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Ectomycorrhizal Community of Red Oak at Harvard Forest 2013
There is evidence that ectomycorrhizal Pezizales prevail on roots at woodland edges or habitats where trees are well spaced, and where there is minimal understory vegetation, soil pH is relatively high, and bare soil is a feature. This observation was repeated in a recent study of mitospores produced by these fungi, where they were found most often at woodland edges, road sides, the middle of paths, and lawns. A key feature that distinguishes Basidiomycota from Ascomycota is that the dikaryon necessary for sexual reproduction is generally formed early after spore germination in the former, but not until fruitbody formation in the latter. Our hypothesis is that the mitospores produced by ectomycorrhizal Pezizales act as spermatia, and that these spores are more effectively produced and dispersed from bare soil than from areas with a thick organic layer. Here we tested our hypothesis by comparing the community of ectomycorrhizal root fungi on red oak trees in Harvard Forest and the Arnold Arboretum.
Taxonomy and Biogeography of Nematode Communities at Harvard Forest 2014
Our overall goal is to describe and map nematode biodiversity in North America. Specifically we will concentrate on Criconematina, a suborder of plant parasitic, soil-dwelling nematodes. Criconematina, commonly referred to as ring-nematodes, are distributed globally associated with a wide range of hosts and habitats. In native grasslands and forests, they may constitute as much as 30% of the below-ground nematode community. Their abundance often approaches 500 individuals per 100cc of soil with as many as a dozen species recorded from a single habitat. Host associations may be broad, covering entire plant families, or they may specialize in feeding on a few closely related plant species. Several are known agronomic pest species, but the vast majority is known only from native habitats and responds negatively to soil disturbance. Due to their sensitivity to disturbance and associations with a range of plant species, some ecologists have suggested that ring nematodes could serve as a below-ground biological indicator of habitat quality. Before this application is possible taxonomic boundaries need to be evaluated and a reference database needs to be established.
Predator Contributions to Belowground Responses to Climate Warming at Harvard Forest 2014
Identifying the factors that control soil CO2 emissions will improve our ability to predict the magnitude of climate change-soil ecosystem feedbacks. Despite the integral role of invertebrates in belowground systems, they are excluded from climate change models. Soil invertebrates have consumptive and non-consumptive effects on microbes, whose respiration accounts for nearly half of soil CO2 emissions. By altering the behavior and abundance of invertebrates that interact with microbes, invertebrate predators may have indirect effects on soil respiration. We examined the effects of a generalist arthropod predator on belowground respiration under different warming scenarios. Based on research suggesting invertebrates may mediate soil CO2 emission responses to warming, we predicted that predator presence would result in increased emissions by negatively affecting these invertebrates. We altered the presence of wolf spiders (Pardosa spp.) in mesocosms containing a forest floor community. To simulate warming, we placed mesocosms of each treatment in ten open-top warming chambers ranging from 1.5 to 5.5° C above ambient at Harvard Forest, MA. As expected, CO2 emissions increased under warming and we found an interactive effect of predator presence and warming, though the effect was not consistent through time. The interaction between predator presence and warming was the inverse of our predictions: mesocosms with predators had lower respiration at higher levels of warming than those without predators. Carbon dioxide emissions were not significantly associated with microbial biomass. We did not find evidence of consumptive effects of predators on the invertebrate community, suggesting that predator presence mediates response of microbial respiration to warming through non-consumptive means. In our system we found a significant interaction between warming and predator presence that warrants further research into mechanism and generality of this pattern to other systems.
Impacts of Climate Warming on Trophic Function at Harvard Forest and Duke Forest 2013
Forest floor food webs play pivotal roles in carbon cycling, but they are rarely considered in models of carbon fluxes, including soil carbon dioxide emissions (respiration), under climatic warming. The indirect effects of invertebrates on heterotrophic respiration through interactions with microbial communities are significant and will be altered by warming. However, the interactive effects of invertebrates and warming on microbes and heterotrophic respiration in the field are poorly understood. In this study we combined field and common garden laboratory approaches to examine relationships between warming, forest floor food web structure, and heterotrophic respiration. We found that soil animals can overwhelm the effects of warming (to 5 degrees Celsius above ambient) on heterotrophic respiration. In particular, the presence of higher trophic levels and burrowing detritivores strongly determined heterotrophic respiration rates in temperate forest soils, dictating the ecosystem response to warming. These effects were, however, context-dependent, with greater effects in a lower-latitude site. Without isolating and including the significant impact of invertebrates, climate models will be incomplete, hindering well-informed policy decisions.
Tree Inventories for Validating Terrestrial Lidar Measurements at Harvard Forest 2007-2014
Our objective is to improve the measurements of canopy structure and biomass of a forest stand and detect their annual changes via a ground-based laser scanning technology, also known as terrestrial lidar (TLS). A TLS instrument utilizes lasers to scan an environment, measure 3D locations of objects encountered by lasers and detect intensities of laser lights scattered by those objects back to the TLS instrument. TLS have shown abilities and is being further explored to retrieve stem diameter, stem count density, stand height, leaf area index, foliage profile, foliage area volume density, aboveground biomass and other useful forest structural parameters rapidly and accurately. Three TLS instruments used in this project include: (1) the Echidna (R) Validation Instrument (EVI), built by CSIRO Australia; (2) Dual-Wavelength Echidna® Lidar (DWEL), built by Boston University, University of Massachusetts, Lowell, University of Massachusetts, Boston and CSIRO Australia; (3) Compact Biomass Lidar (CBL), built by University of Massachusetts, Boston. To validate the forest structural parameters retrieved using these TLS instruments, we set up a one-ha (100 m by 100 m) forest site and collected tree inventory data including: tree location, tree species, DBH, tree height and crown dimension since 2007 with a two-year gap of 2008 and 2009. Lidar data are available from the ORNL DAAC (http://dx.doi.org/10.3334/ORNLDAAC/1045).
Harvard Forest Summer Research Program in Ecology Pre/Post Survey 2006-2015
Program Context Since its inception in 1985, when a single undergraduate worked on a study of old-growth forests, the Harvard Forest Summer Research Program in Ecology (HF-SRPE) has developed into a thriving and well-coordinated program that is central to the educational and research mission of the biological field station. With core support since 1993 from a succession of NSF REU Site awards and NSF REU supplements, and with additional funding from Harvard University, HF-SRPE has grown to support 20-30 undergraduate students annually. Students are mentored by principle investigators and senior scientists in conducting research in ecology, soil science, paleoecology, wildlife biology, conservation biology, and atmospheric sciences. The research conducted by our HF-SRPE students contributes substantially to long-term scientific investigations supported by NSF’s Long-Term Ecological Research (LTER) and National Ecological Observatory Network (NEON), NASA Earth System Science Pathfinder (ESSP) – Earth Ventures (EV) programs, The Smithsonian Institution’s ForestGEO network of plots, and Department of Energy’s (DOE) National Institute for Global Environmental Change (NIGEC). The overarching objectives of the program are to: enhance the ability of students to undertake high-quality interdisciplinary research; build teams of researchers in which students bring different strengths to the table, collaborate on cutting-edge projects, and find their own intellectual “voice”; encourage students to link fundamental and applied issues in their research; and cultivate the next generation of ecological scientists and educators that reflects the diversity of backgrounds and experiences of students in the United States. Problem Statement Starting in 2005 the National Science Foundation (NSF), as one of the largest funders of undergraduate research programs, began emphasizing the use of project evaluations to both qualitatively and quantitatively measure the success of REU programs (R
Harvard Forest Summer Research Program in Ecology Alumni Survey 2013-2015
Program Context Since its inception in 1985, when a single undergraduate worked on a study of old-growth forests, the Harvard Forest Summer Research Program in Ecology (HF-SRPE) has developed into a thriving and well-coordinated program that is central to the educational and research mission of the biological field station. With core support since 1993 from a succession of NSF REU Site awards and NSF REU supplements, and with additional funding from Harvard University, HF-SRPE has grown to support 20-30 undergraduate students annually. Students are mentored by principle investigators and senior scientists in conducting research in ecology, soil science, paleoecology, wildlife biology, conservation biology, and atmospheric sciences. The research conducted by our HF-SRPE students contributes substantially to long-term scientific investigations supported by NSF’s Long-Term Ecological Research (LTER) and National Ecological Observatory Network (NEON), NASA Earth System Science Pathfinder (ESSP) – Earth Ventures (EV) programs, The Smithsonian Institution’s ForestGEO network of plots, and Department of Energy’s (DOE) National Institute for Global Environmental Change (NIGEC). The overarching objectives of the program are to: enhance the ability of students to undertake high-quality interdisciplinary research; build teams of researchers in which students bring different strengths to the table, collaborate on cutting-edge projects, and find their own intellectual “voice”; encourage students to link fundamental and applied issues in their research; and cultivate the next generation of ecological scientists and educators that reflects the diversity of backgrounds and experiences of students in the United States. Problem Statement Starting in 2005 the National Science Foundation (NSF), as one of the largest funders of undergraduate research programs, began emphasizing the use of project evaluations to both qualitatively and quantitatively measure the success of REU programs (R
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.
Continuous Measurement of Canopy Fluorescence at Harvard Forest 2013-2014
Vegetation fluorescence, a very small amount of radiation emitted as a byproduct of photosynthesis, is a direct indicator of plant physiology. Monitoring the solar-induced plant fluorescence provides a powerful tool to understand how the plant photosynthesis responds to environmental factors such as solar radiation, temperature and precipitation as well as to stress and disturbance. We installed the ground-based fluorescence observation system to explore the Franhofer lines in the solar spectrum to monitor the canopy fluorescence. Fluorescence data could also be used to link with eddy covariance data in flux towers, the digital camera data and solar radiation data, providing a good supplementary to numerous data collected at Harvard Forest.
Maple Reproduction and Sap Flow at Harvard Forest since 2011
Seed production assures the persistence of tree populations and forest cover over the long-term, and so has long interested plant demographers and foresters. Many forest tree species produce seeds synchronously and at irregular intervals across large areas, a phenomenon known as masting. Initiated in spring 2011, this study addresses the mechanisms of mast seeding in sugar maple (Acer saccharum), and its impact on pollinators, seed consumers, and forest carbon dynamics at the Harvard Forest. We monitor seed production (via counts of seeds on trees), flower production, and resource status (via sap collection) on 20 trees. Pollinator dynamics and seed predation (by weevils) are also monitored. In 2015, we added sap and seed monitoring of red maple (Acer rubrum) trees to explore the hypothesis that this non-masting species would have muted dynamics compared to its masting congener.
Detection Probability of Red Wood Ants in Friedenweiler, Germany 2015
Estimation of population sizes and species ranges is central to population and conservation biology. It is widely appreciated that imperfect detection of mobile animals must be accounted for when estimating population size from presence-absence data. Sessile organisms also are imperfectly detected, but correction for detection probability in estimating their population sizes is rare. We illustrate challenges of detection probability and population estimation of sessile organisms using censuses of red wood ant (Formica rufa-group) nests as a case study. These ants, widespread in the northern hemisphere, can make large (up to 2m tall), highly visible nests. Using data from a two-day mapping campaign by eight individuals of 147 ant nests spread across sixteen 3600-m2 plots in the Black Forest region of southwest Germany, we developed a Bayesian model for quantifying detection probability of sessile organisms. Detection probabilities by individual observers of red wood ant nests ranged from 0.31 – 0.56, and depended on experience of the observers, size and density of nests, and habitat characteristics. Robust estimation of population density of sessile organisms—even highly apparent ones such as red wood ant nests—requires unbiased estimation of detection probability, just as it does when estimating population density of rare or cryptic species.
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.
Red Maple Seedling Soil Warming Experiment in Harvard Forest Lath House 2015
Microhabitat environmental conditions are an important filter for seedling establishment, controlling the availability of optimal recruitment sites. Understanding how tree seedlings respond to warming soil temperature is critical for predicting population recruitment in the future hardwood forests of northeastern North America, particularly as environmental conditions and thus optimal microhabitat availabilities change. We examined the effect of 5˚C soil warming during the first growing season on germination, survival, phenology, growth, and stem and root biomass allocation in Acer rubrum (red maple) seedlings. While there was no effect of soil warming on germination or survival, seedlings growing in warmer soils demonstrated significantly accelerated leaf expansion, delayed autumn leaf senescence, and an extended leaf production period. Further, seedlings growing in warmer soils showed larger leaf area, stem and root structures at the end of the first growing season, with no evidence of biomass allocation tradeoffs. Results suggest A. rubrum seedlings can capitalize on soil warming by adjusting leaf phenology and leaf production, resulting in a longer period of carbon uptake and leading to higher overall biomass. The absence of growth allocation tradeoffs suggests A. rubrum will respond positively to increasing soil temperatures in northeastern forests, at least in the early life stages.
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
Community and Conservation Survey in Urban, Suburban and Rural Massachusetts 2013-2018
The dynamics of forest cover and the ecosystem services they provide are shaped by the land use and management decisions of thousands of individual landowners and the land use planning and conservation actions of towns and environmental organizations. Through an interdisciplinary investigation of the land use and forest conservation practices across two urban-to-rural transects between Boston and Central Massachusetts, we investigated the complex and coupled socio-ecological processes that shape the structure, function, and transformation of forested landscapes and how examine these processes may vary along urban-to-rural gradients. The survey data archived here is one element of this larger coupled natural-human systems project. The Community and Conservation Survey collected data regarding landowners’ attitudes and management practices on a variety of issues linked to conservation and the use of their own land. The objectives were to collect data that (a) increase our understanding of how landowners’ attitudes and behaviors vary across urban-to-rural gradients and (b) can be coupled with biogeochemical measurements across the study region to model variation in management behaviors.
Effects of Acorn Production on White-Footed Mouse Populations at Harvard Forest 1997-1999
Recently several authors have documented fluctuations in the abundance of white-footed mice (Peromyscus leucopus noveboracensis) with fluctuations in acorn production (Elkinton et al. 1996, Ostfeld et al. 1996, Wolff 1996, Jones et al. 1998). Acorns are the major food source of white-footed mice during winter and are extensively cached. They are also food for many other species as well; over 100 species of birds and mammals feed on acorns (Van Dersal 1940). A large mast crop in fall usually correlates with a large mouse population the following summer, whereas a poor crop correlates with low population numbers. One experimental study supplementing acorns on forest plots demonstrated a concomitant increase in white-footed mice populations (Jones et al. 1998). It has been hypothesized that a large mast crop increases overwinter survival and may allow continued reproduction during the winter months, which results in a larger population the following year. We have four objectives in monitoring acorn abundance at Harvard Forest: 1) test for correlation of estimates of acorn production with estimates of overwinter survival probabilities and abundance of white-footed mice using mark-recapture statistical models (HF054), 2) document annual variation in acorn abundance and quality, which compliments a program at Harvard Forest documenting changes in woody plant phenology with climatic variation (HF003), 3) test hypotheses concerning the correlation of acorn production with environmental factors such as temperature, rainfall, and weevil infestation, and 4) provide data for inter-site comparisons, such as to test for synchrony in production at various scales across the landscape. We estimate acorn production with timed visual surveys following methods adapted from Koenig et al. (1994). Individual tagged trees on two small mammal trapping plots are surveyed each year by two observers. Detailed methods are described in the metadata.
Effects of Warming on Soil Microbial Communities at Harvard Forest 2011
As Earth’s climate warms, soil carbon pools and the microbial communities that process them may change, altering the way in which carbon is recycled in soil. In this study, we used a combination of metagenomics and bacterial cultivation to evaluate the hypothesis that experimentally raising soil temperatures by 5°C for 5, 8, or 20 years increased the potential for temperate forest soil microbial communities to degrade carbohydrates. Warming decreased the proportion of carbohydrate-degrading genes in the organic horizon derived from eukaryotes and increased the fraction of genes in the mineral soil associated with Actinobacteria in all studies. Genes associated with carbohydrate degradation increased in the organic horizon after 5 years of warming but had decreased in the organic horizon after warming the soil continuously for 20 years. However, a greater proportion of the 295 bacteria from 6 phyla (10 classes, 14 orders, and 34 families) isolated from heated plots in the 20-year experiment were able to depolymerize cellulose and xylan than bacterial isolates from control soils. Together, these findings indicate that the enrichment of bacteria capable of degrading carbohydrates could be important for accelerated carbon cycling in a warmer world.
Effects of Warming on Soil Biogeochemistry at Harvard Forest 2014-2015
More than two decades of experimental soil warming in the Prospect Hill tract of the Harvard Forest has revealed non-linear soil respiration (HF005) and soil carbon loss patterns (Melillo et al., Science, 2017). The datasets here were collected to evaluate how the quantity and quality of soil carbon has been affected by 5C warming, and to assess the role that altered extracellular enzyme allocation may play in this. We collected soils over the 2014 growing season, after 23 years of soil warming. We confirmed previous results that warming had depleted the soil of organic matter, and this was accompanied by an overall decrease in microbial biomass particularly apparent in the forest floor in the fall. Using pyrolysis-GCMS, we found that the relative abundance of soil organic matter compound classes was unaffected by warming in the upper organic horizon (“forest floor”). However, lipids increased in relative abundance to the detriment of polysaccharides and lignin in the upper mineral soil, where warming had depleted soil mineral surfaces of organic matter. Despite these changes in soil organic matter quantity and quality, the potential extracellular enzyme activity per gram of soil was unaffected by warming treatment under common lab conditions. However, under in-situ temperature conditions, warming increased enzyme activity per unit microbial biomass, indicating heated plot microbes get better return on their enzyme investment than those in control plots.
Red Wood-Ant Nests and Fault-Related Methane Micro-Seepage 2016
We measured methane (CH4) and stable carbon isotope of methane (ẟ13C-CH4) concentrations in ambient air and within a red wood-ant (RWA; Formica polyctena) nest in the Neuwied Basin (Germany) using high-resolution in-situ sampling to detect microbial, thermogenic, and abiotic fault-related micro-seepage of CH4. Methane degassing from RWA nests was not synchronized with earth tides, nor was it influenced by micro-earthquake degassing or concomitantly measured RWA activity. Two ẟ13C-CH4 signatures were identified in nest gas: −69‰ and −37‰. The lower peak was attributed to microbial decomposition of organic matter within the RWA nest, in line with previous observations that RWA nests are hot-spots of microbial CH4. The higher peak has not been reported in previous studies. We attribute this peak to fault-related CH4 emissions moving via fault networks into the RWA nest, which could originate either from thermogenic or abiotic CH4 formation. Sources of these micro-seepages could be Devonian schists, iron-bearing “Klerf Schichten,” or overlapping micro-seepage of magmatic CH4 from the Eifel plume. Given the abundance of RWA nests on the landscape, their role as sources of microbial CH4 and biological indicators for abiotically-derived CH4 should be included in estimation of methane emissions that are contributing to climatic change.
Life History of a Climax Forest in Pisgah State Forest in Winchester NH 1929-1930
Old-growth forest is uncommon across the northeastern United States, as most areas have been historically cleared for agriculture or harvested for timber. This study provides rare direct insight into the overstory and midstory dynamics across a semi-contiguous old-growth landscape in New England. Pisgah State Park in southwestern New Hampshire comprises 5300 ha of Hardwoods-Hemlock-White Pine forest, all but 300 ha of which was cutover by the 1880s. To protect a high-quality, old-growth stand from harvest, Harvard Forest purchased a 10 ha tract (the Harvard Tract) in 1927. In 1929 and 1930, Branch, Daley, and Lotti located and sampled all of the known remaining old-growth stands in the Pisgah area. This included 74 0.04 ha old-growth stands, 14 of which were located the Harvard Tract. They also surveyed 27 0.04 ha stands that had been cut just prior to the study (stump plots), where stumps as well as the remaining overstory trees were recorded. Note that only 61 old-growth plots and 23 stump plots have valid measurements. Species, diameter class, and position (overstory or midstory) were recorded for each tree; cover type, elevation, and location was described for each plot. Dead and downed trees were also recorded.
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These curated guides explain access requirements, typical timelines, costs, and reuse considerations for widely used research datasets.
Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.