Filters: Tags: dendrochronology (X)
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Categories: Publication;
Tags: Data Visualization & Tools,
Drought,
Drought, Fire and Extreme Weather,
Forests,
Landscapes,
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...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Colorado Front Range,
The Holocene,
USA,
artificial neural networks,
climatic reconstruction,
This data release is tree-ring data near Columbine Lake and surrounding region, Grand County, Colorado (Latitude 40.27˚ N, Longitude -105.83˚ E NAD83). Re-collection of four existing tree-ring sites (Hot Sulphur Springs Psuedotsuga menziessii (HSU), Lexan Creek Picea engelmannii (LCU), Monarch Lake Pinus ponderosa (MLU), and Vasquez Mountain Psuedotsuga menziessii (VMU)) was conducted to update data to the most recent years possible and to maximize data overlap with instrumental records and with historical records of fire occurrence. At the time of collection, initial climate-growth relationships were assessed in a network of previously collected tree-ring sites (collected between 1987 and 2003) to determine which...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Climatology,
Colorado,
Columbine Lake,
Grand Lake,
Rocky Mountain National Park,
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.
Note: this data release is currently being revised and is temporarily unavailable. 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...
Categories: Data;
Tags: Chesapeake Bay,
Chesapeake Bay,
Delaware,
Delmarva Peninsula,
GPS measurement,
U. S. Geological Survey (USGS) scientists completed a stream survey campaign from the 26th of July to the 13th of August in 2021 at thirty 100-meter reaches within the Shenandoah Valley throughout Virginia and West Virginia. In each stream reach, the following survey measurements were made or attempted: three representative channel cross sections, water surface elevation at the top and bottom of each reach, and longitudinal thalweg point data. The survey data will be used with additional geomorphological measurements and habitat information to assess habitat quality of these Shenandoah Valley streams. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the...
Categories: Data;
Tags: Chesapeake Bay,
Chesapeake Bay,
GPS measurement,
Shenandoah Valley,
U.S. Geological Survey,
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...
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...
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.
Categories: Data;
Tags: Missouri River Basin,
USGS Science Data Catalog (SDC),
datasets,
dendrochronology,
hydrology,
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...
Culebra Range of the Sangre de Cristo Mountains, Colorado. Sample Collection: Ponderosa pine (Pinus ponderosa), Douglas-fir (Pseudotsuga menziesii), Bristlecone pine (Pinus aristate), and Limber pine (Pinus flexilis) living in lower and upper montane slopes of the Culebra Range (~Latitude 37˚N, ~Longitude -105˚W WGS84). The Fire-Climate-Human NGGDPP archive collection was obtained in two separate field campaigns. 1) CSU/USFS-led Bar-NI Fire History (Huckaby and Fornwalt, 2001). Sixty-six fire scar cross-sections were collected using a hand saw or chain saw from living, standing dead, and remnant wood at Bar-NI Ranch (37.15°N, -105.02°W). 2) USGS-led fire history (Brice and Kehrwald, 2023). Twenty-two fire scar cross-sections...
Dendrochronological collections during the career of USGS emeritus, Paul Carrara: Douglas-fir (Pseudotsuga menziesii), Black cottonwood (Populus trichocarpa), Spruce (Picea), Shore pine (Pinus contorta contorta), Willow (Salix), Bristlecone pine (Pinus aristate), Engelmann spruce (Picea engelmannii), Aspen (Populus tremuloides), and Limber pine (Pinus flexilis) collections from western North America. The Carrara NGGDPP archive collection is comprised of fifty-two cross-sections obtains for studies of glacial, avalanche, and vegetative histories from Alaska, Montana, and Colorado. Samples were processed following standard dendrochronological methods, including sample surface preparation and annual ring assignment....
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...
Categories: Publication;
Types: Citation;
Tags: El Nin?o-Southern Oscillation (ENSO),
Palmer Drought Severity Index (PDSI),
Southwest,
climate,
dendrochronology,
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;...
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...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Cenozoic,
DNA,
Progress in Physical Geography,
climate change,
dendrochronology,
U. S. Geological Survey (USGS) scientists completed a data collection campaign from the 26th of July 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 recorded observations from the campaign as well as numerous summary metrics to be used in model development. Those "model-ready" data can be found in Summary_Metrics_Deliverable.csv in the parent item, while the two child items containing recorded in-channel observations and recorded survey data. Attached to this release...
Categories: Data;
Tags: Chesapeake Bay,
Chesapeake Bay,
GPS measurement,
Shenandoah Valley,
U.S. Geological Survey,
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...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Colorado,
Ecological Society of America,
Ecology,
San Juan Mountains,
USA,
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...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Global Change Biology,
age-detrending,
climate change,
dendrochronology,
sagebrush,
We measured the percent live canopy and height of randomly-selected cottonwood trees at three sites: Deerlodge Park on the Yampa River (DLP), Island Park on the upper Green (ILP), and Canyonlands National Park on the lower Green (CAN). From these same trees we took increment cores to understand differences in tree growth in each forest over time. This dataset includes four tabular digital files. The file "cottonwood_characteristics_dlp_ilp_can.csv" includes data on location, age, height, live canopy cover, and fire history. The files "dlp.txt", "ilp.txt", and "can.txt" contain annual tree ring width for trees at DLP, ILP and CAN.
Categories: Data;
Tags: Aquatic Biology,
Botany,
Canyonlands National Park,
Colorado,
Dinosaur National Monument,
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