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At least 811 records · Page 45Linked to original sources

USGS2003

Using multiple logistic regression and GIS technology to predict landslide hazard in northeast Kansas, USA

Landslides in the hilly terrain along the Kansas and Missouri rivers in northeastern Kansas have caused millions of dollars in property damage during the last decade. To address this problem, a statistical method called multiple logistic regression has been used to create a landslide-hazard map for Atchison, Kansas, and surrounding areas. Data included digitized geology, slopes, and landslides, manipulated using ArcView GIS. Logistic regression relates predictor variables to the occurrence or nonoccurrence of landslides within geographic cells and uses the relationship to produce a map showing the probability of future landslides, given local slopes and geologic units. Results indicated that slope is the most important variable for estimating landslide hazard in the study area. Geologic units consisting mostly of shale, siltstone, and sandstone were most susceptible to landslides. Soil type and aspect ratio were considered but excluded from the final analysis because these variables did not significantly add to the predictive power of the logistic regression. Soil types were highly correlated with the geologic units, and no significant relationships existed between landslides and slope aspect. ?? 2003 Elsevier Science B.V. All rights reserved.

Engineering Geology↗

USGS2019

Global phylodynamic analysis of avian paramyxovirus-1 provides evidence of inter-host transmission and intercontinental spatial diffusion

Background Avian avulavirus (commonly known as avian paramyxovirus-1 or APMV-1) can cause disease of varying severity in both domestic and wild birds. Understanding how viruses move among hosts and geography would be useful for informing prevention and control efforts. A Bayesian statistical framework was employed to estimate the evolutionary history of 1602 complete fusion gene APMV-1 sequences collected from 1970 to 2016 in order to infer viral transmission between avian host orders and diffusion among geographic regions. Ancestral states were estimated with a non-reversible continuous-time Markov chain model, allowing transition rates between discrete states to be calculated. The evolutionary analyses were stratified by APMV-1 classes I ( n = 198) and II ( n = 1404), and only those sequences collected between 2006 and 2016 were allowed to contribute host and location information to the viral migration networks. Results While the current data was unable to assess impact of host domestication status on APMV-1 diffusion, these analyses supported the sharing of APMV-1 among divergent host taxa. The highest supported transition rate for both classes existed from domestic chickens to Anseriformes (class I:6.18 transitions/year, 95% highest posterior density (HPD) 0.31–20.02, Bayes factor (BF) = 367.2; class II:2.88 transitions/year, 95%HPD 1.9–4.06, BF = 34,582.9). Further, among class II viruses, domestic chickens also acted as a source for Columbiformes (BF = 34,582.9), other Galliformes (BF = 34,582.9), and Psittaciformes (BF = 34,582.9). Columbiformes was also a highly supported source to Anseriformes (BF = 322.0) and domestic chickens (BF = 402.6). Additionally, our results provide support for the diffusion of viruses among continents and regions, but no interhemispheric viral exchange between 2006 and 2016. Among class II viruses, the highest transition rates were estimated from South Asia to the Middle East (1.21 transitions/year; 95%HPD 0.36–2.45; BF = 67,107.8), from Europe to East Asia (1.17 transitions/year; 95%HPD 0.12–2.61; BF = 436.2) and from Europe to Africa (1.06 transitions/year, 95%HPD 0.07–2.51; BF = 169.3). Conclusions While migration appears to occur infrequently, geographic movement may be important in determining viral diversification and population structure. In contrast, inter-order transmission of APMV-1 may occur readily, but most events are transient with few lineages persisting in novel hosts.

BMC Evolutionary Biology↗

USGS2012

A spatial cluster analysis of tractor overturns in Kentucky from 1960 to 2002

Background: Agricultural tractor overturns without rollover protective structures are the leading cause of farm fatalities in the United States. To our knowledge, no studies have incorporated the spatial scan statistic in identifying high-risk areas for tractor overturns. The aim of this study was to determine whether tractor overturns cluster in certain parts of Kentucky and identify factors associated with tractor overturns. Methods: A spatial statistical analysis using Kulldorff's spatial scan statistic was performed to identify county clusters at greatest risk for tractor overturns. A regression analysis was then performed to identify factors associated with tractor overturns. Results: The spatial analysis revealed a cluster of higher than expected tractor overturns in four counties in northern Kentucky (RR = 2.55) and 10 counties in eastern Kentucky (RR = 1.97). Higher rates of tractor overturns were associated with steeper average percent slope of pasture land by county (p = 0.0002) and a greater percent of total tractors with less than 40 horsepower by county (p<0.0001). Conclusions: This study reveals that geographic hotspots of tractor overturns exist in Kentucky and identifies factors associated with overturns. This study provides policymakers a guide to targeted county-level interventions (e.g., roll-over protective structures promotion interventions) with the intention of reducing tractor overturns in the highest risk counties in Kentucky.

Kentucky↗

USGS2014

Evaluation of alternative groundwater-management strategies for the Bureau of Reclamation Klamath Project, Oregon and California

The water resources of the upper Klamath Basin, in southern Oregon and northern California, are managed to achieve various complex and interconnected purposes. Since 2001, irrigators in the Bureau of Reclamation Klamath Irrigation Project (Project) have been required to limit surface-water diversions to protect habitat for endangered freshwater and anadromous fishes. The reductions in irrigation diversions have led to an increased demand for groundwater by Project irrigators, particularly in drought years. The potential effects of sustained pumping on groundwater and surface-water resources have caused concern among Federal and state agencies, Indian tribes, wildlife groups, and groundwater users. To aid in the development of a viable groundwater-management strategy for the Project, the U.S. Geological Survey, in collaboration with the Klamath Water and Power Agency and the Oregon Water Resources Department, developed a groundwater-management model that links groundwater simulation with techniques of constrained optimization. The overall goal of the groundwater-management model is to determine the patterns of groundwater pumping that, to the extent possible, meet the supplemental groundwater demands of the Project. To ensure that groundwater development does not adversely affect groundwater and surface-water resources, the groundwater-management model includes constraints to (1) limit the effects of groundwater withdrawal on groundwater discharge to streams and lakes that support critical habitat for fish listed under the Endangered Species Act, (2) ensure that drawdowns do not exceed limits allowed by Oregon water law, and (3) ensure that groundwater withdrawal does not adversely affect agricultural drain flows that supply a substantial portion of water for irrigators and wildlife refuges in downslope areas of the Project. Groundwater-management alternatives were tested and designed within the framework of the Klamath Basin Restoration Agreement (currently [2013] awaiting authorizing Federal legislation), which would establish a permanent limit on the amount of surface water that can be diverted annually to the Project. Groundwater-management scenarios were evaluated for the period 1970•2004; supplemental groundwater demand by the Project was estimated as the part of irrigation demand that would not have been satisfied by the surface-water diversion allowed under the Klamath Basin Restoration Agreement. Over the 35-year management period, 22 years have supplemental groundwater demand, which ranges from a few thousand acre-feet (acre-ft) to about 100,000 acre-ft in the driest years. The results of the groundwater-management model indicate that supplemental groundwater pumping by the Project can be managed to avoid adverse effects to groundwater discharge that supports critical aquatic habitat. The existing configuration of wells in the Project would be able to meet groundwater-pumping goals in 14 of the 22 years with supplemental groundwater demand; however, substantial irrigation shortages can be expected during drought periods when the demand for supplemental groundwater is highest. The maximum irrigation-season withdrawal calculated by the groundwater-management model is about 60,000 acre-ft, the average withdrawal in drought years is about 54,000 acre-ft, and the amount of unmet groundwater demand reaches a maximum of about 45,000 acre-ft. A comparison of optimized groundwater withdrawals by geographic region shows that the highest annual withdrawals are associated with wells in the Tule Lake and Klamath Valley regions of the Project. The patterns of groundwater withdrawal also show that a substantial amount of the available pumping capacity is unused due to the restrictions imposed by drawdown constraints. Subsequent model applications were used to evaluate the sensitivity of optimization results to various factors. A sensitivity analysis quantified the changes in optimized groundwater withdrawals that result from changes in drawdown-constraint limits. The analysis showed the potential for substantial increases in withdrawals of groundwater with less restrictive drawdown limits at drawdown-control sites in the California part of the model. Systematic variation of the drains-constraint limit yielded a trade-off curve between optimized groundwater withdrawals and the allowable reduction in groundwater discharge to the Project drain system. Additional model applications were used to assess the value of increasing the pumping capacity of the network of wells serving the Project, and the relation between reduced off-Project groundwater pumping and increased pumping by Project irrigators.

California;Oregon↗

USGS1991

System requirements specification for the U.S. Geological Survey's National Water Information System II

The U.S. Geological Survey's Water Resources Division is designing and developing a new computer software system for processing and storing hydrologic data. This system, the National Water Information System (NWIS-II) will replace the current water-data and information systems: the National Water Data Storage and Retrieval System (WATSTORE), the National Water Data Exchange (NAWDEX), and the National Water-Use Information System, as well as the current National Water Information System (NWIS-I). The new system will be utilized across the Nation on the Distributed Information System (DIS-II), a network of 32-bit microcomputers on a wide-area network of desktop workstations and related hardware. The purpose of the NWIS-II System Requirements Specification is to integrate requirements described by eight User Groups representing the disciplines for Surface Water, Ground Water, Water Quality, Water Sediment, Water Use, Biology, Geographic Information, and National Water Data Exchange. The requirements specified in this document will serve as the framework for subsequent design and development activities throughout the life cycle of NWIS-II to ensure that the development products reflect the needs of the users. Specification details and associated data-base plans are contained in the description of the integrated functional requirements, the logical data model and the data dictionary, the plan for transferring data from the existing system to NWIS-II, and the descriptions of performance requirements and design constraints. The NWIS-II will be consistent across hydrologic disciplines and the other major Division software systems. The color-graphics desktop environment of NWIS-II will utilize multi-window and multi-tasking capabilities with multilevel of help for the users. Data will be distributed among nodes and be automatically accessible during input, editing, verification and analysis of data. Hydrologic data will be cataloged independent of the Environmental Protection Agency's storage and retrieval (STORET) codes. Character, digital, and graphical data will be entered into NWIS-II from digital and analog recorders, external files, or keyboard through standard and user-defined input forms. Data will be verified manually or automatically during input, retrieval, and editing of data. Numerous reference lists will be maintained so that entry of codes on forms will not be required. User-defined series of computer actions for standard programs will be supported for processing basic data and other frequently repeated processes. Data will be verified and exchanged through links to other DIS-II software, including a Geographic Information System, and selected external software. Quality assurance of data will include aging of data through change on status type and tracking access violations. Output of data will be to a variety of media in standard and user-defined formats. The data base will be preserved by operations such as backup, recovery, audit trails, archiving, and data histories. In addition, an index of water data from USGS and other agencies will be maintained.

Open-File Report↗

USGS2016

Forecasting tidal marsh elevation and habitat change through fusion of Earth observations and a process model

Reducing uncertainty in data inputs at relevant spatial scales can improve tidal marsh forecasting models, and their usefulness in coastal climate change adaptation decisions. The Marsh Equilibrium Model (MEM), a one-dimensional mechanistic elevation model, incorporates feedbacks of organic and inorganic inputs to project elevations under sea-level rise scenarios. We tested the feasibility of deriving two key MEM inputs—average annual suspended sediment concentration (SSC) and aboveground peak biomass—from remote sensing data in order to apply MEM across a broader geographic region. We analyzed the precision and representativeness (spatial distribution) of these remote sensing inputs to improve understanding of our study region, a brackish tidal marsh in San Francisco Bay, and to test the applicable spatial extent for coastal modeling. We compared biomass and SSC models derived from Landsat 8, DigitalGlobe WorldView-2, and hyperspectral airborne imagery. Landsat 8-derived inputs were evaluated in a MEM sensitivity analysis. Biomass models were comparable although peak biomass from Landsat 8 best matched field-measured values. The Portable Remote Imaging Spectrometer SSC model was most accurate, although a Landsat 8 time series provided annual average SSC estimates. Landsat 8-measured peak biomass values were randomly distributed, and annual average SSC (30 mg/L) was well represented in the main channels (IQR: 29–32 mg/L), illustrating the suitability of these inputs across the model domain. Trend response surface analysis identified significant diversion between field and remote sensing-based model runs at 60 yr due to model sensitivity at the marsh edge (80–140 cm NAVD88), although at 100 yr, elevation forecasts differed less than 10 cm across 97% of the marsh surface (150–200 cm NAVD88). Results demonstrate the utility of Landsat 8 for landscape-scale tidal marsh elevation projections due to its comparable performance with the other sensors, temporal frequency, and cost. Integration of remote sensing data with MEM should advance regional projections of marsh vegetation change by better parameterizing MEM inputs spatially. Improving information for coastal modeling will support planning for ecosystem services, including habitat, carbon storage, and flood protection.

California↗

USGS2020

Drivers and consequences of apex predator diet composition in the Canadian Beaufort Sea

Polar bears ( Ursus maritimus ) rely on annual sea ice as their primary habitat for hunting marine mammal prey. Given their long lifespan, wide geographic distribution, and position at the top of the Arctic marine food web, the diet composition of polar bears can provide insights into temporal and spatial ecosystem dynamics related to climate-mediated sea ice loss. Polar bears with the greatest ecological constraints on diet composition may be most vulnerable to climate-related changes in ice conditions and prey availability. We used quantitative fatty acid signature analysis (QFASA) to estimate the diets of polar bears ( n = 419) in two western Canadian Arctic subpopulations (Northern Beaufort Sea and Southern Beaufort Sea) from 1999 to 2015. Polar bear diets were dominated by ringed seal ( Pusa hispida ), with interannual, seasonal, age- and sex-specific variation. Foraging area and sea ice conditions also affected polar bear diet composition. Most variation in bear diet was explained by longitude, reflecting spatial variation in prey availability. Sea ice conditions (extent, thickness, and seasonal duration) declined throughout the study period, and date of sea ice break-up in the preceding spring was positively correlated with female body condition and consumption of beluga whale ( Delphinapterus leucas ), suggesting that bears foraged on beluga whales during entrapment events. Female body condition was positively correlated with ringed seal consumption, and negatively correlated with bearded seal consumption. This study provides insights into the complex relationships between declining sea ice habitat and the diet composition and foraging success of a wide-ranging apex predator.

Northwest Territories, Yukon↗

USGS2025

Comparative genomics of Bacillus anthracis A and B-clades reveals genetic variation in genes responsible for spore germination

Bacillus anthracis , the causative agent of anthrax, is composed of three genetic clades (A, B, and C). Clade-A is the most common and distributed worldwide, B-clade has a narrow geographic distribution, and C-clade is rare. South Africa's Kruger National Park (KNP) has high diversity of B. anthracis , with strains from A and B clades described from its northernmost region, Pafuri. We employed whole genome sequencing to investigate the genomic diversity of B. anthracis strains isolated from animal carcasses ( n = 34) during the 2012–2015 outbreaks. Whole-genome single-nucleotide polymorphism (wgSNP) analysis assigned the 2012–2015 B. anthracis genomes to the A-clade branch, distributed across the branch's two minor sub-clades A.Br.005/006. Additionally, pan-genomic analysis distinguished the A- and B-clade genomes, identifying unique accessory genes. Notable genetic differences include the biosynthetic spore cell wall genes; long-chain fatty acid CoA ligases ( FaD13 ), Bacillus collagen-like protein of anthracis (BclA) involved in the exosporium germination, as well as a truncated murein DD-endopeptidase ( mepH ) found in the pXO2 plasmid of the B-clade strains. The tryptophan synthase subunit alpha gene ( trpA ), which results in a pseudogene in B-clade genomes separates the A- and B-clade genomes. These differences in biosynthetic cell wall genes suggest variation in adaptability or cell growth of the B-clade strains in the environment, further influenced by the truncation of the trpA gene involved in spore germination. The A.Br.005/006-clade strains in KNP exhibit higher genetic diversity, which may enhance their resilience to environmental stressors. In contrast, the KNP B-clade (B.Br.001/002) strains show limited genetic variation, potentially reducing their adaptability. This pattern is evident through whole-genome SNP analysis and pan-genomics investigating the evolution of B. anthracis .

Kruger National Park↗

USGS2015

Data regarding hydraulic fracturing distributions and treatment fluids, additives, proppants, and water volumes applied to wells drilled in the United States from 1947 through 2010

Comprehensive, published, and publicly available data regarding the extent, location, and character of hydraulic fracturing in the United States are scarce. The objective of this data series is to publish data related to hydraulic fracturing in the public domain. The spreadsheets released with this data series contain derivative datasets aggregated temporally and spatially from the commercial and proprietary IHS database of U.S. oil and gas production and well data (IHS Energy, 2011). These datasets, served in 21 spreadsheets in Microsoft Excel (.xlsx) format, outline the geographical distributions of hydraulic fracturing treatments and associated wells (including well drill-hole directions) as well as water volumes, proppants, treatment fluids, and additives used in hydraulic fracturing treatments in the United States from 1947 through 2010. This report also describes the data—extraction/aggregation processing steps, field names and descriptions, field types and sources. An associated scientific investigation report (Gallegos and Varela, 2014) provides a detailed analysis of the data presented in this data series and comparisons of the data and trends to the literature.

Data Series↗

USGS1995

Evaluation of nonpoint-source contamination, Wisconsin: Land-use and Best-Management-Practices inventory, selected streamwater-quality data, urban-watershed quality assurance and quality control, constituent loads in rural streams, and snowmelt-runoff analysis, water year 1994

The objective of the watershed-management evaluation monitoring program in Wisconsin is to evaluate the effectiveness of best-management practices (BMP) for controlling nonpoint-source contamination in rural and urban watersheds. This report is an annual summary of the data collected for the program by the U.S Geological Survey and a report of the results of several different detailed analyses of the data. A land-use and BMP inventory is ongoing for 12 evaluation monitoring projects to track the sources of nonpoint-source pollution in each watershed and to document implementation of BMP's that may cause changes in the water quality of streams. Updated information is gathered each year, mapped, and stored in a geographic-information-system data base. Summaries of data collected during water years 1989-94 are presented. A water year is the period beginning October 1 and ending September 30; the water year is designated by the calendar year in which it ends. Suspended-sediment and total-phosphorus data (storm loads and annual loads) are summarized for eight rural sites. For all sites, the annual suspended-sediment or suspended-solids load for water year 1993 exceeded the average for the period of data collection; the minimum annual loads were transported in water year 1991 or 1992. Continuous dissolved-oxygen data were collected at seven rural sites during water year 1994. Data for water years 1990-93 are summarized and plotted in terms of percentage of time that a particular concentration is equaled or exceeded. Dissolved-oxygen concentrations in four streams were less than 9 mg/L at least 50 percent of the time, a condition that fails to meet suggested criterion for coldwater streams. The dissolved-oxygen probability curve for one of the coldwater streams is markedly different than the curves for the other streams, perhaps because of differences in aquatic biomass. Blank quality-assurance samples were collected at two of the urban evaluation monitoring sites to isolate contamination in the sample bottle, the automatic sampler and splitter, and the filtration system. Significant contamination caused excessive concentrations of dissolved chloride, alkalinity, and biochemical oxygen demand. The level of contamination may be large enough to affect data for water samples in which these analytes are present at low concentration. Further investigation is being done to determine the source of contamination and take measures to minimize its effect on the sampling. A preliminary regression analysis was done for the rural sites using data collected during water years 1989-93. Loads of suspended solids and total phosphorus in stormflow were regressed against various precipitation-related measures. The results indicate that, for most sites, changes in constituent load on the order of 40 to 50 percent could be detected with a statistical test. For two sites, the change would have to be 60 to 70 percent to be detected. A detailed comparison of snowmelt runoff and rainfall stormflow in urban and rural areas was done using data collected during water years 1985-93. For the rural sites where statistically significant differences were found between constituent loads in snowmelt and storm runoff, the loads of suspended solids and total phosphorus in snowmelt runoff were greater than those in storm runoff. For the urban sites where statistically significant differences were found between snowmelt and storm runoff, the loads of suspended solids and total phosphorus in storm runoff were greater than those in snowmelt runoff. The importance of including snowmelt runoff in designing and analyzing the effects of BMP's on streamwater quality, particularly in rural areas, is emphasized by these results.

Wisconsin↗

USGS2007

A Science Plan for a Comprehensive Regional Assessment of the Atlantic Coastal Plain Aquifer System in Maryland

The Maryland Coastal Plain region is, at present, largely dependent upon ground water for its water supply. Decades of increasing pumpage have caused ground-water levels in parts of the Maryland Coastal Plain to decline by as much as 2 feet per year in some areas of southern Maryland. Continued declines at this rate could affect the long-term sustainability of ground-water resources in Maryland's heavily populated Coastal Plain communities and the agricultural industry of the Eastern Shore. In response to a recommendation in 2004 by the Advisory Committee on the Management and Protection of the State's Water Resources, the Maryland Geological Survey and the U.S. Geological Survey have developed a science plan for a comprehensive assessment that will provide new scientific information and new data management and analysis tools for the State to use in allocating ground water in the Coastal Plain. The comprehensive assessment has five goals aimed at improving the current information and tools used to understand the resource potential of the aquifer system: (1) document the geologic and hydrologic characteristics of the aquifer system in the Maryland Coastal Plain and appropriate areas of adjacent states; (2) conduct detailed studies of the regional ground-water-flow system and water budget for the aquifer system; (3) improve documentation of patterns of water quality in all Coastal Plain aquifers, including the distribution of saltwater; (4) enhance ground-water-level, streamflow, and water-quality-monitoring networks in the Maryland Coastal Plain; and (5) develop science-based tools to facilitate sound management of the ground-water resources in the Maryland Coastal Plain. The assessment, as designed, will be conducted in three phases and if fully implemented, is expected to take 7 to 8 years to complete. Phase I, which was initiated in January 2006, is an effort to assemble all the information and investigation tools needed to do a more comprehensive assessment of the aquifer system. The work will include updating the hydrogeologic framework, developing a Geographic Information System-based aquifer information system, refinement of water-use information, assessment of existing water-quality data, and development of detailed plans for ground-water-flow and management models. Phase II is an intensive study phase during which a regional ground-water-flow model will be developed and calibrated for the entire region of Maryland in the Atlantic Coastal Plain as well as appropriate areas of Delaware and Virginia. The model will be used to simulate flow and water levels in the aquifer system and to study the water budget of the system. The model analysis will be based on published information but will be supplemented with field investigations of recharge and leakage in the aquifer system. Localized and finely discretized ground-water-flow models that are embedded in the regional model will be developed for selected areas of heavy withdrawals. Other modeling studies will be conducted to better understand flow in the unconfined parts of the aquifer system and to support the recharge studies. Phase II will also include selected water-quality studies and a study to determine how hydrologic and water-quality-monitoring networks need to be enhanced to appropriately assess the sustainability of the Coastal Plain aquifer system. Phase III will be largely devoted to the development and application of a ground-water optimization model. This model will be linked to the ground-water-flow model to create a model package that can be used to test different water-management scenarios. The management criteria that will be used to develop these scenarios will be determined in consultation with a variety of state and local stakeholders and policy makers in Phases I and II of the assessment. The development of the aquifer information system is a key component of the assessment. The system will store all relevant aquifer data

Open-File Report↗

USGS2004

Flow path of the 1993 Hokkaido-Nansei-oki earthquake seismoturbidite, suthern margin of the Japan sea north basin, inferred from anisotropy of magnetic susceptibility

A magnetic fabric analysis has been carried out on standard cube samples from one gravity and three multiple cores extracted from the Shiribeshi trough and Okushiri basin in the southern margin of the Japan sea north basin. It is aimed at tracing the flow path of turbidites that are assumed to have deposited in response to the 1993 Hokkaido-Nansei-oki earthquake. Magnetic remanence was used for reorientation to the geographic coordinates. Magnetomineralogical investigations including low-temperature magnetometry, magnetic hysteresis loops and isothermal remanent magnetization (IRM) acquisition experiments indicate that pseudosingle domain to multidomain magnetite is the principal magnetic carrier and is, therefore, capable of providing reliable anisotropy of magnetic susceptibility (AMS) palaeocurrent direction estimates. A well-developed near-horizontal magnetic foliation and minimum susceptibility axes lying close to vertical are recorded at all sites reflecting an original depositional fabric. Clearly defined magnetic lineation was observed at all sites and is considered to reflect the palaeocurrent direction. Down-core changes of susceptibility and key AMS parameters show good correspondence to occurrences of turbidite layers marking the increase of input of influx materials. In agreement with results from recent marine surveys and IZANAGI side-scan sonar images, an NNE transportation trend has been estimated for sediments at sites from the Shiribeshi trough with a possible depositing path initiating from the slope bounding the south and southeastern margin down to the trough floor. Similarly, a SSE palaeocurrent direction has been estimated for sediments from the Okushiri basin with evidence for a relatively strong transporting current flowing through the canyons along the steep slope bounding the north and northeastern margins of the basin. The present results agree with the view that slope failure is the most probable mechanism for the down-slope transport of the sand from the shelves and upper slopes down to floors of basins and troughs in the southern margin of the Japan sea north basin. They further support the ongoing assumption that the 1993 Hokkaido-Nansei-oki and other strong historical earthquakes together with associated tsunamis are the principal triggering forces for the down-slope mass gravitational transport and formation of turbidites in this seismically active area. ?? 2004 RAS.

Geophysical Journal International↗

USGS2010

Grizzly bear density in Glacier National Park, Montana

We present the first rigorous estimate of grizzly bear ( Ursus arctos ) population density and distribution in and around Glacier National Park (GNP), Montana, USA. We used genetic analysis to identify individual bears from hair samples collected via 2 concurrent sampling methods: 1) systematically distributed, baited, barbed-wire hair traps and 2) unbaited bear rub trees found along trails. We used Huggins closed mixture models in Program MARK to estimate total population size and developed a method to account for heterogeneity caused by unequal access to rub trees. We corrected our estimate for lack of geographic closure using a new method that utilizes information from radiocollared bears and the distribution of bears captured with DNA sampling. Adjusted for closure, the average number of grizzly bears in our study area was 240.7 (95% CI = 202–303) in 1998 and 240.6 (95% CI = 205–304) in 2000. Average grizzly bear density was 30 bears/1,000 km 2 , with 2.4 times more bears detected per hair trap inside than outside GNP. We provide baseline information important for managing one of the few remaining populations of grizzlies in the contiguous United States.

Montana↗

USGS2010

A population genetic analysis of the midget faded rattlesnake in Wyoming

Little is known about the population biology of midget faded rattlesnakes, a sensitive subspecies of the Western Rattlesnake, despite conservation efforts to protect them. We conducted a molecular genetic study of midget faded rattlesnakes in southwestern Wyoming to investigate population genetic structure in this area, particularly with reference to Flaming Gorge Reservoir and its associated human activities, and to document levels of genetic diversity. We genotyped 229 snakes from 11 sampling sites using 9 microsatellite loci. We found significant levels of genetic structure among sites that were better explained by geographic region and isolation by distance than by position relative to waterways. Sites on either side of the reservoir at its widest point were not significantly different. Six of the sites showed signatures of a population bottleneck using an alpha value of 0.05. Three of these bottlenecked sites (the three most northern) were the most genetically distinct and occur in areas of greatest impact from human activity.

Wyoming↗

USGS2007

Large-scale causes of variation in the serpentine vegetation of California

Serpentine vegetation in California ranges from forest to shrubland and grassland, harbors many rare and endemic species, and is only moderately altered by invasive exotic species at the present time. To better understand the factors regulating the distribution of common/representative species, endemic/rare species, and the threat of exotics in this important flora, we analyzed broad-scale community patterns and environmental conditions in a geographically stratified set of samples from across the state. We considered three major classes of environmental influences: climate (especially precipitation), soils (especially the Mg2+/Ca2+ ratio), and the indirect influences of climate on soils. We used ordination to identify the major axes of variation in common species abundances, structural equation models to analyze the relationship of community axes and endemic and exotic species richness to the environment, and group analysis techniques to identify consistent groupings of species and characterize their properties. We found that community variation could be explained by a two-axis ordination. One axis ranged from conifer forest to grassland and was strongly related to precipitation. The second axis ranged from chaparral to grassland and had little relationship to current environmental conditions, suggesting a possible role for successional history. Precipitation and elevation were respectively the largest influences on endemic and exotic richness, followed by Mg 2+/Ca2+. The results also support the idea that long-term precipitation patterns have altered the Mg2+/Ca2+ ratio via selective leaching, resulting in indirect influences on endemics (positive) and exotics (negative) but not affecting the abundances of common species. We discuss implications of these findings for the conservation of the California serpentine flora. ?? 2007 Springer Science+Business Media B.V.

Conference Paper↗

USGS2023

Species and physiographic factors drive Indian cucumber root and Canada mayflower plant chemistry: Implications for white-tailed deer forage quality

Nutrition is fundamental to white-tailed deer ( Odocoileus virginianus ) management given its relationship to habitat carrying capacity and population productivity. Ecological Sites (ESs) are a United States federal landscape management unit of specific land potential due to unique soils, topography, climate, parent material, and perhaps deer forage nutritional value. We present results of a study that extends the use of ESs to inform white-tailed deer management by evaluating indicator plant chemistry in two spring forb species, Indian cucumber root ( Medeola virginiana) and Canada mayflower ( Maianthemum canadense ), across the northcentral Appalachians. We sampled spring forbs and underlying soils across two ESs: Dry, upland, oak–maple–hemlock hardwood forest (OMH) and Deep soil, high slope, northern hardwood forests (NHF). Plant elemental content, soil pH, and site aspect, slope and elevation were measured. Our results show that forb chemistry differs between species and within a species geographically. Indian cucumber root, as compared to Canada mayflower, has significantly higher Mg, Na, Cu, Fe, and Zn, and lower Mn. Canada mayflower in the NHF ES, versus OMH ES, was found to have significantly higher K, Mn, and B. Indian cucumber root in the NHF ES, versus the OMH ES, was found to have significantly higher Mg, Al, Fe, and Ca:P ratio but lower K. Linear discriminant analysis shows that plant tissue Mn was the best discriminator between species, and between ESs, Canada mayflower plant tissue Mn and Indian cucumber plant tissue P, K, Ca, Mg and Mn were best discriminators. Given that nutrition determines habitat carrying capacity, differences in forage nutrition between ESs may have different potentials to support deer. Forage nutrition is an important aspect of deer habitat conditions and carrying capacity, thus ESs are likely to support deer populations with different growth potential, which means that even if the same plant species occur in different ESs their nutritional value to deer may differ.

Journal of Environmental Management↗

USGS2018

Global conservation status of turtles and tortoises (order Testudines)

We present a review and analysis of the conservation status and International Union for Conservation of Nature (IUCN) threat categories of all 360 currently recognized species of extant and recently extinct turtles and tortoises (Order Testudines). Our analysis is based on the 2018 IUCN Red List status of 251 listed species, augmented by provisional Red List assessments by the IUCN Tortoise and Freshwater Turtle Specialist Group (TFTSG) of 109 currently unlisted species of tortoises and freshwater turtles, as well as re-assessments of several outdated IUCN Red List assessments. Of all recognized species of turtles and tortoises, this combined analysis indicates that 20.0% are Critically Endangered (CR), 35.3% are Critically Endangered or Endangered (CR+EN), and 51.9% are Threatened (CR+EN+Vulnerable). Adjusting for the potential threat levels of Data Deficient (DD) species indicates that 56.3% of all data-sufficient species are Threatened. We calculated percentages of imperiled species and modified Average Threat Levels (ATL; ranging from Least Concern = 1 to Extinct = 8) for various taxonomic and geographic groupings. Proportionally more species in the subfamily Geoemydinae (Asian members of the family Geoemydidae) are imperiled (74.2% CR+EN, 79.0% Threatened, 3.89 ATL) compared to other taxonomic groupings, but the families Podocnemididae, Testudinidae, and Trionychidae and the superfamily Chelonioidea (marine turtles of the families Cheloniidae and Dermochelyidae) also have high percentages of imperiled species and ATLs (42.9–50.0% CR+EN, 73.8–100.0% Threatened, 3.44–4.06 ATL). The subfamily Rhinoclemmydinae (Neotropical turtles of the family Geoemydidae) and the families Kinosternidae and Pelomedusidae have the lowest percentages of imperiled species and ATLs (0%–7.4% CR+EN, 7.4%–13.3% Threatened, 1.65–1.87 ATL). Turtles from Asia have the highest percentages of imperiled species (75.0% CR+EN, 83.0% Threatened, 3.98 ATL), significantly higher than predicted based on the regional species richness, due to much higher levels of exploitation in that geographic region. The family Testudinidae has the highest ATL (4.06) of all Testudines due to the extinction of several species of giant tortoises from Indian and Pacific Ocean islands since 1500 CE. The family Testudinidae also has an ATL higher than all other larger polytypic families (≥ 5 species) of Reptilia or Amphibia. The order Testudines is, on average, more imperiled than all other larger orders (≥ 20 species) of Reptilia, Amphibia, Mammalia, or Aves, but has percentages of CR+EN and Threatened species and an ATL (2.96) similar to those of Primates and Caudata (salamanders).

Chelonian Conservation and Biology↗

USGS2019

Toward a theory of connectivity among depressional wetlands of the great plains

Functions of inland, freshwater depressional wetlands of the Great Plains are driven by natural disturbance in the form of fluctuating water levels or shifts between wet and dry ecological states. The geographically isolated prairie potholes and playas form broad-scale systems or networks that support biodiversity and provide ecological goods and services. Anthropogenic disturbance, primarily in the form of sediment accretion, results in the functional loss of individual wetlands from the system. The ecological value of individual depressional wetlands has been documented, but there has not been any assessment of the contribution of individual wetlands to the system. Network analysis can be used to prioritize the contribution of individual wetlands to the system for the purpose of conservation and management. We utilized the playas wetland system of the Southern High Plains to illustrate this concept. Playas form a redundant, resilient network based on natural disturbance (i.e., inundation patterns) across broad spatial and temporal scales that support biodiversity. Loss of individual playas to sediment accretion is causing the network to break down, resulting in the need for a greater proportion of inundated playas to provide the original level of ecological goods and services. The effects of decreased functional connectivity due to anthropogenic disturbance at the system scale portend negative effects on movement strategies, dynamics and persistence of local populations, decreased biodiversity, and, ultimately, the redistribution and system-wide extinction of playa wetland-dependent populations and loss of associated functions.

Book chapter↗