Skip to main content
Advanced Search

Filters: Tags: Ecosphere (X)

162 results (302ms)   

View Results as: JSON ATOM CSV
thumbnail
Microbial interactions could play an important role in plant invasions. If invasive plants associate with relatively more mutualists or fewer pathogens than their native counterparts, then microbial communities could foster plant invasiveness. Studies examining the effects of microbes on invasive plants commonly focus on a single microbial group (e.g., bacteria) or measure only plant response to microbes, not documenting the specific taxa associating with invaders. We surveyed root microbial communities associated with co‐occurring native and non‐native lineages of Phragmites australis, across Michigan, USA. Our aim was to determine whether (1) plant lineage was a stronger predictor of root microbial community composition...
Categories: Publication; Types: Citation; Tags: Ecosphere
thumbnail
Artificial additions of nutrients of differing forms such as salmon carcasses and analog pellets (i.e. pasteurized fishmeal) have been proposed as a means of stimulating aquatic productivity and enhancing populations of anadromous and resident fishes. Nutrient mitigation to enhance fish production in stream ecosystems assumes that the central pathway by which effects occur is bottom-up, through aquatic primary and secondary production, with little consideration of reciprocal aquatic-terrestrial pathways. The net outcome (i.e. bottom-up vs. top-down) of adding salmon-derived materials to streams depend on whether or not these subsidies indirectly intensify predation on in situ prey via increases in a shared predator...
Categories: Publication; Types: Citation; Tags: Ecosphere
thumbnail
The migration of animals across long distances and between multiple habitats presents a major challenge for conservation. For the migratory Mexican free-tailed bat (Tadarida brasiliensis mexicana), these challenges include identifying and protecting migratory routes and critical roosts in two countries, the United States and Mexico. Knowledge and conservation of bat migratory routes is critical in the face of increasing threats from climate change and wind turbines that might decrease migratory survival. We employ a new modeling approach for bat migration, network modeling, to simulate migratory routes between winter habitat in southern Mexico and summer breeding habitat in northern Mexico and the southwestern United...
Categories: Publication; Types: Citation; Tags: Ecosphere
thumbnail
Timing can be critical for many life history events of organisms. Consequently, the timing of management activities may affect individuals and populations in numerous and unforeseen ways. Translocations of organisms are used to restore or expand populations but the timing of translocations is largely unexplored as a factor influencing population success. We hypothesized that the process of translocation negatively influences reproductive rates of individuals that are moved just before their birthing season and, therefore, the timing of releases could influence translocation success. Prior to reintroducing fishers (Pekania pennanti) into northern California and onto the Olympic Peninsula of Washington, we predicted...
Categories: Publication; Types: Citation; Tags: Ecosphere
thumbnail
In the present period of rapid, worldwide change in climate and landuse (i.e., global change), successful biodiversity conservation warrants proactive management responses, especially for long-distance migratory species. However, the development and implementation of management strategies can be impeded by high levels of uncertainty and low levels of control over potentially impactful future events and their effects. Scenario planning and modeling are useful tools for expanding perspectives and informing decisions under these conditions. We coupled scenario planning and statistical modeling to explain and predict playa wetland inundation (i.e., presence/absence of water) and ponded area (i.e., extent of water) in...
Categories: Publication; Types: Citation; Tags: Ecosphere
thumbnail
Conservation and management of spatially structured populations is challenging because solutions must consider where individuals are located, but also differential individual space use as a result of landscape heterogeneity. A recent extension of spatial capture–recapture (SCR) models, the ecological distance model, uses spatial encounter histories of individuals (e.g., a record of where individuals are detected across space, often sequenced over multiple sampling occasions), to estimate the relationship between space use and characteristics of a landscape, allowing simultaneous estimation of both local densities of individuals across space and connectivity at the scale of individual movement. We developed two model-based...
Categories: Publication; Types: Citation; Tags: Ecosphere
thumbnail
Contact rates vary widely among individuals in socially structured wildlife populations. Understanding the interplay of factors responsible for this variation is essential for planning effective disease management. Feral swine (Sus scrofa) are a socially structured species which pose an increasing threat to livestock and human health, and little is known about contact structure. We analyzed 11 GPS data sets from across the United States to understand the interplay of ecological and demographic factors on variation in co-location rates, a proxy for contact rates. Between-sounder contact rates strongly depended on the distance among home ranges (less contact among sounders separated by >2 km; negligible between sounders...
Categories: Publication; Types: Citation; Tags: Ecosphere
thumbnail
Understanding invasive species distributions and potential invasions often requires broad‐scale information on the environmental tolerances of the species. Further, resource managers are often faced with knowing these broad‐scale relationships as well as nuanced environmental factors related to their landscape that influence where an invasive species occurs and potentially could occur. Using invasive buffelgrass (Cenchrus ciliaris), we developed global models and local models for Saguaro National Park, Arizona, USA, based on location records and literature on physiological tolerances to environmental factors to investigate whether environmental relationships of a species at a global scale are also important at local...
Categories: Publication; Types: Citation; Tags: Ecosphere
thumbnail
Survival is a key vital rate for projecting the viability of wild populations. Estimating survival is difficult for many rare or elusive species because recapture rates of marked individuals are low, and the ultimate fate of individuals is unknown. Low recapture rates for many species have made it difficult to accurately estimate survival, and to evaluate the importance of individual and environmental covariates for survival. Individual covariates such as size are particularly difficult to include in capture–mark–recapture models for elusive species because the state of the individual is unknown during periods when it is not captured. Here, we integrate a von Bertalanffy growth model with a multi‐state robust‐design...
Categories: Publication; Types: Citation; Tags: Ecosphere
thumbnail
Large mammalian herbivores introduced to islands without predators are predicted to undergo irruptive population and spatial dynamics, but only a few well-documented case studies support this paradigm. We used the Riney-Caughley model as a framework to test predictions of irruptive population growth and spatial expansion of caribou (Rangifer tarandus granti) introduced to Adak Island in the Aleutian archipelago of Alaska in 1958 and 1959. We utilized a time series of spatially explicit counts conducted on this population intermittently over a 54-year period. Population size increased from 23 released animals to approximately 2900 animals in 2012. Population dynamics were characterized by two distinct periods of...
Categories: Publication; Types: Citation; Tags: Ecosphere
thumbnail
Harvesting is the leading cause of adult tree mortality in forests of the northeastern United States. While current rates of timber harvest are generally sustainable, there is considerable pressure to increase the contribution of forest biomass to meet renewable energy goals. We estimated current harvest regimes for different forest types and regions across the U.S. states of New York, Vermont, New Hampshire, and Maine using data from the U.S. Forest Inventory and Analysis Program. We implemented the harvest regimes in SORTIE‐ND, an individual‐based model of forest dynamics, and simulated the effects of current harvest regimes and five additional harvest scenarios that varied by harvest frequency and intensity over...
Categories: Publication; Types: Citation; Tags: Ecosphere
thumbnail
Arctic caribou (Rangifer tarandus) have the longest terrestrial migration of any ungulate but little is known about the spatial and seasonal variation of minerals in summer forages and the potential impacts of mineral nutrition on the foraging behavior and nutritional condition of arctic caribou. We investigated the phenology, availability, and mechanistic relationships of calcium, phosphorus, magnesium, sodium, potassium, iron, manganese, copper, and zinc in three species of woody browse, three species of graminoids, and one forb preferred by caribou over two transects bisecting the ranges of the Central Arctic (CAH) and Western Arctic (WAH) caribou herds in Alaska. Transects traversed three ecoregions (Coastal...
Categories: Publication; Types: Citation; Tags: Ecosphere
thumbnail
Ecohydrological responses to climate change will exhibit spatial variability and understanding the spatial pattern of ecological impacts is critical from a land management perspective. To quantify climate change impacts on spatial patterns of ecohydrology across shrub steppe ecosystems in North America, we asked the following question: How will climate change impacts on ecohydrology differ in magnitude and variability across climatic gradients, among three big sagebrush ecosystems (SB-Shrubland, SB-Steppe, SB-Montane), and among Sage-grouse Management Zones? We explored these potential changes for mid-century for RCP8.5 using a process-based water balance model (SOILWAT) for 898 big sagebrush sites using site- and...
Categories: Publication; Types: Citation; Tags: Ecosphere
thumbnail
The Prairie Pothole Region, situated in the northern Great Plains, provides important stopover habitat for migratory shorebirds. During spring migration in the U.S. Prairie Potholes, 7.3 million shorebirds refuel in the region's myriad small, freshwater wetlands. Shorebirds use mudflats, shorelines, and ephemeral wetlands that are far more abundant in wet years than dry years. Generally, climate change is expected to bring warmer temperatures, seasonality shifts, more extreme events, and changes to precipitation. The impacts to wetland habitats are uncertain. In the Prairie Potholes, earlier spring onset and warmer temperatures may advance drying of wetlands or, alternately, increased spring precipitation may produce...
Categories: Publication; Types: Citation; Tags: Ecosphere
thumbnail
Common raven (Corvus corax; hereafter, raven) population abundance in the sagebrush steppe of the American West has increased threefold during the previous four decades, largely as a result of unintended resource subsidies from human land-use practices. This is concerning because ravens frequently depredate nests of species of conservation concern, such as greater sage-grouse (Centrocercus urophasianus; hereafter, sage-grouse). Grazing by livestock in sagebrush ecosystems is common practice on most public lands, but associations between livestock and ravens are poorly understood. The primary objective of this study was to identify the effects of livestock on raven occurrence while accounting for landscape characteristics...
Categories: Publication; Types: Citation; Tags: Ecosphere
thumbnail
Phenology is an integrative science that comprises the study of recurring biological activities or events. In an era of rapidly changing climate, the relationship between the timing of those events and environmental cues such as temperature, snowmelt, water availability or day length are of particular interest. This article provides an overview of the plant phenology sampling which will be conducted by the U.S. National Ecological Observatory Network NEON, the resulting data, and the rationale behind the design. Trained technicians will conduct regular in situ observations of plant phenology at all terrestrial NEON sites for the 30-year life of the observatory. Standardized and coordinated data across the network...
Categories: Publication; Types: Citation; Tags: Ecosphere
thumbnail
Determining where biodiversity is likely to be most vulnerable to climate change and methods to reduce that vulnerability are necessary first steps to incorporate climate change into biodiversity management plans. Here, we use a spatial climate change vulnerability assessment to (1) map the potential vulnerability of terrestrial biodiversity to climate change in the northeastern United States and (2) provide guidance on how and where management actions for biodiversity could provide long-term benefits under climate change (i.e., climate-smart management considerations). Our model suggests that biodiversity will be most vulnerable in Delaware, Maryland, and the District of Columbia due to the combination of high...
Categories: Publication; Types: Citation; Tags: Ecosphere
thumbnail
Anthropogenic desertification is a problem that plagues drylands globally; however, the factors which maintain degraded states are often unclear. In Canyonlands National Park on the Colorado Plateau of southeastern Utah, many degraded grasslands have not recovered structure and function >40 yr after release from livestock grazing pressure, necessitating active restoration. We hypothesized that multiple factors contribute to the persistent degraded state, including lack of seed availability, surficial soil-hydrological properties, and high levels of spatial connectivity (lack of perennial vegetation and other surface structure to retain water, litter, seed, and sediment). In combination with seeding and surface raking...
Categories: Publication; Types: Citation; Tags: Ecosphere
thumbnail
Understanding how animal density is related to pathogen transmission is important to develop effective disease control strategies, but requires measuring density at a scale relevant to transmission. However, this is not straightforward or well-studied among large mammals with group sizes that range several orders of magnitude or aggregation patterns that vary across space and time. To address this issue, we examined spatial variation in elk (Cervus canadensis) aggregation patterns and brucellosis across 10 regions in the Greater Yellowstone Area where previous studies suggest the disease may be increasing. We hypothesized that rates of increasing brucellosis would be better related to the frequency of large groups...
Categories: Publication; Types: Citation; Tags: Ecosphere
thumbnail
Roads are significant barriers to landscape-scale movements of individuals or populations of many wildlife taxa. The decision by an animal near a road to either cross or not cross may be influenced by characteristics of the road, environmental conditions, traits of the individual animal, and other aspects of the context within which the decision is made. We considered such factors in a mixed-effects logistic regression model describing the nightly road crossing probabilities of invasive nocturnal Brown Treesnakes (Boiga irregularis) through short-term radiotracking of 691 snakes within close proximity to 50 road segments across the island of Guam. All measures of road magnitude (traffic volume, gap width, surface...
Categories: Publication; Types: Citation; Tags: Ecosphere


map background search result map search result map Moving across the border: Modeling migratory bat populations Irruptive dynamics of introduced caribou on Adak Island, Alaska: an evaluation of Riney-Caughley model predictions Irruptive dynamics of introduced caribou on Adak Island, Alaska: an evaluation of Riney-Caughley model predictions Moving across the border: Modeling migratory bat populations