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At least 541 records · Page 30Linked to original sources
USGS2023

A conceptual framework for estimation of initial emergency food and water resource requirements in disasters

Many households lack the necessary food and water supplies to sustain themselves for more than three days during a disaster. Community vulnerability assessments can be used to identify households with more pressing needs for emergency food and water resources. It is critical that these assessments include the interaction between physical impacts to lifeline infrastructure and the social vulnerabilities of food and water insecurity to prioritize, allocate, and distribute emergency resources. In this paper, we review and synthesize relevant literature to propose a new multidisciplinary conceptual framework of community vulnerability assessment for estimating initial emergency food and water resource requirements in a developed country. Using the framework as a guide, we illustrate its practical application through a simplified, deterministic model of initial resource requirements in disaster response, and offer a quantitative, comprehensive description of its application within the geophysical hazard context of the “ShakeOut” scenario—a major M w 7.8 earthquake on California's San Andreas fault , occurring within the Los Angeles Basin, CA (USA) region. Model results estimate that 999,027 households (2,947,130 residents) will require initial emergency food and water resource requirements. Estimates include about 6 million meals and 9 million liters of water, concentrated in Lancaster-Palmdale, El Monte-Baldwin Park, East Los Angeles-Downey in Los Angeles County, the Coachella Valley (Riverside County), and in populated areas of San Bernardino County. A sensitivity analysis of social vulnerability interactions with utility service outages investigates the influence of food insecurity on the amplification of resource needs. This study establishes fundamental knowledge at the nexus of natural hazards, critical infrastructure disruptions, and social vulnerability by providing initial estimates of emergency resource demand while advancing the understanding of social inequity in emergency resource access.

International Journal of Disaster Risk Reduction↗
USGS2012

Building on previous OSL dating techniques for gypsum: a case study from Salt Basin playa, New Mexico and Texas

The long term stability and reliability of the luminescence signal for gypsum has not been well documented or systematically measured until just recently. A review of the current literature for luminescence dating of gypsum is compiled here along with original efforts at dating an intact and in-situ bed of selenite gypsum at Salt Basin Playa, New Mexico and Texas. This effort differs from other documented luminescence dating efforts because the gypsum is not powdery or redistributed from its original growth patterns within the playa basin but is instead of a crystalline form. Sixteen ages from eight cores were ultimately produced with seven of the ages coming from rare detrital quartz encased in or with the gypsum crystals while the remaining ages are from the crystalline gypsum. As far as can be ascertained, the quartz was measured separately from the gypsum and no contaminants were noted in any of the aliquots. Some basic and preliminary tests of signal stability were measured and found to be mitigated by lessening of pre-heat protocols. Ages ranged from 8 ka to 10 ka in the shallow cores and 16 ka to 22 ka in the deeper cores. These ages will be useful in determining rates of gypsum growth within a sequence of evaporates which, in turn, will help to better document historic rates of evaporation and thus estimate, with more precision, the corresponding annual evaporation rates.

Texas;New Mexico↗
USGS2025

The communication of volcano information in New Zealand - A narrative review

Communication of volcano information is critical for effective volcanic risk management. A variety of information is communicated to inform decisions and guide actions for planning, preparedness, and response. Such information needs to be reliable, and fit-for-purpose across different stages of volcanic activity (quiescence, unrest, short or long-term eruptive stages, and the post-eruptive stage). However, an understanding of communication across these different stages of volcanic activity remains limited. We undertook a narrative review of New Zealand literature to explore what information is communicated about volcanoes, across which stages of activity and by whom. Results highlight that NZ literature only documents certain aspects of volcano information and communication, specifically regarding certain locations, stages of volcanic activity (i.e. quiescence or unrest), or hazards. Literature gaps exist regarding volcano communication during unrest and post-eruptive stages, as well as how volcano information evolves between these phases, and how decision-makers use such information. Additional work would be useful to document existing examples of volcano information for different stages of activity. Further research could help in understanding the information needs of decision-makers during each of these stages to improve information and communication.

New Zealand Journal of Geology and Geophysics↗
USGS2022

Priorities for translating goodwill between movement ecologists and conservation practitioners into effective collaboration

Addressing ongoing biodiversity loss requires collaboration between conservation scientists and practitioners. However, such collaboration has proved challenging. Despite the potential importance of tracking animal movements for conservation, reviews of the tracking literature have identified a gap between the academic discipline of movement ecology and its application to biodiversity conservation. Through structured conversations with movement ecologists and conservation practitioners, we aimed to understand whether the identified gap is also perceived in practice, and if so, what factors hamper collaboration and how these factors can be remediated. We found that both groups are motivated and willing to collaborate. However, because their motivations differ, there is potential for misunderstandings and miscommunications. In addition, external factors such as funder requirements, academic metrics, and journal scopes may limit the applicability of scientific results in a conservation setting. Potential solutions we identified included improved communication and better presentation of results, acknowledging each other's motivations and desired outputs, and adjustment of funder priorities. Addressing gaps between science and implementation can enhance collaboration and support conservation action to address the global biodiversity crisis more effectively.

Conservation Science and Practice↗
USGS2020

Getting to the root of restoration: Considering root traits for improved restoration outcomes under drought and competition

A foundational goal of trait‐based ecology, including trait‐based restoration, is to link specific traits to community assembly, biodiversity, and ecosystem function. Despite a growing awareness of the importance of belowground traits for ecological processes, a synthesis of how to root traits can inform restoration of terrestrial plant communities is lacking. We reviewed and summarized existing literature focused on root traits in relation to plant performance measures (i.e. survival, establishment, productivity) in the contexts of drought and competition (including invasion). Root traits related to belowground resource acquisition (e.g. high specific root length, deep roots) are frequently related to drought avoidance (i.e. a plant strategy based on optimizing water uptake to maintain function), whereas studies relating root traits to drought tolerance (i.e. a plant strategy that allows plants to withstand low hydration) remain limited. More studies have linked root traits to plant competitive effects (i.e. the influence of a plant has on neighbors) than to competitive responses (i.e. a plant's ability to resist the effects of neighbors). Because plants with acquisitive traits decrease resources to the detriment of neighbors, root traits associated with rapid resource acquisition (e.g. high specific root length) may be important for understanding competitive effects. Albeit more limited, research suggests root traits associated with resource conservation or stress tolerance (e.g. high root tissue density, high root diameter) may elucidate mechanisms related to competitive responses. Re‐vegetation outcomes may be improved by considering root traits, but only if clear links are made between traits and plant performance in varied contexts.

Restoration Ecology↗
USGS2013

A quantitative analysis of the state of knowledge of turtles of the United States and Canada

The “information age” ushered in an explosion of knowledge and access to knowledge that continues to revolutionize society. Knowledge about turtles, as measured by number of published papers, has been growing at an exponential rate since the early 1970s, a phenomenon mirrored in all scientific disciplines. Although knowledge about turtles, as measured by number of citations for papers in scientific journals, has been growing rapidly, this taxonomic group remains highly imperiled suggesting that knowledge is not always successfully translated into effective conservation of turtles. We reviewed the body of literature on turtles of the United States and Canada and found that: 1) the number of citations is biased toward large-bodied species, 2) the number of citations is biased toward wide-ranging species, and 3) conservation status has little effect on the accumulation of knowledge for a species, especially after removing the effects of body size or range size. The dispersion of knowledge, measured by Shannon Weiner diversity and evenness indices across species, was identical from 1994 to 2009 suggesting that poorly studied species remained poorly-studied species while well-studied species remained well studied. Several species listed as threatened or endangered under the U.S. Endangered Species Act (e.g., Pseudemys alabamensis, Sternotherus depressus, and Graptemys oculifera) remain poorly studied with the estimated number of citations for each ranging from only 13-24. The low number of citations for these species could best be explained by their restricted distribution and/or their smaller size. Despite the exponential increase in knowledge of turtles in the United States and Canada, no species of turtle listed under the Endangered Species Act has ever been delisted for reason of recovery. Therefore, increased knowledge does not necessarily contribute appreciably to recovery of threatened turtles.

Amphibia-Reptilia↗
USGS2011

Terrestrial forest management plan for Palmyra Atoll

This 'Terrestrial Forest Management Plan for Palmyra Atoll' was developed by the U.S. Geological Survey (USGS) for The Nature Conservancy (TNC) Palmyra Program to refine and expand goals and objectives developed through the Conservation Action Plan process. It is one in a series of adaptive management plans designed to achieve TNC's mission toward the protection and enhancement of native wildlife and habitat. The 'Terrestrial Forest Management Plan for Palmyra Atoll' focuses on ecosystem integrity and specifically identifies and addresses issues related to assessing the status and distribution of resources, as well as the pressures acting upon them, most specifically nonnative and potentially invasive species. The plan, which presents strategies for increasing ecosystem integrity, provides a framework to implement and track the progress of conservation and restoration goals related to terrestrial resources on Palmyra Atoll. The report in its present form is intended to be an overview of what is known about historical and current forest resources; it is not an exhaustive review of all available literature relevant to forest management but an attempt to assemble as much information specific to Palmyra Atoll as possible. Palmyra Atoll is one of the Northern Line Islands in the Pacific Ocean southwest of the Hawai`ian Islands. It consists of many heavily vegetated islets arranged in a horseshoe pattern around four lagoons and surrounded by a coral reef. The terrestrial ecosystem consists of three primary native vegetation types: Pisonia grandis forest, coastal strand forest, and grassland. Among these vegetation types, the health and extent of Pisonia grandis forest is of particular concern. Overall, the three vegetation types support 25 native plant species (two of which may be extirpated), 14 species of sea birds, six shore birds, at least one native reptile, at least seven native insects, and six native land crabs. Green and hawksbill turtles forage at Palmyra Atoll, and though rarely documented, beach nesting could be affected by terrestrial management actions. There are various nonnative or invasive species throughout the terrestrial ecosystem. The most notable examples of terrestrial invasive species include coconut palms (Cocos nucifera) and black rats (Rattus rattus). Although it is unclear whether they are nonnative, coconut palms are currently the most dominant plant across Palmyra Atoll. They compete with native plant species for space and resources and are potentially detrimental to sea birds dependent on native vegetation for roosting and nesting habitat. This competition in turn impacts nutrient resource availability, thereby reshaping energy flow in the ecosystem. Black rats are known to prey on ground-nesting sea birds and are likely responsible for the lack of burrowing sea bird reproduction at Palmyra Atoll. In addition, they may be facilitating the invasion of other nonnative species and negatively impacting other native fauna. Although the extent and impacts of these and other nonnative and (or) invasive species are not fully understood, the extent and impacts are clearly a threat to the native species and one of the most urgent threats to the overall ecosystem integrity of Palmyra Atoll. This 'Terrestrial Forest Management Plan for Palmyra Atoll' addresses issues related to invasive species and other problems. Priority goals are established as are associated objectives and strategies. The overarching goal is to perpetuate and where possible restore terrestrial ecosystem integrity through the following techniques: 1. Habitat management: Maintain and enhance habitat to the extent possible to sustain thriving Pisonia grandis forest, coastal strand forest, endemic grassland, self-sustaining populations of sea birds, shore birds, coconut crabs, native lizards, and native insects. 2. Monitoring and assessment: Acquire information on distribution and abundance as needed for conservation of each resour

Open-File Report↗
USGS2018

Assessment of capacity-building activities for forest measurement, reporting, and verification, 2011–15

This report was written as a collaborative effort between the U.S. Geological Survey, SilvaCarbon, and Wageningen University with funding provided by the U.S. Agency for International Development and the European Space Agency, respectively, to address a pressing need for enhanced result-based monitoring and evaluation of delivered capacity-building activities. For this report, the capacity-building activities delivered by capacity-building providers (referred to as “providers” hereafter) during 2011–15 (the study period) to support countries in building measurement, reporting, and verification (MRV) systems for reducing emissions from deforestation and forest degradation (REDD+) were assessed and evaluated. Summarizing capacity-building activities and outcomes across multiple providers was challenging. Many of the providers did not have information readily available, which precluded them from participating in this study despite the usefulness of their information. This issue led to a key proposed future action: Capacity-building providers could establish a central repository within the Global Forestry Observation Initiative (GFOI; http://www.gfoi.org/ ) where data from past, current, and future activities of all capacity-building providers could be stored. The repository could be maintained in a manner to continually learn from previous lessons. Although various providers monitored and evaluated the success of their capacity-building activities, such evaluations only assessed the success of immediate outcomes and not the overarching outcomes and impacts of activities implemented by multiple providers. Good monitoring and evaluation should continuously monitor and periodically evaluate all factors affecting the outcomes of a provided capacity-building activity. The absence of a methodology to produce quantitative evidence of a causal link between multiple capacity-building activities delivered and successful outcomes left only a plausible association. A previous publication argued that plausible association, although not a precise measurement of cause and effect, was a realistic tool. Our review of the available literature on this subject did not find another similar assessment to assess capacity-building activities for supporting the countries in building MRV system for REDD+. Four countries from the main forested regions of Africa, the Americas, and Asia were chosen as subjects for this report based on the length of time SilvaCarbon and other providers have provided capacity-building activities toward MRV system for REDD+: Colombia (the Americas), the Democratic Republic of the Congo (DRC; Africa), Peru (the Americas), and the Republic of the Philippines (referred to as “the Philippines” hereafter; Asia). Several providers were contacted for information to include in this report, but, because of various constraints, only SilvaCarbon, the Food and Agriculture Organization of the United Nations (FAO), and the World Wildlife Fund (WWF) participated in this study. These three providers supported various targeted capacity-building activities through-out Africa, the Americas, and Asia, including the following: technical workshops at national and regional levels (referred to as “workshops” hereafter), hands on training, study tours, technical details by experts, technical consultation between providers and recipients, sponsorship for travel, organizing network meetings, developing sampling protocols, assessing deforestation and degradation drivers, estimating carbon stock and flow, designing monitoring systems for multiple uses, promoting public-private partnerships to scale up investments on MRV system for REDD+, and assisting with the design of national forest monitoring systems. Their activities were planned in coordination with key partners in each country and region and with the support and assistance of other providers. Note that several other organizations and institutions assisted the providers to deliver capacity-building activities, including Boston University, Conservation International, Stanford University, University of Maryland, and Wageningen University & Research.

Open-File Report↗
USGS2023

Synthesis of climate and ecological science to support grassland management priorities in the North Central Region

Grasslands in the Great Plains are of ecological, economic, and cultural importance in the United States. In response to a need to understand how climate change and variability will impact grassland ecosystems and their management in the 21st century, the U.S. Geological Survey North Central Climate Adaptation Science Center led a synthesis of peer-reviewed climate and ecology literature relevant to grassland management in the North Central Region (including Montana, Wyoming, Colorado, North Dakota, South Dakota, Nebraska, and Kansas). This synthesis was done to begin to address grassland managers’ information needs and identify research gaps. This open-file report summarizes the impacts of climate change and variability on temperature, water availability, wildfire, vegetation, wildlife, large-bodied ruminants, grazing, and land-use change and the implications for grassland management in the North Central region. This open-file report also identifies areas in which further research is needed. U.S. Geological Survey funded this project.

Colorado, Kansas, Montana, Nebraska, North Dakota,↗
USGS1980

Selected list of references to modern and ancient alluvial fan deposits

The following list of references on modern and ancient alluvial fan deposits has been compiled from an extensive review of the geologic literature. The information was collected as part of the process of preparing a summary paper on alluvial fan deposits for a memoir of the American Association of Petroleum Geologists. Although we have not examined all of the listed references, each contains information regarding alluvial fan deposits. The most important references are compiled in Tables 1 and 2, in which modern and ancient alluvial fan deposits are temporally and spatially organized. We hope that this list may be helpful to researchers studying fan deposits, and that new references will be added to the list in the future.

Open-File Report↗
USGS1903

Drainage modifications in southeastern Ohio and adjacent parts of West Virginia and Kentucky

The field work upon which this paper is based was carried on intermittently for several years. During the season of 1899 the work in Washington County, Ohio, was conducted under the direction of the Ohio State Academy of Science, the expenses being covered by a grant from the Emerson McMillin special research fund. The field work of the season of 1900 was done under the direction of Dr. T. C. Chamberlin, chief of the Division of Pleistocene Geology of the United States Geological Survey, and to him the author is greatly indebted for many valuable suggestions in relation to the work, and for an extended correspondence concerning the interpretations, during the preparation of this report. The study of this particular region was the natural result of earlier studies of drainage modifications in Ohio, in the region more nearly adjacent to the glaciated area. Until a few years ago but very little systematic study of the drainage features of Ohio had been made. It is not intended at present to make a complete review of the early literature, but to refer only to such portions of it as bear directly on the problem in hand. On account of the lack of good maps of Ohio it has not been possible to make the maps which accompany this paper as accurate as might be desired. They have been constructed from various published maps and from personal observations in the field; and, while they are not strictly accurate, it is hoped that they will set forth the facts with reference to the drainage modifications with sufficient clearness to enable anyone to follow the features in the field, or to serve for purposes of correlation. The map of Flatwoods and Teays valleys has been constructed from four topographic sheets of the United States Geological Survey Ironton, Kenova, Huntington, and Charleston. The author is under obligations to Mr. H. M. Wilson, geographer of the Survey, for data furnished from the unpublished map of the Kenova quadrangle. The photographs illustrating the report were all taken by the author.

Kentucky, Ohio, West Virginia↗
USGS2008

Geographic Names of Iceland's Glaciers: Historic and Modern

Climatic changes and resulting glacier fluctuations alter landscapes. In the past, such changes were noted by local residents who often documented them in historic annals; eventually, glacier variations were recorded on maps and scientific reports. In Iceland, 10 glacier place-names are to be found in Icelandic sagas, and one of Iceland's ice caps, Snaefellsjokull, appeared on maps of Iceland published in the 16th century. In the late 17th century, the first description of eight of Iceland's glaciers was written. Therefore, Iceland distinguishes itself in having a more than 300-year history of observations by Icelanders on its glaciers. A long-term collaboration between Oddur Sigurdsson and Richard S. Williams, Jr., led to the authorship of three books on the glaciers of Iceland. Much effort has been devoted to documenting historical glacier research and related nomenclature and to physical descriptions of Icelandic glaciers by Icelanders and other scientists from as far back as the Saga Age to recent (2008) times. The first book, Icelandic Ice Mountains, was published by the Icelandic Literary Society in 2004 in cooperation with the Icelandic Glaciological Society and the International Glaciological Society. Icelandic Ice Mountains was a glacier treatise written by Sveinn Palsson in 1795 and is the first English translation of this important scientific document. Icelandic Ice Mountains includes a Preface, including a summary of the history and facsimiles of page(s) from the original manuscript, a handwritten copy, and an 1815 manuscript (without maps and drawings) by Sveinn Palsson on the same subject which he wrote for Rev. Ebenezer Henderson; an Editor's Introduction; 82 figures, including facsimiles of Sveinn Palsson's original maps and perspective drawings, maps, and photographs to illustrate the text; a comprehensive Index of Geographic Place-Names and Other Names in the treatise; References, and 415 Endnotes. Professional Paper 1746 (this book) is the second of the three books; it is being published in both English and Icelandic editions. This book provides information about all named glaciers in Iceland, historic and modern. Descriptions, with geographic coordinates, and bibliographic citations to all glacier place-names on published maps, books, and scientific articles are included. Maps, oblique aerial photographs, ground photographs, and satellite images document each of the 269 modern named glaciers of Iceland. The third book, Glaciers of Iceland, is Chapter D of the 11-chapter [volume] U.S. Geological Survey Professional Paper 1386-A-K. Chapter D includes a 1:500,000-scale Map of the Glaciers of Iceland; it is a comprehensive historical and modern review and assessment of what is currently known about glaciers in Iceland's eight Regional Glacier Groups from a review of the scientific literature and from analysis of maps and remotely sensed data (ground, airborne, and satellite); topics include geology and geography, climate and climate variability, types of glaciers, history of glacier variation (including the 21 surge-type glaciers), and frequency and magnitude of volcanic and lacustrine jokulhlaups.

Professional Paper↗
USGS2015

Nutrient attenuation in rivers and streams, Puget Sound Basin, Washington

Nutrients such as nitrogen and phosphorus are important for aquatic ecosystem health. Excessive amounts of nutrients, however, can make aquatic ecosystems harmful for biota because enhanced growth and decay cycles of aquatic algae can reduce dissolved oxygen in the water. In Puget Sound marine waters, low dissolved oxygen concentrations are observed in a number of marine nearshore areas, and nutrients have been identified as a major stressor to the local ecosystem. Delivery of nutrients from major rivers in the Puget Sound Basin to the marine environment can be large. Therefore, it is important to identify factors related to how nutrients are retained (attenuated) within streams and rivers in the Puget Sound Basin. Physical, chemical, and biological factors related to nutrient attenuation were identified through a review of related scientific literature. Numerous empirical modeling approaches for estimating nutrient attenuation in streams and rivers also were compiled, and a subset of these models was applied to the Puget Sound Basin. In particular, models based on the physical characteristics of a river reach (RivR-N model) and on the physical and biological features of a river reach (v f model) were used and compared for the 17 major rivers draining to the Puget Sound. Data on the relative amount of instream attenuation (the fraction of nutrient input removed per kilometer of stream reach) showed some common and general themes. Firstly, headwater reaches throughout the Puget Sound Basin tend to be better than the main stems of the major rivers at attenuating nitrate and orthophosphorus (ortho-P). Secondly, rivers are more efficient at attenuating nitrate than ortho-P, probably because of the close relation between phosphorus and suspended sediment, which was not captured fully in the models. Thirdly, when comparing the RivR-N and v f models for nitrate, physical characteristics of the channel may be more effective predictors of relative nitrate attenuation for main stem reaches, whereas biological factors may be more effective predictors in headwater reaches. These results are explained in terms of four primary factors of attenuation: sinuosity, channel slope, specific discharge, and uptake velocity (v f ) of the reach. A simple scoring procedure based on these four factors showed that reaches where attenuation scores were high had higher relative attenuation of nutrients from the RivR-N and v f models. This attenuation "scorecard" can be used to quickly assess the potential for a given reach to attenuate nutrients. Seasonal relative attenuation at three case studies was greater in summer months (July through September) and much lower and almost constant from January through June. An analysis of relative attenuation across a range of nutrient concentrations showed that, at some point, relative instream attenuation is minimized. For nitrate, relative attenuation reached a minimum value greater than 3 milligrams of nitrogen per liter (mg N/L) during low flow and 1 mg N/L during high flow. For orthophosphate, minimum relative attenuation was observed at about 0.1 milligram of phosphorus per liter (mg P/L) for both low- and high-flow conditions. Generally, the temporal dynamics of nutrient attenuation are dependent on the travel time through a given reach, the proportion of flow in contact with the sediment, and the amount of biological activity. Improved understanding of nutrient attenuation in Puget Sound Basin will benefit from the compilation of more detailed data for specific discharge, channel slope, and channel sinuosity in Puget Sound streams and rivers. Additionally, field studies examining upstream-downstream changes in nutrient load and field-based measurements of v f are needed. From a management perspective, preservation and improvement of instream nutrient attenuation should focus on increasing the travel time through a reach and contact time of water sediment (reactive) surfaces and lowering nutrient concentrations (and loads) to avoid saturation of instream attenuation and increase attenuation efficiency. These goals can be reached by maintaining and restoring channel-flood plain connectivity, maintaining and restoring healthy riparian zones along streams, managing point and nonpoint nutrient loads to streams and rivers, and restoring channel features that promote attenuation such as the addition of woody debris and maintaining pool-riffle morphologies. Many of these management approaches are already being undertaken during projects aimed to restore quality salmon habitat. Therefore, there is a dual benefit to these projects that also may lead to enhanced potential for nitrogen and phosphorus attenuation.

Washington↗
USGS1993

Reconnaissance investigation of the geology and hydrogeology of Lackland Air Force Base, San Antonio, Texas

An investigation at Lackland Air Force Base and Lackland Air Force Base Training Annex (Medina Base) was conducted from May to September 1988 to delineate the subsurface geology, to describe the hydrogeology within the study area, and to determine possible migration pathways for contaminants. Data from this investigation supplement data collected in conjunction with other Air Training Command studies conducted under the Installation Restoration Program. The geologic formations in the vicinity of Lackland Air Force Base and Medina Base consist of sedimentary rocks of Cretaceous, Tertiary, and Quaternary age. The lithology of these formations consists primarily of limestone and marl, with lesser amounts of gravel, sand, silt, shale, and clay. The formations that comprise the geologic setting at Lackland Air Force Base and Medina Base include the Navarro Group of Late Cretaceous age, the Midway Group and Uvalde Gravel of Tertiary age, and the Leona Formation and fluviatile terrace deposits of Quaternary age. The age of the faulting within the study area has not been determined accurately, but the faulting might have occurred during intervals from Early Cretaceous to Holocene time. During these tectonic episodes, uplift of the Edwards Plateau might have occurred. This uplift could have enhanced erosion of the Cretaceous age Edwards Group, which is north of the study area, causing deposition of alluvial deposits south of this tectonic activity. The Leona Formation is composed of limestone gravel deposits forming terraces in the valleys of present streams. In general, these terraces are topographically lower than those formed by the Uvalde Gravel. In contrast, the fluviatile terrace deposits are above flood level along entrenched streams such as Leon and Medio Creeks. The Leona Formation is generally above the level of these fluviatile terrace deposits. A review of the hydrogeologic literature indicated that the Navarro and Midway Groups do not yield water to wells in Bexar County. However, recent studies by the U.S. Geological Survey at Kelly Air Force Base indicate that the uppermost beds of the Navarro Group can be saturated but yield little or no water to wells. Each stream terrace deposit of the Leona Formation and the fluviatile terrace deposits are separate water-bearing units. At Lackland Air Force Base, shallow ground water is present in the Leona Formation and the flow probably is toward Leon Creek. At Medina Base, the fluviatile terrace deposits are present along both banks of Medio Creek and probably are separate water-bearing units. Furthermore, ground-water flow in each of these units probably is toward Medio Creek. The Uvalde Gravel, present only at and west of Medina Base, is not a source of shallow ground water. However, during periods of precipitation, the formation can readily absorb precipitation and surface runoff. Water drains quickly through the formation because of its topographically high position and substantial hydraulic conductivity. Major pathways of potential contaminant migration off the bases include the local streams of Medio and Leon Creeks, and to a lesser extent, the shallow ground water beneath the bases. Although the Uvalde Gravel is not a source of shallow ground water at Medina Base, it drains water quickly, and wastes that might be buried in the gravel could be a potential source of contamination during brief ground-water recharge periods resulting from major precipitation.

Texas↗
USGS2017

Can ozone be used to control the spread of freshwater Aquatic Invasive Species?

The introduction of aquatic invasive species to non-native habitats can cause negative ecological effects and also billions of dollars in economic damage to governments and private industries. Once aquatic invasive species are introduced, eradication may be difficult without adversely affecting native species and habitats, urging resource managers to find preventative methods to protect non-invaded areas. The use of ozone (O 3 ) as a non-physical barrier has shown promise as it is lethal to a wide range of aquatic taxa, requires a short contact time, and is relatively environmentally safe in aquatic systems when compared to other chemicals. However, before O 3 can be considered as an approach to prevent the spread of aquatic invasive species, its effects on non-target organisms and already established aquatic invasive species must be fully evaluated. A review of the current literature was conducted to summarize data regarding the effects of O 3 on aquatic taxa including fish, macroinvertebrates, zooplankton, phytoplankton, microbes, and pathogens. In addition, we assessed the practicality of ozone applications to control the movement of aquatic invasive species, and identified data gaps concerning the use of O 3 as a non-physical barrier in field applications.

Management of Biological Invasions↗
USGS2018

Cougar dispersal and natal homing in a desert environment

We present a review of cougar dispersal literature and the first evidence of natural (i.e., unmanipulated) homing behavior by a dispersing male cougar (Puma concolor) that sustained severe injuries crossing the northern Mojave Desert. Based on Global Positioning System and ground tracking data, the male traveled a total distance of 981.1 km at 5.03 km/d, including 170.31 km from the Desert National Wildlife Refuge to the northwestern Grand Canyon, where he sustained severe injuries. The interkill interval increased from 7.1 ± 2.7 d while he was in his natal range to 17.5 ± 4.9 d during dispersal. While homing, the male appeared to consume only reptiles until he died, 33.7 km from his capture site. In desert environments where prey availability is low, homing behavior may be an important strategy for dispersing cougars, providing a mechanism for persistence when the best quality habitats they encounter are already occupied by adult residents. Therefore, managing for habitat connectivity can ensure successful homing as well as dispersal on a greater scale than has been previously suggested. Elucidating the mechanisms that trigger homing during dispersal may provide critical insight into animal movements often overlooked as mundane behavior.

Arizona, California, Nevada, Utah↗
USGS2014

Phytoplankton primary production in the world's estuarine-coastal ecosystems

Estuaries are biogeochemical hot spots because they receive large inputs of nutrients and organic carbon from land and oceans to support high rates of metabolism and primary production. We synthesize published rates of annual phytoplankton primary production (APPP) in marine ecosystems influenced by connectivity to land – estuaries, bays, lagoons, fjords and inland seas. Review of the scientific literature produced a compilation of 1148 values of APPP derived from monthly incubation assays to measure carbon assimilation or oxygen production. The median value of median APPP measurements in 131 ecosystems is 185 and the mean is 252 g C m −2 yr −1 , but the range is large: from −105 (net pelagic production in the Scheldt Estuary) to 1890 g C m −2 yr −1 (net phytoplankton production in Tamagawa Estuary). APPP varies up to 10-fold within ecosystems and 5-fold from year to year (but we only found eight APPP series longer than a decade so our knowledge of decadal-scale variability is limited). We use studies of individual places to build a conceptual model that integrates the mechanisms generating this large variability: nutrient supply, light limitation by turbidity, grazing by consumers, and physical processes (river inflow, ocean exchange, and inputs of heat, light and wind energy). We consider method as another source of variability because the compilation includes values derived from widely differing protocols. A simulation model shows that different methods reported in the literature can yield up to 3-fold variability depending on incubation protocols and methods for integrating measured rates over time and depth. Although attempts have been made to upscale measures of estuarine-coastal APPP, the empirical record is inadequate for yielding reliable global estimates. The record is deficient in three ways. First, it is highly biased by the large number of measurements made in northern Europe (particularly the Baltic region) and North America. Of the 1148 reported values of APPP, 958 come from sites between 30 and 60° N; we found only 36 for sites south of 20° N. Second, of the 131 ecosystems where APPP has been reported, 37% are based on measurements at only one location during 1 year. The accuracy of these values is unknown but probably low, given the large interannual and spatial variability within ecosystems. Finally, global assessments are confounded by measurements that are not intercomparable because they were made with different methods. Phytoplankton primary production along the continental margins is tightly linked to variability of water quality, biogeochemical processes including ocean–atmosphere CO 2 exchange, and production at higher trophic levels including species we harvest as food. The empirical record has deficiencies that preclude reliable global assessment of this key Earth system process. We face two grand challenges to resolve these deficiencies: (1) organize and fund an international effort to use a common method and measure APPP regularly across a network of coastal sites that are globally representative and sustained over time, and (2) integrate data into a unifying model to explain the wide range of variability across ecosystems and to project responses of APPP to regional manifestations of global change as it continues to unfold.

Biogeosciences↗
USGS1992

Relating results from earthworm toxicity tests to agricultural soil

The artificial soil tests of the European Economic Community and of the Organization for Economic Cooperation produce data relating earthworm mortality to pesticide concentrations in soil under laboratory conditions. To apply these results to agricultural soils it is necessary to relate these concentrations to amounts of pesticide applied per area. This paper reviews the relevant published literature and suggests a simple relation for regulatory use. Hazards to earthworms from pesticides are suggested to be greatest soon after application, when the pesticides may be concentrated in a soil layer a few millimeters thick. For estimating exposure of earthworms, however, a thicker soil layer should be considered, to account for their movement through soil. During favorable weather conditions, earthworms belonging to species appropriate to the artificial soil test have been reported to confine their activity to a layer about 5 cm. If a 5-cm layer is accepted as relevant for regulatory purposes, then an application of 1 kg/ha would be equivalent to 1-67 ppm (dry) in the artificial soil test.

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