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USGS1974

Remote sensing for identification and classification of wetland vegetation

Multispectral photography and ground truth were obtained on an area 12 miles (19.3 km) east of Bemidji, Minnesota, to identify and map wetlands less than 2 acres (0.8 hectare) in size, to map emergent vegetation in lakes, and to explore the feasibility of classifying vegetation from aerial photographs. Wetlands less than 2 acres in size were identified on photography taken in May 1971, and emergent vegetation was recorded on purposely overexposed infrared black and white photography from a flight in September 1971. Several vegetation types and species groups were recognizable with the aid of color, color infrared, and black and white infrared photography. Proper timing of flights, use of multispectral photography, and knowledge of the ecology of the area are considered essential for wetland mapping by remote sensing.

Minnesota↗

USGS2009

Carbon isotope turnover as a measure of arrival time in migratory birds

Arrival time on breeding or non-breeding areas is of interest in many ecological studies exploring fitness consequences of migratory schedules. However, in most field studies, it is difficult to precisely assess arrival time of individuals. Here, we use carbon isotope turnover in avian blood as a technique to estimate arrival time for birds switching from one habitat or environment to another. Stable carbon isotope ratios (δ 13 C) in blood assimilate to a new equilibrium following a diet switch according to an exponential decay function. This relationship can be used to determine the time a diet switch occurred if δ 13 C of both the old and new diet are known. We used published data of captive birds to validate that this approach provides reliable estimates of the time since a diet switch within 1–3 weeks after the diet switch. We then explored the utility of this technique for King Eiders ( Somateria spectabilis ) arriving on terrestrial breeding grounds after wintering and migration at sea. We estimated arrival time on breeding grounds in northern Alaska (95% CI) from red blood cell δ 13 C turnover to be 4–9 June. This estimate overlapped with arrival time of birds from the same study site tracked with satellite transmitters (5–12 June). Therefore, we conclude that this method provides a simple yet reliable way to assess arrival time of birds moving between isotopically distinct environments.

Journal of Ornithology↗

USGS1992

Toxicity reduction of photo processing wastewaters

The photo processing industry can be characterized by treatment processes and subsequent silver recovery. The effluents generated all contain various amounts of silver. The objectives of this study were to determine toxicity of photo processing effluents and to explore their toxicity mitigation. Six samples, from small shops to a major photo processing center, were studied. Two samples (I and VI) were found to be extremely toxic, causing 100 and 99% inhibition of duckweed frond reproduction, respectively, and were used for subsequent toxicity reduction experiments. Lime and sodium sulfide were effective for the toxicity reduction of Sample VI; both reduced its toxicity to negligible. Sample I was far more toxic and was first diluted to 2.2% and then treated with 0.5 g lime/100 mL, reducing toxicity from 100% to 12% inhibition.

Journal of Environmental Science and Health - Part↗

USGS2018

Sediment transport model including short-lived radioisotopes: Model description and idealized test cases

Geochronologies derived from sediment cores in coastal locations are often used to infer event bed characteristics such as deposit thicknesses and accumulation rates. Such studies commonly use naturally occurring, short-lived radioisotopes, such as Beryllium-7 ( 7 Be) and Thorium-234 ( 234 Th), to study depositional and post-depositional processes. These radioisotope activities, however, are not generally represented in sediment transport models that characterize coastal flood and storm deposition with grain size patterns and deposit thicknesses. We modified the Community Sediment Transport Modeling System (CSTMS) to account for reactive tracers and used this capability to represent the behavior of these short-lived radioisotopes on the sediment bed. This paper describes the model and presents results from a set of idealized, one-dimensional (vertical) test cases. The model configuration represented fluvial deposition followed by periods of episodic storm resuspension. Sensitivity tests explored the influence on seabed radioisotope profiles by the intensities of bioturbation and wave resuspension and the thickness of fluvial deposits. The intensity of biodiffusion affected the persistence of fluvial event beds as evidenced by 7 Be. Both resuspension and biodiffusion increased the modeled seabed inventory of 234 Th. A thick fluvial deposit increased the seabed inventory of 7 Be and 234 Th but mixing over time greatly reduced the difference in inventory of 234 Th in fluvial deposits of different thicknesses.

Journal of Marine Science and Engineering↗

USGS1977

High-resolution gamma-ray spectrometry in uranium exploration

Sedimentary-type uranium deposits accumulate at favorable sites along a migration path which may be kilometers in length. Their source is a large volume of rock from which the uranium has been leached. The geochemical mobilities and half lives of uranium and its daughter products vary widely so that they are transported from the source rocks, at different rates, along the migration path to their ultimate site. The radioactive disequilibrium resulting from this process has been well documented in the immediate vicinity of ore deposits, and disequilibrium is commonly recorded on gamma-ray logs up the hydraulic gradient from uranium ore. Little is known about the state of secular equilibrium in the leached host rocks, which often represent the only part of the migration path that is at or near the surface and is thus most accessible to the exploration geophysicist. High-resolution gamma-ray spectrometry provides a means of investigating the disequilibrium associated with uranium leaching and migration. Direct measurement of uranium can be made by this method, and the equivalent weight percents can be determined for six of the seven daughter-product decay groups that characterize the state of radioactive equilibrium. The technique has been used quantitatively in laboratory studies, where the results compare favorably with radiochemical analyses; field experiments suggest that semi-quantitative data may be obtained at the outcrop.

Journal of Research of the U.S. Geological Survey↗

USGS1977

Exploration geochemical studies of some sandstone copper-uranium deposits, Bradford, Columbia, and Lycoming Counties, Pa

Semi-quantitative spectrographic analyses of mineralized and unmineralized sandstone, siltstone, and claystone from the Catskill Formation of Devonian age in Bradford, Columbia, and Lycoming Counties, Pa., suggest that copper, silver, and uranium are the principal metallic elements concentrated in the mineralized rock. Lead, mercury, and molybdenum may be concentrated slightly in mineralized rock but values are too low to be of use in exploration. The deposits are too small to make large anomalies in stream sediments except in drainage basins of less than a few acres. However, if a large deposit were exposed to weathering, it would probably be detectable by stream sediment sampling. Analyses of oxalic acid leachates of the minus 80-mesh fraction of the stream-sediment samples gave more useful values than analyses of the minus 80-mesh samples in separating drainage basins that have copper deposits from those that have no known copper deposits.

Pennsylvania↗

USGS2005

Determinants of wood thrush nest success: A multi-scale, model selection approach

We collected data on 212 wood thrush (Hylocichla mustelina) nests in central New York from 1998 to 2000 to determine the factors that most strongly influence nest success. We used an information-theoretic approach to assess and rank 9 models that examined the relationship between nest success (i.e., the probability that a nest would successfully fledge at least 1 wood thrush offspring) and habitat conditions at different spatial scales. We found that 4 variables were significant predictors of nesting success for wood thrushes: (1) total core habitat within 5 km of a study site, (2) distance to forest-field edge, (3) total forest cover within 5 km of the study site, and (4) density and variation in diameter of trees and shrubs surrounding the nest. The coefficients of these predictors were all positive. Of the 9 models evaluated, amount of core habitat in the 5-km landscape was the best-fit model, but the vegetation structure model (i.e., the density of trees and stems surrounding a nest) was also supported by the data. Based on AIC weights, enhancement of core area is likely to be a more effective management option than any other habitat-management options explored in this study. Bootstrap analysis generally confirmed these results; core and vegetation structure models were ranked 1, 2, or 3 in over 50% of 1,000 bootstrap trials. However, bootstrap results did not point to a decisive model, which suggests that multiple habitat factors are influencing wood thrush nesting success. Due to model uncertainty, we used a model averaging approach to predict the success or failure of each nest in our dataset. This averaged model was able to correctly predict 61.1% of nest outcomes.

Journal of Wildlife Management↗

USGS2013

Bakken, Three Forks largest continuous US oil accumulation

The recent reversal of the declining trend of US oil production is largely due to production from unconventional or "continuous" low-permeability reservoirs by use of multistage hydraulic fracturing of horizontal legs of exploration wells. The US currently produces about 7.4 million bo/d, and the increasing trend in domestic production has led to speculation that the US could become energy independent in oil in the near future. The US still imports an additional 11 million bo/d to meet consumption requirements).1 Critical to the discussion of energy independence are estimates of resources contained in low-porosity and low-permeability (or "tight") continuous oil and gas accumulations, which have formed a critical component of national energy policies in recent years.

Montana, North Dakota, South Dakota, Wyoming↗

USGS2022

Taxonomic boundaries in Lesser Treeshrews (Scandentia, Tupaiidae: Tupaia minor)

The Lesser Treeshrew, Tupaia minor Günther, 1876 , is a small mammal from Southeast Asia with four currently recognized subspecies: T. m. minor from Borneo; T. m. malaccana from the Malay Peninsula; T. m. humeralis from Sumatra; and T. m. sincepis from Singkep Island and Lingga Island. A fifth subspecies, T. m. caedis , was previously synonymized with T. m. minor ; it was thought to occur in northern Borneo and on the nearby islands of Banggi and Balambangan. These subspecies were originally differentiated based on pelage color, a plastic feature that has proven to be an unreliable indicator of taxonomic boundaries in treeshrews and other mammals. To explore infraspecific variation among T. minor populations across the Malay Peninsula, Borneo, Sumatra, and smaller islands, we conducted multivariate analyses of morphometric data collected from the hands and skulls of museum specimens. Principal component and discriminant function analyses reveal limited differentiation in manus and skull proportions among populations of T. minor from different islands. We find no morphometric support for the recognition of the four allopatric subspecies and no support for the recognition of T. m. caedis as a separate subspecies on Borneo.

Borneo, Sumatra↗

USGS2018

James Dwight Dana and John Strong Newberry in the US Pacific Northwest: The roots of American fluvialism

Recognition of the power of rivers to carve landscapes transformed geology and geomorphology in the late nineteenth century. Wide acceptance of this concept—then known as “fluvialism”—owes to many factors and people, several associated with exploration of western North America. Especially famous are the federal geographic and geologic surveys of the US Southwest with John Wesley Powell and Grove Karl Gilbert, which produced key insights regarding river processes. Yet earlier and less-known surveys also engaged young geologists embarking on tremendously influential careers, particularly the 1838–1842 US Exploring Expedition with James Dwight Dana and the 1853–1855 railroad surveys including John Strong Newberry. Informed but little constrained by European and British perspectives on landscape formation, Dana and Newberry built compelling cases for the erosive power of rivers, largely from observations in the US Pacific Northwest. They seeded the insights of the later southwestern surveys, Dana by his writings and station at Yale and his hugely influential Manual of Geology , published in 1863, and Newberry by becoming the first geologist to explore the dramatic river-carved canyons of the Southwest and then a forceful proponent of the federal surveys spotlighting the erosional landscapes. Newberry also gave Gilbert his start as a geologist. Although Dana and Newberry are renowned early American geologists, their geomorphic contributions were overshadowed by the works of Powell, Gilbert, and William Morris Davis. Yet Dana and Newberry were the first ardent American proponents of fluvialism, providing strong roots that in just a few decades transformed western geology, roots nourished in large measure by the geologically fertile landscapes of the US Pacific Northwest.

Journal of Geology↗

USGS2018

Understanding and mitigating wilderness therapy impacts: The Grand Staircase-Escalante National Monument case study

Studies demonstrate that wilderness therapy programs can be beneficial for participants; however, little research has explored the ecological impacts of these programs. A prominent wilderness therapy organization utilizes vast tracts of the Grand Staircase-Escalante National Monument (GSENM) for programming. This study examines the specific ecological impacts stemming from the program in GSENM, concurrently with a content analysis of the training procedures administered by the organization. Results emphasize the need to improve education, training, and mitigation measures to minimize impacts stemming from this and other wilderness therapy programs in GSENM, as well as other wilderness areas in which these programs operate.

Grand Staircase-Escalante National Monument↗

USGS2025

Exploring the science and data foundation for Federal public lands decisions

Public lands provide diverse resources, values, and services worldwide. Laws and policies typically require consideration of science in public lands decisions, and resource managers are committed to science-informed decision-making. However, it can be challenging for managers to use, and document the use of, science and data in their decisions. To better understand science and data use in Federal public lands decisions in the United States, we assessed the number, type, and age of documents cited in 70 Environmental Assessments (EAs) completed by the Bureau of Land Management (BLM) in Colorado from 2015–2019. We focused on the BLM, as they manage the largest area of public lands in the United States. We selected Colorado as our study area, as actions proposed on BLM lands in Colorado are representative of those across the nation. Fifty percent of citations were categorized as science and 23% as data. EAs contained an average of 17 citations (range 0–111), with documents analyzing effects of oil and gas development and recreation actions including the highest and lowest mean number of citations (41 and 6, respectively). Of individual resource analysis sections within EAs, 24% contained ≥1 science citation and 21% contained ≥1 data citation. Journal articles were the most cited type of document (26% of citations) followed by non-BLM inventories (13%). Forty-seven percent of citations were relatively recent (2010 or later); the oldest citation was from 1927. Commonly analyzed resources with the highest mean number of citations were socioeconomics, mineral resources, and noise. Fourteen of 33 commonly analyzed resources included <1 citation on average. Actions and resources with no or few citations represent opportunities for strengthening the transparent use of science and data in public lands decision-making.

Colorado↗

USGS2024

Photogrammetry of the deep seafloor from archived unmanned submersible exploration dives

Large amounts of video images have been collected for decades by scientific and governmental organizations in deep (>1000 m) water using manned and unmanned submersibles and towed cameras. The collected images were analyzed individually or were mosaiced in small areas with great effort. Here, we provide a workflow for utilizing modern photogrammetry to construct virtual geological outcrops hundreds or thousands of meters in length from these archived video images. The photogrammetry further allows quantitative measurements of these outcrops, which were previously unavailable. Although photogrammetry had been carried out in recent years in the deep sea, it had been limited to small areas with pre-defined overlapping dive paths. Here, we propose a workflow for constructing virtual outcrops from archived exploration dives, which addresses the complicating factors posed by single non-linear and variable-speed vehicle paths. These factors include poor navigation, variable lighting, differential color attenuation due to variable distance from the seafloor, and variable camera orientation with respect to the vehicle. In particular, the lack of accurate navigation necessitates reliance on image quality and the establishment of pseudo-ground-control points to build the photogrammetry model. Our workflow offers an inexpensive method for analyzing deep-sea geological environments from existing video images, particularly when coupled with rock samples.

Journal of Marine Science and Engineering↗

USGS1992

Nest guarding from observation blinds: strategy for improving Puerto Rican parrot nest success

The effectiveness of 17 yr of nestguarding from observation blinds for increasing reproductive success of the endangered Puerto Rican Parrot (Amazona vittata) is described. As personnel and time allowed, active nests were guarded part-time during the nest site exploration and selection s stage of the breeding cycle, and part-time to full-time when a nest contained eggs or chicks. Biologists identified nine categories of threat to the success of parrot nests. Since 1973, a minimum of 20 nests, which otherwise would have failed, successfully produced fledglings as a direct result of nest guarding and intervention. Nest success averaged 66% with nest guarding compared to an estimated 38% without guarding. Nest guarding from blinds can help maintain a wild population of a critically endangered species while other management techniques are being developed to stimulate population growth.

Journal of Field Ornithology↗

USGS2016

Motivations of female Black Hills deer hunters

State fish and wildlife agencies are particularly interested in attracting female participation because of the potential to offset declining participation in hunting. Understanding female hunters’ motivations will be critical for designing effective recruitment and retention programs for women hunters. Although female participation in hunting is increasing, males still outnumber females by about tenfold. Gender differences in deer hunters were explored by comparing ratings of eight motivations (social, nature, excitement, meat, challenge, trophy, extra hunting opportunity, and solitude). Hunter types were defined by hunters’ selection of the most important motivation for why they like Black Hills deer hunting. Overall, females and males were relatively similar in their ratings of the eight motivations, and we found 85% gender similarity in the selection of the most important motivation. Women were slightly more motivated by the food aspect of the hunt while men placed slightly more value on the hunt as a sporting activity.

Human Dimensions of Wildlife: An International Jou↗

USGS2011

A Markov decision process for managing habitat for Florida scrub-jays

Florida scrub-jays Aphelocoma coerulescens are listed as threatened under the Endangered Species Act due to loss and degradation of scrub habitat. This study concerned the development of an optimal strategy for the restoration and management of scrub habitat at Merritt Island National Wildlife Refuge, which contains one of the few remaining large populations of scrub-jays in Florida. There are documented differences in the reproductive and survival rates of scrubjays among discrete classes of scrub height (<120 cm or "short"; 120-170 cm or "optimal"; .170 cm or "tall"; and a combination of tall and optimal or "mixed"), and our objective was to calculate a state-dependent management strategy that would maximize the long-term growth rate of the resident scrub-jay population. We used aerial imagery with multistate Markov models to estimate annual transition probabilities among the four scrub-height classes under three possible management actions: scrub restoration (mechanical cutting followed by burning), a prescribed burn, or no intervention. A strategy prescribing the optimal management action for management units exhibiting different proportions of scrub-height classes was derived using dynamic programming. Scrub restoration was the optimal management action only in units dominated by mixed and tall scrub, and burning tended to be the optimal action for intermediate levels of short scrub. The optimal action was to do nothing when the amount of short scrub was greater than 30%, because short scrub mostly transitions to optimal height scrub (i.e., that state with the highest demographic success of scrub-jays) in the absence of intervention. Monte Carlo simulation of the optimal policy suggested that some form of management would be required every year. We note, however, that estimates of scrub-height transition probabilities were subject to several sources of uncertainty, and so we explored the management implications of alternative sets of transition probabilities. Generally, our analysis demonstrated the difficulty of managing for a species that requires midsuccessional habitat, and suggests that innovative management tools may be needed to help ensure the persistence of scrub-jays at Merritt Island National Wildlife Refuge. The development of a tailored monitoring program as a component of adaptive management could help reduce uncertainty about controlled and uncontrolled variation in transition probabilities of scrub-height and thus lead to improved decision making.

Florida↗

USGS2015

The economic viability of smallholder timber production under expanding açaí palm production in the Amazon Estuary

Relatively little attention has been paid to the economic potentials and limitations of tropical timber production and management at smallholder scales, with the most relevant research focusing on community forestry efforts. As a rare tropical example of long-lasting small-scale timber production, in this study we explore the economics of smallholder vertically integrated timber use to better understand the activity in the context of its primary land use alternative in the Amazon Estuary, açaí palm fruit production. We use data from landowner and firm surveys, participatory monitoring of firms, and detailed forest and sawmill operation monitoring to devise financial returns models of smallholder timber micro firms and açaí palm fruit production. We then compare the economics of the two activities to better understand how differences may shape decisions at the small holder scale that impact current land use shifts in the region.

Amazon River, Mazagão watershed↗

USGS2006

Nature and origin of the hematite-bearing plains of Terra Meridiani based on analyses of orbital and Mars Exploration rover data sets

The ∼5 km of traverses and observations completed by the Opportunity rover from Endurance crater to the Fruitbasket outcrop show that the Meridiani plains consist of sulfate‐rich sedimentary rocks that are largely covered by poorly‐sorted basaltic aeolian sands and a lag of granule‐sized hematitic concretions. Orbital reflectance spectra obtained by Mars Express OMEGA over this region are dominated by pyroxene, plagioclase feldspar, crystalline hematite (i.e., concretions), and nano‐phase iron oxide dust signatures, consistent with Pancam and Mini‐TES observations. Mössbauer Spectrometer observations indicate more olivine than observed with the other instruments, consistent with preferential optical obscuration of olivine features in mixtures with pyroxene and dust. Orbital data covering bright plains located several kilometers to the south of the landing site expose a smaller areal abundance of hematite, more dust, and a larger areal extent of outcrop compared to plains proximal to the landing site. Low‐albedo, low‐thermal‐inertia, windswept plains located several hundred kilometers to the south of the landing site are predicted from OMEGA data to have more hematite and fine‐grained olivine grains exposed as compared to the landing site. Low calcium pyroxene dominates spectral signatures from the cratered highlands to the south of Opportunity. A regional‐scale model is presented for the formation of the plains explored by Opportunity, based on a rising ground water table late in the Noachian Era that trapped and altered local materials and aeolian basaltic sands. Cessation of this aqueous process led to dominance of aeolian processes and formation of the current configuration of the plains.

Journal of Geophysical Research E: Planets↗