Datasets

Data Availability Name Description Objective Dates
DownloadableDeer and Moose Browsing in Hemlock Removal Experiment at Harvard Forest 2008Hemlock decline in New England is caused by direct and indirect effects of invasion of the hemlock woolly adelgid. Direct damage from the insect is causing gradual mortality of hemlock. Widespread harvesting of hemlock in advance of mortality, in contrast, causes immediate mortality and removal of biomass from the site. Although both processes affect thousands of acres of forest annually we have only a limited understanding of their effects on forest ecosystem function and productivity and the nature of the subsequent forest community. We anticipate that harvesting will yield different consequences than gradual mortality from the insect. Therefore we designed an experiment to simulate these contrasting impacts, by logging or girdling hemlock stands. Results from the experimental treatments will be compared to the changes observed in forests that are being infested by the adelgid, and can also be included in integrated analyses of a suite of large experiments that form a core component of the Harvard Forest LTER program. Deer and moose foraging can play a key role in shaping forest regeneration after disturbance in temperate forest. In 2008, we initiated a browsing survey of woody stems in the Simes hemlock removal experiment plots. There are regular moose sightings in the study area, and moose pellets are commonly found within the plots. Also, extensive browsing of tree regeneration in the logged plots was Noted starting in 2007.Monitor the role deer and moose browsing plays in shaping forest regeneration after a pest or harvesting disturbance.2008-01-01 to 2008-12-31
DownloadableEcosystem and Vegetation Response to Hemlock Logging in Southern New England 1999-2005This study compares the magnitude and trajectory of vegetation and ecosystem function dynamics associated with the direct impact of hemlock woolly adelgid (Adelges tsuga; HWA) infestation versus the indirect consequences of HWA-induced damage in the form of salvage and pre-emptive logging of hemlock (Tsuga canadensis (L.) Carriere) forests. The study was conducted within an area extending from southern Connecticut up to and including the Connecticut River lowlands west to the Berkshire Plateauin central Massachusetts, USA. Overstory and understory vegetation and ecosystem function parameters such as decomposition and nitrogen cycling were examined in logged and unlogged portions of 10 hemlock stands varying in HWA damage intensity.The objective is to compare the direct impact of hemlock wooly adelgid infestation to the indirect consequences of HWA induced damage from salvage and logging of hemlock.1999-01-01 to 2008-12-31
DownloadableEffects of Warming on Tree Species Recruitment at Harvard Forest and Duke Forest since 2009Climate change is restructuring forests of the United States, although the details of this restructuring are currently uncertain. Rising temperatures of 2 to 8 deg C and associated changes in soil moisture will shift the competitive balance between species that compete for light and water, changing their abilities to produce seed, germinate, grow, and survive. Large scale experiments are being used to determine the effects of warming on the most sensitive stage of species distributions, i.e., recruitment, in mixed deciduous forests in southern New England and in the Piedmont region of North Carolina. Two questions organize our proposed research: (1) Might temperate tree species near the "warm" end of their range in the eastern United States decline in abundance during the coming century due to projected warming? and (2) Might trees near the "cool" end of their range in the eastern United States increase in abundance, or extend their range, during the coming 100 years because of projected warming? To explore these questions, seedlings are exposed to air and soil warming experiments in two eastern deciduous forest sites; one at the Harvard Forest (HF) in central Massachusetts, and the other at the Duke Forest (DF) in the Piedmont region of North Carolina. The focus is on tree species common to both Harvard and Duke Forests.To determine how climate change will restructure mixed deciduous forests in the Eastern United States at both the "warm" and "cool" ends of the tree species range. 2009-01-01 (ongoing)
DownloadableFern Understory as an Ecological Filter at Harvard Forest 1993-1995This project is was an investigation of the role of the fern understory as an ecological filter that influences the organization of the tree seedling bank in New England deciduous forests. The data files summarize a series of field experiments conducted from 1993 to 1995 evaluating the response of seed germination and seedling growth and survival to experimental understory manipulation. These field studies involved three experimental manipulations of the fern understory: 1) removal of ferns 2) ferns tied back (to remove above-ground shading) 3) ferns left intact (control). These manipulations were established in 180 - 1m2 plots spanning six field sites and 2 different fern species (3 understory manipulations x 2 understory fern species x 6 sites x 5 replicates/site = 180 experimental plots).The purpose of this study was to determine the influence of fern understory on tree seedling bank in New England deciduous forests.1993-01-01 to 1995-12-31
DownloadableGap Partitioning Among Maples at Harvard Forest 1986-1989We measured shoot architecture, photosynthesis, survival and growth by seedlings of three shade-tolerant species of maple (Acer pensylvanicum, A. rubrum, A. saccharum) in an experimental test of the gap partitioning hypothesis. Trees were felled to create a total of six cleared, elliptical canopy gaps of two sizes (8m x 12m, 75m2; 16m x 24m, 300m2). Naturally-established, undamaged, unbranched seedlings (15-30 cm tall, 10-20+ years old) of the three study species (2160 total, 720 per species) were transplanted into five plot locations (center and NW, NE, SW, and SE gap edges) within all six gaps and matching understory sites one year before gap creation. All plots were weeded regularly and spaded annually along the edges to remove above and below-ground competition. Measurements of microclimates and Non-competitive seedling responses were made over one year before and two years following gap release.This project used shade tolerant maple seedlings to test the gap partitioning hypothesis.1986-01-01 to 1989-12-31
DownloadableHemlock History Plots at Harvard Forest since 1995Hemlock woolly adelgid (Adelges tsugae) has the potential to change hemlock (Tusga canadensis) forests in New England, and at Harvard Forest in particular. For this project, the investigators surveyed four hemlock-dominated plots in Harvard Forest for community vegetation structure and composition. This project aimed to link the long-term history of hemlock stands at Harvard Forest to other studies of hemlock response to hemlock woolly adelgid infestation, and to provide a baseline for continued intensive study of hemlock dynamics within the stands.1995-01-01 (ongoing)
DownloadableHemlock Understory Vegetation Plots at Harvard Forest since 2002The invasion of the non-native insect, hemlock woolly adelgid (HWA, Adelgids tsugae) into hemlock (Tsuga canadensis) stands in New England has the potential to rapidly change the ecology and function of these forests. The investigators of this project are monitoring how forest structure and function changes as the adelgid invades hemlock stands in Harvard Forest. To do this, this study surveyed community vegetation structure and composition prior to adelgid infestation as well as during the progress of the infestation. To link the history of hemlock stands in New England forests to the current response to adelgid infestations from multiple studies.2002-01-01 (ongoing)
DownloadableHurricane Recovery Plots at Harvard Forest since 1937The New England hurricane of 1938 destroyed many acres of mature and semi-mature forests, thereby initiating new forest associations over a large area. Permanent plots were established across the Harvard Forest in severely damaged stands (many of which were logged subsequent to the hurricane) to assess information about forest succession. Most of the plots involved successions following the blowdown of white pine on glacial till or outwash soils. From 1940 to 1948, and in 1978 and 1991, tree density and the presence or absence of herb and shrub species were tallied. Pioneer species regenerating from seed and advance regeneration of longer-lived species quickly established at the sites.This research study was created to better understand succession of a New England forest after a hurricane.1937-01-01 to 1991-12-31
DownloadableHurricane Recovery Plots at Harvard Forest since 1937The New England hurricane of 1938, by destroying many acres of mature and semi-mature forests, initiated new forest associations over a large area. Permanent plots were established across the Harvard Forest in severely damaged stands (many of which were logged subsequent to the hurricane) to assess forest succession. Most of the plots involved successions following the blowdown of white pine on glacial till or outwash soils. From 1940 to 1948, and in 1978 and 1991, tree density and presence or absence of herb and shrub species were tallied. Pioneer species regenerating from seed and advance regeneration of longer-lived species quickly established at the sites; hemlock was the only species successfully regenerating after year 10, and most tree species were present within 2-4 years of the hurricane. By 1978, pioneer species such as gray birch and pin cherry declined or disappeared and red maple, white pine, paper birch and red oak dominated the plots. By 1991, most understory species present before the hurricane had returned, although there was a small group of understory species that apparently were more sensitive to disturbance and did not recover.To observe the succession of forest stands that were destroyed by a hurricane in 1938 and then, for the most part, logged after the hurricane.1937-01-01 (ongoing)
DownloadableImpacts of Hemlock Harvesting in Central Massachusetts 2003-2009The recent unimpeded infestation of the hemlock woolly adelgid (HWA; Adelgids tsugae) across the Northeastern U.S. is driving large-scale hemlock decline and mortality. HWA has already infested over 40% of the towns in Massachusetts and, as a result, many landowners are considering pre-emptively harvesting their eastern hemlock (Tsuga canadensis) stands. To examine the local impacts of this cutting activity, this study examined stand and ecosystem dynamics in 10 hemlock-dominated sites on public and private lands where hemlocks were harvested between 1 to12 years ago with nearby uncut forests.To observe the local impacts of the cutting of Hemlock trees in the past 1 to 12 years on public and private lands with nearby uncut forests.2003-01-01 to 2009-12-31
DownloadableLandscape Response to Hemlock Woolly Adelgid in Southern New England 1997-2011The hemlock woolly adelgid (Adelges tsuga Annand; HWA), a small, aphid-like insect native to Japan, is currently migrating Northward through eastern North America and threatens to eliminate eastern hemlock (Tsuga canadensis (L.) Carriere), one of the most abundant, long-lived shade tolerant species, across its range. In addition, a second invasive pest, the elongate hemlock scale (Fiorinia externa; EHS), often co-occurs with HWA on hemlock with unknown long-term consequences. This study was started to analyze Hemlock tree stands, the damage created by HWA and the long term consequences of EHS.The major objectives of this study were: (1) To characterize the pre-HWA distribution, composition, and structure of hemlock stands; (2) to characterize the spatial patterns of damage generated by HWA across southern New England since the time of its arrival in 1985; (3) to examine environmental and stand factors that are associated with declines in crown vigor and mortality of hemlock; (4) examine the dynamics of HWA and EHS in hemlock stands over time; and (5) assess whether there is a difference in the response of these insects to abiotic conditions (winter temperature, summer temperature, summer precipitation), and whether the distribution and abundance of each insect species is dependent on biotic interactions with the co-occurring insect species.1997-01-01 to 2001-12-31
DownloadableLong-Term Impacts of the Hemlock Woolly Adelgid on Forest Carbon at Harvard Forest 2008-2011This study used a comparative approach to study potential changes in C fluxes and storage and N cycling associated with Hemlock Wooly Adelgid induced hemlock decline and replacement. The stands include primary and secondary growth hemlock forests (230 and 132 years old, respectively), recently disturbed stands (5 and 18 years old) that now have rapidly growing black birch saplings, and a mature black birch stand of age similar to the second-growth hemlock stand. This study addressed the question of whether the quantity and distribution of C pools in black birch forests are the same as those found in the hemlock stands they replace and, if so, over what time scales.2008-01-01 to 2011-01-01
DownloadableMoose Foraging in Temperate Forests of Central Massachusetts 2005The "re-wilding" of ecosystems with extirpated large mammals has become a focus of recent scientific and conservation initiatives; however, it is unclear how proposed re-introductions will influence systems that are often vastly different from those that occurred before these animals were extirpated. Moose, the Northeast’s largest Holocene browser, have recently expanded across southern New England’s temperate forest landscape after an absence of 200 years, realizing a natural re-wilding experiment. Moose have been well-studied throughout the boreal forest biome; however, because they are rare today in temperate forests, almost Nothing is known of their ecology, behavior, or potential impacts to these ecosystems. This study investigated patterns of winter moose browse in order to: (1) gain insight into the likely influences of this herbivore on the vegetation patterns of the region; and (2) to identify the most important habitat features influencing moose winter foraging activity at a landscape and site scale. Two large forested watersheds in Central Massachusetts were sampled for moose browse, habitat features, and disturbances including forest harvesting and human activity. Chi-square and t-tests were used to identify browse species preferences of moose, and step-wise multiple regression was used to identify habitat variables that are strong predictors of browse intensity.2005-01-01 to 2005-12-31
DownloadablePermanent Plots at Pisgah State Forest in Winchester NH since 1984There are relatively few studies that have examined forest structure and composition both before and after a catastrophic wind disturbance has altered the forest. On a twenty acre parcel of old-growth forest located in the Pisgah State Forest in southwest New Hampshire, the collection of a long term data set from 1907-1995 has made it possible to consider how the hurricane of 1938 altered forest structure, species composition, and subsequent forest development in the stand. Various types of information were gathered throughout the century that allowed the quantification of forest structure and composition: species identification, diameter measurements, tree status (living or dead), tree cores, and individual tree growth and mortality have recently been tracked. The purpose of this project is to study the reaction of an old growth forest after a hurricane and how it changed the structure, species composition and forest development.1984-01-01 to 2015-12-31
DownloadablePhenology and Vegetation Growth in Prospect Hill Soil Warming Experiment at Harvard Forest 1992-1993As the mean annual temperature of Northeast North America rises as a component of global climatic change, it is important to understand how the predominant vegetation of the region will be affected. Existing experimental and correlative evidence from field sites suggests that temperature rise will significantly modify soil processes, nutrient availability, and plant growth. We investigated the responses of temperate deciduous forest vegetation to artificial soil warming at 20 sampling dates during the 1992 and 1993 growing season. We explored whether soil warming measurably altered growth and the temporal dynamics of leaf and fruit production in 26 species of three contrasting plant growth forms (herbaceous perennials, shrubs, and canopy trees). We hypothesized that soil warming would exert differential effects on emergence, phenology, leaf expansion rates, growth, photosynthesis, and vegetative and sexual reproduction among species, with implications for changing community structure in these forests.To determine how soil warming will effect plant growth and if the global climate change will change community structure in these forests.1992-01-01 (ongoing)
DownloadablePlantation Biodiversity Plots at Harvard Forest since 2007A suite of permanent vegetation plots was established throughout tree plantations to assess vegetation structure in plantations and predict future dynamics in harvested and early seral habitats. An initial objective of the baseline survey was to characterize current tree regeneration and understory flora that will, in large part, determine the future composition of these forests as the overstory is harvested or senesces. 2007-01-01 to 2017-12-31
DownloadablePlantation Biodiversity Plots at Harvard Forest since 2007Plantations 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 maximum amount of land in plantations totaled about 270 acres (10% of Harvard Forest’s land base). The tending of the plantations was conducted and carefully documented; however, this work ceased about 1950. Since then, some plantations were out-competed by native tree species, with only scattered planted trees remaining, a few acres of plantations were harvested in the 1950, and about 40 acres of plantations were harvested in the 1990s. As of 2007, approximately 135 acres of plantations remained and ranged in age from 60 to 90 years old. Some stands have substantial areas blown down. In 2008, Harvard Forest developed a management plan to harvest 80 acres of mature plantation forests to terminate these long term experiments, regenerate a diversity of native tree species, 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 and predict future dynamics in harvested and early seral habitats. A suite of permanent vegetation plots was established throughout historical red pine and spruce dominated plantations to assess vegetation structure as plantations transition to native forest stands and predict future dynamics in harvested and early seral habitats. An initial objective of the baseline survey was to characterize current tree regeneration and understory flora that will, in large part determine the future composition of these forests as the overstory is harvested or senesces. 2007-01-01 (ongoing)
DownloadableRed Maple Seedling Soil Warming Experiment in Harvard Forest Lath House 2015Microhabitat 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.To understand the effect of experimental warming on the germination, survival, phenology, growth and biomass of red maple seedlings.2015-01-01 to 2015-12-31
DownloadableRegeneration Following Clearcutting Study at Harvard Forest since 1991This study shows the measurements of regeneration following removal of a 64-year old red pine plantation on the Prospect Hill tract in 1990. Collection of these measurements were continued for the twelfth year in 2001.The goal of this project was to assess regeneration following the cutting of a red pine plantation. 1991-01-01 to 2000-12-31
DownloadableRole of Moose and Deer Browsing in Harvested Forests of Southern New England since 2008In 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, initiated a long-term study of the role of moose and deer in SNE forests using experimental enclosures: full enclosure, partial enclosure, and a control plot.The goal of this project is to quantify forest composition and structure in harvested 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. 2008-01-01 (ongoing)
DownloadableRole of Moose and Deer Browsing in Unharvested Forests of Southern New England since 2011In 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, initiated a long-term study of the role of moose and deer in SNE forests using experimental enclosures: full enclosure, partial enclosure, and control plot. The goal of this project is to quantify forest composition and structure in unharvested 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.2011-01-01 (ongoing)
DownloadableSeed Bank in Hemlock Removal Experiment at Harvard Forest 2004-2015The impending loss of hemlock trees due to hemlock woolly adelgid (Adelges tsuga) infestation prompted the need to identify species of plants able to colonize areas where hemlock has been removed. We investigated species present in the seed bank (in 2004 and 2010), the seedling bank (in 2004 and 2010), and seed rain (from 2005-2015) in the Harvard Forest Hemlock Removal Experiment. This study provides a unique temporal documentation of changes in the seedbank, seed rain, and vegetation under conditions of a changing overstory. 2004-01-01 to 2015-12-31
DownloadableSeedlings and Saplings in the Clearcut Site at Harvard Forest since 2013The aim of this dataset is to quantify the changes over time in woody seedling and sapling abundances and sizes at a site that was clearcut in the fall of 2008, followed by natural regeneration. It evidences successional changes in recruitment, survival, and associated self-thinning, and can be used to quantify an accumulation of aboveground live biomass post-clearing with corresponding allometric relationships.This dataset quantifies the changes over time to woody seeling and sapling abundances and sizes after a clearcutting, in order to quantify aboveground live biomass.2010-01-01 to 2013-12-31
DownloadableTimber Harvesting Field Study in Western Massachusetts 2004-2005Forest harvesting is one of the most significant disturbances affecting forest plant composition and structure in Western Massachusetts, yet few studies have quantified the effects of harvesting in this region. Massachusetts requires all commercial harvest operations above 87 m3 to file a Forest Cutting Plan (FCP) with the state. We have digitized these FCPs (see McDonald et al. 2006), covering all harvests from 1984 to 2003. Our study area is Massachusetts, west of the coastal basin, as defined by Motts and O’Brian (1981). We selected 126 sites for sampling. Two-thirds of the sites (89) were harvested once between 1984 and 2003, and these were selected randomly from the larger FCP database. The remaining one-third of the sites (37) were control sites selected randomly from all unharvested forest in the study area. The boundaries for our field surveys were those filed with the FCP for harvested sites, and were circular for control sites, proportional in size to the mean FCP in the physiographic region (Motts and O'Brien 1981): Connecticut River Valley (10.7 ha), Central Upland (11.3 ha), Berkshire Valley and Taconic Mountains (12.6 ha), and the Western Upland (15.9 ha). Note that our sampled sites were well-dispersed over the study area, and encompassed the variety of past agricultural land-use. This study was created to quantify the effects of forest harvesting in Western Massachusetts.2004-01-01 to 2005-12-31
DownloadableTree Growth and Coarse Woody Debris in Regenerating Forests at Harvard Forest since 2008This 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.This study measures the amount of carbon sequestration and how that amount is influenced by different forestry practices. This information could be used to guide forest management practices for better carbon uptake.2008-01-01 to 2016-12-31
DownloadableTree Seed Dispersal in Hemlock Removal Experiment at Harvard Forest 2005Throughout the Northeast, the hemlock woolly adelgid (Adelges tsugae) threatens eastern hemlock (Tsuga canadensis) through direct mortality resulting from infestation followed by defoliation and indirect mortality in the form of pre-emptive logging. The efficacy of regeneration of vegetation following hemlock decline depends upon advance regeneration of seedlings and saplings, seed dispersal, and recruitment. This study investigated (1) whether the basic parameters of height of release and wind velocity affected seed dispersal distance and (2) the fit of a basic ballistic model of seed dispersal to empirical data in areas both with and without canopies. Empirical data was collected from seed dropping and seed rain experiments at Harvard Forest. Height and wind velocity only affected seed dispersal distance in open areas. Predicted values of dispersal distance generated by the basic ballistic model did not provide a good fit to observed dispersal data. Poor fits of the ballistic model to the data were due to the model’s inability to account for rare, long distance dispersal events. More complex models with additional parameters are necessary to model Non-localized seed dispersal. The purpose of this study was to research the efficacy of regeneration of vegetation following hemlock decline after hemlock wooly adelgid infestation. 2005-01-01 to 2005-12-31
DownloadableTree Seedlings in CRUI Land Use Project at Harvard Forest 1996Forests recovering from agricultural legacies differ in many ways that influence tree seed dispersal and seedling establishment patterns. The number of seedlings (less than 0.5 m tall) of all tree species on a 1 x 1 m resolution across six land use legacy sites (2 plowed, 2 pastured, 2 permanent woodlot) in summer 1996 were recorded to test several predictions about seedling abundance, diversity, and dispersion patterns, and their relationships to forest structure, microclimates, and soil resources.To determine regeneration of a previous agricultural field by monitoring the tree seedling dispersal and patterns of establishment.1996-01-01 to 1996-12-31
DownloadableUnderstory Vegetation in Hemlock Removal Experiment at Harvard Forest since 2003Hemlock decline in New England is caused by direct and indirect effects of invasion of the hemlock woolly adelgid. Direct damage from the insect is causing gradual mortality of hemlock. Widespread harvesting of hemlock in advance of mortality, in contrast, causes immediate mortality and removal of biomass from the site. Although both processes affect thousands of acres of forest annually, we have only a limited understanding of their effects on forest ecosystem function and productivity and the nature of the subsequent forest community. We anticipate that harvesting will yield different consequences than gradual mortality from the insect. Therefore we designed an experiment to simulate these contrasting impacts, by logging or girdling hemlock stands. Results from the experimental treatments are compared to the changes observed in forests that are being infested by the adelgid, and can also be included in integrated analyses of a suite of large experiments that form a core component of the Harvard Forest LTER programThe objective of this study is to collect data that will help compare and contrast the effects of tree removal versus tree death due to adelgid infestation.2003-01-01 (ongoing)
DownloadableUngulate Browsing and Foundation Tree Regeneration in Central New England 2010 In the summer of 2010, we initiated a landscape-scale observational study on ungulate habitat use and browsing on foundation tree species (Quercus spp. and Tsuga canadensis) in unlogged forests. Seventy-two forest plots were sampled across several ecoregions in central and western Massachusetts, southern Vermont and New Hampshire and Northern Connecticut. Tree seedlings, overstory characteristics, browsing, pellet piles, and shrub densities were sampled; and site attributes such as mean annual temperature and forest fragmentation were examined.The goal of this project was to quantify browsing on hemlock and oak species.2010-01-01 to 2010-01-31
DownloadableUngulate-Disturbance Interactions in Hemlock Ecosystems at Harvard Forest since 2012Densities of ungulates are often associated with recent forest disturbances (such as fire, logging and insect outbreaks) as increased resources stimulate tree regeneration, leading to abundant available browse. Despite the often significant role that ungulates play in disturbed forests, surprisingly little is known about ungulate-disturbance interactions. Ungulate herbivory is often excluded from examinations of forest response to disturbance. In the Northeastern United States, a large-scale insect outbreak, the hemlock wooly adelgid (HWA), has begun to have important effects on hemlock forests, both directly and indirectly (i.e., by preemptive salvage logging). No studies have examined the interactions of both moose and deer activity with these associated canopy disturbances. The authors examined the relative abundance of moose and deer in four treatments (2 replicates) at the Hemlock Removal Experiment using three indices of ungulate activity: pellet group density, evidence of past browsing on seedlings and saplings, and the occurrence of animals using game cameras. They also monitored the response of vegetation to ungulate browsing by sampling woody and herbaceous vegetation in fenced enclosures and paired controls in disturbed and undisturbed plots. Our objectives are twofold: to determine (1) the response of ungulates to varying disturbance types and intensities and (2) the influence of ungulate interactions with canopy disturbance on vegetation, other biota, and ecosystem processes. 2012-01-01 to 2013-01-01
DownloadableUngulate-Forest Interactions in Partially Harvested Oak-Pine Stands in Central Massachusetts 2009Ungulates are attracted to forest openings created by natural disturbance and timber harvesting which results in the abundance of high quality browse in these openings. Despite the increased activity and browsing of ungulates in forest openings, the importance of browsing relative to abiotic factors such as light on forest regeneration is often unclear. In southern New England, medium-intensity harvesting is the predominant forest disturbance attracting white-tailed deer and moose. Oaks, which are in decline, are the foundation hardwood taxon and predominant timber tree in the region. Hence, the effects of ungulate browsing on oak forests are of great interest to ecologists, conservationists and forest and wildlife managers. We sampled tree regeneration and ungulate foraging activity across a range of canopy disturbances (35-90% basal area removed) in 34 stands of the Quabbin and Ware River Watershed Forests. Browsing was very high across the plots with about 80% of red maple and oak stems browsed. Taller stems were generally browsed more frequently than shorter stems. Oak regeneration in the smaller size classes was generally lower in stands with higher percent cover of hay-scented fern. The proportion of browsed red maples and oaks generally increased with increasing density of these taxa. Despite intensive herbivory, oaks appear to be regenerating well with increased light in these partially harvested stands.The goal of this project was to quantify the interaction between medium intensity disturbance and ungulate browse.2009-01-01 to 2009-12-31
DownloadableVegetation Response in Simulated Hurricane Experiment at Harvard Forest since 1990Wind disturbance profoundly shapes temperate forests but few studies have evaluated patterns and mechanisms of long-term forest dynamics following major windthrows. In 1990, a large hurricane simulation experiment was initaited in a 0.8 ha manipulation (pulldown) and 0.6 ha control area of a maturing Quercus rubra/Acer rubrum forest in New England. 276 trees were toppled in the pulldown, using a winch and cable, in the Northwesterly direction of natural treefall from major hurricanes. Eighty percent of canopy trees and two-thirds of all trees greater than 5 cm dbh suffered direct and indirect damage. Twenty years of measurements were used to evaluate the trajectory and mechanisms of forest response after intense disturbance. Based on the patch size and disturbance magnitude, we expected pioneer tree and understory species to drive succession.To study how wind disturbance shapes temperate forests following major windthrows over time.1990-01-01 (ongoing)