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At least 451 records · Page 25Linked to original sources
USGS2018

Response to comment by Walker et al. on “From data to decisions: Processing information, biases, and beliefs for improved management of natural resources and environments”

Our different kinds of minds and types of thinking affect the ways we decide, take action, and cooperate (or not). The comment by Walker et al. (2018, https://doi.org/10.1002/2017EF000750 ) illustrates several points made by Glynn et al. (2017, https://doi.org/10.1002/2016EF000487 ) and many other articles. Namely, biases and beliefs often drive scientific reasoning, and scientists, just like other humans, are intimately attached to their values and heuristics. Scientists, just like many other people, also tend to read and interpret text in ways that best match their individual perceptions of a problem or issue: in many cases paraphrasing and changing the meaning of what they read to better match their initial ideas. Walker et al. are doing interesting and important research on uncertainty. Nonetheless, they misinterpret the work, assumptions, and conclusions brought forth by Glynn et al. (2017, https://doi.org/10.1002/2016EF000487 ).

Earth's Future↗
USGS2019

Plot Locator: An app for locating plots in the field

PREMISE: One of the challenges in field biology is locating previously sampled plots. The Plot Locator app was developed to assist field biologists with plot identification and location, with or without GPS or online connectivity. METHODS AND RESULTS: The Plot Locator Android app helps users locate field plots by creating a searchable database that stores study area information, such as site/plot names and numbers, distances from landmarks, optional cardinal directions and GPS coordinates, and field notes. A GPS assist and Google Maps can also be used with the app when connectivity is available. All study location data and field notes are stored in a downloadable CSV file on the user’s device. CONCLUSIONS: The Plot Locator app provides a comprehensive searchable database of study area information, plot location information, and location aids, which are easily accessed in the field.

Applications in Plant Science↗
USGS1990

Identification of isopropylbiphenyl, alkyl diphenylmethanes, diisopropylnaphthalene, linear alkyl benzenes and other polychlorinated biphenyl replacement compounds in effluents, sediments and fish in the Fox River System, Wisconsin

Five polychlorinated biphenyl replacement dye solvents and a diluent present in carbonless copy paper were identified by gas chromatography/mass spectrometry in the following matrices: effluents from a de-inking–recycling paper mill and a municipal wastewater treatment plant receiving wastewaters from a carbonless copy paper manufacturing plant; sediments; and fish collected near both discharges in the Fox River System, Wisconsin. An isopropylbiphenyl dye solvent mixture included mono-, di- and triisopropylbiphenyls. Also identified were two dye solvent mixtures marketed under the trade name Santosol. Santosol 100 comprised ethyl-diphenylmethanes (DPMs), benzyl-ethyl-DPMs, and dibenzyl-ethyl-DPMs. Similarly, Santosol 150 comprised dimethyl-DPMs, benzyl-dimethyl-DPMs, and dibenzyl-dimethyl-DPMs. Diisopropylnaphthalenes, widely used as a dye solvent in Japan, were identified for the first time in the US environment. sec -Butylbiphenyls and di- sec -butylbiphenyls, likely constituents of a sec -butylbiphenyl dye solvent mixture, were tentatively identified. Linear alkyl benzenes (C 10 to C 13 -LABs) constituted the Alkylate 215 diluent mixture. Although known to occur as minor constituents in linear alkyl sulfonate detergents, LAB residues have not been previously attributed to commercial use of LABs.

Wisconsin↗
USGS2021

Experimental evaluation of spatial capture–recapture study design

A principal challenge impeding strong inference in analyses of wild populations is the lack of robust and long-term data sets. Recent advancements in analytical tools used in wildlife science may increase our ability to integrate smaller data sets and enhance the statistical power of population estimates. One such advancement, the development of spatial capture–recapture (SCR) methods, explicitly accounts for differences in spatial study designs, making it possible to equate multiple study designs in one analysis. SCR has been shown to be robust to variation in design as long as minimal sampling guidance is adhered to. However, these expectations are based on simulation and have yet to be evaluated in wild populations. Here we conduct a rigorously designed field experiment by manipulating the arrangement of artificial cover objects (ACOs) used to collect data on red-backed salamanders ( Plethodon cinereus ) to empirically evaluate the effects of design configuration on inference made using SCR. Our results suggest that, using SCR, estimates of space use and detectability are sensitive to study design configuration, namely the spacing and extent of the array, and that caution is warranted when assigning biological interpretation to these parameters. However, estimates of population density remain robust to design except when the configuration of detectors grossly violates existing recommendations.

Massachusetts↗
USGS2019

Knowing your limits: Estimating range boundaries and co-occurrence zones for two competing plethodontid salamanders

Understanding threats to species persistence requires knowledge of where species currently occur. We explore methods for estimating two important facets of species distributions, namely where the range limit occurs and how species interactions structure distributions. Accurate understanding of range limits is crucial for predicting range dynamics and shifts in response to interspecific interactions and climate change. Additionally, species interactions are increasingly recognized as an important but not well‐understood predictor of range shifts. Our objective was to predict range limits and contact zones for two plethodontid salamanders, the highly range‐restricted Shenandoah salamander ( Plethodon shenandoah ) and the wide‐ranging red‐backed salamander ( Plethodon cinereus ). Using detection/non‐detection data, we assess four methodological decisions when estimating species’ distributions: (1) accounting for imperfect detection, (2) covariates to predict species occurrences, (3) accounting for species interactions, and (4) the inclusion of spatial autocorrelation. We found that Shenandoah salamander and red‐backed salamander co‐occurrence would have been underestimated and the range edge misidentified had we not accounted for incomplete detection. Covariates related to habitat were not sufficient to explain species’ range boundaries. Models that included spatial autocorrelation (i.e., a conditional autoregressive random effect) performed better than models that included just species interactions (i.e., detection and occurrence were conditional on the other species being present) and models that included both spatial autocorrelation and species interactions. Further, we found that the breadth of primary contact zones was typically 60–170 m, which is greater on average than previous estimates. In addition, we frequently observed secondary, disjunct contact zones along the range boundary. Understanding the extent to which species co‐occur and how the range boundaries are shaped is crucial to conservation efforts. Our work indicates that accounting for detection is crucial for accurately characterizing range edges and that spatial models may be especially effective in modeling distributions at the boundary.

Ecosphere↗
USGS2022

Woody plant encroachment of grassland and the reversibility of shrub dominance: Erosion, fire, and feedback processes

Many grass-dominated ecosystems in dryland regions have experienced increasing woody plant density and abundance during the past century. In many cases, this process has led to land degradation and declines in ecosystem functions. An example is the Chihuahuan Desert in the southwestern United States, which experienced different stages of shrub encroachment in the past 150 years. Among a wide variety of mechanisms to explain the grass–shrub transitions in this dryland system, soil erosion (both wind and water) and fire are particularly well studied. Here, we synthesize recent developments on the drivers and feedback in the process of shrub encroachment in the Chihuahuan Desert through the intercomparison of two Long Term Ecological Research (LTER) sites, namely Jornada and Sevilleta. Experimental and modeling studies support a conceptual framework, which underscores the important roles of erosion and fire in woody plant encroachment. Collectively, research at the Jornada LTER provided complementary, quantitative support to the well-known fertile-islands framework. Studies at the Sevilleta LTER expanded the framework, adding fire as a major disturbance to woody plants. Conceptual models derived from the synthesis represent the general understanding of shrub encroachment that emerged from research at these two sites, and can guide management interventions aimed at reducing or mitigating undesirable ecosystem state change in many other drylands worldwide.

New Mexico↗
USGS2022

The researcher's lament: Why do they ignore my science?

The researcher's lament is shared by many environmental and conservation scientists who complain about the little support they receive for their research proposals during the review and selection process. Understandably, any hopes of having their anticipated scientific findings applied toward the formulation of environmental management decisions or natural resource policy action are shattered. They attribute this lack of endorsement to shortcomings and limitations among decision makers and proposal selection officials when, in many cases, the rejection of project proposals is often a function of a handful of self-inflicted failures by applied scientists who anchor themselves stubbornly to doomed approaches. Familiar deficiencies in their research proposals perpetuate the disconnect between the enterprise of science and real-world resource management challenges. Researchers themselves can affect conditions that turn up the appetite for their scientific endeavors as a more meaningful component of the decision-making process, namely, to stage and deliver science that is more readily "actionable." Perhaps it is time for them to consider a course correction to improve the viability of their actionable science proposals. A few basic steps may help rejigger the science planning process in this direction and, consequently, help avoid the researcher's lament. The likelihood of gaining support during the proposal review and award adjudication process, and securing practical application of scientific products, increases when the products are (1) the result of active engagement of researchers with decision makers; (2) better connected to social and political priorities; (3) clearly designed to inform specific management decisions; and (4) tailored to fit the needs of targeted end users. These considerations and activities exist beyond the comfort zone of many environmental or conservation scientists. Yet, those who adopt them will spend less time lamenting rejection and become more influential in the production of actionable knowledge.

Ecosphere↗
USGS2025

Using imaging spectroscopy and elevation in machine learning to estimate soil salinity in intermittently tidal wetlands

Coastal soil salinization patterns are changing due to drought, sea level rise (SLR), and changing freshwater inflow. These changes are expected to impact coastal wetland plant health and ecosystem function, such as changes to biomass and productivity. These impacts have led to greater interest in how we monitor soil salinization across spatial and temporal scales. Remote sensing is a promising tool for estimating soil salinity at the spatial scales required for decision making by land managers. However, the development of a remote sensing estimation approach for wetland soil salinity must account for two factors: (1) the high spatial and temporal heterogeneity of coastal wetlands and (2) the fact that soil salinity is the result of multiple historical land use, hydrological, and geomorphic processes. In spring 2022, a combined airborne-field campaign, known as SHIFT, collected a weekly time series of airborne visible to shortwave infrared (VSWIR) image spectroscopy data. This dataset provides a unique opportunity to assess the application of fine spatial (5 m) and temporal (weekly) resolution VSWIR data to estimate root zone soil salinity; when combined with environmental variables such as elevation, these data can account for some of these factors. In this study, we utilized VSWIR and elevation datasets in a random forest regression to predict and map soil salinity in an intermittently tidal estuary, Devereux Slough, located in Santa Barbara County, California. The final model combined spectral indices with elevation to better capture soil salinity dynamics despite lower correlation ( r = 0.85) than solely using elevation ( r = 0.92). This research demonstrates the utility of remote sensing datasets, namely, elevation and the modified Anthocyanin Reflectance Index (mARI), for predicting root zone soil salinity in intermittently tidal coastal wetlands. These findings are an important step in advancing coastal remote sensing by creating a gridded salinity dataset that can be used for salinity monitoring and other coastal applications, such as modeling change in vegetation communities or ecosystems facing the impacts of climatic variability and change.

California↗
USGS2024

How, what, and where you sample environmental DNA affects diversity estimates and species detection

Environmental DNA (eDNA) is a complex mixture of DNA, varying in particle sizes and distributed heterogeneously in aquatic systems. Optimizing eDNA sampling is crucial for maximizing species detection, particularly in high-risk scenarios like invasive species management. In this study, we compare two eDNA sampling methods - namely tow net and grab sample, where the tow nets process large volumes of water (3500–7000 L) through a 64 μm pore size and the grab samples process 1 L sample at a single point through 0.45–1.2 μm pore size membranes. We compared these methods to ascertain what most influences (1) the detection of invasive species ( Dreissena mussels and Burmese pythons) using qPCR or ddPCR and (2) total diversity monitoring of metazoan, protist, and fungi community using a COI marker and plant communities using the ITS marker. Sampling was conducted across a wide geography and diverse aquatic environments in Minnesota and Florida, USA, and Switzerland. The tow net samples had significantly higher eDNA yield compared to grab samples; however, they exhibited equal or lower alpha diversity of OTUs (Operational Taxonomic Units). The two sampling methods measured different beta diversity of communities detected with the COI marker across all three regions, highlighting the impact of the sampling method on the diversity of eDNA captured. In comparison, the beta diversity of plant eDNA was less impacted by the sampling method. We found no clear difference in detection for the invasive species targets based on the eDNA sampling method. These results underscore the need for pilot studies before conducting biodiversity inventory and monitoring, and a need for a greater understanding of not just how much, but also what, eDNA is captured depending on method choice, considering both spatial and particle size heterogeneity.

Florida, Minnesota↗
USGS2017

Group inverse sampling: An economical approach to inverse sampling

Inverse sampling is an adaptive design in the sense that the final sampling effort during a search for rare events will depend on what is found during the survey. Conventional inverse sampling (CIS) designs successively select individual sampling units to find, for example, the k th rare event. In real sampling situations, use of successive one‐by‐one sampling can be cost prohibitive. Here, we introduce an inverse sampling design that uses successive selection of groups instead of individuals, named group inverse sampling (GIS). An unbiased estimator and its variance estimator of the population mean are derived based on the Murthy estimator. CIS is a special case of the generalized design with group size equal to one. We simulate the GIS design to evaluate its efficiency using populations of rare freshwater mussels in West Virginia, USA. For cost consideration, we calculate distance traveled among the sampling units. Results show that GIS was more cost efficient than CIS in all cases. The group size for successive sampling (d ) was the most influential design parameter for reducing cost and increasing precision. Also, GIS found more rare units with greater consistency compared to simple random sampling without replacement (SRS). An important characteristic of the GIS design is that sampling stops when the target number of rare units is found, which prevents unnecessary sampling and contrasts favorably with other adaptive designs such as adaptive cluster sampling.

Environmetrics↗
USGS2020

Thresholds for post-wildfire debris flows: Insights from the Pinal Fire, Arizona, USA

Wildfire significantly alters the hydrologic properties of a burned area, leading to increases in overland flow, erosion, and the potential for runoff-generated debris flows. The initiation of debris flows in recently burned areas is well-characterized by rainfall intensity-duration (ID) thresholds. However, there is currently a paucity of data quantifying the rainfall intensities required to trigger post-wildfire debris flows, which limits our understanding of how and why rainfall ID thresholds vary in different climatic and geologic settings. In this study, we monitored debris-flow activity following the Pinal Fire in central Arizona, which differs from both a climatic and hydrogeomorphic perspective from other regions in the western U.S. where ID thresholds for post-wildfire debris flows are well-established, namely the Transverse Ranges of southern CA. Since the peak rainfall intensity within a rainstorm may exceed the rainfall intensity required to trigger a debris flow, the development of robust rainfall ID thresholds requires knowledge of the timing of debris flows within rainstorms. Existing post-wildfire debris-flow studies in Arizona only constrain the peak rainfall intensity within debris-flow-producing storms, which may far exceed the intensity that actually triggered the observed debris flow. In this study, we used pressure transducers within 5 burned drainage basins to constrain the timing of debris flows within rainstorms. Rainfall ID thresholds derived here from triggering rainfall intensities are, on average, 22 mm/h lower than ID thresholds derived under the assumption that the triggering intensity is equal to the maximum rainfall intensity recorded during a rainstorm. We then use a hydrologic model to demonstrate that the magnitude of the 15-minute rainfall ID threshold at the Pinal Fire site is associated with the rainfall intensity required to exceed a recently proposed dimensionless discharge threshold for debris-flow initiation. Model results further suggest that previously observed differences in regional ID thresholds between Arizona and the San Gabriel Mountains of southern CA may be attributed, in large part, to differences in the hydraulic properties of burned soils.

Arizona↗
USGS2024

Evaluating conservation units using network analysis: A sea duck case study

Conserving migratory wildlife requires understanding how groups of individuals interact across seasons and landscapes. Telemetry reveals individual movements at large spatiotemporal scales; however, using movement data to define conservation units requires scaling up from individual movements to species- and community-level patterns. We developed a framework to define flyways and identify important sites from telemetry data and applied it to long-term, range-wide tracking data from three species (640 individuals) of sea ducks: namely, North American scoters ( Melanitta spp). Our network of 88 nodes included both multispecies hotspots and areas uniquely important to individual species. We found limited spatial overlap between scoters wintering on the Atlantic and Pacific coasts of North America, with differing connectivity patterns between coasts. Finally, we identified four multispecies conservation units that did not correspond to traditional management flyways. From this approach, we show how individual movements can be used to quantify range-wide connectivity of migratory species and reveal gaps in conservation strategies.

Frontiers in Ecology and the Environment↗
USGS2018

“Asian carp” is societally and scientifically problematic. Let's replace it

Bighead Carp Hypophthalmichthys nobilis , Black Carp Mylopharyngodon piceus , Grass Carp Ctenopharyngodon idella , and Silver Carp H. molitrix are considered invasive species in North America and Europe. In North America, they are typically referred to collectively as “Asian carp”, a reference to their native range. The category “Asian carp” fails to acknowledge the cultural value and the ecological differences of these fishes, causes confusion when translated into Chinese, and frequently causes problems of communication with the public and occasionally among professionals when some species are intentionally or inadvertently in‐ or excluded when referred to collectively. Herein we review the long history of aquaculture of these species in China, their human cultural significance, the origin of the category “Asian carp”, and the problems the term “Asian carp” might cause when used in cross‐cultural communication. We recommend discontinuing use of the term Asian carp and replacing it with individual species names. When a group term is required, there are several more favorable alternatives, including existing Chinese terms that have been used for centuries.

Fisheries↗
USGS2013

InSAR Evidence for an active shallow thrust fault beneath the city of Spokane Washington, USA

In 2001, a nearly five month long sequence of shallow, mostly small magnitude earthquakes occurred beneath the city of Spokane, a city with a population of about 200,000, in the state of Washington. During most of the sequence, the earthquakes were not well located because seismic instrumentation was sparse. Despite poor-quality locations, the earthquake hypocenters were likely very shallow, because residents near the city center both heard and felt many of the earthquakes. The combination of poor earthquake locations and a lack of known surface faults with recent movement make assessing the seismic hazards related to the earthquake swarm difficult. However, the potential for destruction from a shallow moderate-sized earthquake is high, for example Christchurch New Zealand in 2011, so assessing the hazard potential of a seismic structure involved in the Spokane earthquake sequence is important. Using interferometric synthetic aperture radar (InSAR) data from the European Space Agency ERS2 and ENVISAT satellites and the Canadian Space Agency RADARSAT-1, satellite we are able to show that slip on a shallow previously unknown thrust fault, which we name the Spokane Fault, is the source of the earthquake sequence. The part of the Spokane Fault that slipped during the 2001 earthquake sequence underlies the north part of the city, and slip on the fault was concentrated between ~0.3 and 2 km depth. Projecting the buried fault plane to the surface gives a possible surface trace for the Spokane Fault that strikes northeast from the city center into north Spokane.

Washington↗
USGS2019

Metabolic rhythms in flowing waters: An approach for classifying river productivity regimes

Although seasonal patterns of ecosystem productivity have been extensively described and analyzed with respect to their primary forcings in terrestrial and marine systems, comparatively little is known about these same processes in rivers. However, it is now possible to perform a large‐scale synthesis on the patterns and drivers of river productivity regimes because of the recent sensor advances allowing for near‐continuous estimates of river productivity. Here, we explore a dataset of 47 U.S. rivers to examine whether there are characteristic river productivity regimes. We use classification approaches to develop a typology of productivity regimes and then use these regimes to examine differences with respect to potential controls of productivity. We identified two distinct metabolic regimes, which we named Summer Peak and Spring Peak Rivers, within our dataset. These regimes meaningfully differed in both the timing and magnitude of productivity and were robust to different approaches to classification. We also found that several variables, including watershed area and characteristics of water temperature or discharge, were able to predict the class membership of these regimes with modest accuracy. Our results support the presence of characteristic metabolic regimes and suggests that these regimes may have common sets of environmental controls. We present classification as one approach to begin exploring the productivity regimes of rivers. The strength of our approach is that it fully leverages these newly available high‐frequency productivity estimates to create classes that can be used to draw inferences about how the controls of river productivity differ between or within systems.

Limnology and Oceanography↗
USGS2020

Reduction of taxonomic bias in diatom species data

Inconsistency in taxonomic identification and analyst bias impede the effective use of diatom data in regional and national stream and lake surveys. In this study, we evaluated the effect of existing protocols and a revised protocol on the precision of diatom species counts. The revised protocol adjusts four elements of sample preparation, taxon identification and enumeration, and quality control (QC). We used six independent datasets to assess the effect of the adjustments on analytical outcomes. The first dataset was produced by three laboratories with a total of five analysts following established protocols (Charles et al. 2002), or their slight variations. The remaining datasets were produced by 1-3 laboratories with a total of 2-3 analysts following a revised protocol. The revised protocol included the following modifications: 1) development of coordinated pre-count voucher floras based on morphological operational taxonomic units (mOTUs), 2) random assignment of samples to analysts, 3) post-count identification and documentation of taxa (as opposed to an approach in which analysts assign names while they enumerate), and 4) increased use of QC samples. The revised protocol reduced taxonomic bias, as measured by reduction in analyst signal, and improved similarity among QC samples. Reduced taxonomic bias improves the performance of biological assessments, facilitates transparency across studies, and refines estimates of diatom species distributions.

Limnology and Oceanography: Methods↗
USGS2018

Fish community responses to submerged aquatic vegetation in Maumee Bay, Western Lake Erie

Submerged aquatic vegetation (SAV) in clearwater systems simultaneously provides habitat for invertebrate prey and acts as refugia for small fishes. Many fishes in Lake Erie rely on shallow, heavily vegetated bays as spawning grounds and the loss or absence of which is known to reduce recruitment in other systems. The Maumee River and Maumee Bay, which once had abundant macrophyte beds, have experienced a decline of SAV and an increase in suspended solids (turbidity) over the last century due to numerous causes. To compare fish communities in open‐water (turbid) and in SAV (clearer water) habitats in this region, which is designated by the U.S. Environmental Protection Agency as an Area of Concern, and to indicate community changes that could occur with expansion of SAV habitat, we sampled a 300‐ha sector of northern Maumee Bay that contained both habitats. Using towed neuston nets through patches of each habitat, we determined that areas of SAV contained more species and a different species complex (based on the Jaccard index and the wetland fish index), than did the open‐water habitat (averaging 8.6 versus 5 species per net trawl). The SAV habitat was dominated by centrarchids, namely Largemouth Bass Micropterus salmoides, Bluegill Lepomis macrochirus, and Black Crappie Pomoxis nigromaculatus. Open‐water habitat was dominated by Spottail Shiner Notropis hudsonius, Gizzard Shad Dorosoma cepedianum, and White Perch Morone americana, an invasive species. These results indicate that restoration efforts aimed at decreasing turbidity and increasing the distribution of SAV could cause substantive shifts in the fish community and address important metrics for assessing the beneficial use impairments in this Area of Concern.

Michigan, Ohio↗
USGS2011

A geographic information system tool for aquatic resource conservation in the Red and Sabine River Watersheds of the southeast United States

Our goal was to build a geographic information system (GIS) tool to enhance modeling and hypothesis testing relevant to watersheds and fish fauna of the Red and Sabine Rivers in the southeastern United States. Species of concern were identified from wildlife action plans and Web sites. Spatial distributions of fish species and mercury in fillets were delineated using data from states. Public georeferenced data were obtained on land cover, soil type, forest canopy, impervious surfaces, wastewater facilities and 303(d) impaired waters. Overlay maps highlighted patterns across 8-digit hydrologic unit codes (HUCs). Bossier City, Louisiana and Beaumont, Texas areas displayed impervious surfaces over 10% and 303(d) waters per HUC were 20% and 8%, respectively. Because bowfin (Amia calva) (n=299) and bass (Micropterus spp.) (n=1493) occurred in up to 44% of HUCs and fillets contained elemental mercury concentrations across ranges monitored, they were appropriate indicators of bioavailable mercury. Of the total fish number showing >0.5ppm, 81% of records were derived from bowfin and bass, and stepwise multiple linear regressions indicated fish with mercury at these concentrations correlated with environmental variables. Detrended correspondence analysis showed total species occurrence and environmental relationships significant, where 81.6% of the variability in fish occurrence was explained by impervious surface, land cover other than canopy or impervious surface (such as wetlands and agricultural area) and canopy (forest type). Two-way indicator species analysis delineated species co-occurrence in HUCs (14 groups) and similarity of species composition (nine groups). Results identified three HUC groupings as potential targets for managerial interest. Quality control concerns for GIS development included site name data and priority rankings of critical fish species. This tool can be used to support modeling and trend analyses for several purposes, such as those relevant for developing and reporting on water quality standards and critical habitat assessments.

Arkansas, Louisiana, Oklahoma, Texas↗