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.
517
datasets available to search
ShareScore release 0.7.1
Dataset results
517 results for “tower”
Monthly Vegetation and Invertebrate Population Monitoring near the Georgia Coastal Ecosystems LTER Flux Tower
Permanent study plots were established in a Spartina alterniflora-dominated marsh in the vicinity of the Georgia Coastal Ecosystems LTER Flux Tower to provide measurements of plant biomass and invertebrate population density over time for comparison with marsh-atmospheric CO2 exchange. Six replicate plots were randomly placed within each of three height zones of Spartina alterniflora (i.e. short, medium and tall Spartina). Beginning in June 2013, surveys were conducted approximately monthly to determine abundance of Littoraria irrorata, Prokelisia marginata, and grasshoppers in each plot. Plant species, stem density, height, and flowering status were also measured in each of the plots, and biomass was calculated using allometric relationships between plant height, flowering status and mass from plant clipping studies. During these surveys, destructive core sampling was also performed in the proximity of the plots (n = 2 per zone - additional cores collected some months in 2014 and 2016) to measure above and below ground biomass for each Spartina zone. Beginning in February 2016, chlorophyll measurements were taken in the proximity of the plots in each Spartina zone (n = 15 per zone).
Above- and below-ground non-structural carbohydrates (NSC) in Spartina alterniflora from 6 permanant plots near the Georgia Coastal Ecosysterms LTER flux tower, on Sapelo Island in Georgia, USA
We studied the dynamics of four non-structural carbohydrates (glucose, fructose, sucrose, and starch) and biomass in 8 different above- and below-ground tissues in Spartina alterniflora over the course of a year in a salt marsh on Sapelo Island, Georgia, USA. Tissue parts sampled included green leaves, green stems, yellow leaves, yellow stems, brown leaves and stem, flowers, belowground biomass from 0-10cm depth and belowground biomass from 10-30cm depth. Samples were collected from tall form S. alterniflora plots near the Georgia Coastal Ecosystems LTER flux tower site monthly between September 2013 and August 2014. This study was conducted to support the development of predictive, mechanistic models of Spartina by providing information on below-ground biomass and its dynamics, and in particular the storage of resources that can be used for spring re-growth.
Eddy covariance 30-minute CO2 fluxes with accompanying biophysical variables from the GCE-LTER flux tower site from January 2014 to December 2017 for sensor Flux1
Eddy covariance (EC) CO2 fluxes from flux sensor set "Flux1" from January 2014 to December 2017 collected over a Spartina alterniflora marsh located on the western side of Sapelo Island bounded by the Duplin River and Barn Creek. EC fluxes were processed in EddyPro 7. Additional biophysical variables included are air temperature, relative humidity, vapor pressure deficit, and water table height from a nearby tidal creek and the marsh platform.
Eddy covariance 30-minute CO2 fluxes with accompanying biophysical variables from the GCE-LTER flux tower site from January 2014 to December 2022 for sensor Flux2
Eddy covariance (EC) CO2 fluxes from sensor set "Flux2" from January 2014 to December 2022 collected over a Spartina alterniflora marsh located on the western side of Sapelo Island bounded by the Duplin River and Barn Creek. EC fluxes were processed in EddyPro 7. Additional biophysical variables included are air temperature, relative humidity, vapor pressure deficit, and water table height from a nearby tidal creek and the marsh platform.
Tree Ring Data from the Harvard Forest EMS Tower 1896-2014
Is it possible to reconstruct aboveground carbon/biomass from tree rings? If so, how far back in time can researchers go when using tree-ring data in the reconstruction of past biomass? Answers to these questions will have a significant impact on our understanding of dynamics in the terrestrial carbon sink. Long tree-ring records of biomass can reveal intra-annual to annual to multidecadal variations that cannot be resolved by forest census data that is not conducted annually. Additionally, while these dynamics might be resolved using remote sensing, most remotely-sensed products are only two decades or less in length. By having long records of carbon biomass, we can then identify not only the dominant drivers of biomass, but how the importance of these drivers might change during different eras as environmental factors change (e.g., climate, air pollution, disturbance). To test these and other questions, we collected tree-ring records from two 20m radius plots set within the footprint of the EMS tower plot at the Harvard Forest installed and continuously operated since 1989. We can convert these data to biomass using allometric equations and compare tree-ring inferred aboveground biomass to the census data going back in time. Dye et al. (2016) have shown that these data fall within the range of uncertainty of census data sampled in the Harvard Forest Lyford plot going back to 1969. Dye, A., Barker Plotkin, A., Bishop, D., Pederson, N., Poulter, B., Hessl, A. 2016. Comparing tree-ring and permanent plot estimates of aboveground net primary production in three eastern U.S. forests. Ecosphere 7: e01454.
Radiation Measurements at Harvard Forest EMS Tower 1991-2007
Measurements of radiation and soil heat flux at the EMS tower on the Prospect Hill Tract, Harvard Forest, Petersham, Massachusetts. Values are hourly averages.
Net Carbon Exchange of an Old-Growth Hemlock Forest at Harvard Forest HEM Tower since 2000
This project estimates carbon exchange rates of multiple forest types at Harvard Forest (see HF072) and compares them to long-term ongoing carbon exchange measurements at the EMS, which is located in a mesic, 60-90 year old red oak and red maple dominated forest on abandoned farmland (HF004). Measurements in each forest type are used to investigate climatic influences on carbon exchange. This mesic hemlock-dominated forest with most trees 100-200 years old on undisturbed soils stored only about 3 Mg/ha of carbon in 2001, compared to over 4 Mg/ha in the 60-90 year old oak/maple stand. However, both sites stored more carbon in 2001 than was measured in the oak/maple stand in any previous year since 1991 (see HF004). The hemlock forest behaved very differently from the oak-maple stand in that the highest rates of carbon storage occurred in spring, while there was very little carbon storage in mid to late summer. Statistical models of carbon exchange in the hemlock forest showed that carbon storage was positively related to daily minimum air temperature in spring, but negatively correlated with soil temperature in the summer. The first effect was attributable to a positive influence of above-freezing minimum temperatures on photosynthesis by hemlock foliage. The negative relationship of soil temperature to carbon storage by hemlock forest in summer was due to exponentially increasing soil and ecosystem respiration, accompanied by a neutral or negative effect of high air temperature on photosynthesis by hemlock trees (see HF063). These effects indicate that carbon storage in the hemlock forest could be strongly affected by climate warming, but the effects will probably be in opposite directions in spring and summer.
Hydrocarbon Concentrations at Harvard Forest EMS Tower 1992-2001
Hydrocarbons are products of incomplete combustion and also emitted by vegetation. Hydrocarbons are important precursors for photochemical ozone formation. A system to quantify concentrations of several low-molecular weight hydrocarbons was installed at the EMS tower in the summer of 1992. The measurements were intended to help resolve questions about the potential reactivity in rural New England atmosphere and identify and quantify biogenic hydrocarbon emissions.
Tree Growth and Above-Ground Biomass at Harvard Forest HEM and LPH Towers since 2001
Tree diameter (“dbh”) at 1.25 m above ground were recorded and stainless steel dendrometer bands for trees above 10 cm dbh were attached. Increases in tree diameter were calculated from increases in the distance between holes punched in the dendrometer bands. Tree diameters and diameter increases were used to estimate aboveground biomass and aboveground carbon storage in order to characterize the forest at the flux tower sites, and to quantify the amount of carbon being stored aboveground annually.
Leaf Area Index at Harvard Forest HEM and LPH Towers since 1998
Leaf area index (LAI) measurements are made to detect changes in forest leaf area that are important in understanding forests’ carbon dioxide (CO2) uptake and water use. Measurements of LAI in different forest types are useful understanding differences between forests in CO2 uptake and water use, while variation in LAI in the same forest type over time helps to explain interannual variation and long-term trends in carbon storage and water use. Within a single year, especially for deciduous forests, seasonal changes in LAI are very important in determining the forest’s cycle of CO2 uptake and water use. LAI measurements at Harvard Forest were begun in the old-growth hemlock stand in 1998 in order to understand and develop a predictive model for its carbon exchange, and were begun at the Little Prospect Hill site in 2002 to better understand CO2 uptake and carbon storage at this site, which were measured by the eddy-covariance method beginning in 2002. Due to a lack of personnel, multiple annual measurements of LAI to examine seasonal change in leaf area did not begin until 2007.
Litterfall at Harvard Forest HEM and LPH Towers since 2002
We measure the dry mass and estimated carbon content of leaves and fine twigs that abscise each year. These data are used to quantify one component of annual net primary productivity (ANPP), an important measure of ecosystem productivity and carbon cycling. Leaf area index (LAI) can also be estimated from these data, if area-to-mass ratios are calculated for leaves of each species. This was done for 2002 and 2003 leaf litterfall at the Little Prospect Hill (LPH) site. The fraction of total leaf mass or estimated total leaf area that is formed by leaves of each species also shows the species composition of the forest canopy. If repeated over many years, these data can indicate whether the forest canopy species composition is changing over time.
Tree Growth in Hemlock and Deciduous Forests at Harvard Forest HEM and LPH Towers 2000-2005
Tree growth was measured to determine tree ages and growth rates and to quantify carbon storage in these forests, and to detect changes in growth and carbon storage that could be associated with climate changes or historic disturbances.
PhenoCam Images and Canopy Phenology at the Harvard Forest EMS Tower since 2008
The PhenoCam Network uses imagery from digital cameras to track vegetation phenology and seasonal changes in vegetation activity in diverse ecosystems across North America and around the world. Imagery is uploaded to the PhenoCam server at the University of New Hampshire, where it is made publicly available in near-real time, every 30 minutes from sunrise to sunset, 365 days a year. The data are processed using simple image analysis tools to yield a measure of canopy greenness, from which phenological metrics are extracted, characterizing the start and end of the growing season. These transition dates have been shown to align well with on-the-ground observations of tree phenology at Harvard Forest (HF003). Long-term PhenoCam data can be used to track the impact of climate variability and change on the rhythm of the seasons. This dataset contains one mid-day image for each camera. Please see the PhenoCam Network website (http://phenocam.sr.unh.edu) for more information and additional images.
CO2 Profile at Harvard Forest HEM and LPH Towers since 2009
Carbon dioxide profile measurements are designed to supplement eddy flux measurements in calculating the carbon exchange of a forest. In the case of the Harvard Forest flux towers, the change in CO2 storage between the ground and the height of the eddy flux system during each half hour must be added to the eddy flux measured above the forest to determine the total carbon exchange. The profile measurements are also necessary in order to calculate CO2 movement by advection, or horizontal air transport. The amount of CO2 removed from a particular site by advection is the product of the total CO2 within the air a given range of height above the ground, and the average velocity of airflow parallel to the ground surface within that height range.
Microclimate at Harvard Forest HEM, LPH and EMS Towers since 2005
Microclimatic data are collected continuously within footprint areas of the flux towers in order to (1) understand relationships between climatic and microclimatic conditions and carbon dioxide and water vapor exchange between forest and atmosphere, (2) to develop predictive models for the exchange rates of these gases, based on microclimate data, (3) detect long-term trends in climate and microclimate at the sites and (4) determine whether the response of carbon dioxide and water vapor exchange processes to climate or microclimate is changing over time. The primary climatic and microclimatic variables measured at these sites include: above-canopy photosynthetically active radiation (PAR), forest understory PAR at 1 m height, total net radiation exchange measured above the forest canopy, air temperature and relative humidity above the forest canopy, forest understory air temperature at 20 cm and 1 m above ground level (shielded but not ventilated thermocouple sensors, used only to estimate nighttime understory air temperature), soil temperature at 10 cm depth, and soil moisture.
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
Microclimate at Harvard Forest HDW Tower since 2014
The HDW (Hardwood) microclimate and walkup tower at Harvard Forest became operational in April 2014. The site was chosen to represent the mixed hardwood forest around the EMS and NEON towers and to provide a platform for research projects without access to those towers. Microclimate data are archived annually and recent data are available upon request. Measured values include air temperature, relative humidity, PAR, net radiation, albedo, wind speed and direction, soil temperature and soil moisture.
Fluxes of Molecular Hydrogen (H2) at Harvard Forest EMS Tower 2010-2012
Molecular hydrogen (H2) is an atmospheric trace gas with a large microbe-mediated soil sink, yet cycling of this compound throughout ecosystems is poorly understood. Measurements of the sources and sinks of H2 in various ecosystems are sparse, resulting in large uncertainties in the global H2 budget. Constraining the H2 cycle is critical to understanding its role in atmospheric chemistry and climate. We measured H2 fluxes at high frequency in a temperate mixed deciduous forest for 15 months using a tower-based flux-gradient approach to determine both the soil-atmosphere and the net ecosystem flux of H2. The data presented here along with other data available at Harvard Forest can be used for efforts to model the H2 soil sink.
Canopy-Atmosphere Exchange of Carbon, Water and Energy at Harvard Forest EMS Tower since 1991
The tower-based CO2 measurements and key meteorological drivers are intended to examine how regional and ecosystem level processes in a mid-latitude forest contribute to global carbon cycling. Specifically, we endeavor to understand quantitatively how and why forested ecosystems take up or release carbon, on time scales from hours to decades, and to elucidate responses to climate changes and management interventions. The tower was installed 1989 and the resulting eddy-flux measurements constitute the longest running record of the net-ecosystem carbon exchange in a North American Forest. The resulting long-term record of Net Ecosystem Exchange (NEE) has shown the effects of climate anomalies on carbon fluxes for seasonal and annual time scales. For example, reduced soil frost allows greater respiration in the winter leading to lower C sequestration. Cumulative gross photosynthesis depends on when the canopy emerges in the spring. Warmer springtime temperatures lead to greater uptake of C. As the NEE record is extended and augmented by supporting ecological measurements, we can further identify longer-term effects of climate perturbations on carbon fluxes and further define the relationship between stand history and carbon sequestration. Climatic anomalies in one season or year may have a longer-term effect on the sequestration of carbon in subsequent seasons or years. The flux and ecological measurements are coordinated with studies at other sites through the AmeriFlux network. By examining the relationships between carbon fluxes and the driving physical and biological variables across a range of sites we are enhancing understanding of the processes that control NEE.
PhenoCam Images and Canopy Phenology at the Harvard Forest LPH Tower 2010-2021
The PhenoCam Network uses imagery from digital cameras to track vegetation phenology and seasonal changes in vegetation activity in diverse ecosystems across North America and around the world. Imagery is uploaded to the PhenoCam server at the University of New Hampshire, where it is made publicly available in near-real time, every 30 minutes from sunrise to sunset, 365 days a year. The data are processed using simple image analysis tools to yield a measure of canopy greenness, from which phenological metrics are extracted, characterizing the start and end of the growing season. These transition dates have been shown to align well with on-the-ground observations of tree phenology at Harvard Forest (HF003). Long-term PhenoCam data can be used to track the impact of climate variability and change on the rhythm of the seasons. This dataset contains one mid-day image for each camera. Please see the PhenoCam Network website (https://phenocam.nau.edu/webcam/) for more information and additional images.
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.