influence of top-down and bottom-up drivers of fire in a region where frequent fire regimes continued well into the 20th century. Using a network of 67 sites, we assessed (1) fire synchrony and the scales at which synchrony is evident, (2) climate drivers of fire, and (3) asynchrony in fire regime changes. We found high …

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Daphnia Inhibits The Emergence Of Spatial Pattern In A Simple Consumer-Resource System, Gustavo S. Betini, Tal Avgar, Kevin S. Mccann, John M. Fryxell

Wildland Resources Faculty Publications

Spatial self-organization can occur in many ecosystems with important effects on food web dynamics and the maintenance of biodiversity. The consumer-resource interaction is known to generate spatial patterning, but only a few empirical studies have investigated the effect of the consumer on resource distribution. Here we report results from a large aquatic mesocosm experiment used to investigate the effect of the consumer Daphnia magna on the distribution of its resource, the green algae Chlorella vulgaris. We maintained large tanks with capacity for 26 ,000 L with either algae or both algae and Daphnia in different temperature conditions. We found that …

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Greater Sage-Grouse Resource Selection Drives Reproductive Fitness Under A Conifer Removal Strategy, Charles P. Sandford, Michel T. Kohl, Terry A. Messmer, David K. Dahlgren, Avery Cook, Brian R. Wing

Wildland Resources Faculty Publications

The link between individual variation in resource selection (e.g., functional response) and fitness creates a foundation for understanding wildlife-habitat relationships. Although many anthropogenic activities adversely affect these relationships, it is largely unknown whether projects implemented to benefit wildlife populations actually achieve this outcome. For sagebrush (Artemisia spp.) obligate species such as the greater sage-grouse (Centrocercus urophasianus; sage-grouse), expansion of juniper (Juniperus spp.) and pinyon-pine (Pinus spp.; conifers) woodlands into sagebrush ecosystems has been identified as a conservation threat. This threat is intensified when a sagebrush ecosystem is bounded by naturally unsuitable habitats. As such, federal, state, …

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Why Are We Not Evaluating Multiple Competinghypotheses In Ecology And Evolution?, Gustavo S. Betini, Tal Avgar, John M. Fryxell

Wildland Resources Faculty Publications

The use of multiple working hypotheses to gain strong inference is widely promoted as a means to enhance the effectiveness of scientific investigation. Only 21 of 100 randomly selected studies from the ecological and evolutionary literature tested more than one hypothesis and only eight tested more than two hypotheses. The surprising rarity of application of multiple working hypotheses suggests that this gap between theory and practice might reflect some fundamental issues. Here, we identify several intellectual and practical barriers that discourage us from using multiple hypotheses in our scientific investigation. While scientists have developed a number of ways to avoid …

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Full-Text Articles in Physical Sciences and Mathematics

The Value Of Native Plants And Local Production In An Era Of Global Agriculture, Oren Shelef, Peter J. Weisberg, Frederick D. Provenza

Wildland Resources Faculty Publications

Phenology Largely Explains Taller Grass At Successful Nests In Greater Sage-Grouse, Joseph T. Smith, Jason D. Tack, Kevin Doherty, Brady W. Allred, Jeremy D. Maestas, Lorelle I. Berkeley, Seth J. Dettenmaier, Terry A. Messmer, David E. Naugle

Wildland Resources Faculty Publications

Uv Screening In Native And Non-Native Plant Species In The Tropical Alpine: Implications For Climate Change-Driven Migration Of Species To Higher Elevations, Paul W. Barnes, Ronald J. Ryel, Stephan D. Flint

Wildland Resources Faculty Publications

Relative Selection Strength: Quantifying Effectsize In Habitat- And Step-Selection Inference, Tal Avgar, Subhash R. Lele, Jonah L. Keim, Mark S. Boyce

Wildland Resources Faculty Publications

The Relationship Between Species Richness And Ecosystem Variability Is Shaped By The Mechanism Of Coexistence, Andrew T. Tredennick, Peter B. Adler, Frederick R. Adler

Wildland Resources Faculty Publications

Wildland Resources Faculty Publications

Estimating Utilization Distributions From Fitted Step-Selectionfunctions, Johannes Signer, John Fieberg, Tal Avgar

Wildland Resources Faculty Publications

Wildland Resources Faculty Publications

Patterns In Greater Sage-Grouse Population Dynamics Correspond With Public Grazing Records At Broad Scales, Adrian P. Monroe, Cameron L. Aldridge, Timothy J. Assal, Kari E. Veblen, David A. Pyke, Michael L. Casazza

Wildland Resources Faculty Publications

Climate Drives Fire Synchrony But Local Factors Control Fire Regime Change In Northern Mexico, Larissa L. Yocom Kent, Peter Z. Fule, J. Brown, E. Cerano, E. Cornejo-Oviedo, C. Cortés Montaño, S. A. Drury, D. A. Falk, J. Meunier, H. M. Poulos, C. N. Skinner, S. L. Stephens, J. Villanueva-Diaz

Wildland Resources Faculty Publications

Daphnia Inhibits The Emergence Of Spatial Pattern In A Simple Consumer-Resource System, Gustavo S. Betini, Tal Avgar, Kevin S. Mccann, John M. Fryxell

Wildland Resources Faculty Publications

Greater Sage-Grouse Resource Selection Drives Reproductive Fitness Under A Conifer Removal Strategy, Charles P. Sandford, Michel T. Kohl, Terry A. Messmer, David K. Dahlgren, Avery Cook, Brian R. Wing

Wildland Resources Faculty Publications

Why Are We Not Evaluating Multiple Competinghypotheses In Ecology And Evolution?, Gustavo S. Betini, Tal Avgar, John M. Fryxell

Wildland Resources Faculty Publications