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The feasibility of reconstructing total spring precipitation for the South Platte River basin from tree-ring chronologies using artificial neural networks is explored. The use of artificial neural networks allows a comparison of reconstructions resulting from both linear and nonlinear models. Both types of models produced reconstructions that explained more than 40% of the variation in spring precipitation and were well verified with independent data. Although the nonlinear models produced higher R2 values than did the linear model for the calibration period, they performed less well in the independent period. This result and other model evaluation statistics suggest that, in this study, the nonlinear models contain...
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U. S. Geological Survey (USGS) scientists completed a stream surveying campaign from the 26th of July to the 13th of August in 2021 at thirty 100m reaches within the Shenandoah Valley throughout Virginia and West Virginia. The goal was to collect three cross sections, water surface elevation at the top and bottom of each reach, and thalweg point data at each study location to use the geomorphological surveys alongside habitat information. Together, these two sources of data can be used to create a habitat assessment of Shenandoah Valley streams. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
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Tree growth (annual tree ring measurements) and plant community composition data of tidal freshwater forested wetlands along longitudinal riverine positions (upper, lower, and stressed tidal river sites, and nearby upstream non-tidal forested floodplains) of the adjoining Pamunkey and Mattaponi Rivers, Virginia.
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These data were compiled in order to represent long-term (multi-decadal) forest growth across eight different experimental forests in the United States, each with replicated levels of density treatments, as well as an important drought index correlated to growth. Forests around the world are experiencing severe droughts and elevated competitive intensity due to increased tree density. These data can be utilized to not only examine differences in within-stand competition, as well the trends and impact of drought in different forests across a broad climatic gradient, but also the influence of interactions between drought and competition on forest growth. Growth is measured as a treatment level, annual basal area increment...
Categories: Data; Tags: Argonne Experimental Forest, Arizona, Bartlett Experimental Forest, Birch Lake Experiment, Black Hills Experimental Forest, All tags...
Shrubs have increased in abundance and dominance in arctic and alpine regions in recent decades. This often dramatic change, likely due to climate warming, has the potential to alter both the structure and function of tundra ecosystems. The analysis of shrub growth is improving our understanding of tundra vegetation dynamics and environmental changes. However, dendrochronological methods developed for trees, need to be adapted for the morphology and growth eccentricity of shrubs. Here, we review current and developing methods to measure radial and axial growth, estimate age, and assess growth dynamics in relation to environmental variables. Recent advances in sampling methods, analysis and applications have improved...
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Andrews Meadow in the Loch Vale watershed, Rocky Mountain National Park. Sample Collection: Englemann spruce (Picea engelmannii) living on slopes surrounding and at the edge of Andrews meadow (Latitude 40˚ 17’ 24” N, Longitude 105˚ 40’ 01” W NAD83). At the time of collection, the climate-sensitive upland P. engelmannii trees were growing on well-drained slopes above the meadow. Seventeen trees, two cores per tree when possible, were collected using a 5mm-diameter increment borer. During sample collection, diameter at breast height (DBH) was also measured. These cores were processed following standard dendrochronological methods. The annual (TW) and earlywood (EW) ring-widths of each core were measured to 0.001mm...
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Tree-ring reconstructions of water-year (Oct 1 through Sep 30th) flow for 31 gaging sites in Missouri River basin, with complete data for 1685 through 1977 (n = 293 water years). The complete 105 tree-ring reconstructions of streamflow used in the Nature Scientific Reports paper were obtained from various sources; 74 flow reconstructions were obtained from the web resource, TreeFlow (http://www.treeflow.info/), and an additional 31 flow reconstructions (provided here) for the Missouri River basin were obtained from the U.S. Geological Survey in Bozeman, Montana.
This paper summarizes the current state of knowledge concerning the climate of the Southwest. Low annual precipitation, clear skies, and year-round warm weather over much of the Southwest are due in large part to a quasi-permanent subtropical high-pressure ridge over the region. However, the Southwest is located between the mid-latitude and subtropical atmospheric circulation regimes, and this positioning relative to shifts in these regimes is the fundamental reason for the region's climatic variability. El Nin?o, which is an increase in sea surface temperature of the eastern equatorial Pacific Ocean with an associated shift of the active center of atmospheric convection from the western to the central equatorial...
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U. S. Geological Survey (USGS) scientists completed a data collection campaign from the 25th of April to the 10th of June in 2022, using various methods to record geomorphic and habitat indicators throughout 30 streams on the Delmarva Peninsula. Field methods included GNSS surveys, gravelometer-based pebble count readings, visual assessments, and riparian analyses. This metadata record contains all raw observations from the campaign as well as numerous summary metrics to be used in model development. Those "model-ready" data can be found in Delmarva_Model_Deliverable.csv in the parent item, while the two child items containing raw in-channel observations and raw survey data. Attached to this release is a data dictionary...
Shrubs have increased in abundance and dominance in arctic and alpine regions in recent decades. This often dramatic change, likely due to climate warming, has the potential to alter both the structure and function of tundra ecosystems. The analysis of shrub growth is improving our understanding of tundra vegetation dynamics and environmental changes. However, dendrochronological methods developed for trees, need to be adapted for the morphology and growth eccentricity of shrubs. Here, we review current and developing methods to measure radial and axial growth, estimate age, and assess growth dynamics in relation to environmental variables. Recent advances in sampling methods, analysis and applications have improved...
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This data release consists of the following components: Sex ratio data from cottonwood trees at random points on the floodplain in the North and South units of Theodore Roosevelt National Park, ND. These data were used to investigate the effects of age, height above, and distance from the channel on mortality of male and female trees of plains cottonwood (Populus deltoides subsp. monilifera) as described in the Friedman and Griffin (2017) report. Tree core and tree ring data from the North and South Units of Theodore Roosevelt National Park, North Dakota. South Unit data was collected in April 2012, North Unit data was collected in the summer and fall of 2010. The trees are located on the floodplain of the Little...
Mountain big sagebrush (Artemisia tridentata Nutt. ssp. vaseyana) covers large areas in arid regions of western North America. Climate-change models predict a decrease in the range of sagebrush, but few studies have examined details of predicted changes on sagebrush growth and the potential impacts of these changes on the community. We analyzed effects of temperature, precipitation, and snow depth on sagebrush annual ring width for 1969 to 2007 in the Gunnison Basin of Colorado. Temperature at all times of year except winter had negative correlations with ring widths; summer temperature had the strongest negative relationship. Ring widths correlated positively with precipitation in various seasons except summer;...
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U. S. Geological Survey (USGS) scientists completed a data collection campaign from the 25th of April to the 10th of June in 2022, using various methods to record geomorphic and habitat indicators throughout 30 streams on the Delmarva Peninsula. Field methods included GNSS surveys, gravelometer-based pebble count readings, visual assessments, and riparian analyses. These data contain all raw field metrics from the in-channel habitat assessment as well as the rapid riparian assessment. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
This article evaluates drought scenarios of the Upper Colorado River basin (UCRB) considering multiple drought variables for the past 500 years and positions the current drought in terms of the magnitude and frequency. Drought characteristics were developed considering water-year data of UCRB’s streamflow, and basin-wide averages of the Palmer Hydrological Drought Index (PHDI) and the Palmer Z Index. Streamflow and drought indices were reconstructed for the last 500 years using a principal component regression model based on tree-ring data. The reconstructed streamflow showed higher variability as compared with reconstructed PHDI and reconstructed Palmer Z Index. The magnitude and severity of all droughts were...
Understanding climate change and its potential impact on species, populations and communities is one of the most pressing questions of twenty-first-century conservation planning. Palaeobiogeographers working on Cenozoic fossil records and other lines of evidence are producing important insights into the dynamic nature of climate and the equally dynamic response of species, populations and communities. Climatic variations ranging in length from multimillennia to decades run throughout the palaeo-records of the Quaternary and earlier Cenozoic and have been shown to have had impacts ranging from changes in the genetic structure and morphology of individual species, population sizes and distributions, community composition...
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U. S. Geological Survey (USGS) scientists completed a data collection campaign from the 26th of June to the 13th of August in 2021, using various methods to record geomorphic and habitat indicators throughout streams in the Shenandoah Valley. Field methods included GNSS surveys, gravelometer-based pebble count readings, visual assessments, and riparian analyses. This metadata record contains all raw observations from the campaign as well as numerous summary metrics to be used in model development. Those "model-ready" data can be found in Shenandoah_Model_Deliverable.csv in the parent item, while the two child items containing raw in-channel observations and raw survey data. Attached to this release is a data dictionary...
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U. S. Geological Survey (USGS) scientists completed a stream surveying campaign from the 25th of April to the 10th of June in 2022 at 100m reaches throughout 30 streams on the Delmarva Peninsula. The goal was to collect three cross sections, water surface elevation at the top and bottom of each reach, and thalweg point data at each study location to use the geomorphological surveys alongside habitat information. Together, these two sources of data can be used to create a habitat assessment of Delmarva Peninsula streams. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Fire severity, frequency, and extent are expected to change dramatically in coming decades in response to changing climatic conditions, superimposed on the adverse cumulative effects of various human-related disturbances on ecosystems during the past 100 years or more. To better gauge these expected changes, knowledge of climatic and human influences on past fire regimes is essential. We characterized the temporal and spatial properties of fire regimes in ponderosa pine forests of the southern San Juan Mountains of southwestern Colorado by collecting 175 fire-scarred tree samples from nine sites across a wide range of topographic settings. All tree rings and fire scars were dated using standard dendrochronological...
Global models project impending climate changes that could significantly alter plant species composition in ecosystems. Climate manipulation experiments provide an opportunity to investigate such effects. Here we describe and apply a method for extracting the age-detrended growth rate of sagebrush (Artemisia tridentata Nutt.) and show that experimental ecosystem warming enhances the growth rate of this shrub. Snowmelt date, not soil temperature or moisture, is demonstrated to be the dominant climate variable controlling the observed effect. Our findings suggest that global climate change will result in increased growth and range expansion of sagebrush near northern or high-elevation range boundaries in the Western...


map background search result map search result map Cottonwood Management at Theodore Roosevelt National Park, North Dakota Long-term Experimental Forest Growth and Drought Data Paleohydrologic reconstructions of water-year streamflow for 31 stream gaging sites in the Missouri River Basin with complete data for 1685 through 1977 Data on Tree Growth and Plant Community Composition in Mid-Atlantic Tidal Freshwater Forested Wetlands Shenandoah Valley Stream Health and Habitat Assessments in West Virginia and Virginia, 2021 (ver. 2.0, November 2023) Shenandoah Valley Stream Survey (2021) Tree-ring widths of Picea engelmannii at Andrews Meadow, Rocky Mountain National Park Delmarva Peninsula Stream Health and Habitat Assessments in Maryland and Delaware (2022) Delmarva Peninsula Raw Habitat and Riparian Assessment Data (2022) Delmarva Peninsula Stream Survey (2022) Tree-ring widths of Picea engelmannii at Andrews Meadow, Rocky Mountain National Park Data on Tree Growth and Plant Community Composition in Mid-Atlantic Tidal Freshwater Forested Wetlands Cottonwood Management at Theodore Roosevelt National Park, North Dakota Delmarva Peninsula Stream Health and Habitat Assessments in Maryland and Delaware (2022) Delmarva Peninsula Raw Habitat and Riparian Assessment Data (2022) Delmarva Peninsula Stream Survey (2022) Shenandoah Valley Stream Health and Habitat Assessments in West Virginia and Virginia, 2021 (ver. 2.0, November 2023) Shenandoah Valley Stream Survey (2021) Paleohydrologic reconstructions of water-year streamflow for 31 stream gaging sites in the Missouri River Basin with complete data for 1685 through 1977 Long-term Experimental Forest Growth and Drought Data