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The effects of catchment size and landscape organization on runoff generation are poorly understood. Little research has integrated hillslope and riparian runoff investigation across catchments of different sizes to decipher first-order controls on runoff generation. We investigated the role of catchment sizes on riparian and hillslope dynamics based on hydrometric and tracer data observed at five scales ranging from trenched hillslope sections (55–285 m2) to a 280-ha catchment at Maimai on the west coast of the South Island, New Zealand. The highly organized landscape is comprised of similar headwater catchments, regular geology, steep highly dissected topography, relatively consistent soil depths, and topographically...
Recent work has demonstrated that the topological properties of real river networks deviate significantly from predictions of Shreve's random model. At the same time the property of mean self-similarity postulated by Tokunaga's model is well supported by data. Recently, a new class of network model called random self-similar networks (RSN) that combines self-similarity and randomness has been introduced to replicate important topological features observed in real river networks. We investigate if the hypothesis of statistical self-similarity in the RSN model is supported by data on a set of 30 basins located across the continental United States that encompass a wide range of hydroclimatic variability. We demonstrate...
The invasion paradox describes the co-occurrence of independent lines of support for both a negative and a positive relationship between native biodiversity and the invasions of exotic species. The paradox leaves the implications of native?exotic species richness relationships open to debate: Are rich native communities more or less susceptible to invasion by exotic species? We reviewed the considerable observational, experimental, and theoretical evidence describing the paradox and sought generalizations concerning where and why the paradox occurs, its implications for community ecology and assembly processes, and its relevance for restoration, management, and policy associated with species invasions. The crux...
Modelling strategies for predicting the potential impacts of climate change on the natural distribution of species have often focused on the characterization of a species’ bioclimate envelope. A number of recent critiques have questioned the validity of this approach by pointing to the many factors other than climate that play an important part in determining species distributions and the dynamics of distribution changes. Such factors include biotic interactions, evolutionary change and dispersal ability. This paper reviews and evaluates criticisms of bioclimate envelope models and discusses the implications of these criticisms for the different modelling strategies employed. It is proposed that, although the complexity...
Land used for agricultural production comprises a significant portion of the United States (US) land area and is increasingly the focus of conservation efforts. These efforts include programs to protect and improve the quality of water, soil, and wildlife habitat. Government conservation efforts in the US focus on voluntary conservation programs. As the success of these programs depends on the participation of agricultural producers, much research has examined factors influencing producer decision-making. This research has provided important insights regarding micro and meso-scale factors influencing participation, but has tended to overlook macro-scale political and economic factors that increasingly shape production...
Recent energy development has resulted in rapid and large-scale changes to western shrub-steppe ecosystems without a complete understanding of its potential impacts on wildlife populations. We modeled winter habitat use by female greater sage-grouse (Centrocercus urophasianus) in the Powder River Basin (PRB) of Wyoming and Montana, USA, to 1) identify landscape features that influenced sage-grouse habitat selection, 2) assess the scale at which selection occurred, 3) spatially depict winter habitat quality in a Geographic Information System, and 4) assess the effect of coal-bed natural gas (CBNG) development on winter habitat selection. We developed a model of winter habitat selection based on 435 aerial relocations...
Three watersheds within a marsh system draining into Lake Michigan in northwest Indiana, USA, were studied for differences among land use, habitat conditions and water quality to determine their influence on macroinvertebrate community structure. Much of this area had been altered for agricultural, commercial, industrial and residential land uses. Land use, habitat conditions and water quality were significantly different among watersheds. Water quality varied more among streams than within streams. Several variables were related to land use, especially dissolved ions. Macroinvertebrate communities depicted neither a healthy wetland nor a healthy stream system. Some sites were typical of a sand-based, erosional...
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Landscape Conservation Cooperatives are public-private partnerships composed of federal, state, and local governments, Tribes and First Nations, non-governmental organizations, universities, interested public and private organizations, international jurisdictions, and others working together to address landscape and seascape scale conservation issues. However, numerous approaches to landscape conservation design (LCD) exist and the nuances among these efforts makes integration of LCD with other planning efforts and products, both within and across Landscape Conservation Cooperative boundaries, a challenge. We reviewed and synthesized information on LCD projects in the eastern United States to better understand challenges...
The relative importance of macro-and micro-scale processes in the biosphere is controversial, with some researchers emphasizing micro-scale population dynamics and others macro-scale landscape dynamics. I hypothesize that there is spatial variation in the linkage between and importance of macro-and micro-environmental influences on vegetation, and explore this hypothesis in a case study of riparian vegetation in the mountains of western Colorado. I estimate percent cover, by species, in 115-0.1 ha samples of riparian vegetation at relatively undisturbed sites. Environmental variables measured at each site include several channel characteristics, valley characteristics, geographical coordinates, and drainage basin...
Conclusions:Habitat heterogeneity is often perceived as fragmentation by certain species depending on spatial scales.Thresholds/Learnings:
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The distance within which populations respond to features in a landscape (scale of effect) can indicate how disturbance and management may affect wildlife. Using annual counts of male Greater Sage-grouse (Centrocercus urophasianus) attending 584 leks in southwest Wyoming (2003-2019) and estimates of sagebrush cover from the Rangeland Condition Monitoring Assessment and Projection (RCMAP), we used a scale selection approach to jointly estimate the scale of effect and the effect of sagebrush cover in the surrounding landscape for sage-grouse population trends. We estimated these parameters using a state-space model fit with a Bayesian approach. Data formatting necessary for this analysis produced data stored in two...
Between 1989-1991, I studied the effects of livestock grazing on vegetation and small mammals in semiarid shrub-grassland habitats of south-central Utah. Responses were measured at 2 spatial habitat scales; patches and macrohabitats. Patch-scale data were obtained from 4 small (<1 ha) livestock exclosures and nearby grazed areas. Macrohabitat-scale data were collected at 4 actively grazed sites and 4 comparable, excellent condition sites, ungrazed for 30+ years. Ungrazed patch and macrohabitat sites had more surface litter, greater perennial grass cover, and taller perennial grass plants, but treatment response varied among sites. Small mammal responses were apparent only at the macrohabitat scale, where ungrazed...
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The assessment of ecological integrity remains a primary component of present-day conservation strategies for freshwater ecosystems, but approaches vary widely in method, scale, efficiency, and sustainability. The need for standardized assessment practices have been noted in several national conservation initiatives. The range of approaches under development or in use by LCCs and partner agencies offered a timely opportunity to summarize the range of approaches, identify data that would facilitate particularly promising methods, and evaluate the success with which assessments are currently integrated into broad conservation planning and management. The investigators goals for this project were to provide LCCs and...
    map background search result map search result map Integrating Approaches to Conservation Design across the LCC Network in the East Systematic review of aquatic ecological integrity assessments in western North America, Identifying challenges and opportunities for integration into landscape conservation plans Sagebrush (Artemisia spp.) scale of effect for Greater Sage-grouse (Centrocercus urophasianus) population trends in southwest Wyoming, USA 2003-2019 Sagebrush (Artemisia spp.) scale of effect for Greater Sage-grouse (Centrocercus urophasianus) population trends in southwest Wyoming, USA 2003-2019 Systematic review of aquatic ecological integrity assessments in western North America, Identifying challenges and opportunities for integration into landscape conservation plans Integrating Approaches to Conservation Design across the LCC Network in the East