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At least 613 records · Page 34Linked to original sources
USGS1997

The sandflat habitat: Scaling from experiments to conclusions

Ecological systems are characterised by spatial and temporal variations in the density of organisms and resources, and in the intensity of processes which affect them (e.g. Watt, 1947, Dayton, 1971, Addicot et al., 1987, Kolasa and Pickett, 1991 and Giller et al., 1994). This heterogeneity represents both a difficulty for field study design and statistical testing, and a challenge to describe the spatial structuring of populations, communities and ecosystems (Legendre, 1993). Patterns in ecological and environmental variables are fundamental to developing hypotheses and in designing subsequent field studies, because they determine the spatial and temporal scales of study. Spatial and/or temporal patterns also provide useful stepping stones for addressing issues of scale. Patterns apparent at one scale can collapse to noise when viewed from other scales, indicating that patterns, processes and our perceptions vary in a scale-dependent manner. Perhaps the most important but rarely discussed issue is the question of how to scale-up from small-scale surveys and experiments to conclusions relevant at larger spatial and temporal scales.

Conference Paper↗
USGS2023

Density-dependent processes and population dynamics of native sculpin in a mountain river

Understanding the processes governing population dynamics is important for effective conservation and environmental management. Disentangling the relative role of density-dependent versus density-independent processes on population dynamics is often made difficult by the inability to control for abiotic or biotic factors, but long-term datasets are invaluable in this pursuit. We used a 14-year dataset from the Logan River, Utah, to assess long-term trends in abundance and evidence of density-dependent and density-independent effects on population dynamics of Paiute sculpin ( Cottus beldingii ) across six sites. Additionally, we evaluated the feeding ecology of sculpin over 4 years. Sculpin densities generally increased from upstream to downstream, and the annual per capita rate of increase was negatively and significantly correlated with sculpin density at four of six sites. We observed a negative relationship between total gut content and sculpin density but did not observe a negative relationship between relative condition and density. Sculpin displayed a generalist feeding strategy, and interannual differences in diet composition appeared to be influenced by interannual differences in flow, particularly years with higher magnitude flow. The observed spatial patterns in sculpin abundance throughout the watershed matched those of invasive brown trout ( Salmo trutta ), the top piscivore in the Logan River, and likely represent affinities for the suite of ecological conditions associated with downstream sections of the Logan River. Our results suggest that sculpin populations are regulated largely by density-dependent processes and match those from other studies on sculpin population dynamics including a range of species and habitats that differ vastly in abiotic conditions.

Ecology of Freshwater Fish↗
USGS1999

Genetic and morphometric assessment of an unusual tortoise (Gopherus agassizii) population in the Black Mountains of Arizona

Under recent regulatory designation of the U.S. Fish and Wildlife Service, desert tortoises (Gopherus agassizii) occurring east and south of the Colorado River constitute the Sonoran population, whereas those to the west and north form the Mojave population. These management units, distinguished by significant genetic, morphometric, and ecological differences, represent deep phylogenetic subdivisions within G. agassizii and are of high conservation value. We provide genetic and morphological profiles for an unusual tortoise population inhabiting the Black Mountains of Arizona, some 40 km east of the Colorado River. Both mitochondrial (mt) DNA and morphometric analyses revealed predominately Mojavean features: ten of eleven Black Mountain tortoises possessed Mojave mtDNA markers, and 24 of 37 animals exhibited Mojave morphometric phenotypes. Our results indicate west-to-east movement of tortoises across the Colorado River, though how or when a Mojave lineage became established in the Black Mountains is difficult to ascertain. Active dispersal, river meander, and human transport (early or modern peoples) serve as plausible explanations. Future management of the Black Mountain tortoises should emphasize the population's Mojavean affinities.

Journal of Herpetology↗
USGS2014

Accounting for rate variation among lineages in comparative demographic analyses

Genetic analyses of contemporary populations can be used to estimate the demographic histories of species within an ecological community. Comparison of these demographic histories can shed light on community responses to past climatic events. However, species experience different rates of molecular evolution, and this presents a major obstacle to comparative demographic analyses. We address this problem by using a Bayesian relaxed-clock method to estimate the relative evolutionary rates of 22 small mammal taxa distributed across northwestern North America. We found that estimates of the relative molecular substitution rate for each taxon were consistent across the range of sampling schemes that we compared. Using three different reference rates, we rescaled the relative rates so that they could be used to estimate absolute evolutionary timescales. Accounting for rate variation among taxa led to temporal shifts in our skyline-plot estimates of demographic history, highlighting both uniform and idiosyncratic evolutionary responses to directional climate trends for distinct ecological subsets of the small mammal community. Our approach can be used in evolutionary analyses of populations from multiple species, including comparative demographic studies.

Evolution↗
USGS2015

Evaluating abundance and trends in a Hawaiian avian community using state-space analysis

Estimating population abundances and patterns of change over time are important in both ecology and conservation. Trend assessment typically entails fitting a regression to a time series of abundances to estimate population trajectory. However, changes in abundance estimates from year-to-year across time are due to both true variation in population size (process variation) and variation due to imperfect sampling and model fit. State-space models are a relatively new method that can be used to partition the error components and quantify trends based only on process variation. We compare a state-space modelling approach with a more traditional linear regression approach to assess trends in uncorrected raw counts and detection-corrected abundance estimates of forest birds at Hakalau Forest National Wildlife Refuge, Hawai‘i. Most species demonstrated similar trends using either method. In general, evidence for trends using state-space models was less strong than for linear regression, as measured by estimates of precision. However, while the state-space models may sacrifice precision, the expectation is that these estimates provide a better representation of the real world biological processes of interest because they are partitioning process variation (environmental and demographic variation) and observation variation (sampling and model variation). The state-space approach also provides annual estimates of abundance which can be used by managers to set conservation strategies, and can be linked to factors that vary by year, such as climate, to better understand processes that drive population trends.

Hawai'i↗
USGS2010

Population dynamics of the sand shiner (notropis stramineus) in non-wadeable rivers of Iowa

The sand shiner ( Notropis stramineus ) is a common cyprinid found throughout the Great Plains region of North America that plays an important ecological role in aquatic systems. This study was conducted to describe population dynamics of sand shiners including age structure, growth, mortality, and recruitment variability in 15 non-wadeable rivers in Iowa. Fish were collected during June-August (2007–2008) using a modified Missouri trawl, a seine, and boat-mounted electrofishing. Scales were removed for age and growth analysis. A total of 3,443 fish was sampled from 15 populations across Iowa, of which 676 were aged. Iowa's sand shiner populations consisted primarily of age-1 fish (53% of all fish sampled), followed by age-2 fish (30%), age-0 fish (15%), and age-3 fish (2%). Sand shiners grew an average of 38.5 mm (SE = 5.7) during their first year, 13.8 mm (4.5) during their second year, and 9.0 mm (6.9) during their third year. Total annual mortality varied from 35.0% to 92.3% among populations with a mean of 77.9% (0.2). Incremental mortality rates were 84.5% (0.2) between age 1 and age 2, and 92.0% (0.1) between age 2 and age 3. Recruitment was highly variable, as indicated by a mean recruitment variation index of-0.12 (0.54). Overall, the sand shiner was characterized by relatively low mean age, fast growth, high mortality, and high recruitment variability. Indices of sand shiner population dynamics were poorly correlated with habitat characteristics.

Iowa↗
USGS2017

Using multiple data types and integrated population models to improve our knowledge of apex predator population dynamics

Current management of large carnivores is informed using a variety of parameters, methods, and metrics; however, these data are typically considered independently. Sharing information among data types based on the underlying ecological, and recognizing observation biases, can improve estimation of individual and global parameters. We present a general integrated population model (IPM), specifically designed for brown bears ( Ursus arctos ), using three common data types for bear ( U . spp.) populations: repeated counts, capture–mark–recapture, and litter size. We considered factors affecting ecological and observation processes for these data. We assessed the practicality of this approach on a simulated population and compared estimates from our model to values used for simulation and results from count data only. We then present a practical application of this general approach adapted to the constraints of a case study using historical data available for brown bears on Kodiak Island, Alaska, USA. The IPM provided more accurate and precise estimates than models accounting for repeated count data only, with credible intervals including the true population 94% and 5% of the time, respectively. For the Kodiak population, we estimated annual average litter size (within one year after birth) to vary between 0.45 [95% credible interval: 0.43; 0.55] and 1.59 [1.55; 1.82]. We detected a positive relationship between salmon availability and adult survival, with survival probabilities greater for females than males. Survival probabilities increased from cubs to yearlings to dependent young ≥2 years old and decreased with litter size. Linking multiple information sources based on ecological and observation mechanisms can provide more accurate and precise estimates, to better inform management. IPMs can also reduce data collection efforts by sharing information among agencies and management units. Our approach responds to an increasing need in bear populations’ management and can be readily adapted to other large carnivores.

Ecology and Evolution↗
USGS2019

Improving population estimates of threatened spectacled eiders: Correcting aerial counts for visibility bias

Listed as threatened under the Endangered Species Act in 1993, the Spectacled Eider (Somateria fischeri) population in western Alaska has since rebounded, prompting an assessment of their suitability for delisting. This assessment, however, is limited by aerial-based population estimates that are incompletely corrected for unobserved eiders. Notably, aerial counts of eiders are corrected with a visibility correction factor (VCF), calculated as the ratio of ground-based nest counts to aerial pair counts, which disregards spatial variation in eider density. Accordingly, we (1) stratified our study area into zones of low, medium, and high eider density, (2) developed density-adjusted VCFs for each stratum, (3) evaluated the influence of several ecological factors on VCFs, and (4) estimated eider population size using our density-adjusted VCFs. For the low-density stratum, we estimated a VCF (± SE) of 1.35 ± 0.15, indicating that aerial counts of eider pairs closely matched ground counts of nests. In medium and high-density strata, VCFs increased to 2.46 ± 0.17 and 3.09 ± 0.19, respectively, suggesting that aerial detection decreased as eider densities increased. VCFs also increased for surveys that occurred late relative to nest initiation. Population estimates produced with our density-adjusted VCFs were 42% (5580 eiders) lower, on average, than those produced with the traditional VCF, which is currently used. Such large differences underscore the importance of accounting for density when correcting counts for incomplete detection, and, for threatened species such as Spectacled Eiders, may determine whether populations retain protected status.

Endangered Species Research↗
USGS2017

Ecology of the Eastern Kingsnake (Lampropeltis getula) at Rainey Slough, Florida: A vanished Eden

Eastern Kingsnakes ( Lampropeltis getula ) are an important component and predator in herpetofaunal communities, but many Eastern Kingsnake populations have declined precipitously in the last few decades, particularly in the southeastern United States. Here, we describe an intensive capture–mark–recapture study of L. getula conducted during 1974–1978 in a canal bank–Water Hyacinth ( Eichhornia crassipes ) community at Rainey Slough in southern Florida, where annual capture probabilities of adults ranged from 0.662–0.787. Population size and structure, seasonal activity, movements, microhabitat use, behavior, thermal ecology, and predator–prey relationships are described. At this site kingsnakes were susceptible to capture mostly in winter and spring, were diurnal, used rodent ( Sigmodon hispidus ) burrows on canal banks as nocturnal retreats, and emerged from burrows on 13–26% of the sampling days. Overlap of burrow use by both sexes was extensive with no evidence of territoriality. Kingsnakes readily entered the Water Hyacinths to bask, pursue mates, and forage. At Rainey Slough only snakes were detected in the diet of kingsnakes. Concurrent sampling of potential snake prey in the hyacinths and on canal banks revealed 10 species that varied in use of the two sampled habitats and in body size. A range-wide analysis confirmed that in descending order snakes, reptile eggs, and lizards dominate the diet of L. getula in Florida (94.8%) and remain important prey types elsewhere (80.2%). At Rainey Slough the density of six species of semiaquatic snakes in Water Hyacinths averaged 3534 individuals/ha with a mean annual biomass of 135.8 kg/ha, and kingsnake biomass was only 2.2–3.9% of prey snake biomass. We estimated that the kingsnake population consumed 36.82–63.58 kg/yr, or about 10.0–17.2% of the standing crop of snakes in the Water Hyacinth community. Adult male L. getula lost on average 39.3% of their body mass associated with the spring reproductive season, whereas females lost only 3.4% in the same period. Body condition indices for both sexes improved substantially thereafter. In follow-up surveys at Rainey Slough during 2006–2010 no kingsnakes were found. Semiaquatic snake densities in the Water Hyacinths were 77.2% lower (807.4/ha) than in the 1970s and consisted of only three species. Compared to the enigmatic declines and extirpation of L. getula populations elsewhere, at Rainey Slough the primary cause likely was unsustainable mortality from road reconstruction and paving in the winter–spring of 1979 and subsequent roadkill. Other potentially causative agents of extirpation of L. getula in this system are discussed.

Florida↗
USGS2017

Effects of climate change on ecological disturbance in the northern Rockies

Disturbances alter ecosystem, community, or population structure and change elements of the biological and/or physical environment. Climate changes can alter the timing, magnitude, frequency, and duration of disturbance events, as well as the interactions of disturbances on a landscape, and climate change may already be affecting disturbance events and regimes. Interactions among disturbance regimes, such as the cooccurrence in space and time of bark beetle outbreaks and wildfires, can result in highly visible, rapidly occurring, and persistent changes in landscape composition and structure. Understanding how altered disturbance patterns and multiple disturbance interactions might result in novel and emergent landscape behaviors is critical for addressing climate change impacts and for designing land management strategies that are appropriate for future climates This chapter describes the ecology of important disturbance regimes in the Northern Rockies region, and potential shifts in these regimes as a consequence of observed and projected climate change. We summarize five disturbance types present in the Northern Rockies that are sensitive to a changing climate--wildfires, bark beetles, white pine blister rust (Cronartium ribicola), other forest diseases, and nonnative plant invasions—and provide information that can help managers anticipate how, when, where, and why climate changes may alter the characteristics of disturbance regimes.

Rocky Mountains↗
USGS2024

Range-wide salamander densities reveal a key component of terrestrial vertebrate biomass in eastern North American forests

Characterizing the population density of species is a central interest in ecology. Eastern North America is the global hotspot for biodiversity of plethodontid salamanders, an inconspicuous component of terrestrial vertebrate communities, and among the most widespread is the eastern red-backed salamander, Plethodon cinereus . Previous work suggests population densities are high with significant geographic variation, but comparisons among locations are challenged by lack of standardization of methods and failure to accommodate imperfect detection. We present results from a large-scale research network that accounts for detection uncertainty using systematic survey protocols and robust statistical models. We analysed mark–recapture data from 18 study areas across much of the species range. Estimated salamander densities ranged from 1950 to 34 300 salamanders ha −1 , with a median of 9965 salamanders ha −1 . We compared these results to previous estimates for P. cinereus and other abundant terrestrial vertebrates. We demonstrate that overall the biomass of P. cinereus , a secondary consumer, is of similar or greater magnitude to widespread primary consumers such as white-tailed deer ( Odocoileus virginianus ) and Peromyscus mice, and two to three orders of magnitude greater than common secondary consumer species. Our results add empirical evidence that P. cinereus , and amphibians in general, are an outsized component of terrestrial vertebrate communities in temperate ecosystems.

Biology Letters↗
USGS1995

Arctic nesting geese: Alaskan populations

North American populations of most goose species have remained stable or have increased in recent decades (USFWS and Canadian Wildlife Service 1986). Some populations, however, have declined or historically have had small numbers of individuals, and thus are of special concern. Individual populations of geese should be maintained to ensure that they provide aesthetic, recreational, and ecological benefits to the nation. Monitoring and management efforts for geese should focus on individual populations to ensure that genetic diversity is maintain (Anderson et al. 1992). Alaska is the only state with viable breeding populations of arctic geese. Five species (11 subspecies) nest in Alaska, and although these species also breed in arctic regions of Canada or Russia, most geese of the Pacific Flyway originate in Alaska or use Alaskan habitats during migration. Alaskan geese are often hunted for subsistence by Alaskan natives. While data for some areas are lacking, populations of greater white-fronted geese ( Anser albifrons frontalis ) and medium-sized Canada geese ( Branta canadensis ) in interior and northern Alaska appear stable or have increased (King and Derksen 1986). Although only a small number of lesser snow geese ( Chen caerulescens caerulescens ) nest in Alaska, substantial populations occur in Canada and Russia. Populations of Pacific black brant ( B. bernicla nigricans ), emperor geese ( C. canagica ), greater white-fronted geese, and cackling Canada geese ( B.c. minima ) on the Yukon-Kuskokwim Delta (YKD) of western Alaska have declined from their historical numbers and are the focus of special management efforts (USFWS 1989). In addition, populations of tule white-fronted geese ( A.a. gambeli ), Aleutian Canada geese ( B.c. leucopareia ), Vancouver Canada Geese ( B.c. fulva ), and dusky Canada geese ( B.c. occidentalis ) are of special concern because of their limited geographic distributions and small numbers.

Book chapter↗
USGS2017

Spatiotemporal ecology of Apalone spinifera in a large, Great Plains river ecosystem

Sparse information exists about the ecology of Spiny Softshell Turtles (Apalone spinifera) in large rivers, at the northwestern extent of their natural range, and in Montana, where they are disjunct from downstream populations and a State Species of Concern. We determined spatiotemporal ecology of 47 female and 12 male turtles from 2009 through 2012 and identified fundamental habitats in the Missouri River in east-central Montana. Movement rates of females were greater than those of males and peaked before nesting. Movement rates of males peaked before overwintering, and movement rates of both sexes were minimal in winter. Home range sizes were not different between sexes, varied among individuals and seasons, and were similar to those reported elsewhere in their northern range. Turtles aggregated and showed interannual fidelity to separate and disparate habitats in different seasons. Turtles often chose fine substrates, tributary confluences, and reaches with islands during summer and mainstem outside bends in the winter. They inhabited shallow, slow water velocity areas from May to September. They inhabited deeper, moderate velocity areas from October to April. We did not observe ice jams and associated riverbed scour at hibernacula, but did observe them elsewhere. Ice jams may be spatially predictable and influence the distribution of riverine turtles during autumn and winter. Preservation of dissimilar habitats used during major portions of the life cycle (lateral habitats, islands, and hibernacula) and natural streamflow patterns, which influenced timing of habitat availability and turtle movement, may facilitate continued existence of Spiny Softshell Turtles in the Missouri River in Montana

Herpetological Conservation and Biology↗
USGS2019

Sampling and analysis frameworks for inference in ecology

1. Reliable statistical inference is central to ecological research, much of which seeks to estimate population attributes and their interactions. The issue of sampling design and its relationship to inference has become increasingly important due to rapid proliferation of modeling methodology (line transect modeling, capture-recapture, estimation of occurrence, model selection procedures, hierarchical modeling) and new sampling approaches (adaptive sampling, other specialized designs). It is important for ecologists using these advanced methods to be aware of how the linkages between sample selection and data analysis can potentially affect inference. 2. We examine design-based and model-based inference frameworks for ecological data collected randomly, purposively, or opportunistically. We elucidate differences in the probability structures for data arising from these frameworks, clarify the assumptions that underlie them, and demonstrate their differences. 3. Design-based inference builds on a probability structure inherited from randomized data collection, whereas model-based inference relies on an assumed stochastic model of the data. By itself, a design-based approach is of limited value for inferences about causal hypotheses. In contrast, model-based inference is dependent on a conditionality principle that can seldom be shown to be met for an ecological system. We describe the conditions under which one can safely ignore sampling design in model-based analysis, along with inferential implications if these conditions are not met. The special case of opportunistic sampling is discussed. 4. We present a combined framework that takes advantage of both approaches to inference, and provides a robust methodology that can deal with the modeling of sampling problems such as nondetection and misclassification, as well as the exploration of causal hypotheses. The combined framework can be useful for identifying optimal sampling strategies. 5. Each approach to inference has its strengths and weaknesses, and practitioners should be aware of these in order to tailor designs and analyses to specific questions. We use the approaches and their underlying rationales to provide guidelines for choosing designs and estimators for reliable inference.

Methods in Ecology and Evolution↗
USGS2006

Population dynamics of Greater Scaup breeding on the Yukon-Kuskokwim Delta, Alaska

Populations of greater scaup ( Aythya marila ) remained relatively stable during a period when populations of lesser scaup ( A. affinis ) have declined from historic levels. To assist in describing these differences in population trends, from 1991 through 2000, we studied the survival, nesting ecology, and productivity of greater scaup on the Yukon-Kuskokwim Delta (Y-K Delta), Alaska, to develop a model of population dynamics. We located nests, radio-marked females for renesting studies, estimated duckling survival, and leg-banded females to examine nest site fidelity and annual survival. Greater scaup initiated egg laying later than other species, and most clutches (>80%) were initiated over 20 days each year. We located 1,056 nests; nest success ranged from 7 to 61 % among years. Following loss of their first clutch, 51 % of radio-tagged females attempted to renest. Duckling survival to 30 days of age was 37.5%. Our best model suggested that annual survival did not vary among years and averaged 81 %. Survival rate was positively related to structural body size. Only 8 of 214 banded individuals were reported as recovered (1 each in Maryland, Michigan, Minnesota, Washington, and Alaska and 3 in California). Using a stochastic model, we estimated that, on average, breeding females produced 0.57 young females/nesting season. We combined this estimate of productivity with our annual estimates of adult survival and an assumed population growth rate of 1.0, then solved for an estimate of first-year survival (0.40). Under these conditions the predicted stable age distribution of breeding females (i.e., the nesting population) was 15.1% 1-year-old, 4.1% 2-year-old first-time breeders, and 80.8% 2-year-old and older, experienced breeders. We subjected this stochastic model to perturbation analyses to examine the relative effects of demographic parameters on k. The relative effects of productivity and adult survival on the population growth rate were 0.26 and 0.72, respectively. Thus, compared to productivity, proportionally equivalent changes in annual survival would have 2.8 times the effect on k. However, when we examined annual variation in predicted population size using standardized regression coefficients, productivity explained twice as much variation as annual survival. Thus, management actions focused on changes in survival or productivity have the ability to influence population size; however, substantially larger changes in productivity are required to influence population trends.

Wildlife Monographs↗
USGS2000

Microsatellites: Evolutionary and methodological background and empirical applications at individual, population, and phylogenetic levels

The recent proliferation and greater accessibility of molecular genetic markers has led to a growing appreciation of the ecological and evolutionary inferences that can be drawn from molecular characterizations of individuals and populations (Burke et al. 1992, Avise 1994). Different techniques have the ability to target DNA sequences which have different patterns of inheritance, different modes and rates of evolution and, concomitantly, different levels of variation. In the quest for 'the right marker for the right job', microsatellites have been widely embraced as the marker of choice for many empirical genetic studies. The proliferation of microsatellite loci for various species and the voluminous literature compiled in very few years associated with their evolution and use in various research applications, exemplifies their growing importance as a research tool in the biological sciences. The ability to define allelic states based on variation at the nucleotide level has afforded unparalleled opportunities to document the actual mutational process and rates of evolution at individual microsatellite loci. The scrutiny to which these loci have been subjected has resulted in data that raise issues pertaining to assumptions formerly stated, but largely untestable for other marker classes. Indeed this is an active arena for theoretical and empirical work. Given the extensive and ever-increasing literature on various statistical methodologies and cautionary notes regarding the uses of microsatellites, some consideration should be given to the unique characteristics of these loci when determining how and under what conditions they can be employed.

Book chapter↗
USGS2006

Effect of dispersal at range edges on the structure of species ranges

Range edges are of particular interest to ecology because they hold key insights into the limits of the realized niche and associated population dynamics. A recent feature of Oikos summarized the state of the art on range edge ecology. While the typical question is what causes range edges, another important question is how range edges influence the distribution of abundances across a species geographic range when dispersal is present. We used a single species population dynamics model on a coupled-lattice to determine the effects of dispersal on peripheral populations as compared to populations at the core of the range. In the absence of resource gradients, the reduced neighborhood and thus lower connectivity or higher isolation among populations at the range edge alone led to significantly lower population sizes in the periphery of the range than in the core. Lower population sizes mean higher extinction risks and lower adaptability at the range edge, which could inhibit or slow range expansions, and thus effectively stabilize range edges. The strength of this effect depended on the potential population growth rate and the maximum dispersal distance. Lower potential population growth rates led to a stronger effect of dispersal resulting in a higher difference in population sizes between the two areas. The differential effect of dispersal on population sizes at the core and periphery of the range in the absence of resource gradients implies that traditional, habitat-based distribution models could result in misleading conclusions about the habitat quality in the periphery. Lower population sizes at the periphery are also relevant to conservation, because habitat removal not only eliminates populations but also creates new edges. Populations bordering these new edges may experience declines, due to their increased isolation. ?? OIKOS.

Oikos↗
USGS2015

Arctic biodiversity: Increasing richness accompanies shrinking refugia for a cold-associated tundra fauna

As ancestral biodiversity responded dynamically to late-Quaternary climate changes, so are extant organisms responding to the warming trajectory of the Anthropocene. Ecological predictive modeling, statistical hypothesis tests, and genetic signatures of demographic change can provide a powerful integrated toolset for investigating these biodiversity responses to climate change, and relative resiliency across different communities. Within the biotic province of Beringia, we analyzed specimen localities and DNA sequences from 28 mammal species associated with boreal forest and Arctic tundra biomes to assess both historical distributional and evolutionary responses and then forecasted future changes based on statistical assessments of past and present trajectories, and quantified distributional and demographic changes in relation to major management regions within the study area. We addressed three sets of hypotheses associated with aspects of methodological, biological, and socio-political importance by asking (1) what is the consistency among implications of predicted changes based on the results of both ecological and evolutionary analyses; (2) what are the ecological and evolutionary implications of climate change considering either total regional diversity or distinct communities associated with major biomes; and (3) are there differences in management implications across regions? Our results indicate increasing Arctic richness through time that highlights a potential state shift across the Arctic landscape. However, within distinct ecological communities, we found a predicted decline in the range and effective population size of tundra species into several discrete refugial areas. Consistency in results based on a combination of both ecological and evolutionary approaches demonstrates increased statistical confidence by applying cross-discipline comparative analyses to conservation of biodiversity, particularly considering variable management regimes that seek to balance sustainable ecosystems with other anthropogenic values. Refugial areas for cold-adapted taxa appear to be persistent across both warm and cold climate phases and although fragmented, constitute vital regions for persistence of Arctic mammals.

Ecosphere↗