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6,175 results for “Composite”
Cedar Creek Ecosystem Science Reserve site, station Composite of several Cedar Creek stations, study of air temperature (mean minimum) in units of celsius on a yearly timescale
The EcoTrends project was established in 2004 by Dr. Debra Peters (Jornada Basin LTER, USDA-ARS Jornada Experimental Range) and Dr. Ariel Lugo (Luquillo LTER, USDA-FS Luquillo Experimental Forest) to support the collection and analysis of long-term ecological datasets. The project is a large synthesis effort focused on improving the accessibility and use of long-term data. At present, there are ~50 state and federally funded research sites that are participating and contributing to the EcoTrends project, including all 26 Long-Term Ecological Research (LTER) sites and sites funded by the USDA Agriculture Research Service (ARS), USDA Forest Service, US Department of Energy, US Geological Survey (USGS) and numerous universities. Data from the EcoTrends project are available through an exploratory web portal (http://www.ecotrends.info). This web portal enables the continuation of data compilation and accessibility by users through an interactive web application. Ongoing data compilation is updated through both manual and automatic processing as part of the LTER Provenance Aware Synthesis Tracking Architecture (PASTA). The web portal is a collaboration between the Jornada LTER and the LTER Network Office. The following dataset from Cedar Creek Ecosystem Science Reserve (CDR) contains air temperature (mean minimum) measurements in celsius units and were aggregated to a yearly timescale.
Freshwater macroinvertebrate community composition and diversity data from lagoons on Navarino Island, Chile
This study was carried out during the austral summer of 2015 (15 January to 15 February) and assessed freshwater macroinvertebrate diversity associated with lakes and ponds along the altitudinal gradient of the Róbalo river watershed, located in the Magellanic sub-Antarctic ecoregion. The latter has a steep elevational gradient, peaking at around 1000 m a.s.l., and marked changes in temperature and landscape composition can be observed over relatively short distances. Four lagoons were chosen, as they were located on different altitudinal levels, thus allowing for comparison between the different zones found within the gradient. Along with the physical description of each lagoon (temperature, pH and conductivity), the surrounding habitats were characterized. Within each lagoon, four different habitat types were identified based on substrate composition, and the presence/absence and type of vegetation (vascular or non-vascular).
Chemistry and isotopic composition of resource pools in lakes of the Sierra Nevada, CA
The extent to which terrestrial organic matter supports aquatic consumers remains uncertain because factors regulating resource flows are poorly understood. We sampled 12 lakes throughout the Sierra Nevada (California, USA) spanning large gradients in elevation and size to evaluate how watershed attributes and lake morphometry influence resource flows to lake carbon pools and zooplankton. We found that the size and composition of carbon pools in lakes were often more strongly determined by watershed or lake features rather than by elevational position. Using three different tracers of resource origin (δ13C, Δ14C, C:N ratio), we found terrestrial contributions to most lake resource pools (DOC, POM, sediments) and pelagic consumers (zooplankton) were more strongly related to local-scale watershed features such as vegetation cover or watershed area:lake area rather than to elevation. Landscape patterns in multiple tracers indicated consistent contribution of within-lake C sources to bulk resource pools across elevations (POM, sediments, zooplankton). δ13C-enrichment of lake C pools and overlap with δ13C of terrestrial resources can arise due to reduced fractionation of 13C by phytoplankton under CO2 limitation, therefore we recommend careful consideration of potential environmental drivers when interpreting among-lake patterns in δ13C. Our findings emphasize the importance of local-scale variation in mediating terrestrial contributions to lake food webs.
Stable Isotopic Composition of Nitrates and POM in BES Streams
In the Baltimore urban long-term ecological research (LTER) project, (Baltimore Ecosystem Study, BES) we use the watershed approach to evaluate integrated ecosystem function. The LTER research is centered on the Gwynns Falls watershed, a 17,150 ha catchment that traverses a gradient from the urban core of Baltimore, through older urban residential (1900 - 1950) and suburban (1950- 1980) zones, rapidly suburbanizing areas and a rural/suburban fringe. Stable isotopic analyses were carried out on stream samples collected bi-weekly from June 2005 through December 2005 as part of the routine Baltimore LTER sampling. Sites included POBR (forest), MCDN (agricultural), BARN (low-residential), GFGL (suburban), DRKR (urban), GFCP (urban), and RGHT (storm drain). Samples were also taken from a small tributary to the Gwynns Falls (GFGR), approximately 300 m above GFCP, that was highly contaminated with sewage. A major sewer leak to this stream was identified and repaired in April 2004. Stable isotopic analyses of soil water underneath fertilized lawns and atmospheric deposition was measured in long-term lawn study plots on the campus of the University of Maryland Baltimore County. Storm samples were also collected from 6 locations (DR1, DR3.1, DR3.2, DR4, DR5, DRKR gauge) within the Dead Run watershed over July 2005. At one site (DR3), two sets of samples were collected, one just above (DR3.1) and just below (DR3.2) an overflowing sewer. All stormflow samples were collected on the receding limb of the storm hydrograph, as the flashy nature of these urban streams makes sampling the rising limb difficult in terms of both timing and personal safety. Nitrate concentrations are a separate set of chemical analyses than the routine weekly analyses.
Impact of urbanization on small rodent abundance and community composition
To determine the impacts of urban activities on small rodent populations, we conducted population surveys both inside and outside the urban core of Phoenix, AZ over one fall and spring season. We used Sherman traps and larger wire traps to target small vertebrates such as mice, rats, and squirrels for two consecutive trap nights at four desert remnant parks inside the city and four desert parks outside the city. Overall, small rodent abundances and diversity at the species level were statistically similar in the urban and rural parks, but rural parks hosted a significantly greater diversity at the genus level and an overall difference in community composition between the two locations.
Desert Fertilization Experiment: composition of annual plants in study plots within desert preserves in and around the greater Phoenix metropolitan area, spring 2008
Launched in 2006 with support from the National Science Foundation (NSF) and leveraged by the CAP LTER, the Carbon and Nitrogen deposition (CNdep) project sought to answer the fundamental question of whether elemental cycles in urban ecosystems are qualitatively different from those in non-urban ecosystems. Ecosystem scientists, atmospheric chemists, and biogeochemists tested the hypothesis that distinct biogeochemical pathways result from elevated inorganic nitrogen and organic carbon deposition from the atmosphere to the land. To test the hypothesis, scientists examined the responsiveness of Sonoran desert ecosystems to nutrient enrichment by capitalizing on a gradient of atmospheric deposition in and around the greater Phoenix metropolitan area. Fifteen desert study sites were established, with five locations each west and east of the urban core, and in the urban core in desert preserves. In addition to the gradient of atmospheric deposition in and around the urban core, select study plots at each of the fifteen desert locations receive amendments of nitrogen, phosphorus, or nitrogen + phosphorus fertilizer. Measured variables include soil properties, perennial and annual plant growth, and atmospheric deposition of nitrogen. At the close of the initial grant period, the CAP LTER assumed responsibility for the project, renamed the Desert Fertilization Experiment, which provides a remarkable platform to study the long-term effects of nutrient enrichment on ecosystem properties. This data set features the composition of annual plants in subplots at project study sites assessed in spring 2008. These data are published independently of surveys of annual plants in subsequent years owing to slightly differnet methods employed in 2008 relative to other years. Investigators interested in annual plants composition data from other years, or for other Desert Fertilization Experiment data, should search the data repository for 'desert fertilization experiment'.
Root biomass data: Natural Enemies, Plant Diversity and Plant Community Composition
The purpose of this experiment is to determine the influences of natural enemies, including plant pathogenic fungi and insect pests, influence plant community composition, productivity, and diversity over time. The experiment is being conducted in a subset of plots within the Big Biodiversity field, including monoculture, 2-species, 4-species, 8-species, 16-species, and 32-species plots. There are 5 different treatments: foliar fungicide, soil drench fungicide, foliar insecticide, the combination of all pesticides, and nontreated control. The pesticides are applied repeatedly throughout the growing season. Within the plots, community productivity, species composition, percent cover, and pest damage are being quantified over time.
Streptomyces pathogen suppressive activity in plant communities varying in diversity:Plant host and plant diversity effects on rhizosphere microbial community composition, diversity, structure, and function.
Effects of plant host and plant community diversity on soil rhizosphere microbial community composition, diversity, structure, and function were explored in long-term experimental plots. Soil samples were collected from the rhizosphere of one of 4 target plants species (Andropogon gerardii, Schizachyrium scoparium, Lespedeza capitata, or Lupinus perennis) growing in 1, 4, 8, 16, or 32-species plots. Pathogen-suppressive activities of soil streptomycetes were determined for every sample. In addition, soil metagenomic analyses were performed targeting bacterial or streptomycete communities. Soil edaphic characteristics were determined for every sample. Analyses consider both the effects of plant host and plant community diversity on microbial community structure and function, and the relationships of diverse taxa with plant host, plant community diversity, and soil edaphic characteristics.
Leaf carbon, nitrogen and phosphorus:Natural Enemies, Plant Diversity and Plant Community Composition
The purpose of this experiment is to determine the influences of natural enemies, including plant pathogenic fungi and insect pests, influence plant community composition, productivity, and diversity over time. The experiment is being conducted in a subset of plots within the Big Biodiversity field, including monoculture, 2-species, 4-species, 8-species, 16-species, and 32-species plots. There are 5 different treatments: foliar fungicide, soil drench fungicide, foliar insecticide, the combination of all pesticides, and nontreated control. The pesticides are applied repeatedly throughout the growing season. Within the plots, community productivity, species composition, percent cover, and pest damage are being quantified over time.
Multispectral Radiometry percent reflectance:Natural Enemies, Plant Diversity and Plant Community Composition
The purpose of this experiment is to determine the influences of natural enemies, including plant pathogenic fungi and insect pests, influence plant community composition, productivity, and diversity over time. The experiment is being conducted in a subset of plots within the Big Biodiversity field, including monoculture, 2-species, 4-species, 8-species, 16-species, and 32-species plots. There are 5 different treatments: foliar fungicide, soil drench fungicide, foliar insecticide, the combination of all pesticides, and nontreated control. The pesticides are applied repeatedly throughout the growing season. Within the plots, community productivity, species composition, percent cover, and pest damage are being quantified over time.
Greenhouse test of pesticide effects on plant growth:Natural Enemies, Plant Diversity and Plant Community Composition
The purpose of this experiment is to determine the influences of natural enemies, including plant pathogenic fungi and insect pests, influence plant community composition, productivity, and diversity over time. The experiment is being conducted in a subset of plots within the Big Biodiversity field, including monoculture, 2-species, 4-species, 8-species, 16-species, and 32-species plots. There are 5 different treatments: foliar fungicide, soil drench fungicide, foliar insecticide, the combination of all pesticides, and nontreated control. The pesticides are applied repeatedly throughout the growing season. Within the plots, community productivity, species composition, percent cover, and pest damage are being quantified over time.
TeRaCON eight years data - species composition, productivity (NPP), soil carbon emissions and plant carbon stocks:BioCON: Biodiversity, CO2, and Nitrogen
BioCON (Biodiversity, CO2, and Nitrogen) is an ecological experiment started in 1997 at the University of Minnesota's Cedar Creek Ecosystem Science Reserve. BioCON's goal is to explore the ways in which plant communities will respond to three environmental changes that are known to be occurring on a global scale: increasing nitrogen deposition, increasing atmospheric CO2, and decreasing biodiversity. Why Biodiversity, CO2, and Nitrogen? While there are many uncertainties in global change biology, there are also some well documented facts. Some of these are: 1. The amount of carbon dioxide (CO2) in the atmosphere is rising. Since the industrial revolution, the CO2 concentration in the atmosphere has increased from approximately 275 parts per million (ppm) to about 378 ppm today. This has been largely the result of fossil fuel burning. It is expected that CO2 levels will continue to rise, and that by the year 2050 these levels will be approximately 550 ppm. CO2 is the raw material for photosynthesis and is known to affect plant growth and development. 2. The amount of nitrogen moving through terrestrial ecosystems has increased in the recent past. While natural "background" levels of nitrogen fixation have remained constant, human additions to the system through fertilizer production and fossil fuel use have increased dramatically. Nitrogen is a key nutrient for plant growth and plays a critical role in plant community structure and composition in many environments. 3. Biodiversity levels are falling. While the research and data are not as complete as they are for CO2 and nitrogen, data indicate that the number of species globally, is being reduced. Perhaps more important for ecosystem function, diversity levels on local to regional scales have fallen due to land use change, biotic invasion and many other drivers. While much is known about how each of these factors affects ecosystem functioning, many questions remain. There is also little data on how these issues affe
Lake water quality, chemistry and zooplankton composition for 16 lakes surrounding the Green Lakes Valley, 2016
This dataset contains water chemistry measurements made from 16 different lakes north and south of LTER site in the green lakes valley. At each visit water samples were collected for analysis of chlorophyll a and nutrient analysis and field measurements were recorded for pH, temperature, specific conductivity, dissolved oxygen (DO), % saturation, secchi depth, PAR. Secchi depth was measured using a 30cm disk to the nearest 0.25 meter and here recorded at the 0m row in the data file however it is a measurement of depth and so the units are meters. Most samples were collected between 0900 and 1300 MST. The first sampling date occurred shortly after lake had become ice free and then if the lake was at least 3 meters deep it was re-surveyed at approximately 2 week intervals. All data are collected from an inflatable raft at the point of deepest depth. All water samples were taken at the surface (0m), and the hypolimnion (about 2m above the lake sediment) using a Van Dorne sampler. Chlorophyll-a was extracted from water sample filters and absorbance was measured before and after acidification to quantify chlorophyll a concentration. Field measurements were conducted using a YSI either DO or multiple probe meter (YSI MPS 556) and a Li-Cor meter with a quantum sensor. Zooplankton samples were collected opportunistically 3 times throughout the summer, once immediately after ice-out and two more times with at least 14 days bewteen each subsequent visit. Zooplankton were sampled at the deepest location of each lake by pulling a conical net (Wisconsin net) vertically through the water column (i.e., vertical tow sample). The Wisconsin net is 0.9m long with an opening of an inner diameter of 0.2m and a mesh size of 80um. The vertical tow samples are taken from approximately 0.5 m off the lake bottom. After the net is raised and the sides rinsed, the sample is transferred to a 250 mL jar and preserved in a solution of 80% Ethanol. Jars are labeled with date (yyyy-mm-dd), time hh:
Stable isotope composition (d18O) of seawater from stations in the Palmer LTER Study Site
The west Antarctic Peninsula (WAP) is a region of marked climatic variability, exhibiting strong changes in sea ice extent, retreat of the majority of its glaciers, and shifts in the amount and form of precipitation. These changes can have significant impacts on the oceanic freshwater budget and marine biogeochemical processes; it is thus important to ascertain the relative balance of the drivers, and the spatial scales over which they operate. We present a new 7-year summer-season (October to March; 2011 to 2018) series of oxygen isotopes in seawater (δ18O), augmented with some winter sampling, collected adjacent to Anvers Island at the WAP. These data are used to attribute oceanic freshwater changes to sea ice and meteoric sources, and to deduce information on the spatial scales over which the changes are driven. Sea ice melt shows strong seasonality (~9% range) and marked interannual changes, with pronounced maxima in seasons 2013/14 and 2016/17. Both of these extrema are driven by anomalous winds, but reflect strongly contrasting dynamic and thermodynamic sea ice responses. Meteoric water also shows marked seasonality (~7% range), with interannual variability reflecting changes in the input of accumulated precipitation and glacial melt to the ocean. Unlike sea ice melt, meteoric water extremes are especially pronounced in thin (<10m) surface layers close to Marr Ice Piedmont, associated with enhanced ocean stratification. Isotopic tracers help to deconvolve the complex spatio-temporal scales inherent in the coastal freshwater budget, and hence improve knowledge of the separate and cumulative physical and ecological impacts.
Chemical composition of precipitation at the Virginia Coast Reserve 1990-2015
This data set characterizes the chemical composition of precipitation sampled weekly on the Virginia eastern shore in collaboration with the VCR LTER. The early portion of the record corresponds to precipitation sampled adjactent to the meteorological station on Hog Island. The latter portion of the record corresponds to precipitation sampled at the GATR site on the Eastern Shore Wildlife Refuge. Samples were analyzed at the University of Virginia using procedures similar to those employed by the Global Precipitation Chemistry Project (GPCP), Western Atlantic Ocean Experiment (WATOX), and the Atmosphere Ocean Chemistry Experiment (AEROCE). Following extensive damage to the collection system by Hurricane Isabel in Sept. 2003, the unit was moved to the property of the Anheuser Busch Coastal Research Center in Oyster, VA. Data collection was terminated on 12/30/2015.
Settlement-Era Tree Composition, Eastern US: Level 1
Witness tree counts within town/township polygons were tallied from early land survey records of town outlines and lotting subdivisions. Overall dates ranged from 1623 to 1870, but varied by town and were recorded about the time of first settlement of the town. A myriad of archived sources were tapped from town, state and national repositories, historical societies and private collections. The SetTreeComp_Northeast_Level1_v1.0 database includes records throughout the domain collated by Charles Cogbill, and include contributions from southern New England by John Burk, from the Catskills, New York by Robert McIntosh, and from the Finger Lakes, New York by Peter Marks. Every effort was used to avoid duplication of trees. The taxa classes were generally genera or unambiguous categories based on the vernacular names used by the surveyors. In several cases (black gum/sweet gum, ironwood, poplar/tulip poplar, cedar/juniper), because of ambiguity in the common tree names used by surveyors, a group represents trees from different families and even orders. This material is based upon work supported by the National Science Foundation under grants #DEB-1241874, 1241868, 1241870, 1241851, 1241891, 1241846, 1241856, 1241930.
Settlement-Era Tree Composition, Ohio: Level 1
Ohio Township Surveys (OTS) provide spatially aggregated witness tree counts within the town/township polygons that were tallied from early land survey records of town outlines and lotting subdivisions. Overall dates ranged from 1623 to 1870, but varied by town and were recorded about the time of first settlement of the town. A myriad of archived sources were tapped from town, state and national repositories, historical societies and private collections. The SetTreeComp_Ohio_Level1_v1.0 database includes records throughout the domain from the Connecticut Western Reserve at the Connecticut State Archives and various records in the Ohio State Archives collated by Charles Cogbill, the collections of the Ohio Biological Survey through the efforts of Ronald Stuckey and the McLachlan lab at Notre Dame University, and records of the Ohio Land Company by James Dyer and the Marietta College Archives. Every effort was used to avoid duplication of trees. The taxa classes were generally genera or unambiguous categories based on the vernacular names used by the surveyors. In several cases (black gum/sweet gum, ironwood, poplar/tulip poplar, cedar/juniper), because of ambiguity in the common tree names used by surveyors, a group represents trees from different families and even orders. This material is based upon work supported by the National Science Foundation under grants #DEB-1241874, 1241868, 1241870, 1241851, 1241891, 1241846, 1241856, 1241930.
PLSS Composition by Taxa, Upper Midwest: Level 1
EuroAmerican land use and its legacies have transformed forest structure and composition across the United States (US). More accurate reconstructions of historical states are critical to understanding the processes governing past, current, and future forest dynamics. Gridded (8x8km) estimates of pre-settlement (1800s) forests from the upper Midwestern US (Minnesota, Wisconsin, and most of Michigan) using 19th Century Public Land Survey System (PLSS) records provide relative composition, biomass, stem density, and basal area for 26 tree genera. This mapping is more robust than past efforts, using spatially varying correction factors to accommodate sampling design, azimuthal censoring, and biases in tree selection. We compare pre-settlement to modern forests using US Forest Service Forest Inventory and Analysis (FIA) data to show the prevalence of lost forests, pre-settlement forests with no current analogue, and novel forests, modern forests with no past analogs. Differences between PLSS and FIA forests are spatially structured as a result of differences in the underlying ecology and land use impacts in the Upper Midwestern United States. Modern biomass is higher than pre-settlement biomass in northern Minnesota, northwestern and south central Wisconsin along the former prairie-forest border through Minnesota that was largely open savanna and the Big Woods of Minnesota. PLSS biomass was higher than today in northern Wisconsin and upper and lower Michigan due to shifts in species composition and, presumably, average stand age. Modern forests are more homogeneous, and ecotonal gradients are more diffuse today than in the past. Novel forest assemblages represent 29% of all FIA cells, while 25% of pre-settlement forests no longer exist in a modern context. Lost forests are centered around the forests of the Tension Zone, particularly in hemlock dominated forests of north-central Wisconsin, and in oak-elm-basswood forests along the forest-prairie boundary in south central
Video of 1/1-45° braided composite tube tested under torsion on Instron 8802
<p>Supplementary data for article</p> <p>Chai, Yuan, Ying Wang, Zeshan Yousaf, Nghia T. Vo, Tristan Lowe, Prasad Potluri, and Philip J. Withers. "Damage evolution in braided composite tubes under torsion studied by in-situ X-ray computed tomography." <em>Composites Science and Technology</em> (2019): 107976.</p> <p><a href="https://doi.org/10.1016/j.compscitech.2019.107976">https://doi.org/10.1016/j.compscitech.2019.107976</a></p>
Figure 5 in Species composition of the orb-weaving families Araneidae and Tetragnathidae (Araneae: Araneoidea) in natural habitats in Trinidadı West Indies
Figure 5. Dendrogram of cluster analysis done on natural habitats according to site sampled for the period March 2006 to May 2009.
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These curated guides explain access requirements, typical timelines, costs, and reuse considerations for widely used research datasets.
Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.