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Soil Respiration in Hemlock Removal Experiment at Harvard Forest 2003-2009
Soil respiration (SR) is a combination of autotrophic (root respiration) and heterotrophic (microbial respiration). As a combination of these two belowground processes, separating their relative contributions to SR from is difficult. The hemlock removal experiment provided an opportunity to look at these two components of SR. Girdling and logging result in the death and/or removal of aboveground biomass (trees) and subsequently death of root biomass. As a result the measured respiration in these treatment plots should then be comprised primarily of the microbial respiration component of SR. By measuring SR in control plots, and taking the difference with girdled and logged plots, we may determine the relative contribution of root and microbial respiration.
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.
Soil Respiration in CRUI Land Use Project at Harvard Forest 1997
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 examined soil surface (at 10cm above the soil surface) CO2 concentrations and soil respiration at the land use sites. Soil respiration and surface CO2 concentrations were highest in the woodlot sites and lowest in the formerly plowed sites.
Soil Respiration at Harvard Forest HEM and LPH Towers 1996-2007
Soil respiration, including both CO2 produced during decomposition of organic matter in soil and surface litter, and CO2 produced during respiration of living roots, is a major component of forest-atmosphere carbon exchange, typically comprising 60 to 80% of whole-forest respiration. Soil respiration data can explain a major part of a forest ecosystem’s response to changing climate, and help in evaluating the accuracy of nighttime eddy flux data as estimates of whole-ecosystem respiration measurements. Soil respiration in the footprint areas of the Harvard Forest Hemlock and Little Prospect Hill eddy flux towers has shown generally similar responses to soil temperature and precipitation as soil respiration near the EMS flux tower (see data set HF006), but also some differences. Soil respiration at the Hemlock tower site has been lower than at the other tower sites during very wet summer weather, but higher during dry summer periods. Average estimated annual total soil respiration has been close to the same for all three tower footprint areas, however. There has been some evidence of lower soil respiration in the parts of the Little Prospect Hill tower footprint with lowest soil moisture (those with a high slope position, 100 m from the tower), as compared with other sites during very dry summer periods, but such periods have been very rare during the period of data collection. Soil respiration measured near the Little Prospect Hill tower in summer has also been higher than ecosystem respiration as estimated from nighttime carbon flux measured by an eddy covariance system. This indicates that during some nighttime periods, CO2 is being removed from the volume of air below the eddy flux system by a route other than through the top of the forest canopy near the flux tower, possibly by downslope advection, even under conditions when it initially appeared that atmospheric turbulence was high enough to prevent removal of CO2 by these other mechanisms.
Soil Water Content at Harvard Forest HEM and LPH Towers 1998-2007
Water content of the top 20 cm of soil was measured using 1.5 inch diameter soil cores. Soil water content is of particular interest and importance in explaining patterns of soil respiration (including root respiration) and ecosystem respiration, 60 to 75% of which occurs below the ground surface at Harvard Forest. Soil water content in deciduous forest near the Little Prospect Hill Forest was in general found to be more variable than near the Hemlock tower. One influence contributing to this is the presence of a water table within 1 m of the soil surface near the hemlock tower, compared to a water table at unknown depth in the deeply drained soils in most parts of Little Prospect Hill. Relatively low evapotranspiration at the Hemlock tower site during the period when deciduous trees are foliated also contributes to higher water content in soil there, and a relatively thick surface organic layer. These influences tend to maintain soil respiration at higher levels in the hemlock forest during dry summers, but excessive moisture in the soil at the Hemlock site during very wet summers appears to suppress soil respiration.
Harvard Forest Snow Pillow since 2009
Water storage in snowpack is a key factor in the hydrological cycle of central New England. The Harvard Forest Snow Pillow provides continuous long-term measurements of the water content of snowpack (snow water equivalent) during the winter months. The snow pillow is located in a mature mixed hardwood stand with scattered conifers about 50 m north of the Nelson Brook Big Weir. For current data, please see: https://harvardforest.fas.harvard.edu/met-hydro-stations.
Sapwood Temperatures in Hemlock Trees at Harvard Forest HEM Tower 1997-1998
Sapwood temperatures in four large hemlocks, 130-200 years old and about 40 to 90 cm basal diameter and 25 to 29 m tall, were measured in order to estimate sapwood respiration in these trees as part of a physiological model for hemlock forest carbon exchange. As expected, sapwood temperature varied most in small branches and least in the main bole of the tree near the ground. An additional finding from these measurements is that sapwood begins to freeze at -1 to -2 degrees C, as shown by a stabilization and in some cases an increase of about 1 degree C in sapwood temperature when air temperature cooled continuously to below this temperature range.
Leaf Litter Moisture Content at Harvard Forest HEM and LPH Towers 2006
Leaf litter was collected at the time of soil respiration measurements and its moisture content was measured in order to determine the contribution of leaf litter decomposition to measurements of total soil respiration including the litter layer. Leaf litter moisture has been shown to strongly affect CO2 release from organic soil layers (Borken et al. 2003).
Moths, Ants and Pitcher Plants in Bogs at Harvard Forest and Belchertown MA 2007-2013
Ecologists have long recognized that coexistence of interacting species depends on a diversity of separate, but linked habitats. Most models of species coexistence treat these habitat "patches" as unchanging elements of the landscape, but in reality, they are constantly changing in size and shape. The structure and dynamics of the food webs that inhabit them both control and depend on these changes. In this five-year (2006-2011) collaborative project, we are using a combination of extensive field surveys and intensive field experiments to understand how species interactions change the spatial distribution of dynamic habitat patches across the landscape, and to determine how food webs are structured within and among these patches. The experimental system for this five-year research project is the Sarracenia "microecosystem": the northern pitcher-plant Sarracenia purpurea; the unique food web of bacteria, protozoa, rotifers, mites, and fly larvae that live within its rainwater-filled leaves; three species of bog-inhabiting ants that are the primary prey for this carnivorous plant; and larvae of the pitcher-plant moth, Exyra fax, which cut and drain pitchers and remove food web habitat. Results from surveys of bogs in all six New England state and field experiments conducted at bogs at Harvard Forest and Belchertown, Massachusetts will be used to parameterize a simulation model to predict changes in spatial structure of ant, moth, and plant populations, and the structure and composition of the aquatic food web associated with the plant. This work is funded by the U.S. National Science Foundation, through collaborative awards 0541680 and 0541936.
Plantation Biodiversity Plots at Harvard Forest since 2007
Plantations have been part of forestry at Harvard Forest since its beginning. Plantations were established from 1911-1944, usually on open or cut-over land. The objectives for plantation forests at Harvard Forest were to: increase the amount of productive forest land; examine the suitability of various species and cultivars to New England conditions; and test planting and tending methods. At first, mainly small plantings (less than 1 to 4 acres) were established primarily on "blank" lands. Some larger plantations (20+ acres) were established on cut-over land around 1930. The bulk of the plantings were red pine, white pine and spruce (white and Norway), but several other conifers were also planted. The maximum amount of land in plantations came to about 270 acres (less than 10% of Harvard Forest’s land base). Tending of the plantations, especially weeding in the decade following establishment, but also in-filling, pruning and thinning, was conducted and carefully documented. However, tending of plantations ceased about 1950. Since then, the fate of the plantations has been mixed. Some plantations were out-competed by native forest with only scattered planted trees remaining. A few acres of plantations were harvested in the 1950s. About 40 acres of plantations were harvested in the 1990s. As of 2007, approximately 135 acres remained. These stands range in age from 60-90 years old. Some stands have substantial areas blown down. We developed a management plan to harvest about 80 acres of mature plantation forests beginning in 2008 in order to terminate these long term experiments, to regenerate a diversity of native tree species and restore native forests to these sites, and to initiate a new suite of long term experiments. For the next 10-15 years, the harvested areas will provide early successional habitat for a variety of wildlife species. A suite of permanent vegetation plots was established throughout the plantations to assess vegetation structure in plantations an
Short-Term Effects on Vegetation in Soil Warming Plus Nitrogen Addition Experiment at Harvard Forest 2006
The purpose of this experiment is to examine the interactive affects of warming and N additions on plant diversity. The experiment consists of four treatments (control, heated +N, heated -N, +N only) with six replicates per treatment in a completely randomized design. Average soil temperature in the heated plots will be elevated 5 deg C above ambient by the use of buried heating cables placed at 10 cm depth in the soil and spaced 20 cm apart. The heating cables will be controlled by a data logger that monitors thermistors (5 per plot) every 10 min. Plots will automatically turn on and off to maintain a 5 deg C temperature difference between the heated and control plots. The N addition plots (heated +N, +N only) will be fertilized following the protocol of the Chronic Nitrogen Addition Study. An aqueous solution of NH4NO3 will be applied at a rate equivalent to the low N plots at the chronic N study (5 g m-2 yr-1). Fertilizer will be applied in equal monthly doses during the growing season (Apr-Oct). The control plots and unfertilized, heated plots (heated -N) will receive water only.
Umbilicaria Mammulata and Nitrogen Deposition at Harvard Forest 2006
Atmospheric N has quadrupled due to anthropogenic inputs and is projected to double again by 2050. The lichen Umbilicaria mammulata relies primarily on atmospheric deposition for nutrients, including N. Much of this species’ geographic distribution coincides with the N deposition gradient in the eastern US. We were interested in the potential impacts of N deposition on this species under realistic field conditions. Lichens were collected at six sites, ranging from Maine (low deposition) to West Virginia (high deposition). Thalli were analyzed for %C, %N, C:N, specific thallus weight (a measure of thickness), chlorophyll content, and chlorophyll fluorescence. Using stepwise regression we identified the most predictive model(s) using N deposition, environmental variables, and climate to predict differences in lichen ecophysiology and biochemistry across the gradient. While N deposition was important in predicting some responses, the model that best predicted %N in lichen only included mean minimum temperature, mean annual precipitation, and substrate slope. In controlled experiments at Grandfather Mountain (Linville NC) lichens were fertilized in situ with N to mimic deposition projected for 2050. There were no significant differences between control and fertilized thalli for any response variables, but differences did exist among sites. The results of this study highlight the complexities associated with sampling along a gradient of one factor in a multivariate environment.
Barn Tower Meteorological Station at Harvard Forest since 2015
The Barn Tower (40 m) was installed in 2009 to support meteorological and phenological measurements and to provide a relay point for the Harvard Forest field wireless network. A wind instrument was later installed at the top of the tower to provide continuous measurements of wind speed and direction.
Ecophysiology of Carnivorous Plants Worldwide 1980-2011
Identification of trade-offs among physiological and morphological traits and their use in cost-benefit models and ecological or evolutionary optimization arguments have been hallmarks of ecological analysis for at least 50 years. Carnivorous plants are model systems for studying a wide range of ecophysiological and ecological processes and the application of a cost-benefit model for the evolution of carnivory by plants has provided many novel insights into trait-based cost-benefit models. Central to the cost-benefit model for the evolution of botanical carnivory is the relationship between nutrients and photosynthesis; of primary interest is how carnivorous plants efficiently obtain scarce nutrients that are supplied primarily in organic form as prey, digest and mineralize them so that they can be readily used, and allocate them to immediate versus future needs. Most carnivorous plants are terrestrial - they are rooted in sandy or peaty wetland soils - and most studies of cost-benefit trade-offs in carnivorous plants are based on terrestrial carnivorous plants. However more than 10% of carnivorous plants are unrooted aquatic plants. By examining data published between 1980 and 2011, we ask whether the cost-benefit model applies equally well to aquatic carnivorous plants and what general insights into trade-off models are gained by this comparison. Nutrient limitation is more pronounced in terrestrial carnivorous plants, which also have much lower growth rates and much higher ratio of dark respiration to photosynthetic rates than aquatic carnivorous plants. Phylogenetic constraints on ecophysiological trade-offs among carnivorous plants remain unexplored. Despite differences in detail, the general cost-benefit framework continues to be of great utility in understanding the evolutionary ecology of carnivorous plants. We provide a research agenda that if implemented would further our understanding of ecophysiological trade-offs in carnivorous plants and also would pro
Role of Personal Connections in Shaping Decisions About Private Forest Use in Central Massachusetts 2008
We begin with a simple premise: Social and ecological systems are interconnected in complex ways. Forests are, perhaps, one of the most intriguing examples of this interconnectedness--particularly those in private ownerships. Forested landscapes are essential in maintaining human systems through the provision of multiple ecosystem services that span public (e.g., clean water, nutrient cycling) and private (e.g., fiber, maple syrup, home sites) goods. However, the majority of forestland in the Eastern United States is a mosaic of small landholdings (less than 20 ha) where property management is largely uncoordinated. On such landscapes, decentralized, ownership-centric decision-making defines the mix of ecosystem services provided and the landscape patterns present now and in the future. While somewhat effective for less spatially sensitive ecosystem services (e.g., fiber production), this ownership-centric approach is ill suited to spatially sensitive ones (e.g., water quality) and may, in some cases, be detrimental to them (e.g., habitat fragmentation). Improving the ecological and landscape sensitivity of private forest conservation and management is a major challenge facing researchers, practitioners, and policymakers in sustaining forest ecosystems. Central to unraveling this challenge is a fundamental understanding of how landowners simultaneously fit within their social and bio-physical landscapes. Despite their importance to broader forest sustainability, our collectively understanding of forest landowners has been primarily concerned with individual landowners and/or individual properties. For example, most research surrounding private forest landowners centers on primarily agent-based theories of behavior or decision-making (e.g., rational actor, theory of planned behavior). This perspective is useful in predicting and effecting behavior at broad scales, but lacks the specificity needed to address local landscape concerns and/or opportunities. Other studies
Role of Moose and Deer Browsing in Harvested Forests of Southern New England since 2008
In the past 20 years, moose have spread south from Vermont and New Hampshire and recolonized their pre-historical range limit in southern New England from which they had been extirpated almost 200 years earlier. Intensive moose browsing in the boreal forest has caused declines in forest density and shifts in species composition in some areas, generating considerable interest and concern among foresters, wildlife managers, and ecologists as to how moose along with white-tailed deer will impact forest development in this region. Harvard Forest in collaboration with researchers at the USGS Massachusetts Cooperative Research Unit has initiated a long-term study of the role of moose and deer in SNE forests using experimental exclosures. The design is a randomized block with 3 factors -- full exclosure, partial exclosure, and control plot. Full exclosures exclude both moose and deer but allow access to small mammals such as mice, squirrels, and rabbits. Partial exclosures have a 60cm opening around the bottom perimeter of the fence, which excludes moose but allows access to deer and other small and medium-sized animals. The design enables us to quantify forest composition and structure in areas (1) exposed to moose and deer browsing,(2) protected from moose and deer browsing, and (3) exposed to deer browsing but protected from moose browsing.
Tree Growth and Coarse Woody Debris in Regenerating Forests at Harvard Forest since 2008
This project is a field-based study to measure sequestration of atmospheric carbon dioxide in a regenerating New England forest. This study established long-term biometric plots suitable for measuring changes in carbon storage through time in three forest stands: an early-20th-century conifer plantation, a naturally regenerating former conifer plantation harvested in the 1990s, and a conifer plantation scheduled for harvest next winter. The first three years of this project determined the initial carbon budget of these forest stands, measured carbon fluxes into and out of these stands, and laid the groundwork for future investigations. Subsequent years will investigate larger-scale questions, such as how successional patterns affect carbon sequestration, and how these patterns change with stand age. The work also addresses how forestry practices influence carbon sequestration, and provide guidance for how forest management could enhance terrestrial carbon uptake in the future.
Nonstructural Carbohydrates in Forest Trees at Harvard Forest 2007-2010
Forest trees accumulate and store surplus nonstructural carbohydrates (NSC) as resources to be used to support future growth. This can be viewed as a conservative investment strategy, providing reserves that the tree can utilize in times of stress. NSC reserves are thus important in the context of forest responses to climate change, and forest ecosystem carbon cycling. At quarterly intervals over a three year period, we have monitored stemwood nonstructural carbohydrate (NSC) reserves of the dominant tree species of New England at three sites along a forest composition gradient: an oak-dominated transition hardwood forest (Harvard Forest), a maple-beech-birch northern hardwood forest (Bartlett Experimental Forest), and a spruce-fir boreal transition forest (Howland Forest). Adding to recent evidence indicating that in mature forest trees the nonstructural carbohydrate pool is surprisingly large, our results suggest that this pool is also highly dynamic, and unexpectedly old. In most species, seasonal dynamics in starch (2-4x higher in the growing season, lower in the dormant season) mirrored those of sugars. This data set contains 3 y of quarterly NSC concentration measurements (stemwood starch and sugars - sucrose, glucose, fructose, raffinose, stachyose - in mg per g OD wood tissue) for red maple, eastern hemlock, and red oak at the Harvard Forest.
Stream Suspended Sediment and Particulate Organic Matter at Harvard Forest 2009-2010
In addition to conveying water and nutrients and providing habitat to a variety of ecosystems, streams transport downstream mineral sediment and other particulate matter washed in from hillslopes and eroded from its channel and banks. At high levels, suspended sediment can be a devastating pollutant for aquatic organisms. The amount of suspended material in a stream varies tremendously with discharge; typically, suspended sediment increases with discharge, as stormwater runoff and overland flow carry particles from the hillslopes into the channel. Suspended sediment can also be a function of land use and vegetation, both of which affect the infiltration capacity of the landscape; more infiltration generally means less surface runoff and thus less sediment. Forested watersheds such as the Bigelow Brook watershed will typically have less suspended sediment than similar watersheds in urban environments. By analyzing how suspended sediment varies with discharge, I will be able to compare the relative effectiveness of overland flow of stormwater in washing materials into the streams. It is also possible that tree loss due to the wooly adelgid, ice storms, or fire in the watershed may increase the amount of sediment to Bigelow Brook, as a loss in tree canopy may result in more soil erosion due to rain splash and more water overall reaching the stream. For this reason, I hope to continue monitoring sediment in Bigelow Brook for an extended period of time to record any significant changes due to changing vegetation. Furthermore, by determining how much of the suspended sediment consists of particulate organic matter (using standard LOI techniques), I will be able to estimate the net carbon export from the two watersheds via that pathway. Preliminary, back-of-the-envelope calculations suggest that as much as 3-5% of the total annual carbon export leaves the Harvard Forest watershed via stream-transported particulate organic matter. To this end, I propose to measure suspended
Inorganic Nitrogen Pools and Tree Composition in Hemlock Removal Experiment at Harvard Forest 2007-2009
This study assessed how the change in leaf litter input and environmental conditions, from that of hemlock stands to earlier successional deciduous stands, will affect inorganic nitrogen availability at the interface of the mineral soil and LFH horizons. In early October 2007 we exchanged 0.5 x 0.5 m "loaves" of LFH horizons from hemlock and deciduous stands between forest types, while keeping control plots in the original forest stands. Inorganic nitrogen outputs from the litter loaves were monitored for 20 months using ion-exchange resins, removing and replacing the resins three times at 5 - 8 month intervals. Results indicated that there were differences between the control hemlock and deciduous loaves - NO3 and NH4 availability were higher in deciduous stands. However, the transfer of litter loaves from one stand type to another did not reveal changes in nutrient availability due to a shift in habitat. Rather, the methodology of moving litter loaves to a new site caused greater changes in nutrient availability, particularly over the summer months.
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Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.