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At least 217 records · Page 12Linked to original sources
USGS2008

The Landslide Handbook - A Guide to Understanding Landslides

This handbook is intended to be a resource for people affected by landslides to acquire further knowledge, especially about the conditions that are unique to their neighborhoods and communities. Considerable literature and research are available concerning landslides, but unfortunately little of it is synthesized and integrated to address the geographically unique geologic and climatic conditions around the globe. Landslides occur throughout the world, under all climatic conditions and terrains, cost billions in monetary losses, and are responsible for thousands of deaths and injuries each year. Often, they cause long-term economic disruption, population displacement, and negative effects on the natural environment. Outdated land-use policies may not always reflect the best planning for use of land that is vulnerable to landslides. The reasons for poor or nonexistent land-use policies that minimize the perceived or actual danger and damage potential from geologic hazards are many and encompass the political, cultural, and financial complexities and intricacies of communities. Landslides often are characterized as local problems, but their effects and costs frequently cross local jurisdictions and may become State or Provincial or national problems. Growing populations may be limited in their geographic expansion, except to occupy unstable, steep, or remote areas. Often, stabilizing landslide-scarred areas is too costly, and some inhabitants have no other places to relocate. Fortunately, simple, 'low-tech' precautions and actions can be adopted to at least ensure an individual's immediate safety, and this handbook gives a brief overview of many of these options. We strongly suggest that, where possible, the assistance of professional engineers/geologists or those experienced in the successful mitigation of unstable slopes be consulted before actions are taken. This handbook helps homeowners, community and emergency managers, and decisionmakers to take the positive step of encouraging awareness of available options and recourse in regard to landslide hazard. We provide a list of references, available in print or on the World Wide Web (Internet), that can be used for further knowledge about landslides. We recommend this handbook to managers and decisionmakers in communities in the hope that the information will be disseminated by such officials to other members of those communities. In response to the differing levels of literacy around the globe, we have emphasized visual information through the use of photographs and graphics. We plan to translate the handbook into additional languages as funding permits to further facilitate its use. We welcome comments and critiques and have provided our contact information and the names and addresses of our respective agencies.

Circular↗
USGS2017

Multinomial N-mixture models improve the applicability of electrofishing for developing population estimates of stream-dwelling Smallmouth Bass

Failure to account for variable detection across survey conditions constrains progressive stream ecology and can lead to erroneous stream fish management and conservation decisions. In addition to variable detection’s confounding long-term stream fish population trends, reliable abundance estimates across a wide range of survey conditions are fundamental to establishing species–environment relationships. Despite major advancements in accounting for variable detection when surveying animal populations, these approaches remain largely ignored by stream fish scientists, and CPUE remains the most common metric used by researchers and managers. One notable advancement for addressing the challenges of variable detection is the multinomial N -mixture model. Multinomial N -mixture models use a flexible hierarchical framework to model the detection process across sites as a function of covariates; they also accommodate common fisheries survey methods, such as removal and capture–recapture. Effective monitoring of stream-dwelling Smallmouth Bass Micropterus dolomieu populations has long been challenging; therefore, our objective was to examine the use of multinomial N -mixture models to improve the applicability of electrofishing for estimating absolute abundance. We sampled Smallmouth Bass populations by using tow-barge electrofishing across a range of environmental conditions in streams of the Ozark Highlands ecoregion. Using an information-theoretic approach, we identified effort, water clarity, wetted channel width, and water depth as covariates that were related to variable Smallmouth Bass electrofishing detection. Smallmouth Bass abundance estimates derived from our top model consistently agreed with baseline estimates obtained via snorkel surveys. Additionally, confidence intervals from the multinomial N -mixture models were consistently more precise than those of unbiased Petersen capture–recapture estimates due to the dependency among data sets in the hierarchical framework. We demonstrate the application of this contemporary population estimation method to address a longstanding stream fish management issue. We also detail the advantages and trade-offs of hierarchical population estimation methods relative to CPUE and estimation methods that model each site separately.

Missouri, Oklahoma↗
USGS2018

Survival of whirling disease resistant rainbow trout fry in the wild: A comparison of two strains

Introduced pathogens can affect fish populations, and three main factors affect disease occurrence: the environment, host, and pathogen. Manipulating at least one of these factors is necessary for controlling disease. Myxobolus cerebralis , the parasite responsible for salmonid whirling disease, became established in Colorado during the 1990s and caused significant declines in wild Rainbow Trout Oncorhynchus mykiss populations. Attempts to re-establish Rainbow Trout have focused on manipulating salmonid host resistance. A Rainbow Trout strain known as GR × CRR was developed for stocking in Colorado by crossing a whirling-disease-resistant strain known as the German Rainbow Trout (GR) with the Colorado River Rainbow Trout (CRR). The GR × CRR fish exhibit resistance similar to that shown by GR, and survival and reproduction were expected to be similar to those of CRR. One disadvantage of stocking GR × CRR is that outcrossing and backcrossing could decrease resistance, and laboratory studies have indicated that this can occur. A potential disadvantage of stocking pure GR is lower survival due to domestication. To compare fry survival between the strains, a field experiment was conducted in 1.6-km reaches of nine Colorado streams. Each stream was stocked in August 2014 with 5,000 GR × CRR and 5,000 GR individuals. In October 2014, April 2015, and August 2015, apparent survival was assessed. Two laboratory predation experiments were also conducted. The field experiment revealed that short-term apparent survival was influenced by stream, and growth rate was influenced by strain and stream. However, after 12 months, there was no difference in apparent survival or growth rate between the GR and GR × CRR strains. Laboratory experiments showed that survival did not differ between the strains when confronted with Brown Trout Salmo trutta predation. Our results indicate that the GR strain is a viable option for stocking in streams where M. cerebralis is enzootic. Further evaluation is needed to determine whether GR fish will survive to maturity and reproduce.

Journal of Aquatic Animal Health↗
USGS2004

Historical perspectives on the concept of ecosystem degradation

The concept of environmental degradation has evolved with the development of human society and settlement. In early human development, tribes went through a series of cycles of taming or developing mastery over the environment, to utilizing the resources of that environment until they could no longer support the population, which lead to moving on to do it again in a new area. There seems to have been little sense that human activity was causing any degradation, it was only that there was no longer enough food. This sense of the concept of degradation can even be seen as late as the 16th and 17th centuries in North America as Europeans "tamed" the land from the south, east, and north. For the Europeans, this taming of the "dangerous" and "inhospitable" lands even included the indigenous peoples. World-wide, as humans gathered into towns and cities, the impacts on the environment became increasingly widespread. Goods had to be brought to the people from further and further away. While agriculture and herd management were being developed, there was still the sense that these activities were improvements. It is a rather modern social understanding that human activities can and do damage and degrade natural ecosystems. The concept began to dawn when society began to understand that some activities caused degraded human health. Only recently has society begun to understand the need for generally healthy natural ecosystems and this understanding has brought with it a whole host of legal and political actions to make it happpen. ?? International Scientific Publications, New Delhi.

Conference Paper↗
USGS2012

Timing and synchrony of births in bighorn sheep: implications for reintroduction and conservation

Context: Timing (mean birthdate) and synchrony (variance around that date) of births can influence survival of young and growth in ungulate populations. Some restored populations of ungulates may not adjust these life-history characteristics to environments of release sites until several years after release, which may influence success of reintroductions. Aims: We quantified timing and synchrony of births from 2005 to 2007 in four populations of reintroduced bighorn sheep ( Ovis canadensis ) occupying two ecoregions (Central Basin and Range and Wasatch and Uinta Mountains) in Utah, USA, to investigate whether bighorns would adjust these life-history characteristics to environmental conditions of the two ecoregions. We also compared timing and synchrony of births for bighorns in their source herd (Antelope Island) with bighorns in an ecologically similar release site (Stansbury Mountains) during 2006 and 2007. Methods: We relocated female bighorns to record birthdates of young, and observed groups of collared bighorns to quantify use of elevation by those ungulates. We also calculated the initiation, rate and timing of peak green-up by ecoregion, using the normalised difference vegetation index. Key results: We quantified 274 birthdates, and although only separated by 57 km, bighorn populations occupying the Central Basin and Range Mountains gave birth an average of 29 days earlier than did those on the Wasatch and Uinta Mountains, which corresponded with the initiation of vegetation green-up. Additionally, bighorn sheep on the Stansbury Mountains (ecologically similar release site) gave birth at similar times as did bighorns on Antelope Island (source area). Conclusions: Populations of bighorn sheep that were reintroduced into adjacent ecoregions adjusted timing of births to environments and green-up of vegetation in restoration areas. Timing and synchrony of births for reintroduced bighorn sheep in an ecologically similar release site were the same as those of their source area. Implications: Consideration should be given to the adjustment of timing and synchrony of births when reintroducing bighorns, especially when animals are released into different ecoregions. Also, biologists should select release sites that are ecologically similar to source areas, thereby reducing potential negative effects of animals adjusting timing and synchrony of births to environmental conditions of restoration areas.

Wildlife Research↗
USGS2024

Network connectivity contributes to native small-bodied fish assemblages in the upper Mississippi River system

Effective management and conservation of fishes requires understanding habitat use across multiple life stages while ensuring necessary habitats are both available and accessible. Tributary habitats may play an important role in recruitment and dispersal of fishes in anthropogenically modified rivers such as the Mississippi and Illinois Rivers of the Midwest U.S.A. Identifying source locations that contribute to recruitment of fish populations can determine the importance of connectivity within river networks and pinpoint critical habitats that sustain fish populations. In the Upper Mississippi River System (UMRS), the environments that fish use in early life stages (i.e., natal origin) can be identified using otolith trace element analysis due to stability and distinctness in water chemistry (strontium: calcium [Sr:Ca]) among water bodies that is reflected in otoliths. Here, we used trace element analysis to determine natal origin of six small-bodied fishes including bullhead minnow ( Pimephales vigilax ), emerald shiner ( Notropis atherinoides ), gizzard shad ( Dorosoma cepedianum ), bluegill ( Lepomis macrochirus ), orangespotted sunfish ( Lepomis humilis ), and yellow perch ( Perca flavescens ) across six reaches of the UMRS (Pools 4, 8, 13, 26, the Open River of the Middle Mississippi River, and the La Grange Pool of the Illinois River). Otolith core Sr:Ca for fishes was quantified using laser ablation inductively coupled plasma mass spectrometry. Using the resulting Sr:Ca chemical signatures of otolith cores, natal origin (tributary, immigrant, or potential resident) was determined for individual fish based on family-specific relationships between otolith and water chemistries. We found that all species originated from tributaries and other reaches (i.e., were immigrants) to varying extents, which acted as evidence for network connectivity. Specifically, tributaries contributed up to 48% of individuals at a given reach. In certain reaches, Pool 26 and the Open River reach, up to 80% of individuals in a species immigrated from another mainstem river reach. Network connectivity was also important in both upstream and downstream directions. Contributions from network connectivity varied among species: bullhead minnow used less whereas orangespotted sunfish used more network connectivity than when all species were combined. Further, the use of network connectivity varied spatially where individuals captured in Pool 8 and the La Grange Pool less often and those from Pool 26 and the Open River more often originated from network connectivity compared to the whole assemblage across reaches. These results indicate that species' life history traits probably interacted with the physical environment, which differs spatially, to yield observed recruitment source patterns. Our results show that network connectivity contributes to established assemblages of native small-bodied fishes throughout the UMRS and underscore the role of interjurisdictional management in maintaining network connectivity to sustain fish populations.

Illinois, Iowa, Minnesota, Missouri, Wisconsin↗
USGS2024

Food, water quality, and the growth of a freshwater mussel: Implications for population restoration

Unknown causes behind the loss of freshwater mussel populations have prompted population restoration as a tool to recover these imperiled species. However, water quality conditions that support mussel species within natural environments and potential causes of water quality impairment in systems with declining populations are typically unknown and may be critical knowledge needed before reintroducing mussels. Our objective was to relate the growth and survival of declining freshwater mussel populations of the Brook Floater Alasmidonta varicosa (Lamarck, 1819) to water quality parameters within 4 Massachusetts, USA, rivers containing extant populations. We deployed propagated age-1 and age-2 Brook Floater in contained systems (silos) for 1 growing season (June–October). Through biweekly sampling, we tracked the growth and survival of mussels then modeled their relationships with water quality variables. Mussels had a higher growth rate at a higher chlorophyll a ( Chl a ) value (2.82 µg/L) over the temperature range measured (biweekly mean = 16–26°C) when compared with lower Chl a values (0.61 and 1.17 µg/L). Age-1 mussel growth rate was negatively affected by low Chl a concentration (0.61 µg/L) across the temperature range, but age-2 mussel growth rate was not negatively affected until temperatures were above ~22°C. Na + limited the growth rate of mussels, with the rate of change in growth rate for age-1 mussels greater than for age-2 mussels. Other cations (Mg 2+ , K + , and Ca 2+ )—potentially linked to road deicers—also negatively affected growth rate in all 4 rivers but may have had a greater impact on mussels in rivers with reduced growth rates from lower temperatures and Chl a . However, survival was uniformly high across all rivers, indicating water quality parameters may have sublethal but not lethal effects. Additional assessments for chronic water quality stressors along with changing land cover, land management, and climates are important considerations for restoration potential and the long-term persistence of populations.

Massachusetts↗
USGS1999

Design approaches in quarrying and pit-mining reclamation

Reclaimed mine sites have been evaluated so that the public, industry, and land planners may recognize there are innovative designs available for consideration and use. People tend to see cropland, range, and road cuts as a necessary part of their everyday life, not as disturbed areas despite their high visibility. Mining also generates a disturbed landscape, unfortunately one that many consider waste until reclaimed by human beings. The development of mining provides an economic base and use of a natural resource to improve the quality of human life. Equally important is a sensitivity to the geologic origin and natural pattern of the land. Wisely shaping out environment requires a design plan and product that responds to a site's physiography, ecology, function, artistic form, and publication perception. An examination of selected sites for their landscape design suggested nine approaches for mining reclamation. The oldest design approach around is nature itself. Humans may sometimes do more damage going to an area in the attempt to repair it. Given enough geologic time, a small-site area, and stable adjacent ecosystems, disturbed areas recover without mankind's input. Visual screens and buffer zones conceal the facility in a camouflage approach. Typically, earth berms, fences, and plantings are used to disguise the mining facility. Restoration targets social or economic benefits by reusing the site for public amenities, most often in urban centers with large populations. A mitigation approach attempts to protect the environment and return mined areas to use with scientific input. The reuse of cement, building rubble, macadam meets only about 10% of the demand from aggregate. Recognizing the limited supply of mineral resources and encouraging recycling efforts are steps are steps in a renewable resource approach. An educative design approach effectively communicates mining information through outreach, land stewardship, and community service. Mine sites used for art show a celebration of beauty and experience -- abstract geology. The last design approach combines art and science in a human-nature ecosystem termed integration. With environmental concerns, an operating or reclaimed mine site can no longer be considered isolated from its surroundings. Site analysis of mine works needs to go beyond site-specific information and relate to the regional context of the greater landscape. Understanding design approach can turn undesirable features (mines and pits) into something perceived as desirable by the public.

Book↗
USGS2022

Diet energy density estimated from isotopes in predator hair associated with survival, habitat, and population dynamics

Sea ice loss is fundamentally altering the Arctic marine environment. Yet there is a paucity of data on the adaptability of food webs to ecosystem change, including predator-prey interactions. Polar bears ( Ursus maritimus ) are an important subsistence resource for Indigenous people and an apex predator that relies entirely on the under-ice food web to meet their energy needs. Here, we assessed whether polar bears maintained dietary energy density by prey switching in response to spatial-temporal variation in prey availability. We compared the macronutrient composition of diets inferred from stable carbon and nitrogen isotopes in polar bear guard hair (primarily representing summer/fall diet) during periods when bears had low and high survival 2004-2016, between bears that summered on land versus pack ice, and between bears occupying different regions of the Alaskan and Canadian Beaufort Sea. Polar bears consumed diets with lower energy density during periods of low survival suggesting that concurrent increased dietary proportions of beluga whales ( Delphinapterus leucas ) did not offset reduced proportions of ringed seals ( Pusa hispida ). Diets with the lowest energy density and proportions from ringed seal blubber were consumed by bears in the western Beaufort Sea (Alaska) during a period when polar bear abundance declined. Intake required to meet energy requirements of an average free-ranging adult female polar bear was 2.1 kg/day on diets consumed during years with high survival but rose to 3.0 kg/day when survival was low. Although bears that summered onshore in the Alaskan Beaufort Sea had higher fat diets than bears that summered on the pack ice, access to the remains of subsistence-harvested bowhead whales ( Balaena mysticetus ) contributed little to improving diet energy density. Because most bears in this region remain with the sea ice year-round, prey-switching and consumption of whale carcasses onshore appear insufficient to augment diets when availability of their primary prey, ringed seals, is reduced. Our results show that a strong predator-prey relationship between polar bears and ringed seals continues in the Beaufort Sea. The method of estimating dietary blubber using predator hair, demonstrated here, provides a new metric to monitor predator-prey relationships that affect individual health and population demographics.

Ecological Applications↗
USGS2012

Chiral pesticides: Identification, description, and environmental implications

Anthropogenic chemicals, including pesticides, are a major source of contamination and pollution in the environment. Pesticides have many positive uses: increased food production, decreased damage to crops and structures, reduced disease vector populations, and more. Nevertheless, pesticide exposure can pose risks to humans and the environment, so various mitigation strategies are exercised to make them safer, minimize their use, and reduce their unintended environment effects. One strategy that may help achieve these goals relies on the unique properties of chirality or molecular asymmetry. Some common terms related to chirality are defined in Table 1.

Archives of Environmental Contamination and Toxico↗
USGS2015

Population characteristics of channel catfish near the northern edge of their distribution: implications for management

Channel catfish, Ictalurus punctatus (Rafinesque), populations in six lakes in northern Idaho, USA, were sampled to describe their population characteristics. During the summers of 2011 and 2012, 4864 channel catfish were sampled. Channel catfish populations had low to moderate catch rates, and length structure was dominated by fish <400 mm. Channel catfish were in good body condition. All populations were maintained by stocking age-1 or age-2 fish. Growth of fish reared in thermally enriched environments prior to stocking was fast compared to other North American channel catfish populations. After stocking, growth of channel catfish declined rapidly. Once stocked, cold water temperatures, prey resources and (or) genetic capabilities limited growth. Total annual mortality of age 2 and older channel catfish was generally <40%. Tag returns indicated that angler exploitation was low, varying from 0 to 43% among lakes. This research provides insight on factors regulating channel catfish population dynamics and highlights important considerations associated with their ecology and management.

Fisheries Management and Ecology↗
USGS2006

Geology, Water, and Wind in the Lower Helmand Basin, Southern Afghanistan

This report presents an overview of the geology, hydrology, and climate of the lower Helmand Basin, a large, closed, arid basin in southern Afghanistan. The basin is drained by the Helmand River, the only perennial desert stream between the Indus and Tigris-Euphrates Rivers. The Helmand River is the lifeblood of southern Afghanistan and has supported desert civilizations in the Sistan depression for over 6,000 years. The Helmand Basin is a structurally closed basin that began to form during the middle Tertiary as a consequence of the collision of several Gondwanaland fragments. Aeromagnetic studies indicate the basin is 3-5 kilometers deep over basement rocks. Continued subsidence along basin-bounding faults in Iran and Pakistan throughout the Neogene has formed the Sistan depression in the southwest corner of the basin. Lacustrine, eolian, and fluvial deposits are commonly exposed in the basin and were intruded by latest Miocene-middle Quaternary volcanoes, which indicates that depositional environments in the lower Helmand Basin have not substantially changed for nearly 10 million years. Lakes expanded in the Sistan depression during the Quaternary; however, the size and extent of these pluvial lakes are unknown. Climate conditions in the lower Helmand Basin likely mirrored climate changes in the Rajasthan Desert to the east and in Middle Eastern deserts to the west: greater aridity during global episodes of colder temperatures and increased available moisture during episodes of warmer temperatures. Eolian processes are unusually dominant in shaping the landscape in the basin. A strong wind blows for 120 days each summer, scouring dry lakebeds and creating dune fields from annual flood deposits. Nearly one-third of the basin is mantled with active or stabilized dunes. Blowing winds combined with summer temperatures over 50? Celsius and voluminous insect populations hatched from the deltaic wetlands create an environment referred to as the 'most odious place on earth' by 19th century visitors. During dry years, large plumes of dust originating from Sistan are recorded by weather satellites. The Helmand River drains about 40 percent of Afghanistan and receives most of its moisture from melting snow and spring storms. Similar to many desert streams, the Helmand and its main tributary, the Arghandab River, are characterized by large fluctuations in monthly and annual discharges. Water from the Helmand accumulates in several hamuns (shallow lakes) in the Sistan depression. The wetlands surrounding these hamuns are the largest in western Asia and are directly affected by droughts and floods on the Helmand. Average annual discharge on the Helmand is about 6.12 million megaliters (million cubic meters), and the annual discharge varies by a factor of five. In 2005, the region was just beginning to recover from the longest drought (1998-2005) of record back to 1830. Annual peak discharges range from less than 80 cubic meters per second in 1971 to nearly 19,000 cubic meters per second in 1885. Large floods fill each hamun to overflowing to create one large lake that overflows into the normally dry Gaud-i Zirreh basin. The interaction of flooding, active subsidence, and wind erosion causes frequent channel changes on the Helmand delta. A major development effort on the Helmand River was initiated after World War II with substantial aid from the United States. Two dams and several major canals were completed in the 1950s; however, poor drainage conditions on the newly prepared agricultural fields caused extensive waterlogging and salinization. New drains were installed and improved agricultural methods were implemented in the 1970s, and some lands became more productive. Since 1980, Afghanistan has endured almost constant war and civil and political strife. In 2005, the country was on a path to rebuild much of its technical infrastructure. Revitalization of agricultural lands in the lower Helmand Basin and improved managem

Scientific Investigations Report↗
USGS2006

Genetic Considerations for the Restoration of Smooth Cordgrass (Spartina alterniflora) Within Its Native Range

In order to remain viable over many generations, plant populations require the ability to respond adaptively to a changing environment. Such adaptive potential is directly controlled by underlying genetic variation, which can be measured in terms of both heterozygosity at the individual level and clonal, or genotypic diversity at the population level. This report summarizes research relating to the importance of genetic diversity in the restoration of salt marsh smooth cordgrass, Spartina alterniflora, a dominant member of low elevation intertidal marshes throughout the northern Gulf of Mexico and Atlantic Coasts of North America. Recent research has indicated that S. alterniflora is a partially clonal species characterized by the recruitment of seedlings exclusively during the initial colonization phase of population establishment. A major consequence of this finding is that clonal diversity generally peaks rather early in the development of a restored marsh, depending on the rate of natural immigration and/or the clonal diversity of planting units, and then undergoes a steady decline over geological time spans because of stochastic mortality and intraspecific competition. Low levels of clonal diversity resulting from restricted immigration or clonally depauperate planting materials in turn places strict limits on opportunities for outcrossing in a species known to suffer from severe inbreeding depression. Low clonal diversity may further lead to declining levels of heterozyosity of individual clones, which directly affects competitive ability. In addition, the planting of genetically diverse plant materials should take into account the genetic and adaptive differentiation that takes place when plant populations are widely separated in space and/or dwell under varying sets of environmental conditions. Thus, steps should be taken to ensure that S. alterniflora clones developed for restorative plantings are both genetically diverse and sufficiently pre-adapted to environmental conditions at the proposed restoration site. This can be achieved by growing plant materials collected from local sources and by either taking care to maintain relatively high levels of clonal diversity or by planting clones at sufficiently low densities that they will not quickly grow to monopolize a restoration site without first producing several generations of sexual recruits through crosses with nearby native populations.

Open-File Report↗
USGS2013

Breeding site heterogeneity reduces variability in frog recruitment and population dynamics

Environmental stochasticity can have profound effects on the dynamics and viability of wild populations, and habitat heterogeneity provides one mechanism by which populations may be buffered against the negative effects of environmental fluctuations. Heterogeneity in breeding pond hydroperiod across the landscape may allow amphibian populations to persist despite variable interannual precipitation. We examined recruitment dynamics over 10 yr in a high-elevation Columbia spotted frog ( Rana luteiventris ) population that breeds in ponds with a variety of hydroperiods. We combined these data with matrix population models to quantify the consequences of heterogeneity in pond hydroperiod on net recruitment (i.e. number of metamorphs produced) and population growth rates. We compared our heterogeneous system to hypothetical homogeneous environments with only ephemeral ponds, only semi-permanent ponds, and only permanent ponds. We also examined the effects of breeding pond habitat loss on population growth rates. Most eggs were laid in permanent ponds each year, but survival to metamorphosis was highest in the semi-permanent ponds. Recruitment success varied by both year and pond type. Net recruitment and stochastic population growth rate were highest under a scenario with homogeneous semi-permanent ponds, but variability in recruitment was lowest in the scenario with the observed heterogeneity in hydroperiods. Loss of pond habitat decreased population growth rate, with greater decreases associated with loss of permanent and semi-permanent habitat. The presence of a diversity of pond hydroperiods on the landscape will influence population dynamics, including reducing variability in recruitment in an uncertain climatic future.

Montana↗
USGS2019

Considerations for maximizing the adaptive potential of restored coral populations in the western Atlantic

Active coral restoration typically involves two interventions: crossing gametes to facilitate sexual larval propagation; and fragmenting, growing, and outplanting adult colonies to enhance asexual propagation. From an evolutionary perspective, the goal of these efforts is to establish self‐sustaining, sexually reproducing coral populations that have sufficient genetic and phenotypic variation to adapt to changing environments. Here, we provide concrete guidelines to help restoration practitioners meet this goal for most Caribbean species of interest. To enable the persistence of coral populations exposed to severe selection pressure from many stressors, a mixed provenance strategy is suggested: genetically unique colonies (genets) should be sourced both locally as well as from more distant, environmentally distinct sites. Sourcing three to four genets per reef along environmental gradients should be sufficient to capture a majority of intraspecies genetic diversity. It is best for practitioners to propagate genets with one or more phenotypic traits that are predicted to be valuable in the future, such as low partial mortality, high wound healing rate, high skeletal growth rate, bleaching resilience, infectious disease resilience, and high sexual reproductive output. Some effort should also be reserved for underperforming genets because colonies that grow poorly in nurseries sometimes thrive once returned to the reef and may harbor genetic variants with as yet unrecognized value. Outplants should be clustered in groups of four to six genets to enable successful fertilization upon maturation. Current evidence indicates that translocating genets among distant reefs is unlikely to be problematic from a population genetic perspective but will likely provide substantial adaptive benefits. Similarly, inbreeding depression is not a concern given that current practices only raise first‐generation offspring. Thus, proceeding with the proposed management strategies even in the absence of a detailed population genetic analysis of the focal species at sites targeted for restoration is the best course of action. These basic guidelines should help maximize the adaptive potential of reef‐building corals facing a rapidly changing environment.

Ecological Applications↗
USGS2013

Diffuse migratory connectivity in two species of shrubland birds: evidence from stable isotopes

Connecting seasonal ranges of migratory birds is important for understanding the annual template of stressors that influence their populations. Brewer’s sparrows ( Spizella breweri ) and sagebrush sparrows ( Artemisiospiza nevadensis ) share similar sagebrush ( Artemisia spp.) habitats for breeding but have different population trends that might be related to winter location. To link breeding and winter ranges, we created isoscapes of deuterium [stable isotope ratio (δ) of deuterium; δ 2 H] and nitrogen (δ 15 N) for each species modeled from isotope ratios measured in feathers of 264 Brewer’s and 82 sagebrush sparrows and environmental characteristics at capture locations across their breeding range. We then used feather δ 2 H f and δ 15 N f measured in 1,029 Brewer’s and 527 sagebrush sparrows captured on winter locations in southwestern United States to assign probable breeding ranges. Intraspecies population mixing from across the breeding range was strong for both Brewer’s and sagebrush sparrows on winter ranges. Brewer’s sparrows but not sagebrush sparrows were linked to more northerly breeding locations in the eastern part of their winter range. Winter location was not related to breeding population trends estimated from US Geological Survey Breeding Bird Survey routes for either Brewer’s or sagebrush sparrows. Primary drivers of population dynamics are likely independent for each species; Brewer’s and sagebrush sparrows captured at the same winter location did not share predicted breeding locations or population trends. The diffuse migratory connectivity displayed by Brewer’s and sagebrush sparrows measured at the coarse spatial resolution in our analysis also suggests that local environments rather than broad regional characteristics are primary drivers of annual population trends.

Oecologia↗
USGS2020

Integrating broad‐scale data to assess demographic and climatic contributions to population change in a declining songbird

Climate variation and trends affect species distribution and abundance across large spatial extents. However, most studies that predict species response to climate are implemented at small spatial scales or are based on occurrence‐environment relationships that lack mechanistic detail. Here, we develop an integrated population model (IPM) for multi‐site count and capture‐recapture data for a declining migratory songbird, Wilson's warbler ( Cardellina pusilla ), in three genetically distinct breeding populations in western North America. We include climate covariates of vital rates, including spring temperatures on the breeding grounds, drought on the wintering range in northwest Mexico, and wind conditions during spring migration. Spring temperatures were positively related to productivity in Sierra Nevada and Pacific Northwest genetic groups, and annual changes in productivity were important predictors of changes in growth rate in these populations. Drought condition on the wintering grounds was a strong predictor of adult survival for coastal California and Sierra Nevada populations; however, adult survival played a relatively minor role in explaining annual variation in population change. A latent parameter representing a mixture of first‐year survival and immigration was the largest contributor to variation in population change; however, this parameter was estimated imprecisely, and its importance likely reflects, in part, differences in spatio‐temporal distribution of samples between count and capture‐recapture data sets. Our modeling approach represents a novel and flexible framework for linking broad‐scale multi‐site monitoring data sets. Our results highlight both the potential of the approach for extension to additional species and systems, as well as needs for additional data and/or model development.

Ecology and Evolution↗
USGS2022

Spatial models can improve the experimental design of field-based transplant gardens by preventing bias due to neighborhood crowding

Field-based transplant gardens, including common and reciprocal garden experiments, are a powerful tool for studying genetic variation and gene-by-environment interactions. These experiments assume that individuals within the garden represent independent replicates growing in a homogenous environment. Plant neighborhood interactions are pervasive across plant populations and could violate assumptions of transplant garden experiments. We demonstrate how spatially explicit models for plant–plant interactions can provide novel insights on genotypes' performance in field-transplant garden designs. We used individual-based models, based on data from a sagebrush ( Artemisia spp.) common garden, to simulate the impact of spatial plant–plant interactions on between-group differences in plant growth. We found that planting densities within the range of those used in many common gardens can bias experimental outcomes. Our results demonstrate that higher planting densities can lead to inflated group differences and may confound genotypes' competitive ability and genetically underpinned variation. Synthesis. We propose that spatially explicit models can help avoid biased results by informing the design and analysis of field-based transplant garden experiments. Alternately, including neighborhood effects in post hoc analyses of transplant garden experiments is likely to provide novel insights into the roles of biotic factors and density dependence in genetic differentiation.

Ecology and Evolution↗