Find research datasets worth reusing
Search datasets from major research repositories and use ShareScore to quickly assess how well each record supports discovery, access, and reuse.
257
datasets available to search
ShareScore release 0.9.0
Dataset results
257 results for “composition changes”
Biomarker assessment of spatial and temporal changes in the composition of flocculent material (floc) in the subtropical wetland of the Florida Coastal Everglades (FCE) from May 2007 to December 2009
Flocculent material (floc) is an important energy source in wetlands. In the Florida Everglades, floc is present in both freshwater marshes and coastal environments and plays a key role in food webs and nutrient cycling. However, not much is known about its environmental dynamics, in particular its biological sources and bio-reactivity. We analysed floc samples collected from different environments in the Florida Everglades and applied biomarkers and pigment chemotaxonomy to identify spatial and seasonal differences in organic matter sources. An attempt was made to link floc composition with algal and plant productivity. Spatial differences were observed between freshwater marsh and estuarine floc. Freshwater floc receives organic matter inputs from local periphyton mats, as indicated by microbial biomarkers and chlorophyll-a estimates. At the estuarine sites, the floc is dominated by mangrove as well as diatom inputs from the marine end-member. The hydroperiod (duration and depth of inundation) at the freshwater sites influences floc organic matter preservation, where the floc at the short-hydroperiod site is more oxidised likely due to periodic dry-down conditions. Seasonal differences in floc composition were not consistent and the few that were observed are likely linked to the primary productivity of the dominant biomass (periphyton in the freshwater marshes and mangroves in the estuarine zone). Molecular evidence for hydrological transport of floc material from the freshwater marshes to the coastal fringe was also observed. With the on-going restoration of the Florida Everglades, it is important to gain a better understanding of the biogeochemical dynamics of floc, including its sources, transformations and reactivity.
DOM composition changes in Altamaha River and Sapelo Sound estuaries measured by FT-ICR mass spectrometry from September 2015 to September 2016
Dissolved organic matter (DOM) is a large and complex mixture of compounds with source inputs that differ with location, season and environmental conditions. Here, we investigated drivers of DOM composition changes in a marsh-dominated estuary off the southeastern U.S. Monthly water samples were collected at a riverine and estuarine site from September 2015 to September 2016, and bulk, optical, and molecular analyses were conducted on samples before and after dark incubations. Results showed that river discharge was the primary driver changing the DOM composition at the mouth of the Altamaha River. For discharge higher than ~ 150 m3 s-1, DOC concentrations and the terrigenous character of the DOM increased approximately linearly with river flow. For low discharge conditions, a clear signature of salt marsh-derived compounds was observed in the river. At the head of Sapelo Sound, changes in DOM composition were primarily driven by river discharge and possibly by summer algae blooms. Microbial consumption of DOC was larger during periods of high discharge at both sites, potentially due to the higher mobilization and influx of fresh material to the system. The Georgia coast was hit by Hurricane Matthew in October 2016, which resulted in a large input of carbon to the estuary. The DOC concentration was ~ 2 times higher and DOM composition was more aromatic with a stronger terrigenous signature compared to the seasonal maximum observed earlier in the year during peak river discharge conditions. This suggests that extreme events notably impact DOM quantity and quality in estuarine regions.
The effects of changing vegetative composition on the abundance, species diversity and activity of birds at the Jornada Basin LTER site, 1997
This data package contains bird abundance data collected in plots that have had various plant functional groups or species experimentally removed at the Jornada Basin LTER site in southern New Mexico, USA. This data was collected in an effort to distinguish the differential effects of plant community biomass, plant community functional groups, and biodiversity within functional groups on plant community function, including effects on animals. To make these distinctions, treatments were established by the selective removal of plant species or functional groups within experimental plots. There are eight treatments: control (C, no removals); four functional group removal treatments (PG, perennial grass removed; S, shrubs removed; SSh, subshrubs removed; Succ, succulents removed), and three species richness manipulation treatments. Richness manipulations included a simplified treatment (Simp), where only the single most abundant species of each growth form is preserved and all other species in the growth form are removed, a reduced‐Larrea treatment (rL), where the Larrea is assumed to be the dominant and is removed while minority components remain, and a reduced-Prosopsis treatment (rP), where Prosopis rather than Larrea is removed as the shrub dominant. Following treatments, bird abundance and habitat preference data was collected in 1997. This data set consists of plot number, treatment type, and time of bird presence by taxa and by habitat and behavior. This study is complete.
NGE01 Chronic Addition of Nitrogen Gradient Experiment (ChANGE): Assessing threshold responses of plant community composition and ecosystem processes at Konza Prairie
Chronic nutrient additions can lead to drastic shifts in the plant community through time, both within tallgrass prairie in other grassland ecosystems worldwide. Nutrient addition experiments have answered many questions about patterns of diversity loss and community shifts; however, the level of nutrients which must be added to cause community shifts is unknown. To date, all nitrogen (N) addition experiments at Konza have added 10 g m-2 (e.g., NutNet Plots; Phosphorus (P) Plots; Belowground Plots), yet current rates of N deposition are one-tenth of that level. Even predicted rates of future N deposition in grasslands are not expected to exceed 5 g m-2 by the year 2050 and will likely be around 2 g m-2 for most of the US. This mismatch begs the question will 10 g/m2 affect grasslands the same way 2 or 5 g m-2 will? There are two main goals for this long-term experiment (1) to identify the nutrient threshold needed to drive plant community change with nutrient additions, and (2) to determine what factors underlie those threshold responses (build up of nutrients, mycorrhizal loss, invertebrate herbivory). Konza ChANGE is part of a multi-site experiment spanning grasslands on two different continents: North America – tallgrass prairie (KNZ) and shortgrass steppe (SGS), and China – three sites in Inner Mongolia. By including multiple grasslands, we expand our ability to make generalizations about how grasslands are affected by N additions, and whether thresholds, if they exist, vary with precipitation, natural nutrient availability, and species identity/composition. Research Questions: (1) Do ecosystems have N tolerance thresholds above which community composition will change, and does that differ between grassland types (i.e. mesic and xeric grasslands)? (2) Does adding a large amount of nutrients in one season result in an equivalent community change as adding a small amount over multiple years? (For example does 5 g m-2 for 6 years create the same community change as
Linking temporal changes in species composition and biomass in a globally distributed grassland experiment: The Nutrient Network
Global change drivers, such as anthropogenic nutrient inputs, are increasing globally. Nutrient deposition simultaneously alters plant biodiversity, species composition, and ecosystem processes like aboveground biomass production. These changes are underpinned by species extinction, colonization, and shifting relative abundance. Here, we use the Price equation to quantify and link the contributions of species that are lost, gained, or that persist to change in aboveground biomass in 59 experimental grassland sites. Under ambient (control) conditions, compositional and biomass turnover was high, and losses (i.e., local extinctions) were balanced by gains (i.e. colonization). Under fertilization, the decline in species richness resulted from increased species loss and from decreases in species gained. Biomass increase under fertilization resulted mostly from species that persist, and to a lesser extent from species gained. Drivers of ecological change can interact relatively independently with diversity, composition, and ecosystem processes and functions such as aboveground biomass due to the individual contributions of species lost, gained, or persisting.
Temporal and spatial changes of the abundance and species composition of phytoplankton in the California Current from samples collected aboard CalCOFI cruises from summer 1996 through 2022.
The abundances of 385 taxonomic categories of phytoplankton (species where possible) are presented for the 26.5 -year period beginning with summer, 1996 and concluding with autumn 2022. There were four cruises per year. Samples were water samples collected from the second depth, which was designed to sample the mixed layer when a mixed layer existed, generally between 5m - 15m. Before counting, samples from single stations were pooled into four regions: NE (northern inshore), SE (southern inshore), Alley (the region of the California Current) and Offshore (Central Pacific). Pooled samples were enumerated with an inverted microscope. The species data are presented by seven major taxonomic categories followed by the sums of those major taxa. The species codes are defined in the table metadata.
Data from "Grassland woody plant management rapidly changes woody vegetation persistence and abiotic habitat conditions but not herbaceous community composition"
These files contain microhabitat, soil, vegetation structure, and woody plant species data used in the paper "Grassland woody plant management rapidly changes woody vegetation persistence and abiotic habitat conditions but not herbaceous community composition". The project was conducted at seven publicly accessible remnant (i.e., unplowed or old-growth) tallgrass prairie within 100 miles of Madison, Wisconsin, United States starting in the 2020 growing season and commencing following the 2022 growing season. The goal was to assess the initial effects of different management interventions on woody vegetation persistence, abiotic habitat conditions, and herbaceous community composition, including physical and chemical management interventions and their combination.
Fig. 1 in Yearly and seasonal changes in species composition of hornets (Hymenoptera: Vespidae) caught with bait traps on the Sea of Japan coast
Fig. 1. Yearly changes in the species composition of hornets in Sakata Park (A) and campus of Niigata University (B).
Fig. 3 in Regional uniqueness of tree species composition and response to forest loss and climate change
Fig. 3 | Response of tree species to climate change across biomes. The median absolute latitude and median elevation shift among species, fraction of lost and gained species, and change in taxonomic and phylogenetic composition under climate change were computed for each forest ecoregion. The boxplots show statistics for n = 239 ecoregions for Tropical Moist Broadleaf Forests, n = 14 ecoregions for Tropical Coniferous Forests, n = 55 ecoregions for Tropical Dry Broadleaf Forests, n = 26 ecoregions for Boreal Forests, n = 91 ecoregions for Temperate Broadleaf Forests, n = 49 ecoregions for Temperate Conifer Forests and n = 61 ecoregions for Mediterranean Forests. The center line of the boxplots shows the median, the box limits the quartiles, the whiskers 1.5 times the interquartile range, and the points the outliers.Changes are computed between predicted distributions with climate variables for 1981-2010 and climate projections for 2071-2100 under climate change scenario SSP 5.85. Changes in composition are computed as the Euclidean distance between scaled NMDS and evoPCA values computed at the ecoregion level. Source data are provided as a Source Data file.
Fig. 2 in Regional uniqueness of tree species composition and response to forest loss and climate change
Fig. 2 | Species occupancy range distribution and loss. a Distributions of species occupancy range sizes globally (gray) and constrained to forests (at least 10% tree cover, color) for species in each forest biome. b Boxplot of relative range reduction across species in each forest biome with the center line showing the median, the box limits the quartiles, the whiskers 1.5 times the interquartile range, and the points the outliers. The distributions and boxplots are computed for n = 6810 species for Tropical Moist Broadleaf Forests, n = 588 species for Tropical Coniferous Forests, n = 1101 species for Tropical Dry Broadleaf Forests, n = 54 species for Boreal Forests, n = 1744 species for Temperate Broadleaf Forests, n = 178 species for Temperate Conifer Forests and n = 580 species for Mediterranean Forests. c Global map of median species range size constrained to forests, created with QGIS110. The gray base map corresponds to all areas for which model predictors were available. d Plot of species' median latitude against range size constrained to forests, colored by point density, where red indicates the highest density. Source data are provided as a Source Data file.
Fig. 1 in Regional uniqueness of tree species composition and response to forest loss and climate change
Fig. 1 | Gradients in taxonomic and phylogenetic composition show a near- a, c. Scatter plot of taxonomic and phylogenetic ordinations in environmental unique biodiversity signature of every single location on the planet. Taxonomic space, a 2-dimensional space made up of the 2 first axes of a PCA of the environcomposition is represented by a 3-axis non-metric dimensional scaling (NMDS) and mental variables used for species distribution modeling: mean annual temperature phylogenetic beta-diversity is represented by the 3 first axes of a phylogenetic (MAT), temperature seasonality (T season), annual precipitation (Annual P), preordination (evoPCA). Both the taxonomic and phylogenetic ordinations are com- cipitation seasonality (P season), growing season length (GSL), net primary proputed on the global community matrix derived from the modeled distributions of ductivity (NPP),silt content (Silt),coarse fragments (CF),and soil pH (pH).b, d. Map n = 10,590 tree species sampled at a resolution of 100 km, resulting in n = 12,548 of taxonomic and phylogenetic ordinations in geographical space. Source data are sites. The 3 axes of each ordination are mapped to red, green, and blue with provided as a Source Data file. The maps were created with QGIS110 and the gray minimum and maximum values corresponding to the 10th and 90th percentiles. base map corresponds to all areas for which model predictors were available.
A precipitation gradient drives change in macroinvertebrate composition and interactions within bromeliads.
<p>Tank bromeliads accumulate water inside their leaf axils, providing habitat for communities of aquatic macro invertebrates. Here we sampled the macro invertebrate community in 100 bromeliads along the sand dunes of coastal Brazil in the states of Rio de Janeiro and São Paulo. We sampled ten sites, seven of which were within the Jurubatiba National Park in Rio de Janeiro state, Brazil. The other three sites were located in the sand dunes of Arraial do Cabo (Rio de Janeiro), Marica (Rio de Janeiro), and Ilha Bela (Sao Paulo).</p> <p>We sampled all macroinvertebrate communities between March and May 2015. In each site, we dissected ten bromeliads (totalling 100 bromeliads across all sites) to collect all the invertebrates in each plant. Macroinvertebrates were counted and identified to genus level whenever possible. For every bromeliad, we measured a suite of environmental variables to assess the amount and quality of habitat available to the invertebrates including: the height (cm) and diameter (cm, measured as the maximum distance between leaf tips) of the plant, maximum water volume (mL, calculated by emptying the plant and calculating how much water the plant could hold before it overflowed), actual water volume (mL), longest leaf length (cm), longest leaf width (cm), number of leaves, canopy cover (% of shaded pixels in photos taken looking directly up from the bromeliad), total detritus (g dry mass), pH, oxygen concentration (% saturation), salinity (ppt), temperature (oC), and turbidity (NTU). Water chemistry and temperature variables were measured using a portable multiparameter waterproof meter in the field as soon as the water was collected from the plant.</p> <p>The zip file contains two csv files. Environment contains all the environmental variables described above, and Species_presence contains the species ID and whether it is present in a given bromeliad. </p> <p> </p>
FIGURE 2 in First early Eocene lizards from Spain and a study of the compositional changes between late Mesozoic and early Cenozoic Iberian lizard assemblages
FIGURE 2. Paleogeographic map of Western Europe during the early Eocene (modified from Marandat et al., 2012) and situation of the Catalan localities yielding material described in the text and other contemporaneous European fossil sites. Note that the localities of the Southern Pyrenean Basin (Escarlà, La Roca, Masia de l'Hereuet, Barranc del Fusteró and Font del Torricó) are geographically very close, although situated in different sub-basins (see text).
FIGURE 1. Selected lizard and amphisbaenian material from studied localities. 1-2 in First early Eocene lizards from Spain and a study of the compositional changes between late Mesozoic and early Cenozoic Iberian lizard assemblages
FIGURE 1. Selected lizard and amphisbaenian material from studied localities. 1-2, Geiseltaliellus sp.: 1, left dentary (IPS 49740); 2, maxilla (IPS 83552); 3-4, Iguanidae indet.: 3, fragment of dentary (IPS 83535) with one preserved tooth, 4, fragment of?maxilla with four preserved teeth (IPS 49756); 5-6, Agamidae indet.: 5, Fragment of toothbearing bone preserving one tooth (IPS 83546), 6, fragment of dentary preserving two teeth (IPS 83543). 7-8, Gekkota indet.: 7, posterior portion of left dentary (IPS 59559), 8, anterior portion of left dentary (IPS 83520); 9, Scincoidea (?Scincidae) indet., fragment of right dentary (IPS 49752); 10,?Lacertidae indet., fragment of tooth-bearing bone perserving two teeth (IPS 49762); 11, Amphisbaenia indet., vertebra (IPS 59529); 12, cf. Placosaurus sp., partial parietal with fused osteoderms (IPS 59567); 13, Glyptosaurini indet., skull osteoderm (IPS 83532); 14, Glyptosaurinae indet., body osteoderm (IPS 83533); 15-18, Anguinae indet.: 15, keeled body osteoderm (IPS 83540), 16, unkeeled body osteoderm (IPS 83533), 17, partial parietal (IPS 83557), 18, vertebra (IPS 59538); 19-20, "Necrosauridae" indet.: 19, partial left dentary (IPS 83545), 20, osteoderm (IPS 49741). 1, 2, 5, 6, 11, 15 and 17-20 from Masia de l'Hereuet (MP8+9); 3, 4, 7, 8, 10 and 14 from La Morera (MP10); 12 from Escarlà (MP10); 13 and 16 from Font del Torricó. 1-10 and 19 in labial view; 11-12, 17 in dorsal view; 13-16 and 20 in external view; 18 in ventral view.
FIGURE 3 in First early Eocene lizards from Spain and a study of the compositional changes between late Mesozoic and early Cenozoic Iberian lizard assemblages
FIGURE 3. Distribution of lizard and amphisbaenian taxa from the latest Cretaceous to the late Eocene in the Iberian Peninsula. Records from Font del Torricó are omitted because its exact age inside the early Eocene is unknown. Black squares indicate unambiguous records, whereas grey squares indicate uncertainty. LaMa: Late Maastrichtian; eLaMa: earliest Late Maastrichtian; E/LaMa: Early or Late Maastrichtian; Late Campanian.
Fig. 2 in Compositional change in fish assemblages along the Andean piedmont - Llanos floodplain gradient of the río Portuguesa, Venezuela
Fig. 2. DCA ordination of species assemblages at survey sites in three different elevational zones along the longitudinal gradient of the Portuguesa River, Venezuela: Camaguan, 50-100 m (open squares); Middle, 100-150 m (filled circles); and Upper, 150-200 m (open triangles). The three regions were significantly different in assemblage composition (MANOVA, p <0.0001).
Fig.1 in Compositional change in fish assemblages along the Andean piedmont - Llanos floodplain gradient of the río Portuguesa, Venezuela
Fig.1. Map of Venezuela with inset showing locations of survey sites (n=28, filled circles) along the río Portuguesa elevational gradient.
Fig. 3 in Vegetation of Paektu Mt. alpine tundra and changes of species composition in its ecotone
Fig. 3. Numerical classification of 42 relevés (20 ✕ 20m) of alpine tundra and adjacent larch forest vegetation from Paektu Mt. (North Korea). JACCARD's coefficient and β-flexible clustering method was used (β= -0.25). Explanations: see page 7–8.
Fig. 6 in Vegetation of Paektu Mt. alpine tundra and changes of species composition in its ecotone
Fig. 6. Light-park larch forest (Rhododendro aurei-Laricetum olgensis) – ground layer contents species of alpine tundra, e.g. Rhododendron aureum, Bupleurum euphorbioides, and Juniperus sibirica (photo I. Jarolímek).
Fig. 5 in Vegetation of Paektu Mt. alpine tundra and changes of species composition in its ecotone
Fig. 5. Timber-line on Paektu Mt. – contact zone of alpine tundra and light-park larch forest (Rhododendro aurei-Laricetum olgensis) (photo I. Jarolímek).
ScienceDex guides
Understand access before you commit
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.