Hegeman E.E.,Utah State University |
Hegeman E.E.,Conservation Science Partners Inc. |
Miller S.W.,Utah State University |
Mock K.E.,Utah State University
Canadian Journal of Fisheries and Aquatic Sciences | Year: 2014
The habitat requirements of many native freshwater mussels remain unclear despite their imperiled status and ecological importance. To explore scale-specific habitat associations in the three genera of mussels found in the western United States (Anodonta, Gonidea, and Margaritifera) we used a multiscale random forest modeling approach to assess functional habitat parameters throughout a 55 km segment of the upper Middle Fork John Day River in northeastern Oregon. We characterized mussel occurrence and density with respect to the hierarchical, hydrogeomorphic structure by sampling reaches of varying valley confinement and channel units nested within individual reaches. Each genus exhibited unique longitudinal trends and channel unit-use patterns. In particular, the large-scale longitudinal trends in Margaritifera occurrence were associated with hydrogeomorphic characteristics at the reach and channel unit scale, with Margaritifera densities peaking in narrow valley segments and in riffles and runs. At the scale of the channel unit, all mussel genera responded to variation in physical habitat characteristics, particularly those that indicated more stable parts of the channel. Our results suggest that spatial patterns in freshwater mussels are associated with the hierarchical structuring of the lotic ecosystem and may provide guidance to restoration efforts. © 2014 Can. J. Fish. Aquat. Sci. All rights reserved.
Ray C.T.,Northern Arizona University |
Dickson B.G.,Northern Arizona University |
Dickson B.G.,Conservation Science Partners Inc. |
Sisk T.D.,Northern Arizona University |
And 2 more authors.
Forest Ecology and Management | Year: 2014
Wildlife species of conservation concern can present forest managers with a particular challenge when habitat needs appear to be in contrast with other management objectives, particularly fuel reduction to reduce wildfire risk. Proposed actions can be opposed by stakeholders, delaying management activities until a resolution is met. In the southwestern USA, the primary goal of forest management is to reduce the risk of severe wildfire through forest restoration treatments. The USDA Forest Service has designated the northern goshawk (Accipiter gentilis) a management indicator species in this region. However, it has been difficult to achieve a common understanding of goshawk habitat needs among forest stakeholders. We combined two separate and complementary modeling approaches - a statistically based occurrence model and alternative forest treatment models - to yield predictions about forest management effects on the goshawk in ponderosa pine-dominated forests (Pinus ponderosa) on the Kaibab Plateau, Arizona. Forest treatment models were developed based on USDA Forest Service recommendations for goshawk habitat and post-treatment data from ecological restoration experiments, both of which were also components of forest treatment guidance from the Kaibab Forest Health Focus collaborative planning effort. All treatment alternatives resulted in a 22-26% reduction in estimated goshawk occurrence, but the declines were not uniform across the study area, varied by forest type, and were not as large as the effects of recent and severe wildfire (44% reduction in occurrence). Considering the controversial history of forest management with respect to the goshawk, it is prudent to interpret results from this study in the context of tradeoffs between wildfire risk reduction and wildlife habitat quality that can be effectively evaluated through science-based collaborative assessment and planning. While developed for a specific, high-profile species in the southwestern USA, the approach is applicable to many other species whose occurrence has been monitored over multiple years. © 2014 Elsevier B.V.
Harrison-Atlas D.,Colorado State University |
Theobald D.M.,Colorado State University |
Theobald D.M.,Conservation Science Partners Inc. |
Goldstein J.H.,Colorado State University
International Journal of Biodiversity Science, Ecosystems Services and Management | Year: 2016
Global threats to freshwater resources are prompting widespread concern about their management and implications for well-being. In recent decades, hydrologic ecosystem services (HES) have emerged as an innovative concept to evaluate freshwater resources, providing opportunity for researchers to engage in decision-relevant science. We conducted a systematic review of studies published within the last decade, documenting approaches for mapping and quantifying HES and classifying the decision context. To gauge the relevance of HES science, we evaluated 49 case studies using multiple criteria for credibility, legitimacy, and saliency. We found compelling evidence that much of the variability in the quantification of HES can be explained by research motivations and scoping, reflecting the decision-oriented framing of the ecosystem services concept. Our review highlights key knowledge gaps in the state of the science including the need to articulate beneficiaries and to make connections to policy and management more explicit. To strengthen the potential for impact of HES science, we provide recommendations to assist researchers, practitioners, and decision-makers in identifying goals, formulating relevant questions, and selecting informative approaches for quantifying HES. We argue that sustained progress in applying HES requires critical evaluation and careful framing to link science and practice. © 2016 Informa UK Limited, trading as Taylor & Francis Group.
Gray M.E.,Conservation Science Partners Inc. |
Dickson B.G.,Conservation Science Partners Inc. |
Dickson B.G.,Northern Arizona University
Landscape Ecology | Year: 2016
Context: Strategic placement of fuel treatments across large landscapes is an important step to mitigate the collective effects of fires interacting over broad spatial and temporal extents. On landscapes where highly invasive cheatgrass (Bromus tectorum) is increasing fire activity, such an approach could help maintain landscape resilience. Objectives: Our objectives are to 1) model and map fire connectivity on a cheatgrass-invaded landscape, as well as the centrality of large cheatgrass patches, in order to inform a landscape fuel treatment (i.e., a network of greenstrips); and 2) evaluate the modeled greenstrip network based on changes to cheatgrass patch centrality. Methods: Our analysis covers 485-km2 on the Kaibab National Forest in Northern Arizona. We apply a circuit-theoretic model of fire connectivity between all pairs of large cheatgrass patches. Based on these results, we calculate a measure of centrality for each patch to inform fuel treatment placement. We evaluate the modeled greenstrip network by comparing the pre- and post-treatment centrality of each patch. Results: After modeling fire connectivity across the landscape, we identify 25 of 68 large cheatgrass patches with relatively high centrality. When we simulate greenstrips around these focal patches, model results suggest that they are effective in reducing the centrality for at least 19 of the 25 patches. Conclusions: Fire connectivity models provide robust network centrality measures, which can help generate multiple, landscape fuel treatment alternatives and facilitate on-the-ground decisions. The extension of these methods is well suited for landscape fuels management in other vegetation communities and ecosystems. © 2016 Springer Science+Business Media Dordrecht
Brodie J.F.,University of British Columbia |
Giordano A.J.,Texas Tech University |
Dickson B.,Conservation Science Partners Inc. |
Dickson B.,Northern Arizona University |
And 5 more authors.
Conservation Biology | Year: 2015
Habitat corridors are important tools for maintaining connectivity in increasingly fragmented landscapes, but generally they have been considered in single-species approaches. Corridors intended to facilitate the movement of multiple species could increase persistence of entire communities, but at the likely cost of being less efficient for any given species than a corridor intended specifically for that species. There have been few tests of the trade-offs between single- and multispecies corridor approaches. We assessed single-species and multispecies habitat corridors for 5 threatened mammal species in tropical forests of Borneo. We generated maps of the cost of movement across the landscape for each species based on the species' local abundance as estimated through hierarchical modeling of camera-trap data with biophysical and anthropogenic covariates. Elevation influenced local abundance of banded civets (Hemigalus derbyanus) and sun bears (Helarctos malayanus). Increased road density was associated with lower local abundance of Sunda clouded leopards (Neofelis diardi) and higher local abundance of sambar deer (Rusa unicolor). Pig-tailed macaque (Macaca nemestrina) local abundance was lower in recently logged areas. An all-species-combined connectivity scenario with least-cost paths and 1 km buffers generated total movement costs that were 27% and 23% higher for banded civets and clouded leopards, respectively, than the connectivity scenarios for those species individually. A carnivore multispecies connectivity scenario, however, increased movement cost by 2% for banded civets and clouded leopards. Likewise, an herbivore multispecies scenario provided more effective connectivity than the all-species-combined scenario for sambar and macaques. We suggest that multispecies habitat connectivity plans be tailored to groups of ecologically similar, disturbance-sensitive species to maximize their effectiveness. © 2014 Society for Conservation Biology.