USGS Science⌕ Search

SEARCH · USGS Science

Results for “Technical Report”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 685 records · Page 38Linked to original sources
USGS2018

Effects of climate change on ecological disturbance in the Northern Rockies Region [Chapter 8]

This chapter describes the ecology of important disturbance regimes in the Forest Service, U.S. Department of Agriculture (USFS) Northern Region and the Greater Yellowstone Area, hereafter called the Northern Rockies region, and potential shifts in these regimes as a consequence of observed and projected climate change. The term disturbance regime describes the general temporal and spatial characteristics of a disturbance agent - insect, disease, fire, weather, even human activity - and the effects of that agent on the landscape (table 8.1). More specifically, a disturbance regime is the cumulative effect of multiple disturbance events over space and time (Keane 2013). Disturbances disrupt an ecosystem, community, or population structure and change elements of the biological environment, physical environment, or both (White and Pickett 1985). The resulting shifting mosaic of diverse ecological patterns and structures in turn affects future patterns of disturbance, in a reciprocal, linked relationship that shapes the fundamental character of landscapes and ecosystems. Disturbance creates and maintains biological diversity in the form of shifting, heterogeneous mosaics of diverse communities and habitats across a landscape (McKinney and Drake 1998), and biodiversity is generally highest when disturbance is neither too rare nor too frequent on the landscape (Grime 1973).

General Technical Report↗
USGS2018

Effects of climate change on forest vegetation in the Northern Rockies Region

The projected rapid changes in climate will affect the unique vegetation assemblages of the Northern Rockies region in myriad ways, both directly through shifts in vegetation growth, mortality, and regeneration, and indirectly through changes in disturbance regimes and interactions with changes in other ecosystem processes, such as hydrology, snow dynamics, and exotic invasions (Bonan 2008; Hansen and Phillips 2015; Hansen et al. 2001; Notaro et al. 2007). These impacts, taken collectively, could change the way vegetation is managed by public land agencies in this area. Some species may be in danger of rapid decreases in abundance, while others may undergo range expansion (Landhäusser et al. 2010). New vegetation communities may form, while historical vegetation complexes may simply shift to other areas of the landscape or become rare. Juxtaposed with climate change concerns are the consequences of other land management policies and past activities, such as fire exclusion, fuels treatments, and grazing. A thorough assessment of the responses of vegetation to projected climate change is needed, along with an evaluation of the vulnerability of important species, communities, and vegetation-related resources that may be influenced by the effects, both direct and indirect, of climate change. This assessment must also account for past management actions and current vegetation conditions and their interactions with future climates.

General Technical Report↗
USGS2018

Estimating freshwater productivity, overwinter survival, and migration patterns of Klamath River Coho Salmon

An area of great importance to resource management and conservation biology in the Klamath Basin is balancing water usage against the life history requirements of threatened Coho Salmon. One tool for addressing this topic is a freshwater dynamics model to forecast Coho Salmon productivity based on environmental inputs. Constructing such a forecasting tool requires local data to quantify the unique life history processes of Coho Salmon inhabiting this region. Here, we describe analytical methods for estimating a series of sub-models, each capturing a different life history process, which will eventually be synchronized as part of a freshwater dynamics model for Klamath River Coho Salmon. Specifically, we draw upon extensive population monitoring data collected in the basin to estimate models of freshwater productivity, overwinter survival, and migration patterns. Our models of freshwater productivity indicated that high summer temperatures and high winter flows can both adversely affect smolt production and that such relationships are more likely in tributaries with naturally regulated flows due to substantial intraannual environmental variation. Our models of overwinter survival demonstrated extensive variability in survival among years, but not among rearing locations, and demonstrated that a substantial proportion (~ 20%) of age-0+ fish emigrate from some rearing sites in the winter. Our models of migration patterns indicated that many age-0+ fish redistribute in the basin during the summer and winter. Further, we observed that these redistributions can entail long migrations in the mainstem where environmental stressors likely play a role in cueing refuge entry. Finally, our models of migration patterns indicated that changes in discharge are important in cueing the seaward migration of smolts, but that the nature of this behavioral response can differ dramatically between tributaries with naturally and artificially regulated flows. Collectively, these analyses demonstrate that environmental variation interacts with most phases of the freshwater life history of Klamath River Coho Salmon and that anthropogenic environmental variation can have a particularly large bearing on productivity.

Arcata Fisheries Technical Report↗
USGS2018

Estimation of stream conditions in tributaries of the Klamath River, northern California

Because of their critical ecological role, stream temperature and discharge are requisite inputs for models of salmonid population dynamics. Coho Salmon inhabiting the Klamath Basin spend much of their freshwater life cycle inhabiting tributaries, but environmental data are often absent or only seasonally available at these locations. To address this information gap, we constructed daily averaged water temperature models that used simulated meteorological data to estimate daily tributary temperatures, and we used flow differentials recorded on the mainstem Klamath River to estimate daily tributary discharge. Observed temperature data were available for fourteen of the major salmon bearing tributaries, which enabled estimation of tributary-specific model parameters at those locations. Water temperature data from six mid-Klamath Basin tributaries were used to estimate a global set of parameters for predicting water temperatures in the remaining tributaries. The resulting parameter sets were used to simulate water temperatures for each of 75 tributaries from 1980-2015. Goodness-of-fit statistics computed from a cross-validation analysis demonstrated a high precision of the tributary-specific models in predicting temperature in unobserved years and of the global model in predicting temperatures in unobserved streams. Klamath River discharge has been monitored by four gages that broadly intersperse the 292 kilometers from the Iron Gate Dam to the Klamath River mouth. These gages defined the upstream and downstream margins of three reaches. Daily discharge of tributaries within a reach was estimated from 1980-2015 based on drainage-area proportionate allocations of the discharge differential between the upstream and downstream margin. Comparisons with measured discharge on Indian Creek, a moderate-sized tributary with naturally regulated flows, revealed that the estimates effectively approximated both the variability and magnitude of discharge.

California↗
USGS2018

A test of sex specific genetic markers in the Hawaiian hoary bat and relevance to population studies

We tested the utility of a protocol using genetic markers that previously proved successful to identify the sex of Vespertilionid bats on tissues collected from live bats and carcasses of varying age from the Hawaiian hoary bat (Lasiurus cinereus semotus). This molecular method is based on genes unique to X and Y chromosomes in mammals and previously was used successfully on North American hoary bats (L. c. cinereus). We amplified two markers within intron regions of the zinc-finger-X (Zfx) and zinc-finger-Y (Zfy) genes using a multiplexed polymerase chain reaction technique and obtained product bands that were easily visualized using gel electrophoresis. Genotyping determined the sex of 36 individual Hawaiian hoary bat carcasses previously assigned sex only by external genitalia and identified sex for 29 “unknown” bat carcasses that could not be classified by external genitalia. Employing this method for sexing Hawaiian hoary bats will permit more reliable evaluation of the ratio of males to females in subpopulations affected by fatalities from emerging threats. This is critical to the conservation and management of this endangered bat.

Technical Report↗
USGS2018

Climate, disturbance, and vulnerability to vegetation change in the Northwest Forest Plan Area

Climate change is expected to alter the composition, structure, and function of forested ecosystems in the United States (Vose et al. 2012). Increases in atmospheric concentrations of greenhouse gases (e.g., carbon dioxide [CO2]) and temperature, as well as altered precipitation and disturbance regimes (e.g., fire, insects, pathogens, and windstorms), are expected to have profound effects on biodiversity, socioeconomics, and the delivery of ecosystem services within the Northwest Forest Plan (NWFP, or Plan) area over the next century (Dale et al. 2001, Franklin et al. 1991). The ecological interactions and diversity of biophysical settings in the region are complex. The effects of climate change on ecological processes will occur through a variety of mechanisms at a range of spatial scales and levels of biological organization, ranging from the physiological responses of individual plants to the composition and structure of stands and landscapes (Peterson et al. 2014a). Understanding and incorporating how climate change projections and the potential ecological effects and uncertainties differ within the region (e.g., Deser et al. 2012) is essential for developing adaptation and mitigation strategies.

California, Oregon, Washington↗
USGS2018

Updated statewide abundance estimates for the Florida manatee

Knowing how many manatees live in Florida is critical for conservation and management of this threatened species. Martin et al. (2015) flew aerial surveys in 2011–2012 and estimated abundance in those years using advanced techniques that incorporated multiple data sources. We flew additional aerial surveys in 2015–2016 to count manatees and again applied advanced statistical techniques to estimate their abundance. We also made several methodological advances over the earlier work, including accounting for how sea state (water surface conditions) and synchronous surfacing behavior affect the availability of manatees to be detected and incorporating all parts of Florida in the area of inference. We estimate that the number of manatees in Florida in 2015–2016 was 8,810 (95% Bayesian credible interval 7,520–10,280), of which 4,810 (3,820–6,010) were on the west coast of Florida and 4,000 (3,240–4,910) were on the east coast. These estimates and associated uncertainty, in addition to being of immediate value to wildlife managers, are essential new data for incorporation into integrated population models and population viability analyses.

Florida↗
USGS2018

2017-2018 Palila abundance estimates and trend

The palila (Loxioides bailleui) population was surveyed annually from 1998–2018 on Mauna Kea Volcano to determine abundance, population trend, and spatial distribution. In the latest surveys, the 2017 population was estimated at 1,177−1,813 birds (point estimate: 1,461) and the 2018 population was estimated at 778−1,420 (point estimate: 1,051). Only two palila were detected outside the core survey area during a mountain-wide survey in 2017, suggesting that most, if not all, palila inhabit the western slope during the annual survey period. Since 1998, the size of the area containing palila detections on the western slope did not show a significant change, suggesting that the range of the species has remained stable; although this area represents only about 5% of its historical extent. During 1998−2003, palila numbers fluctuated moderately (coefficient of variation [CV] = 0.20). After peaking in 2003, population estimates declined steadily through 2011; since 2010, estimates have continued to decline at a slower rate. The average rate of decline during 1998−2018 was 168 birds per year with very strong statistical support for an overall declining trend in abundance. Over the 21-year monitoring period, the estimated rate of change equated to a 76% decline in the population.

Hawai`i↗
USGS2019

Economical environmental sampler designs for detecting airborne spread of fungi responsible for Rapid `Ōhi`a Death

We designed two new samplers for monitoring airborne particulates that rely on either natural wind currents (Passive Environmental Sampler) or a battery-operated fan (Active Environmental Sampler). Both samplers are significantly less expensive than commercial devices such as Rotorod® and Burkard Samplers that are used in the agricultural and health science industries. They are economical enough to be deployed in large numbers across broad landscapes. We evaluated their use for detecting airborne spread of ambrosia beetle frass that may contain infective spores of the fungi (Ceratocystis lukuohia and C. huliohia) that are responsible for Rapid `Ōhi`a Death (ROD), a newly documented pathosystem on Hawai`i Island. We compared performance of the new samplers to Rotorod® Model 20 Samplers by releasing synthetic polyethylene spheres (12–160 µm in diameter) and also Xyleborus spp. frass known to contain C. lukuohia and C. huliohia propagules under controlled laboratory and field conditions. Overall, the Active Environmental Sampler proved to be 3–4 times more effective in capturing polyethylene spheres and 2–3 times more effective in capturing frass than either the Passive or Rotorod® Samplers. Significant differences between the Passive and Rotorod® Samplers were not detected. For the frass release experiment, C. lukuohia DNA was detected once by qPCR in an Active Environmental Sampler and C. huliohia DNA was detected during two different trials, once with an Active Environmental Sampler and once with a Passive Environmental Sampler. No detections were made with Rotorod® Samplers. Both Active and Passive Samplers were used in the field for detection of airborne dispersal of C. lukuohia and C. huliohia at Orchidlands Estates in the Puna District of Hawai`i Island. We found that airborne dispersal of potentially infective beetle frass was uncommon over short distances with qPCR detections in up to 10% of weekly sampler collections.

Hawai`i Cooperative Studies Unit Technical Report↗
USGS2008

Wildland fire in ecosystems: Fire and nonnative invasive plants

This state-of-knowledge review of information on relationships between wildland fire and nonnative invasive plants can assist fire managers and other land managers concerned with prevention, detection, and eradication or control of nonnative invasive plants. The 16 chapters in this volume synthesize ecological and botanical principles regarding relationships between wildland fire and nonnative invasive plants, identify the nonnative invasive species currently of greatest concern in major bioregions of the United States, and describe emerging fire-invasive issues in each bioregion and throughout the nation. This volume can help increase understanding of plant invasions and fire and can be used in fire management and ecosystem-based management planning. The volume’s first part summarizes fundamental concepts regarding fire effects on invasions by nonnative plants, effects of plant invasions on fuels and fire regimes, and use of fire to control plant invasions. The second part identifies the nonnative invasive species of greatest concern and synthesizes information on the three topics covered in part one for nonnative invasives in seven major bioregions of the United States: Northeast, Southeast, Central, Interior West, Southwest Coastal, Northwest Coastal (including Alaska), and Hawaiian Islands. The third part analyzes knowledge gaps regarding fire and nonnative invasive plants, synthesizes information on management questions (nonfire fuel treatments, postfire rehabilitation, and postfire monitoring), summarizes key concepts described throughout the volume, and discusses urgent management issues and research questions.

General Technical Report↗
USGS2019

Scientific Framework for resilience research on the Upper Mississippi River System

The goal of this research framework is to outline research that would continue to improve our understanding of ecological resilience of the Upper Mississippi River System (UMRS) and inform management of the system for health and resilience. We provide a broad overview of recently completed and ongoing work that has been funded as a part of the UMRS Ecological Resilience Assessment and related efforts to provide context for how proposed research questions build upon our current knowledge and may inform restoration planning and design. We describe two primary objectives within this research framework - the first objective is to investigate hypothesized drivers and feedbacks related to specified resilience, and the second is to expand our utility of general resilience indicators through further development and evaluation. The intended audience for this framework is the Upper Mississippi River Restoration Program (UMRR). The UMRR partnership is made up of natural resource agencies from five states (Illinois, Iowa, Minnesota, Missouri and Wisconsin) and five federal agencies (U.S. Army Corps of Engineers, U.S. Environmental Protection Agency, U.S. Fish and Wildlife Service, U.S. Geological Survey, and USDA Natural Resources Conservation Service).

Illinois, Iowa, Minnesota, Missouri, Wisconsin↗
USGS2011

Demonstration/validation of the Snap sampler passive groundwater sampling device

Laboratory studies and a field demonstration were conducted to determine the ability of the Snap Sampler to recover representative concentrations of several types of inorganic analytes from ground water. Analytes included non-metals, transition metals, alkaline earth metals, alkali metals, and a metalloid. In the laboratory studies, concentrations of analytes in Snap Sampler samples were com-parable with concentrations of the analytes in samples collected from a standpipe (i.e., control samples). For the field demonstration, there were sampling events at the former Pease Air Force Base. Samples taken using a Snap Sampler were compared with samples collected using conventional low-flow purging and sampling and a regenerated cellulose passive diffusion sampler. Based upon statistical analyses, analyte concentrations were found to be equivalent to those in the low-flow samples with one exception – unfiltered iron, where concentrations were significantly higher in the Snap Sampler samples. Differences were most pronounced in samples collected from the two stainless steel wells and from wells with higher turbidity levels. Elevated turbidities may have resulted from installing additional sampling equipment (including the baffle, pump, samplers, and bottom weight) in the well before sampling. We will examine this issue further at our next test site.

New Hampshire↗
USGS2020

Mapping the thermal landscape of the Upper Mississippi River

Temperature has a fundamental influence on physical, chemical and biological processing in aquatic ecosystems. River temperatures respond to a diverse array of drivers including air temperature, streamflow, and thermal inputs, but the physical template has been shown to play a significant role in structuring spatial and temporal variation in water temperature. How these factors interact to affect water temperature in complex floodplain river habitats such as those present in the Upper Mississippi River System (UMRS) is not well-studied. We used a combination of airborne thermal imagery and continuous temperature loggers deployed across aquatic area types to evaluate spatial and temporal patterns in water temperature in Navigation Pool 8 during the summer and fall of 2017. The mid-wave infrared thermal camera available for this study is not commonly used for thermal imagery acquisition over water, so we discuss accommodations that were made to account for potential interferences and describe considerations for future users interested in using the technology. We quantified thermal metrics from imagery and continuous loggers (e.g., mean, coefficient of variation, range) and compared those to hydrogeomorphic variability across aquatic areas using a Geographic Information System (GIS) dataset. Our findings showed that both temporal and spatial temperature patterns were linked to variation in depth and connectivity of aquatic areas across the pool. Despite some of the technical challenges associated with acquiring this imagery, the method shows promise for characterizing spatial variation in surface temperatures in the UMRS associated with complex physical features such as habitat rehabilitation and enhancement projects.

Iowa, Illinois, Minnesota, Wisconsin↗