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6,175 results for “composition”
Long-term composited and land cover-adjusted Enhanced Normalized Difference Impervious Surface Index (ENDISI) for the greater Phoenix, Arizona, USA, metropolitan area and the surrounding Sonoran desert derived from annual and seasonal Landsat imagery, 1998 to 2020
This data package consists of multiple decades of Enhanced Normalized Difference Impervious Surface Index (ENDISI) raster data across the Central Arizona-Phoenix Long-Term Ecological Research (CAP LTER) study area within metropolitan Phoenix, Arizona, USA, temporally aggregated by year and by four meteorological seasons (winter, spring, summer, fall). To serve as a proxy measurement of impervious surface and urbanization across years and seasons, we derived values of ENDISI – following the methods of Chen et al. 2019 from annual and seasonal composites of 30-m resolution Landsat 5-9 Level-2 Surface Reflectance imagery. Next, we corrected the underestimated ENDISI values of dark impervious surface cover and the overestimated ENDISI values of bright bare soils based on visible Landsat bands and 2020 land cover (Sabu et al. 2023). Finally, we exported images as individual GeoTIFF raster files, each with five bands corresponding values summarized annually (band 1) and seasonally (bands 2-5). All imagery retrieval and data processing were completed with Google Earth Engine (Gorelick et al. 2017) and program R. A complete description of data processing methods, including the aggregation of imagery by year and season and the calculation of the spectral index, can be found in the data package metadata (see 'Methods and Protocols') and accompanying Javascript code. ### citations - Gorelick N, Hancher M, Dixon M, et al. (2017) Google Earth Engine: Planetary-scale geospatial analysis for everyone. Remote Sensing of Environment 202:18–27. https://doi.org/10.1016/j.rse.2017.06.031 - Sabu, S., Frazier, A., & Rashid, B. (2023). Land use and land cover (LULC) classification of the CAP LTER study area (central Arizona, USA) using Landsat imagery: 2015 and 2020 [Dataset]. Environmental Data Initiative. https://doi.org/10.6073/PASTA/BF18E5856215BD2D4DAB3B024BA87A7E
Long-term composited Enhanced Normalized Difference Impervious Surface Index (ENDISI) for the greater Phoenix, Arizona, USA, metropolitan area and the surrounding Sonoran desert derived from annual and seasonal Landsat imagery, 1998 to 2023
This data package consists of multiple decades of Enhanced Normalized Difference Impervious Surface Index (ENDISI) raster data across the Central Arizona-Phoenix Long-Term Ecological Research (CAP LTER) study area within metropolitan Phoenix, Arizona, USA, temporally aggregated by year and by four meteorological seasons (winter, spring, summer, fall). To serve as a proxy measurement of impervious surface and urbanization across years and seasons, we derived values of ENDISI – following the methods of Chen et al. 2019 – from annual and seasonal composites of 30-m resolution Landsat 5-9 Level-2 Surface Reflectance imagery. Finally, we exported images as individual GeoTIFF raster files, each with five bands corresponding values summarized annually (band 1) and seasonally (bands 2-5). All imagery retrieval and data processing were completed with Google Earth Engine (Gorelick et al. 2017) and program R. A complete description of data processing methods, including the aggregation of imagery by year and season and the calculation of the spectral index, can be found in the data package metadata (see 'Methods and Protocols') and accompanying Javascript code. ### citations - Gorelick N, Hancher M, Dixon M, et al. (2017) Google Earth Engine: Planetary-scale geospatial analysis for everyone. Remote Sensing of Environment 202:18–27. https://doi.org/10.1016/j.rse.2017.06.031
Carbon and nitrogen content and stable isotope compositions from biota samples from lagoon sites along the Alaska Beaufort Sea coast, 2018-ongoing
Stable isotopic composition can be used to differentiate between predominantly marine and terrestrial food sources in nearshore marine food webs. The Beaufort Lagoon Ecosystems LTER (BLE LTER) Core Program employs spatial and temporal sampling regimes to track shifts in diet, both seasonally (ice cover, ice break-up, and open water), and spatially among lagoons along the Alaskan Beaufort Sea coast. Ice coring, net tows, ponar grabs, and trawls are employed to collect organisms associated with the sea-ice interface, the water column, and the benthos respectively. Tissues are analyzed for stable isotopic composition as well as organic carbon and nitrogen content.
Long-term composited Normalized Difference Vegetation Index (NDVI) for the greater Phoenix, Arizona, USA, metropolitan area and the surrounding Sonoran desert derived from annual and seasonal Landsat imagery, 1998 to 2023
### overview This data package consists of multiple decades of normalized difference vegetation index (NDVI) raster data across the Central Arizona-Phoenix Long-Term Ecological Research (CAP LTER) study area within metropolitan Phoenix, Arizona (USA), temporally aggregated by year and by four meteorological seasons (Winter, Spring, Summer, Fall). To serve as a proxy measurement of vegetation greenness and productivity across years and seasons, NDVI was derived from annual and seasonal composites of 30-m resolution Landsat 5-9 Level-2 Surface Reflectance imagery. All imagery retrieval and data processing were completed with Google Earth Engine (Gorelick et al. 2017) and program R. A complete description of data processing methods, including the aggregation of imagery by year and season and the calculation of the spectral index, can be found in the data package metadata (see 'Methods and Protocols') and accompanying Javascript code. ### citations - Gorelick N, Hancher M, Dixon M, et al. (2017) Google Earth Engine: Planetary-scale geospatial analysis for everyone. Remote Sensing of Environment 202:18–27. https://doi.org/10.1016/j.rse.2017.06.031
Plant species composition in black sand extended growing season experiment, 2018 - 2023.
As a result of climate change, the Rocky Mountain Front Range is experiencing warmer summers and earlier snowmelt. Due to the importance of snow for regulating soil temperature, growing season length, and available moisture in alpine ecosystems, even small shifts in the snow-free period could have large impacts. The focus of the Black Sand Extended Growing Season Length Experiment is to examine how terrain-related differences in climate exposure influence the way alpine habitats respond to climate change via earlier snowmelt. To simulate how climate exposure may affect plant communities, NWT LTER researchers established 5 experimental sites each containing a pair 10 x 40m rectangular plots. These sites include north and south facing aspects, subalpine and alpine tundra meadows in a range of hydrological conditions (e.g. dry meadows, moist meadows, wet meadows). We accelerated snowmelt in one plot of each block by adding chemically inert black sand, while keeping the second plot as an unmanipulated control; black sand was added to these plots after snow had naturally melted. This dataset includes measurements of plant species composition.
Zooplankton and macroinvertebrate size spectra, biomass, and community composition; and harvest of bigmouth buffalo and common carp in six shallow lakes in Iowa, USA (2018-2020)
This data product contains biological data collected within six shallow lakes in Iowa, USA between 2018 - 2020, where four lakes were undergoing targeted removals of common carp (Cyprinus carpio) and bigmouth buffalo (Ictiobus cyprinellus). Parts of these data were a portion of Albright et al. 2022 (https://doi.org/10.6073/pasta/1d3797fd573208bae6f78963479445a0), however the data herein include additional survey data from the Ambient Lake Monitoring network instituted through Iowa State University and the Iowa Department of Natural Resources (https://www.iowadnr.gov/environmental-protection/water-quality/water-monitoring/ambient-lake-monitoring#ambient-lake-monitoring-sampling-plan). Data are packaged and formatted specifically for size spectra analysis and compositional analysis.
Carbon and nitrogen content and stable isotope compositions from particulate organic matter samples from lagoon, river, and open ocean sites along the Alaska Beaufort Sea coast, 2018-ongoing
Multiple water types (river, lagoon, ocean) from the North Slope of Alaska and nearshore Beaufort Sea are sampled seasonally by the Beaufort Lagoon Ecosystems LTER (BLE LTER) Core Program to investigate biogeochemical linkages between terrestrial, lagoon, and open ocean ecosystems. Water samples are collected during full ice cover (April), ice break-up (mid-June to early July), and open water (late July and August) periods, and analyzed for particulate organic carbon (POC) and particulate organic nitrogen (PON) content and stable isotopic composition.
Carbon and nitrogen content and stable isotope composition from sediment organic matter from lagoon sites along the Alaska Beaufort Sea coast, 2018-ongoing
Multiple sediment samples from lagoons along the nearshore Beaufort Sea are sampled seasonally by the Beaufort Lagoon Ecosystems LTER (BLE LTER) Core Program to investigate biogeochemical linkages between terrestrial, lagoon, and open ocean ecosystems. Sediment samples are collected during full ice cover (April), ice break-up (mid-June to early July), and open water (late July and August) periods, and analyzed for carbon and nitrogen content and stable isotopic composition.
Composition and biodegradability of dissolved organic matter in supra-permafrost groundwater and surface waters near Simpson Lagoon, Alaska
Supra-permafrost groundwater (SPGW) is an important source of terrestrial dissolved organic matter (DOM) to the Arctic Ocean, yet few studies have investigated the quality or characteristics of this DOM. We sampled fresh SPGW, run-off, and rivers near Simpson Lagoon, Alaska during spring ice break-up (mid-June), summer open water (late July), and fall freeze-up (late September - early October). We measured dissolved organic carbon (DOC) concentrations in these samples and analyzed the composition of DOM using high-resolution mass spectrometry (Fourier transform ion cyclotron resonance mass spectrometry; FT-ICR MS). To measure biodegradable dissolved organic carbon (BDOC), we conducted an aerobic incubation experiment following the methods suggested by Vonk et al. (2015). Briefly, water samples were incubated at 20C for 28 days to measure DOC loss due to remineralization by in-situ microbial communities.
Ramped Pyrolysis Oxidation (RPO) coupled radiocarbon (14C-DOC) and stable carbon (13C-DOC), high-resolution molecular composition (FT-ICR MS), and biodegradable dissolved organic carbon (BDOC) of groundwater, river water, and lagoon water in northeast Alaska, 2017
Supra-permafrost groundwater (SPGW), river water, and lagoon water were sampled near Kaktovik, AK to assess the reactivity and origin of dissolved organic matter (DOM) across interconnected hydrologic systems during late summer. Water samples were collected on August 17th 2017 from SPGW along the beach of Jago Lagoon (Jago GW), surface water from the Jago River’s main channel above tidal influence (Jago R), and from the water column of Kaktovik Lagoon at 2–3 m depth (KA LW). Measurements were made from grab samples for river and lagoon water, and from a composite sample for SPGW gathered from 10 individual shoreline locations. Data include dissolved organic carbon concentration (DOC, mg C L-1), Ramped Pyrolysis Oxidation (RPO) derived fraction compositions of 13C-DOC (δ13C ‰), 14C-DOC (in fraction modern), and method/instrumental error in the 14C and 13C results, and Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) molecular composition and summarized compound classes. Biodegradable DOC (BDOC) bottle experiments were performed using all three sample types, where DOC concentration was subsequently measured at 2, 7, 14, and 28 days. FT-ICR MS composition was subsequently measured at the 28-day timepoint to track changes in molecular formulae and compound class relative abundance following biodegradation. Data from RPO serial thermal oxidation include temperature and normalized CO2 profiles for each background sample. Thermal-oxidation profiles of CO2 were transformed into non-parametric activation energy (E) distributions using an inverse model. Model output includes C mass of oxidized CO2 (µg C), Tmax (K), Emax (kJ mol-1), Emean (kJ mol-1), Estd (kJ mol-1), and p(0,E)max of user-defined sample fractions. FT-ICR MS results include a summary table of the relative abundance of compound classes (e.g., unsaturated phenolic, polyphenolic, aliphatic, condensed aromatics, peptide-like) and elemental groupings (e.g., CHO-type, CHON-type, CHOS-type, CHON
Long-term composited land surface temperature for the greater Phoenix, Arizona, USA, metropolitan area and the surrounding Sonoran desert derived from annual and seasonal Landsat imagery, 1998 to 2023
This data package consists of multiple decades of land surface temperature (LST) raster data across the Central Arizona-Phoenix Long-Term Ecological Research (CAP LTER) study area within metropolitan Phoenix, Arizona (USA), temporally aggregated by year and by four meteorological seasons (Winter, Spring, Summer, Fall). We derived LST values based on the thermal band from annual and seasonal composites of 30-m resolution Landsat 5-9 Level-2 Surface Reflectance imagery. All imagery retrieval and data processing were completed with Google Earth Engine (Gorelick et al. 2017) and program R. A complete description of data processing methods, including the aggregation of imagery by year and season and the calculation of the spectral index, can be found in the data package metadata (see 'Methods and Protocols') and accompanying Javascript code. ### citations: - Gorelick N, Hancher M, Dixon M, et al. (2017) Google Earth Engine: Planetary-scale geospatial analysis for everyone. Remote Sensing of Environment 202:18–27. https://doi.org/10.1016/j.rse.2017.06.031
Ant Diversity and Vegetation Composition in Hemlock Removal Experiment at Harvard Forest 2006
Ants comprise a considerable amount of animal biomass in terrestrial ecosystems and play major roles in ecological processes ranging from seed dispersal to soil turnover. Invasion by the hemlock woolly adelgid will transform late-successional hemlock forests into earlier successional mixed hardwood-white pine forests or red-maple wetlands. Understanding how ant assemblages vary in different habitat types allows for predictions of how hemlock decline could alter the composition of ant assemblages, with implications for a wide range of ecosystem processes. An ongoing study at the Simes Tract of Harvard Forest is documenting the effects of invasion and land-use history on ant biodiversity. Surveys from 2003 to 2005 focused on ant structure in hemlock and hardwood microhabitats in the Harvard Forest Hemlock Removal Experiment, in which hemlock forest response to deforestation by the hemlock woolly adelgid (Adelges tsugae) and to selective logging is being examined (Ellison et al. 2005). In the summer of 2006, we surveyed a greater range of microhabitat types with two objectives. First, to collect rare or elusive species in hemlock and hardwood stands that may have gone uncollected in previous years. Second, to sample forest communities not included in previous years - white pine, swamp, and rocky slope - for ant species unique to these microhabitats. We found fourteen newly documented species of ants in the Simes Tract - nine of which were in an open, swamp. Aphaenogaster rudis and Camponotus pennsylvanicus were the only ant species found in all microhabitat types. In a canonical correspondence analysis, A. rudis and C. pennsylvanicus were associated most strongly with hemlock stands and low species richness of understory plants.
Herbaceous Community Composition in CRUI Land Use Project at Harvard Forest 1996
Patterns of vascular plant species richness were investigated in six land use legacy sites (2 formerly plowed, 2 formerly pastured, and 2 permanent woodlot) in Prospect Hill to test predictions about the effects of disturbance, light and soil resources, and forest floor environmental heterogeneity on community composition. The occurrence of vascular taxa was recorded in each of the 60 5 m x 5 m contiguous plots within the 30 m x 50 m permanently gridded study plot in each land use legacy site in June 1996. Identification was made to species in most cases. Woodlots showed higher average species richness at the site level (53) than either pastured (52 species) or plowed (49) sites. However woodlots also show greater spatial variation in richness at the 5 m x 5 m resolution than either the plowed or pastured sites (in that order) as represented by the range, standard deviation, and coefficient of variation. Seasonally-averaged light levels at 50 cm are approximately twice as high in the plowed and pastured sites as in the woodlots, but the woodlots show significantly greater soil organic matter, carbon, nitrogen and water-holding capacity than the post-agricultural sites. These results suggest that soil resources may be more important than light in fostering higher herbaceous stratum richness. However, woodlot richness is also affected by the presence of taxa that are slow to re-colonize heavily disturbed sites (e.g., Epigaea repens) and to distinctive microsites that are less common in the plowed or pastured sites in the Harvard Forest system (e.g., exposed boulders). The greater spatial variation in woodlot richness is strongly influenced by both substrate diversity and by scattered hemlock trees, which substantially depress the herb stratum in localized patches.
Isotopic Composition of Net Ecosystem CO2 Exchange at Harvard Forest EMS Tower since 2011
This archive features long-term measurements of the eddy and storage fluxes of 16O12C16O, 16O13C16O, and 18O12C16O at the Harvard Forest EMS flux tower. Provided are the individual isotopologue fluxes, the total CO2 flux, the δ13C and δ18O isofluxes, and various ancillary flux and environmental data. The data are described in Wehr et al (2013), Long-term eddy covariance measurements of the isotopic composition of the ecosystem–atmosphere exchange of CO2 in a temperate forest, Agricultural and Forest Meteorology 181, 69–84. They are also analyzed in Wehr and Saleska (2015), An improved isotopic method for partitioning net ecosystem–atmosphere CO2 exchange, Agricultural and Forest Meteorology 214-215, 515–531, as well as in Wehr et al 2016, Seasonality of Temperate Forest Photosynthesis and Daytime Respiration, Nature (in press). The eddy (iso)fluxes were measured by eddy covariance (EC), with a 30- or 35-minute integration period on a 40- or 45-minute duty cycle (the precise duty cycle was changed during the record to accommodate various synergistic measurement campaigns). The storage fluxes were measured as the increase in storage below 29 m during the EC integration period, based on vertical integrations over 7 air sampling heights on the tower (0.2, 1.0, 7.5, 12.7, 18.1, 24.1, 29.0 m, prior to July 3, 2012), or over 6 air sampling heights on the tower (0.2, 1.0, 7.5, 12.7, 18.1, 29.0 m, after July 3, 2012). Some periods are missing at regular intervals because the system was being used for other measurements, not reported here. Corrected and uncorrected versions of the eddy (iso)fluxes are provided; the corrections account for high-frequency signal attenuation, and were made by comparing w-CO2 and w-T cospectra. The precise method is novel and complex and is described, along with all further details of the measurements, in Wehr et al (2013), Long-term eddy covariance measurements of the isotopic composition of the ecosystem–atmosphere exchange of CO2 in a temperat
Physical soil characteristics, microbial community composition, extracellular enzymatic activity, biologically based phosphorus (BBP) pools, and available phosphorus from two soil depths, four microhabitats, and four landforms at the Jornada Experimental Range, 2021.
This dataset contains physical soil characteristics, PLFA based microbial community composition, extracellular enzymatic activity, nitrate and ammonium activity, and phosphorus availability in various phosphorus pools (Biologically Based Phosphorus, potassium sulfate, Olsen-P). Soils were collected from two depths (0-2cm, 2-30 cm), four microhabitats (grass, shrub, biocrust, interspace), and four landforms (alluvial flat, alluvial fan remnant, erosional scarplet, fan piedmont – see coordinates) within the Jornada Experimental Range in July 2021 to answer questions about how these variables change across these spatial scales in drylands. This project was a collaboration between researchers at New Mexico State University and The University of Texas at El Paso as part of the Drylands Critical Zone Thematic Cluster within the Critical Zone Network. This dataset is complete.
Lake Mendota, Wisconsin, USA, Phytobenthos Abundance and Community Composition 2016-2018
We sampled the phytobenthos (epibenthic periphyton) of Lake Mendota from 2016-2018 to track impacts of invasive zebra mussels (Dreissena polymorpha) which were discovered in Lake Mendota in 2015 and grew exponentially to densities greater than 10,000 m-2 in shallow, rocky habitat by 2018. We sampled along three transects inherited from Karatayev et al. (2013) at five different depths (1, 3, 5, 8, and 10 m) twice a summer (June and August) from 2016-2018. A pared-down version of this routine sampling continued from 2019 onward but is not included here. This dataset complements zebra mussel and zoobenthos data collected according to the same routine sampling structure, for which data is also archived with EDI.
Lake Mendota, Wisconsin, USA, (Non-Dreissenid) Benthic Macroinvertebrate Abundance, Biomass, and Community Composition 2016-2018
We sampled the zoobenthos (macroinvertebrates of the benthos) of Lake Mendota from 2016-2018 to track impacts of invasive zebra mussels (Dreissena polymorpha) which were discovered in Lake Mendota in 2015 and grew exponentially to densities greater than 10,000 m-2 in shallow, rocky habitat by 2018. The data presented here exclude all zebra mussels, which are archived in a separate datset. We sampled along three transects inherited from Karatayev et al. (2013) at five different depths (1, 3, 5, 8, and 10 m) twice a summer (June and August) from 2016-2018. These data also contain some samples opportunistically taken from deeper depths along these transects that do not follow the routine sampling structure. A pared-down version of this routine sampling continued from 2019 onward but is not included here. This dataset complements zebra mussel and phytobenthos data collected according to the same routine sampling structure, for which data is also archived with EDI.
Snowbed experiment species composition and hobo data for Niwot Ridge, 2012 - ongoing.
Niwot Ridge climate records indicate a trend of warmer spring and summer temperatures and earlier timing of snowmelt. In alpine tundra plant communities where snow cover limits growing season length, the current climatic trend is conducive to a longer growing season. The snowbed experiment was established in order to monitor changes in plant cover and community composition in the alpine tundra in response to extended summer growing season conditions. Of particular interest are late-melting snowbed areas where plant colonization and survival are most restricted or entirely prevented by a limited number of snow-free days with the sunlight and temperature necessary for plant establishment and growth. In 2012, fifteen 1 x 1 m plots were established at 5 sites where there are persistent, late-melting snowbeds. Plots were placed along (1) an elevation gradient and (2) a snow-cover gradient from persistent snowbeds, where snowpack is greatest and melt-out dates latest in the season, to wind-scoured dry meadows, where snow pack is least and melt-out dates earliest. In 2015 the one site was dropped from the experiment because the snowbed there was quite different from the other four.
Turf Transplant species composition, 2024 - ongoing.
The Turf Transplant Experiment was set up in the summer of 2024. Paired experimental sites were established in two tundra community types - dry meadow and moist meadow - with one site of each community type pair in a lower elevation/warmer area and one site in a higher elevation/cooler area. Subplot turfs (25 cm^2) were transplanted (1) between sites of the same community type at different elevations/temperatures, (2) between plots within the same site or (3) left in place as non-transplant controls. Plant species composition was measured once per year at approximately peak flowering.
Seawater chromium concentrations and isotope compositions in the Southern Ocean during the austral summer of 2016/2017, on board the Antarctic Circumnavigation Expedition (ACE).
<p><strong>Dataset abstract</strong></p> <p>Dissolved seawater chromium (Cr) concentrations and stable isotope compositions measured on samples collected with a trace metal clean rosette system in the Southern Ocean. Stations TM 7 to TM 12 reflect a north-south transect from Hobart, Tasmania to Mertz Glacier in Antarctica. Stations TM 14 and TM 15 neighbour the Balleny Islands. Stations TM 18 and TM 20 are located in the Drake Passage. Water samples were collected down to a depth of 1000 metres. The water was filtered in a class 100 clean container aboard the ship through pre-rinsed Supor Acropak capsule filters (0.2 um). Subsequently the samples were acidified and stored at a pH < 2 for several months prior to analysis. Reported values therefore represent bulk seawater chromium (Cr III and Cr VI). The data was obtained using the double-spike technique.</p> <p><strong>Dataset contents</strong></p> <ul> <li>ace_chromium_isotope_concentration.csv, data file, comma-separated values</li> <li>data_file_header.txt, metadata, text format</li> <li>README.txt, metadata, text format</li> </ul> <p><strong>Dataset license</strong></p> <p>This chromium concentration and isotope composition dataset is made available under the Creative Commons Attribution 4.0 International License (CC BY 4.0) whose full text can be found at <a href="https://creativecommons.org/licenses/by/4.0/">https://creativecommons.org/licenses/by/4.0/</a></p>
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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.