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At least 73 records · Page 4Linked to original sources
USGS2002

Ecological restoration of southwestern ponderosa pine ecosystems: A broad perspective

The purpose of this paper is to promote a broad and flexible perspective on ecological restoration of Southwestern (U.S.) ponderosa pine forests. Ponderosa pine forests in the region have been radically altered by Euro-American land uses, including livestock grazing, fire suppression, and logging. Dense thickets of young trees now abound, old-growth and biodiversity have declined, and human and ecological communities are increasingly vulnerable to destructive crown fires. A consensus has emerged that it is urgent to restore more natural conditions to these forests. Efforts to restore Southwestern forests will require extensive projects employing varying combinations of young-tree thinning and reintroduction of low-intensity fires. Treatments must be flexible enough to recognize and accommodate: high levels of natural heterogeneity; dynamic ecosystems; wildlife and other biodiversity considerations; scientific uncertainty; and the challenges of on-the-ground implementation. Ecological restoration should reset ecosystem trends toward an envelope of “natural variability,” including the reestablishment of natural processes. Reconstructed historic reference conditions are best used as general guides rather than rigid restoration prescriptions. In the long term, the best way to align forest conditions to track ongoing climate changes is to restore fire, which naturally correlates with current climate. Some stands need substantial structural manipulation (thinning) before fire can safely be reintroduced. In other areas, such as large wilderness and roadless areas, fire alone may suffice as the main tool of ecological restoration, recreating the natural interaction of structure and process. Impatience, overreaction to crown fire risks, extractive economics, or hubris could lead to widespread application of highly intrusive treatments that may further damage forest ecosystems. Investments in research and monitoring of restoration treatments are essential to refine restoration methods. We support the development and implementation of a diverse range of scientifically viable restoration approaches in these forests, suggest principles for ecologically sound restoration that immediately reduce crown fire risk and incrementally return natural variability and resilience to Southwestern forests, and present ecological perspectives on several forest restoration approaches.

Ecological Applications↗
USGS2026

How Indigenous socio-cultural systems resist, accept, or direct ecological transformation: A research agenda

Anthropogenic ecological transformations are challenging conventional environmental management paradigms, as maintaining historical ecological structures and functions becomes increasingly untenable. The resist–accept–direct (RAD) framework offers a strategic tool to navigate these shifts. However, as a product of the dominant socio-cultural system, the RAD framework risks perpetuating the same patterns of thinking that have contributed to unsustainable social-ecological dynamics. Indigenous socio-cultural systems, considered here through the lens of long-term coevolution with their environments, offer valuable empirical models for adaptive responses to environmental change. Such Indigenous socio-cultural responses, grounded in narratives, governance institutions, value systems, and other cultural elements collectively referred to as Indigenous Knowledge (IK), hold relevance for addressing today’s intertwined environmental and social challenges. We provide a targeted review of existing literature at the intersection of IK and the RAD framework, along with a broader conceptual overview of relevant insights across related fields. These reveal contrasting assumptions about Indigenous responses to environmental change, such as consistently resisting to preserve cultural fidelity or uniformly accepting, reflecting deeper cultural, temporal, and ecological complexity. We propose a structured research agenda to investigate Indigenous socio-cultural responses to environmental change through empirical research, theoretical synthesis, hypothesis development, and practical application. This agenda is grounded in comprehensive collaboration, emphasizing shared power and integrating both emic and etic perspectives throughout all stages of research and implementation. By bridging the adaptive dynamics of coevolved social-ecological systems and mainstream management strategies, an IK–RAD framework could enhance the efficacy of responses to global environmental change.

Human Ecology↗
USGS2018

Selenium, mercury, and their molar ratios in sportfishes from drinking water reservoirs

Mercury (Hg) bioaccumulates in aquatic ecosystems and may pose a risk to humans who consume fish. Selenium (Se) has the ability to reduce Hg toxicity, but the current guidance for human consumption of fish is based on Hg concentration alone. The purpose of the present study was to examine the relationship between Se and Hg in freshwater sportfish, for which there is a paucity of existing data. We collected three species of fish from different trophic positions from two drinking water reservoirs in central North Carolina, USA, to assess Hg and Se concentrations in relation to fish total length and to compare two measures of the protective ability of Se, the Se:Hg molar ratio and Se health benefit value (HBV Se ), to current guidance for Hg. According to the Se:Hg molar ratio, all of the low trophic position fish sampled and the middle trophic position fish sampled from one of the reservoirs were safe for consumption. The same number of fish were considered safe using the HBV Se . More fish were deemed unsafe when using the Se:Hg molar ratio and HBV Se than were considered unsafe when using the U.S. Environmental Protection Agency (USEPA) Hg threshold. These findings suggest that the measures of Se protection may be unnecessarily conservative or that the USEPA Hg threshold may not be sufficiently protective of human health, especially the health of sensitive populations like pregnant or nursing mothers and young children. Future examination of the Se:Hg molar ratio and HBV Se from a variety of fish tissue samples would help refine the accuracy of these measures so that they may be appropriately utilized in ecological and human health risk assessment.

International Journal of Environmental Research an↗
USGS2007

Cascading events in linked ecological and socioeconomic systems

Cascading events that start at small spatial scales and propagate non-linearly through time to influence larger areas often have major impacts on ecosystem goods and services. Events such as wildfires and hurricanes are increasing in frequency and magnitude as systems become more connected through globalization processes. We need to improve our understanding of these events in order to predict their occurrence, minimize potential impacts, and allow for strategic recovery. Here, we synthesize information about cascading events in systems located throughout the Americas. We discuss a variety of examples of cascading events that share a common feature: they are often driven by linked ecological and human processes across scales. In this era of globalization, we recommend studies that explicitly examine connections across scales and examine the role of connectivity among non-contiguous as well as contiguous areas.

Frontiers in Ecology and the Environment↗
USGS2018

Evaluating and managing environmental water regimes in a water-scarce and uncertain future

While the number of environmental flows and water science programmes continues to grow across the globe, there remains a critical need to better balance water availability in support of human and ecological needs and to recognise the environment as a legitimate user of water. In water‐stressed areas, this recognition has resulted in friction between water users in the public and private sectors. An opportunity exists for practitioners to be on the forefront of the science determining best practices for supporting environmental water regimes. This Special Issue brings together a collection of environmental flows science and water management papers organised around three major themes: (1) method development and testing; (2) application case studies; and (3) efficacy evaluation. Contents of this Special Issue are intended to foster collaboration and broaden transferability of the information, technical tools, models and methods needed to support environmental water management programmes. The technical sophistication of methods and modelling tools, while important to the advancement of environmental water science, may come at the expense of easily interpretable outcomes that positively influence management decisions. Researchers need to be more proactive in translating the results of advanced modelling methodologies into user‐friendly tools and methods. This will allow stakeholders and water managers to proactively test alternative water allocation scenarios to help address growing human water demands in the face of droughts and changes in climatic patterns. The application of environmental flows science and water management strategies cannot be done in isolation. Implementation involves a complex decision‐making process that integrates ecological, hydrologic and social science across diverse multifaceted governance systems and requires active stakeholder involvement. Scientists and managers must strengthen partnerships at multiple scales to develop sensible science investment strategies so that collective knowledge can be translated into wise environmental water management decisions.

Freshwater Biology↗
USGS2017

Selenium

Selenium (Se) was discovered in 1817 in pyrite from copper mines in Sweden. It is a trace element in Earth’s crust, with an abundance of three to seven orders of magnitude less than the major rock-forming elements. Commercial use of selenium began in the United States in 1910, when it was used as a pigment for paints, ceramic glazes, and red glass. Since that time, it has had many other economic uses—notably, in the 1930s and 1940s, when it was used in rectifiers (which change alternating current to direct current), and in the 1960s, when it began to be used in the liner of photocopier drums. In the 21st century, other compounds have replaced selenium in these older products; modern uses for selenium include energy-efficient windows that limit heat transfer and thin-film photovoltaic cells that convert solar energy into electricity. In Earth’s crust, selenium is found as selenide minerals, selenate and selenite salts, and as substitution for sulfur in sulfide minerals. It is the sulfide minerals, most commonly those in porphyry copper deposits, that provide the bulk of the selenium produced for the international commodity market. Selenium is obtained as a byproduct of copper refining and recovered from the anode slimes generated in electrolytic production of copper. Because of this, the countries that have the largest resources and (or) reserves of copper also have the largest resources and (or) reserves of selenium. Because selenium occurs naturally in Earth’s crust, its presence in air, water, and soil results from both geologic reactions and human activity. Selenium is found concentrated naturally in soils that overlie bedrock with high selenium concentrations. Selenium mining, processing, use in industrial and agricultural applications, and disposal may all contribute selenium to the environment. A well-known case of selenium contamination from agricultural practices was discovered in 1983 in the Kesterson National Wildlife Refuge in California. There, waters draining from agricultural fields created wetlands with high concentrations of dissolved selenium in the water. The selenium was taken up by aquatic wildlife and caused massive numbers of embryonic deformities and deaths. Regulatory agencies have since worked to safeguard ecological and human health by creating environmental exposure guidelines based upon selenium concentrations in water and in fish tissue. Any attempt to regulate selenium concentrations requires a delicate balance because selenium occurs naturally and is also a vital nutrient for the health of wildlife, domestic stock, and humans. Selenium is commonly added as a vitamin to animal feed, and in some regions of the United States and the world, it is added as an amendment to soils for uptake by agricultural crops. The important role of selenium in economic products, energy supply, agriculture, and health will continue for well into the future. The challenge to society is to balance the benefits of selenium use with the environmental consequences of its extraction. Increased understanding of the elemental cycle of selenium in the earth may lead to new (or unconventional) sources of selenium, the discovery of new methods of extraction, and new technologies for minimizing the transfer of selenium from rock to biota, so to protect environmental and human health.

Professional Paper↗
USGS2016

Cyanobacterial harmful algal blooms and U.S. Geological Survey science capabilities

Cyanobacterial harmful algal blooms (CyanoHABs) are increasingly a global concern because CyanoHABs pose a threat to human and aquatic ecosystem health and cause economic damages. Despite advances in scientific understanding of cyanobacteria and associated compounds, many unanswered questions remain about occurrence, environmental triggers for toxicity, and the ability to predict the timing, duration, and toxicity of CyanoHABs. U.S. Geological Survey (USGS) scientists are leading a diverse range of studies to address CyanoHAB issues in water bodies throughout the United States, using a combination of traditional methods and emerging technologies, and in collaboration with numerous partners. By providing practical applications of cutting edge CyanoHAB research, USGS studies have advanced scientific understanding, enabling the development of approaches to help protect ecological and human health.

Open-File Report↗
USGS2021

Evaluating low flow patterns, drivers and trends in the Delaware River Basin

In the humid, temperate Delaware River Basin (DRB) where water availability is generally reliable, summer low flows can cause competition between various human and ecological water uses. As temperatures continue to rise, population increases and development expands, it is critical to understand historical low flow variability to anticipate and plan for future flows. Using a sample of 325 U.S. Geological Survey gages, we evaluated spatial patterns in several low flow metrics, the biophysical and climatic drivers of these metrics, and trends in low flows for two periods: 1950-2018 and 1980-2018. We calculated the annual 7-day low flow and date, low flow deficit as the departure below a long-term daily flow threshold and the number of discrete low flow periods below this threshold. We also aggregated several climate metrics to watershed scale and used existing watershed properties quantifying land cover, topography, soils, geology, and human activity. Random forest models were used to assess the hierarchy of variable importance in explaining mean-annual low flow variability for each low flow metric using all gages. We find muted regional patterns in mean-annual low flow and low flow variability, likely due to the myriad of anthropogenic, landscape, and flow modifications that obscure flow regimes from their natural characteristics. In contrast, individual years show markedly different spatial patterns in low flow magnitude and severity. Coincident with increases in precipitation, 7-day low flows have generally increased and low flow deficits decreased for both 1950-2018 and 1980-2018 periods. However, 7-day low flows have decreased in the Coastal Plain physiographic province where water use and impervious area have increased in recent decades, highlighting the effects of land and water management on low flows. With continued change expected in the DRB, additional research needs are highlighted to enable estimation of future low flows and to plan for periods of prolonged low flow.

Delaware, New Jersey, New York, Pennsylvania↗
USGS2024

Enhanced microplastic fragmentation along human built structures in an urban waterway

Plastic pollution and microplastic (MP, 1 µm to 5 mm) generation are growing problems affecting the global community and a wide range of natural and disturbed environments. Urban and suburban waterways are directly impacted by plastic pollution due to their proximity to population centers and many different types single use plastic waste sources. In this study, plastic waste accumulation and fragmentation was investigated along the Cooper River in Camden County, NJ. Polymer composition was identified for individual plastic waste particles collected along the Cooper River using Fourier transform infrared (FTIR) spectrometry. Multiple human-built structures (Wallworth Lake, Evans Pond and Hopkins Pond dams) along the Cooper River were found to accumulate different types of plastic waste. The accumulation of plastic waste along these structures resulted in the initial stages of plastic fragmentation and the identification of large MP particles (1 to 5 mm). Quantitative analysis revealed that fragmented polystyrene (PS) particles constituted 82.8% of the total plastic fragments identified, most of which were identified at the Wallworth Lake dam. Many other types of fragmented plastic litter, including polyethylene and polypropylene, were identified at the Wallworth Lake dam, as well. This research demonstrates that engineered structures within urban and suburban aquatic ecosystems serve as significant aggregators of plastic debris, thereby catalyzing its breakdown into microplastics. Considering the escalating ecological and human health ramifications of microplastic proliferation, the fragmentation of plastic waste in an urban and suburban waterway observed in this study can also result in potentially toxic smaller MP particles, and increased exposure to aquatic organisms and humans.

New Jersey↗
USGS2024

Prioritizing water availability study settings to address geogenic contaminants and related societal factors

Water availability for human and ecological uses depends on both water quantity and water quality. The U.S. Geological Survey (USGS) is developing strategies for prioritizing regional-scale and watershed basin-scale studies of water availability across the nation. Previous USGS ranking processes for basin-scale studies incorporated primarily water quantity factors but are now considering additional water quality factors. This study presents a ranking based on the potential impacts of geogenic constituents on water quality and consideration of societal factors related to water quality. High-concentration geogenic constituents, including trace elements and radionuclides, are among the most prevalent contaminants limiting water availability in the USA and globally. Geogenic constituents commonly occur in groundwater because of subsurface water–rock interactions, and their distributions are controlled by complex geochemical processes. Geogenic constituent mobility can also be affected by human activities (e.g., mining, energy production, irrigation, and pumping). Societal factors and relations to drinking water sources and water quality information are often overlooked when evaluating research priorities. Sociodemographic characteristics, data gaps resulting from historical data-collection disparities, and infrastructure condition/age are examples of factors to consider regarding environmental justice. This paper presents approaches for ranking and prioritizing potential basin-scale study areas across the contiguous USA by considering a suite of conventional physical and geochemical variables related to geogenic constituents, with and without considering variables related to societal factors. Simultaneous consideration of societal and conventional factors could provide decision makers with more diverse, interdisciplinary tools to increase equity and reduce bias in prioritizing focused research areas and future water availability studies.

Environmental Monitoring and Assessment↗
USGS2015

Progress toward a National Water Census

Increasing demand and competition for limited regional water resources make it difficult to ensure adequate water availability for both human and ecological needs now and into the future. Recognizing the need to improve the tools and information that are available to effectively evaluate water-resource availability, the U.S. Geological Survey (USGS) identified a National Water Census (NWC) as one of its six core science directions for the decade 2007–17. In 2009, the SECURE Water Act (Public Law 111–11) authorized the USGS to develop a national water availability and use assessment program that would update the most recent national assessment of the status of water resources in the United States as well as develop the science to improve forecasts of water availability and quality for future needs. By evaluating large-scale effects of changes in land use and land cover, water use, and climate on occurrence and distribution of water, water quality, and human and aquatic-ecosystem health, the NWC will also help to inform a broader initiative by the Department of the Interior, WaterSMART (Sustain and Manage America's Resources for Tomorrow), which provides multiagency funding to pursue a sustainable water supply for the Nation as directed under the SECURE Water Act. Through the NWC, the USGS actively engages Federal, regional, and local stakeholders to identify research priorities and leverages current studies and program activities to provide information that is relevant at both the national and regional scales.

Fact Sheet↗
USGS2017

Human presence diminishes the importance of climate in driving fire activity across the United States

Growing human and ecological costs due to increasing wildfire are an urgent concern in policy and management, particularly given projections of worsening fire conditions under climate change. Thus, understanding the relationship between climatic variation and fire activity is a critically important scientific question. Different factors limit fire behavior in different places and times, but most fire-climate analyses are conducted across broad spatial extents that mask geographical variation. This could result in overly broad or inappropriate management and policy decisions that neglect to account for regionally specific or other important factors driving fire activity. We developed statistical models relating seasonal temperature and precipitation variables to historical annual fire activity for 37 different regions across the continental United States and asked whether and how fire-climate relationships vary geographically, and why climate is more important in some regions than in others. Climatic variation played a significant role in explaining annual fire activity in some regions, but the relative importance of seasonal temperature or precipitation, in addition to the overall importance of climate, varied substantially depending on geographical context. Human presence was the primary reason that climate explained less fire activity in some regions than in others. That is, where human presence was more prominent, climate was less important. This means that humans may not only influence fire regimes but their presence can actually override, or swamp out, the effect of climate. Thus, geographical context as well as human influence should be considered alongside climate in national wildfire policy and management.

PNAS↗
USGS2022

Identifying shared priorities for a bioregional approach to restoration in the Northern Gulf of Mexico

Natural resource management is often challenged with a mismatch between the scale of decision-making and the scale of the biological, ecological, and physical processes that control a system. Bioregional approaches to adaptive management have emerged as an approach to inform natural resource management at ecologically relevant scales and across multi-level governance structures. The implementation of adaptive management requires the determination of ecological and social priorities that can inform a desired system state across multiple governing bodies. We use the Northern Gulf of Mexico, United States, as a case study for a bioregional approach to adaptive management and illustrate a method for developing objectives and management priorities across programs and jurisdictions. Through this synthesis, using qualitative coding methods to develop a shared vocabulary across the diverse dataset, we identified commonalities and differences in ecological and human community priorities across the five states which line the Northern Gulf of Mexico. Using these shared priorities, we conceptualize a network of priority-focused objectives as a starting point for further stakeholder engagement and effectively monitoring and evaluating progress across boundaries. This approach serves as a framework for cross-program adaptive management by illustrating a desired system state that reflects the shared priorities among decision-making authorities in this region and offering individual programs or projects a method to articulate their contributions to the broader set of shared priorities Gulf-wide. This method can be used by restoration managers in any region of the world to align project objectives within cross-jurisdictional boundaries and illustrate the value of a bioregional approach to restoration.

Gulf of Mexico↗
USGS2020

Climate- and disturbance-driven changes in subsistence berries in coastal Alaska: Indigenous knowledge to inform ecological inference

Berry-producing plants are a key subsistence resource in Indigenous Alaskan communities. High-latitude coastal regions are particularly impacted by global climate change due to their location at the land-sea ecotone subjecting them to terrestrial stressors as well as shifts in ocean dynamics. While vegetation changes have been documented for the subarctic coastal region of Alaska, we know little about permafrost underlain portions of the landscape that support berry communities. To fill this gap surveys were administered in four communities within the Yukon-Kuskokwim Delta, to identify observations of changes in berry resources and integrate Indigenous Knowledge of drivers of changes with climate projections. We found that while most participants agreed on several observed changes and drivers, many important differences were identified at the community level. Regional consensus can be used in combination with climate projections to forecast potential future impacts to berry resources while distinctions at the community level can help us to untangle local scale disturbances.

Alaska↗
USGS2019

Natural resource condition assessment: Channel Islands National Park

The Natural Resource Condition Assessment (NRCA) Program aims to provide documentation about the current conditions of important Park natural resources through a spatially explicit, multidisciplinary synthesis of existing scientific data and knowledge. Findings from the NRCA will help Channel Islands National Park (CINP) managers to develop near-term management priorities. The central objectives of this assessment were to evaluate the current conditions and trends of key Park resources, identify important knowledge gaps, and determine key stressors and threats. Because a recent report provided an assessment of marine resources (Engle 2006), which constitute 50% of the park, this NRCA focused on terrestrial resources. For this NRCA, CINP resource managers identified that the greatest Park need was to know whether or not vegetation (primarily woody vegetation) is recovering on the Channel Islands and how this may be influencing recovery of the native terrestrial vertebrates. To address this, the CINP NRCA team evaluated the condition of island vegetation and vertebrate communities using both: 1) already available, summarized information from reports, theses, and journal articles and 2) new analyses of recently available, existing data collected on the islands. Descriptions of specific methods used to analyze available data by the NRCA team are provided within the assessment sections in Chapter 4 of this report. The Team used the Vital Signs indicators as identified by Fancy et al. (2009) for monitoring the condition of Natural Resources in U.S. National Parks. Using this framework, the focal study resource components were the five CINP islands, because these are the bio-geophysical resources of greatest interest to the CINP. Each of the islands has its own unique history of human impacts, ecological conditions, restoration efforts, and natural resource monitoring. The Team evaluated island scrub recovery by assessing changes over time in two metrics: 1) vegetation community structure (species composition, cover, and spatial extent), and 2) vertebrate abundance, relative to the reference condition of each island. The reference conditions for this NRCA were the particular island’s ecological state prior to European settlement or ranching, which represent the ecological state to which the NPS desires the park return. For each metric, the Team determined the Reference Conditions/Values, Current Condition, Trend, and Recovery Potential (based on a review of the literature and from the NRCA team’s analysis of newly available data), Threats and Stressors, Data Gaps, Overall Condition. A qualitative statement of overall current condition was created for each metric, after all data and literature relevant to the measures (i.e., vegetation and vertebrates) of each resource component (i.e., island) were reviewed and evaluated. All information gathered for this NRCA is available and managed by CINP, so that the compilation of resources would be available not only for the assessment team, but will be provided for future Park reference. Chapter 1 of this NRCA provides a descriptive background of NRCAs. Chapter 2 provides Park-wide natural resource background information, while Chapter 3 describes the overall methodological approach used in this assessment. Chapter 4 provides a detailed assessment of each island’s condition, which is then summarized Park-wide and for each island in Chapter 5. Based on both vegetation recovery and vertebrate population abundances, our assessment found Santa Cruz Island (SCI), Santa Rosa Island (SRI), San Miguel Island (SMI), and Anacapa Island (AI) to be, overall, in moderate condition and slowly recovering following the removal of non-native herbivores. The condition of Santa Barbara Island (SBI) is poor and remains in a state that is not likely to improve without assisted recovery by the Park. All islands have exhibited some level of native vegetation recovery, with most of the observed natural recovery occurring on SCI, SRI, SMI, and AI; very little recovery has occurred at present on SBI. Vegetation recovery is uneven across each island and largely limited to mesic areas, such as north-facing slopes. Areas that will likely require some assisted recovery efforts are those that are: at risk of erosion, isolated, lacking native seed banks, and plagued with high competition of non-native grasses and other invasives. Some plant communities, such as exposed upland vegetation on SRI, also have lower natural recovery potential and will likely require assisted recovery. The overall condition of the Park’s terrestrial island vertebrate species generally appears to be good and improving, with high potential for further recovery to reach pre-ranching era reference conditions. This is particularly true for vertebrates on SCI, SRI, and SMI. Although there are limited data for AI, the data that are available suggest that vertebrates on that island are in good condition and improving as well. However, the condition of SBI vertebrates is only moderate, with natural recovery potential being low, with many landbird species’ populations currently declining, extinct, or not improving. An overarching theme across the Park’s terrestrial island vertebrate populations is that many of them are in good condition because the particular animals are habitat generalists, so their population dynamics are not strongly tied to habitat conditions. However, those landbirds associated with riparian vegetation are not showing signs of recovery across the Park islands, and riparian areas appear to be one of the habitats with limited natural recovery potential on the islands. Overwhelmingly, the most critical data gap that emerged from our analysis was the lack of current vegetation maps for most of the islands (AI, SCI, SRI, SMI). The lack of this information made it difficult to assess spatial changes in island vegetation over time, and to relate those changes to observed changes in vertebrate species abundances. Therefore, we were limited in our spatial assessment of vegetation recovery for AI, SCI, SRI, and SMI, and were only able to relate the current vegetation with island landbird analysis for SBI. Another common theme across islands was the lack of information on best techniques for shrub reintroduction and recovery, and the success of invasive species removal and re-vegetation efforts. Abundance, distribution, and habitat affinities of reptiles and amphibians are poorly known for AI, SCI, SRI, and SMI, making it difficult to assess their population condition and trends, and their potential responses to shrub recovery. Mammal and landbird populations are reasonably well-sampled across most of the islands, but data are lacking for most vertebrates from AI, especially West and Middle AI where no vertebrate sampling occurs. The population status, cause of declines, and recovery needs are lacking for several landbird species across multiple islands, including loggerhead shrikes ( Lanius ludovicianus ssp.) on SCI and SRI, and Santa Cruz Island rufous crowned sparrows ( Aimophila ruficeps obscura ) on AI. Additionally, island song sparrows ( Melospiza melodia graminea ) remain extirpated on SBI and data are needed for assessing their recovery potential on the island. The potentially major threats facing the islands’ flora and fauna today are: areas of continued erosion, potential new non-native introductions, and climate change. The Park islands have already experienced warming over the last several decades due to human-induced climate change, and are projected to experience continued warming. These increasing stresses imposed by climate change may slow and inhibit natural recovery potentials for island fauna, and especially flora.

California↗
USGS2013

The influence of global climate change on the scientific foundations and applications of Environmental Toxicology and Chemistry: Introduction to a SETAC international workshop

This is the first of seven papers resulting from a Society of Environmental Toxicology and Chemistry (SETAC) international workshop titled “The Influence of Global Climate Change on the Scientific Foundations and Applications of Environmental Toxicology and Chemistry.” The workshop involved 36 scientists from 11 countries and was designed to answer the following question: How will global climate change influence the environmental impacts of chemicals and other stressors and the way we assess and manage them in the environment? While more detail is found in the complete series of articles, some key consensus points are as follows: (1) human actions (including mitigation of and adaptation to impacts of global climate change [GCC]) may have as much influence on the fate and distribution of chemical contaminants as does GCC, and modeled predictions should be interpreted cautiously; (2) climate change can affect the toxicity of chemicals, but chemicals can also affect how organisms acclimate to climate change; (3) effects of GCC may be slow, variable, and difficult to detect, though some populations and communities of high vulnerability may exhibit responses sooner and more dramatically than others; (4) future approaches to human and ecological risk assessments will need to incorporate multiple stressors and cumulative risks considering the wide spectrum of potential impacts stemming from GCC; and (5) baseline/reference conditions for estimating resource injury and restoration/rehabilitation will continually shift due to GCC and represent significant challenges to practitioners.

Environmental Toxicology and Chemistry↗
USGS2024

An introduction to Criteria for Reporting and Evaluating Exposure Datasets (CREED) for use in environmental assessments

Risks posed by environmental exposure to chemicals are routinely assessed to inform activities ranging from environmental status reporting to authorization and registration of chemicals for commercial uses. Environmental risk assessment generally relies on two key values generated from exposure data and ecotoxicity data. Data sets of measured concentrations of chemicals in environmental matrices, referred to here as exposure data, are widely used to support environmental risk management, decision-making, and reporting, such as for chemical screening, ecological or human health risk assessments, and establishment of guidelines. Practitioners have developed schemes to determine the suitability of ecotoxicity data for specific purposes, focused on evaluating reliability and relevance, but analogous schemes are not available for exposure data. Moreover, regulatory guidance arguably provides less resolution on reporting and evaluating exposure data sets compared to ecotoxicity data. The evaluation of exposure data sets is subject to limitations from variable or unreported data quality objectives and/or from differences in expert judgments, potentially introducing bias and leading to decisions based on flawed and/or inconsistent information. Exposure data sets should be evaluated for reliability and relevance prior to use in environmental assessments. This paper is the first of a four-paper series detailing the outcomes of a Society of Environmental Toxicology and Chemistry technical workshop that has developed Criteria for Reporting and Evaluating Exposure Datasets (CREED). The workshop participants developed practical, systematic criteria for consistent and transparent evaluation of the reliability (quality) and relevance (fitness for purpose) of exposure data. This guidance should apply to many different (unspecified) purposes of assessment. CREED can be used to evaluate existing data sets, but can also inform data generators interested in improving their data collection and reporting to maximize data utility to other users. This first paper details existing frameworks for the evaluation of exposure data sets and demonstrates the need for CREED, drawing from different regulatory assessments, and describes the technical workshop.

Integrated Environmental Assessment and Management↗
USGS2003

Landscape trends in Mid-Atlantic and Southeastern United States ecoregions

Landscape pattern and composition metrics are potential indicators for broad-scale monitoring of change and for relating change to human and ecological processes. We used a probability sample of 20-km × 20-km sampling blocks to characterize landscape composition and pattern in five US ecoregions: the Middle Atlantic Coastal Plain, Southeastern Plains, Northern Piedmont, Piedmont, and Blue Ridge Mountains. Land use/land cover (LULC) data for five dates between 1972 and 2000 were obtained for each sample block. Analyses focused on quantifying trends in selected landscape pattern metrics by ecoregion and comparing trends in land cover proportions and pattern metrics among ecoregions. Repeated measures analysis of the landscape pattern documented a statistically significant trend in all five ecoregions towards a more fine-grained landscape from the early 1970s through 2000. The ecologically important forest cover class also became more fine-grained with time (i.e., more numerous and smaller forest patches). Trends in LULC, forest edge, and forest percent like adjacencies differed among ecoregions. These results suggest that ecoregions provide a geographically coherent way to regionalize the story of national land use and land cover change in the United States. This study provides new information on LULC change in the southeast United States. Previous studies of the region from the 1930s to the 1980s showed a decrease in landscape fragmentation and an increase in percent forest, while this study showed an increase in forest fragmentation and a loss of forest cover.

Environmental Management↗