Find research datasets worth reusing

openCC (other)Nov 2025View details →

Borrichia removal experiment at Dean Creek marsh on Sapelo Island, Georgia between 1995 and 2001

To examine the effect of Borrichia on Batis and Sarcocornia sp., I completely clipped all vegetation from six 0.5 x 0.5 m quadrats in a mixed stand of the three species at the Dean Creek marsh in June 1995. Six additional plots were left unmanipulated as controls. Removal and control plots were fully interspersed. I clipped Borrichia from the removal plots every 6 months but allowed other plant species to re-colonize.

Foliar and Soil Chemistry at Harvard Forest Chronic Nitrogen Amendment Experiment 1995-2009

The aim of the chronic N study at Harvard Forest is to increase our understanding of ecosystem nitrogen dynamics in response to elevated nitrogen inputs. In recent, nitrogen deposition in the Northeastern United States has been 10 to 20 times above historic background levels which could possibly saturate the retention capacity of a forest ecosystem. Long-term elevated N deposition typically leads to an increase in the concentration of total foliar N, with or without similar changes in the important base elements such as Ca, Mg and K. This increase in leaf N content also leads to significant shifts in the internal partitioning of N within the leaf. For example, in conifers, N deposition has been shown to significantly increase leaf N present in the form of free amino acids such as arginine. Little is known about N partitioning for hardwoods under these conditions. These changes in N partitioning are possibly connected to leaf function. The present study was conducted to experimentally test whether the alterations in N partitioning do occur due to long-term N deposition and if so do they have a positive or a negative effect on photosynthetic capacity and biomass production. A possible decoupling of the relationship between foliar N and photosynthetic rate may occurs under these conditions. The treatment plots used in this study are part of the Chronic Nitrogen Amendment Study at the Harvard Forest LTER site (42.5°N, 72°W). The site has a temperate climate with monthly temperatures ranging from -7°C in January to 20°C in July. Average annual precipitation is 110 cm (http://harvardforest.fas.harvard.edu). The site averages approximately 8 kg ha-1 year-1 of total N deposition. As reported earlier, the land-use history of the pine and hardwood stands used in this study is very different. Two adjacent stands were chosen for the study: an even-aged red pine (Pinus resinosa Ait.) stand and a 50-year-old mixed hardwood stand that had regenerated naturally after clearcutting i

Juvenile Tree Responses to Soil Warming at Harvard Forest since 1995

The main goal of this study is to assess eastern tree species’ growth, survivorship, and phenological responses to soil warming in order to forecast future changes in forest succession and carbon dynamics. From 2003 through 2010, we determined that shade-tolerant, normally slower-growing species benefitted most from warming. We are continuing to study species-species responses to investigate the duration of and mechanisms behind species- and functional group responses to climate warming. Monitoring long-term demographic and physiological responses of juvenile trees with and without soil warming will allow us to model future eastern tree species successional shifts under warmer climate conditions.

Hemlock History Plots at Harvard Forest since 1995

Hemlock (Tsuga canadensis) forests in New England are changing rapidly with the invasion of the hemlock woolly adelgid (HWA, Adelges tsugae), a non-native insect pest that kills hemlock trees. The adelgid is just beginning to be observed at Harvard Forest, making this the right moment to begin intensive physiological, ecological and monitoring studies of our hemlock forests. We gathered detailed baseline information for several hemlock stands across Harvard Forest. We surveyed community vegetation structure and composition, and began to monitor soil nitrogen cycling. These measurements will allow us to link the long-term history of these hemlock stands to other current studies of hemlock response to adelgid infestation, and will provide the basis for intensive study of hemlock dynamics with the stands' anticipated decline.

openCC (other)Sep 2023View details →

Biomass removal at the initiation of a biodiversity experiment at the Jornada Basin LTER site in 1995

This dataset contains data on vegetation biomass removed from treatment plots during the establishment of a biodiversity experiment at the Jornada Basin LTER site in southern New Mexico, USA. In fall of 1995, various combinations of plant functional groups or species were experimentally removed from 25 x 25 meter plots with the objective to distinguish the differential effects of plant community biomass, functional groups, and biodiversity within functional groups on ecosystem and plant community function. Eight different treatments were established with selective removal of species or functional groups: 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. The amount of plant material removed during the establishment of these treatments was recorded for later use as covariate or measure of disturbance. Removed fresh material was weighed in the field by species, then converted to dry mass using a subset of removed plot vegetation that was oven-dried and weighed in the lab. Variables in this file summarize the dry mass of plants removed by growth form (functional group, i.e. shrub, subshrub, perennial grass, succulent), and by total live dry mass, for each plot in the biodiversity experiment. Also provided are masses of dead material collected from plots (same groups as live material removed for each treatment) and total dry mass, live plus dead. Species-level data are available upo

openCC (other)May 2024View details →

Hubbard Brook Experimental Forest: Chemistry of Streamwater – Monthly Fluxes, Watershed 8, 1995 - ongoing

These data are monthly fluxes of solutes in stream water measured in watersheds of the Hubbard Brook Experimental Forest and are a part of the Hubbard Brook Watershed Ecosystem Record (HBWatER), which is a long-term record of stream and precipitation chemistry and volume. The solute fluxes in stream water are calculated as the product of the volume of stream water and solute concentrations. There are nine gaged watersheds at the Hubbard Brook Experimental Forest, some of which have been subjected to experimental manipulations. The calculation of fluxes is currently supervised by John Campbell (US Forest Service). The long-term stream water record is collected and maintained by the US Forest Service. The collection and management of the long-term stream and precipitation chemistry record was initiated in 1963 by Gene E. Likens, F. Herbert Bormann, Robert S. Pierce, and Noye M. Johnson. HBWatER is currently sustained by Tammy Wooster (Cary IES) and Jeff Merriam (USFS) and the dataset is curated and maintained by a team of researchers: Chris Solomon (Cary IES), Emma Rosi (Cary IES), Emily Bernhardt (Duke), Lindsey Rustad (USFS), John Campbell (USFS), Bill McDowell (UNH), Charley Driscoll (Syracuse U.), Mark Green (Case Western), and Scott Bailey (USFS). Current Financial Support for HBWatER is provided by NSF LTREB # 1907683 and the USDA Forest Service Northern Research Station. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the US Forest Service, Northern Research Station.

openCC (other)May 2024View details →

Hubbard Brook Experimental Forest: Chemistry of Streamwater – Monthly Fluxes, Watershed 9, 1995 - ongoing

openCC (other)May 2024View details →

Hubbard Brook Experimental Forest: Chemistry of Precipitation – Monthly Fluxes, Watershed 9, 1995 - ongoing

These data are monthly fluxes of solutes in precipitation collected at the Hubbard Brook Experimental Forest and are a part of the Hubbard Brook Watershed Ecosystem Record (HBWatER), which is a long-term record of stream and precipitation chemistry and volume. The solute fluxes in precipitation are calculated as the product of precipitation volume and solute concentrations. There are nine gaged watersheds at the Hubbard Brook Experimental Forest, some of which have been subjected to experimental manipulations. The calculation of fluxes is currently supervised by John Campbell (US Forest Service). The long-term stream water record is collected and maintained by the US Forest Service. The collection and management of the long-term stream and precipitation chemistry record was initiated in 1963 by Gene E. Likens, F. Herbert Bormann, Robert S. Pierce, and Noye M. Johnson. HBWatER is currently sustained by Tammy Wooster (Cary IES) and Jeff Merriam (USFS) and the dataset is curated and maintained by a team of researchers: Chris Solomon (Cary IES), Emma Rosi (Cary IES), Emily Bernhardt (Duke), Lindsey Rustad (USFS), John Campbell (USFS), Bill McDowell (UNH), Charley Driscoll (Syracuse U.), Mark Green (Case Western), and Scott Bailey (USFS). Current Financial Support for HBWatER is provided by NSF LTREB # 1907683 and the USDA Forest Service Northern Research Station. These data were gathered as part of the Hubbard Brook Ecosystem Study (HBES). The HBES is a collaborative effort at the Hubbard Brook Experimental Forest, which is operated and maintained by the US Forest Service, Northern Research Station.

Soil Properties in CRUI Land Use Project at Harvard Forest 1995-1998

Soil properties and processes were evaluated on three types of colonial agricultural land-use - plowing, pasturing, and selective tree removal in a woodlot that ceased in the mid to late 1800s. Plowing, the most intensive type of agricultural disturbance, mixes soil to a depth of approximately 15cm, homogenizing the soil resources and likely reducing diversity in microenvironments. Removing trees and replacing them with grasses for pasture decreases the organic matter amount and types of inputs to the system, decreasing resource diversity. Woodlots, altered by selective and chronic tree removal, would have more limited decreases in resources and microenvironments. This study defines forest soil legacies using data from plots located at Harvard Forest in both amounts of soil resources and spatial heterogeneity of those soil resources. We found that for several soil parameters measured on previously cultivated and preciously pastured lands at the Harvard Forest, a legacy exists in the mineral soil, but the forest floor appears to have largely recovered from the agricultural disturbance. Parameters examined included soil mass, bulk density, organic matter content, pH, C, N, nitrogen mineralization and nitrification, Ca, Mg, K, and P.

openCC0Jan 2024View details →

Stand and Community Response to Hemlock Woolly Adelgid in Southern New England since 1995

Hemlock woolly adelgid (HWA), Adelges tsugae, an introduced aphid-like insect from Asia, is expanding its range across the northeastern United States through the range of Tsuga canadensis (eastern hemlock) and can severely reduce or eliminate this important late-successional species. As part of a study investigating stand- and landscape-level forest dynamics resulting from HWA infestation, we examined initial community response of eight T. canadensis stands in south-central Connecticut and then continued to monitor these stands every other year. Our major objectives were to assess mortality patterns in T. canadensis, evaluate subsequent changes in stand microenvironment, and relate these and stand composition to initial patterns of regeneration, understory response, and community reorganization. Tsuga canadensis damage varied broadly across the study area ranging from near zero to greater than 95 % mortality. All size and age classes sampled were attacked by HWA, although smaller trees exhibited higher mortality rates than larger trees. All remaining T. canadensis sampled in seven of the eight stands were infested with HWA and over 90 % suffered at least 50 % foliar loss. Since 1995, overstory and understory mortality has risen 5 to 15 % per year to overall values of 50 to 99%. There has been no sign of tree recovery and the health and vigor of remaining trees deteriorated in all infested stands. Results suggest that trees on some sites can remain alive for over 10 years following initial infestation and remain standing for 6 to 8 years following mortality. Substantial accumulations of downed woody debris have developed in stands with severe HWA damage. Canopy gaps created by HWA damage significantly increased the amount of light reaching the forest floor and resulted in rapid understory vegetation responses. Prolific Betula lenta (black birch) establishment occurred in stands with moderate to severe T. canadensis mortality. In addition, opportunistic herbaceous spe

openCC0Nov 2023View details →

Soil Respiration, Temperature and Moisture at Harvard Forest EMS Tower 1995-2014

We have been making long-term soil respiration measurements at our transect sites since the summer of 1995. The rainfall exclusion experiment began in May of 2001 and autochamber measurements began in 2003. A root exclusion experiment (trenching) was conducted from 2012-2014.

openCC (other)Nov 2022View details →

North Temperate Lakes LTER: Primary Production - Trout Lake Area 1986 - 1995

Primary production on three lakes (Crystal, Sparkling, Trout) is measured using C14 laboratory incubation under controlled temperature and light conditions. Sampling Frequency: fortnightly during ice-free season Number of sites: 3 Please consult NTL's website for information on experimental lake manipulations and the DNR's website for management activities

openCC (other)Dec 2022View details →

Cascade Project at North Temperate Lakes LTER Phosphorus, Chlorophyll, DOC, Color, and pH for Twenty UNDERC Lakes 1995 - 2003

Data on total phosphorous, chlorophyll a, dissolved organic carbon, water color, and pH for a set of lakes located at the University of Notre Dame Environmental Research Center (UNDERC). Surface water samples were collected monthly from May through August either from shore with a telescoping pole or from a boat. Twenty lakes were sampled from 1995-2000. Fifteen of these lakes were sampled from 2001-2003.

openCC (other)Nov 2022View details →

Cascade Project at North Temperate Lakes LTER: Phytoplankton 1984 - 1995

Data on epilimnetic phytoplankton from 1984-95, determined by light microscopy from pooled Van Dorn samples at 100percent, 50percent, and 25percent of surface irradiance. There have been 4 counters during this period, with the same counter from 1991-95. Standardization among counters is difficult, so I recommend sticking to the 1991-95 data if possible. Cottingham (1996) describes the counting protocols in detail. Sampling Frequency: varies Number of sites: 5

openCC (other)Nov 2022View details →

North Temperate Lakes LTER: Phytoplankton - Madison Lakes Area 1995 - current

Phytoplankton samples for the 4 southern Wisconsin LTER lakes (Mendota, Monona, Wingra, Fish) have been collected for analysis by LTER since 1995 (1996 Wingra, Fish) when the southern Wisconsin lakes were added to the North Temperate Lakes LTER project. Samples are collected as a composite whole-water sample and are preserved in gluteraldehyde. Composite sample depths are 0-8 meters for Lake Mendota (to conform to samples collected and analyzed since 1990 for a UW/DNR food web research study), and 0-2 meters for the other three lakes. A tube sampler is used for the 0-8 m Lake Mendota samples; samples for the other lakes are obtained by collecting water at 1-meter intervals using a Kemmerer water sampler and compositing the samples in a bucket. Samples are taken in the deep hole region of each lake at the same time and location as other limnological sampling. Phytoplankton samples are analyzed by PhycoTech, Inc., a private lab specializing in phytoplankton analyses (see data protocol for procedures). Samples for Wingra and Fish lakes are archived but not routinely counted. Permanent slide mounts (3 per sample) are prepared for all analyzed Mendota and Monona samples as well as 6 samples per year for Wingra and Fish; the slide mounts are archived at the University of Wisconsin - Madison Zoology Museum. Phytoplankton are identified to species using an inverted microscope (Utermohl technique) and are reported as natural unit (i.e., colonies, filaments, or single cells) densities per mL, cell densities per mL, and algal biovolume densities per mL. Multiple entries for the same species on the same date may be due to different variants or vegetative states - (e.g., colonial or attached vs. free cell.) Biovolumes for individual cells of each species are determined during the counting procedure by obtaining cell measurements needed to calculate volumes for geometric solids (e.g., cylinders, spheres, truncated cones) corresponding to actual cell shapes. Biovolume concentratio

openCC (other)Jun 2024View details →

Snow grain data for Niwot Ridge and Green Lakes Valley, 1995 - ongoing.

Snow pits were excavated at various locations on Niwot Ridge and within the Green Lakes Valley. Temperature and snow density were measured at various depths throughout the snow cover profiles to characterize the temperature and snow water equivalent (SWE) of the snowpack throughout the year. Snow density was measured at 10-cm intervals using a 1000-ml cutter. Data on snow grain qualities were collected beginning in the 1994-95 snow season.

openOpenApr 2022View details →

Bonanza Creek LTER: Hourly Barometric Pressure Measurements from 1995 to Present in the Bonanza Creek Experimental Forest near Fairbanks, Alaska

A Campbell Scientific data logger and pressure sensor were used to measure barometric pressure at the LTER1 meteorological station in the Bonanza Creek Experimental Forest (BCEF) beginning in 1995.

openOpenApr 2022View details →

Bonanza Creek LTER: Hourly Air Temperature Measurements (mean, min, max) at Various Heights from 1995 to Present in the Caribou-Poker Creeks Research Watershed near Fairbanks, Alaska

This dataset contains the hourly output from Temperature sensors for the Cariou-Poker Creeks Research Watershed (CPCRW). Any temperature data collected in this area is reported here. This includes Level 3 weather stations as well as smaller scale and temporal studies. This data can be sorted and viewed by site, year, hour, height of measurement, mean, min, and max value. Updates of each site are different since some are still on going while other had only a 2-3 year life cycle. This information can be found in the site descriptions and in the metadata.

openCC (other)Apr 2022View details →

Quadrat vegetation cover data on 1m x 1m plots from the long-term Small Mammal Exclusion Study (SMES) at Jornada Basin LTER, 1995-2020

This data package contains vegetation cover from plots with various levels of herbivore exclusion on the Jornada Experimental Range (JER) and Chihuahuan Desert Rangeland Research Center (CDRRC) in Dona Ana County, southern New Mexico, USA. Study sites were established in 1995; one in black grama grassland and the other in creosotebush shrubland to compare the impact of herbivores on ecosystem processes between these vegetation types. Parallel studies were established at the Sevilleta LTER site (New Mexico, USA) and Mapimi Biosphere Reserve (Durango, Mexico). Each study site is 1 km by 0.5 km in area. Four replicate experimental blocks were randomly located at the grassland study site to measure vegetation responses using exclusion treatments including a) all mammalian herbivores, including cattle, lagomorphs, and rodents, b) lagomorphs and cattle only, c) cattle only, and d) control accessible to all herbivores. Because grazing cattle are excluded from the entire creosote site, only three replicate experimental blocks were randomly located there including a) all mammalian herbivores, including lagomorphs, and rodents, b) lagomorphs only, and c) control accessible to all herbivores. Thirty-six sampling points were positioned at 5.8-meter intervals on a systematically located 6 by 6 point grid within each plot. A permanent one-meter by one-meter vegetation measurement quadrat is located at each of the 36 points. At each quadrat, percent cover by individual plant species is measured. Other measurements include height (cm) of each species in the quadrat, and plant condition (living or dead). Data were collected in the spring and fall of every year from 1995 to 2005. After 2005, sampling frequency changed to every 5 years in the fall. This study is ongoing.