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Understanding the effects of climatic variability is important to development of water resources, mitigation of flood hazards, and interpretation of geomorphic surfaces. Climatic variability, which is characterized by temporal changes in variability of seasonal climate that spans decades or centuries, may be more important to water-resources evaluations than changes in mean climatic conditions. Changes in variability of climate has a large effect on the probability of occurrence of extreme events, such as floods or droughts. Understanding of climatic variability and its effect on the landscape is of paramount importance for estimation of flood frequency, sediment transport rates, and long-term watershed and channel...
Male boreal toads (Bufo boreas) are thought to return to the breeding site every year but, if absent in a particular year, will be more likely to return the following year. Using Pollock's robust design we estimated temporary emigration (the probability a male toad is absent from a breeding site in a given year) at three locations in Colorado, USA: two in Rocky Mountain National Park and one in Chaffee County. We present data that suggest that not all male toads return to the breeding site every year. Our analyses indicate that temporary emigration varies by site and time (for example, from 1992 to 1998, the probability of temporary emigration ranged from 10% to 29% and from 3% to 95% at Lost Lake and Kettle Tarn,...
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We present a combined analysis of data from two large-scale surveys of bird populations. The North American Breeding Bird Survey is conducted each summer; the Christmas Bird Count is conducted in early winter. The temporal staggering of these surveys allows investigation of seasonal components of population change, which we illustrate with an examination of the effects of severe winters on the Carolina Wren (Thryothorus ludovicianus). Our analysis uses a hierarchical log-linear model with controls for survey-specific sampling covariates. Temporal change in population size is modeled seasonally, with covariates for winter severity. Overall, the winter?spring seasons are associated with 82% of the total population...
Categories: Publication; Types: Citation; Tags: Ecology
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This data is part of the Gulf Watch Alaska (GWA) long term monitoring program, nearshore monitoring component. The data consists of date, time, and temperature measurements from intertidal rocky sampling sites. The dataset is 5 comma separated files exported from a download from the HOBO temperature logger. Sites are in Alaska and include locations in Katmai National Park and Preserve, Kenai Fjords National Park and northern and western Prince William Sound. There are five sites in each of those areas. The time interval includes 2014-2016. Temperature loggers were set to record hourly. Each file is comprised of data from a single site from a given year. Loggers were re-used so the logger serial number is included...
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Parasitologists have worked out many complex life cycles over the last ~150 years, yet there have been few efforts to synthesize this information to facilitate comparisons among taxa. Most existing host-parasite databases focus on particular host taxa, do not distinguish final from intermediate hosts, and lack parasite life-history information. We summarized the known life cycles of trophically transmitted parasitic acanthocephalans, cestodes, and nematodes. For 973 parasite species, we gathered information from the literature on the hosts infected at each stage of the parasite life cycle (8510 host-parasite species associations), what parasite stage is in each host, and whether parasites need to infect certain...
Categories: Publication; Types: Citation; Tags: Ecology
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These datasets contain aquatic macroinvertebrate and water quality data collected from 159 wetlands in Montana and North Dakota within the Prairie Pothole Region of the Williston Basin.
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Sea Otter (Enhydra lutris), well documented as "keystone" predators in rocky marine communities, were found to exert a strong influence on infaunal prey communities in soft-sediment habitats. Direct and indirect effects of sea otter predation on subtidal soft-bottom prey communities were evaluated along a temporal gradient of sea otter occupancy around the Kodiak Archipelago. The results indicate that Kodiak otters forage primarily on bivalve prey and dramatically reduce infaunal bivalve and green sea urchin (Strongylocentrotus droebachiensis) prey populations. Bivalve prey abundance, biomass, and size were inversely related to duration of sea otter occupancy. The relative conditions of shells discarded by otters...
Categories: Publication; Types: Citation; Tags: Ecology
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The Forest and Rangeland Ecosystem Science Center 's mission is to provide scientific understanding and the technology needed to support sound management and conservation of our nation's natural resources, with emphasis on western ecosystems. The scientists from FRESC capitalize on their diverse expertise to answer critically important scientific questions shaped by the equally diverse environments of the western United States. FRESC scientists collaborate with each other and with partners to provide rigorous, objective, and timely information and guidance for the management and conservation of biological systems in the West and worldwide. Research activities are concentrated in Washington, Oregon, Idaho, Nevada,...
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Ecological structures and processes occur at specific spatiotemporal scales, and interactions that occur across multiple scales mediate scale-specific (e.g., individual, community, local, or regional) responses to disturbance. Despite the importance of scale, explicitly incorporating a multi-scale perspective into research and management actions remains a challenge. The discontinuity hypothesis provides a fertile avenue for addressing this problem by linking measureable proxies to inherent scales of structure within ecosystems. Here we outline the conceptual framework underlying discontinuities and review the evidence supporting the discontinuity hypothesis in ecological systems. Next we explore the utility of this...
Categories: Publication; Types: Citation; Tags: Ecology
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A productive way forward in studies of animal populations is to efficiently make use of all the information available, either as raw data or as published sources, on critical parameters of interest. In this study, we demonstrate two approaches to the use of multiple sources of information on a parameter of fundamental interest to ecologists: animal density. The first approach produces estimates simultaneously from two different sources of data. The second approach was developed for situations in which initial data collection and analysis are followed up by subsequent data collection and prior knowledge is updated with new data using a stepwise process. Both approaches are used to estimate density of a rare and elusive...
Categories: Publication; Types: Citation; Tags: Ecology
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In tallgrass prairie, belowground processes are even more important than in forested systems because aboveground biomass and standing dead litter are periodically removed by frequent fires or grazers. Thus, studies that address factors regulating belowground processes are especially relevant for tallgrass prairie. We predicted that effects of grazing and burning differ belowground and that changes in root productivity caused by burning or grazing provide feedback that affects ecosystem fluxes of C and N. These differences in belowground response should be driven largely by changes in N dynamics and the degree to which burning and grazing affect the pathway and magnitude of N loss and the degree of N limitation in...
Categories: Publication; Types: Citation; Tags: Ecology
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We propose a general framework for modeling anuran abundance using data collected from commonly used calling surveys. The data generated from calling surveys are indices of calling intensity (vocalization of males) that do not have a precise link to actual population size and are sensitive to factors that influence anuran behavior. We formulate a model for calling-index data in terms of the maximum potential calling index that could be observed at a site (the 'latent abundance class'), given its underlying breeding population, and we focus attention on estimating the distribution of this latent abundance class. A critical consideration in estimating the latent structure is imperfect detection, which causes the observed...
Categories: Publication; Types: Citation; Tags: Ecology
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Corn and Muths (2002) describe how seasonal and annual variation in estimated flux of ultraviolet-B (UV-B) radiation, combined with year-to-year variation in amphibian breeding, phenology, introduces considerable variability in the UV-B exposures to amphibians. The response to our paper by Blaustein et al. (2004) misstates the objective and conclusions of our study, contains other errors of interpretation, and critiques our study for adopting practices that they themselves use. We are confident that an unbiased assessment will show that the conclusions of Corn and Muths (2002) are valid and robust with respect to montane amphibians, and that the criticisms raised by Blaustein et al. (2004) are either invalid or...
Categories: Publication; Types: Citation; Tags: Ecology
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Distance-sampling methods are commonly used in studies of animal populations to estimate population density. A common objective of such studies is to evaluate the relationship between abundance or density and covariates that describe animal habitat or other environmental influences. However, little attention has been focused on methods of modeling abundance covariate effects in conventional distance-sampling models. In this paper we propose a distance-sampling model that accommodates covariate effects on abundance. The model is based on specification of the distance-sampling likelihood at the level of the sample unit in terms of local abundance (for each sampling unit). This model is augmented with a Poisson regression...
Categories: Publication; Types: Citation; Tags: Ecology
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Many studies of pond-breeding amphibians involve sampling individuals during migration to and from breeding habitats. Interpreting population processes and dynamics from these studies is difficult because (1) only a proportion of the population is observable each season, while an unknown proportion remains unobservable (e.g., non-breeding adults) and (2) not all observable animals are captured. Imperfect capture probability can be easily accommodated in capture?recapture models, but temporary transitions between observable and unobservable states, often referred to as temporary emigration, is known to cause problems in both open- and closed-population models. We develop a multistate mark?recapture (MSMR) model,...
Categories: Publication; Types: Citation; Tags: Ecology
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Population viability analysis is an important tool for conservation biologists, and matrix models that incorporate stochasticity are commonly used for this purpose. However, stochastic simulations may require assumptions about the distribution of matrix parameters, and modelers often select a statistical distribution that seems reasonable without sufficient data to test its fit. We used data from long-term (5a??10 year) studies with 27 populations of five perennial plant species to compare seven methods of incorporating environmental stochasticity. We estimated stochastic population growth rate (a measure of viability) using a matrix-selection method, in which whole observed matrices were selected at random at each...
Categories: Publication; Types: Citation; Tags: Ecology
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Although nonparametric statistical methods have a role to play in the analysis of data, often their virtues are overstated and their deficiencies overlooked. A recent Special Feature in Ecology advocated nonparametric methods because of an erroneously stated advantage that they require no assumptions regarding the distribution underlying the observations. The present paper points out some often—ignored feature of nonparametric tests comparing two means, and advocates parameter estimation as a preferred alternative to hypothesis testing in many situations.
Categories: Publication; Types: Citation; Tags: Ecology
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My Concepts and Synthesis paper (Lafferty 2009),which inspired this Forum, echoed the premise that earlyreviews about climate change exaggerated claims thatinfectious diseases will increase in the future (Randolph2009). The paper sparked five well-reasoned commen-taries from ecologists with considerable expertise ininfectious diseases (Dobson 2009, Harvell et al. 2009,Ostfeld 2009, Pascual and Bouma 2009, Randolph2009). These reviews illustrate several examples andcase studies which corr elate i ncreases in infectiousdisease with existing climate variation, though alterna-tive explanations exist for many of these patterns(Dobson 2009, Harvell et al. 2009, Ostfeld 2009, Pascualand Bouma 2009, Randolph 2009). A common...
Categories: Publication; Types: Citation; Tags: Ecology


map background search result map search result map Marine Water Quality, Water Temperature from Prince William Sound, Katmai National Park and Preserve, and Kenai Fjords National Park, 2014-2016 Macroinvertebrate and water quality data from the Prairie Pothole Region of the Williston Basin (2014-2016) Macroinvertebrate and water quality data from the Prairie Pothole Region of the Williston Basin (2014-2016) Marine Water Quality, Water Temperature from Prince William Sound, Katmai National Park and Preserve, and Kenai Fjords National Park, 2014-2016