Monthly Highlights

• 2008 April | March | February | January
• 2007 December| November | October |September | August | July | June | May | April | March | February | January
• 2006 December | November |October | September | August | July | June | May | April | March | February | January
• 2005 December| November | October | September | August | July | June | May | April | March | February | January
• 2004 December | November | October | September | August | July | June | May | April | March | February | January
• 2003 December | November | October | September | August | July | June

April 2008 Highlights

Harvard Forest Biodiversity Studies: The Vascular Flora

Jerry Jenkins, former Bullard Fellow and researcher with the Wildlife Conservation Society, Glenn Motzkin, ecologist at Harvard Forest, and Kirsten Ward, a former summer student at the Harvard Forest, have completed a study of the vascular plants of the Harvard Forest. The study compares the results of field studies that the authors conducted between 2004 and 2007 with previous three previous field studies in the 20th century. It documents the present and historical floras, gives a quantitative analysis of their structure and dynamics, and relates their changes to disturbance and environmental change.

Jenkins, J., G. Motzkin, and K. Ward. 2008. The Harvard Forest Flora. An Inventory, Analysis and Ecological History. Harvard Forest Paper no.28. pp. 266. Note this download is very large

Summer Institute for Teachers

The Harvard Forest offers a Forest Ecology training institute for teachers of grades 2-12. Learn from professional Ecologists how to implement field studies with your students, right in your schoolyard.

Teachers from all districts are encouraged to participate in this orientation on August 6th, 2008 to our year long Schoolyard Ecology program which includes two Schoolyear Seminars in addition to the summer institute. PDPs awarded to all participants. Registration flyer and forms are now available.

Wildlands and Woodlands: Gaining Ground

The 2008 Update has been released. In this issue, it describes momentum with a diverse constituency which has banded together in the Wildlands and Woodlands Partnership to promote the larger W & W vision. This group has encouraged the formation of regional partnerships focused on land protection and forest stewardship, promoted new policy initiatives to fund broad scale land protection and has worked with a large group of landowners in western Massachusetts to develop a regional forest protection effort. Read the update

Harvard Forest Publication

Harvard Forest Ecologist Kristina Stinson, along with former Bullard Fellow John Klironomos (University of Guelph) and researchers at University of Montana and Wright State University, followed up recent work on the antimicrobial properties of the invasive plant, Alliaria petiolata (garlic mustard). Their forthcoming paper in the journal Ecology provides new evidence for a novel mechanism by which garlic mustard disrupts below-ground mutalisms between plants and their beneficial microbes. As one of North America’s most aggressive invaders of undisturbed forests, garlic mustard is known to inhibit mycorrhizal fungal mutualists of North American native plants. The authors tested whether these inhibitory effects on mycorrhizas in invaded North American soils are stronger than on mycorrhizas in European soils where A. petiolata is native. They found that suppression of North American mycorrhizal fungi by A. petiolata corresponds with severe inhibition of North American plant species that rely on these fungi, whereas congeneric European plants are only weakly affected. The chemicals involved were identified as a combination of flavinoids and glucosinolates. These results indicate that antifungal phytochemicals, benign to resistant mycorrhizal symbionts in the home range, impose a novel threat to native North American plant species.

Callaway, R.M., D. Cipollini, K. Barto, G.C. Thelen, S.G. Hallett, D Prati, K. Stinson and J. Klironomos. 2008. Novel Weapons: Invasive Plant Suppresses Fungal Mutualists in America but not in Its Native Europe. Ecology.

March 2008 Highlights

Annual Harvard Forest Ecology Symposium

The nineteenth annual Harvard Forest Ecology Symposium will be held March 18, 2008 from 9:00am - 5:00pm at the Harvard Forest. This year's symposium will feature talks and discussion on: New England Landscape Response to Climate Change and Disturbance: Ecosystem Science Addressing Policy Concerns and The Future of Microbial Ecology at Harvard Forest. Learn more, RSVP and/or submit abstracts.

Harvard Forest Ecologist and Former REU Student Receive Award

Haley Smith, an undergraduate student at Oklahoma State University and REU student from the summer of 2007, and forest ecologist David Orwig recently won an award for their poster, "Influence of hemlock woolly adelgid and elongate hemlock scale on leaf-level physiological performance of eastern hemlock." The poster was presented at the 2008 USDA-sponsored Fourth Hemlock Woolly Adelgid Symposium in Hartford, CT.

Dean Establishes Fund to Support FAS Courses Taught at Harvard Forest

The Forest is pleased to announce that FAS Dean Michael Smith has established a fund to support courses being taught at the Forest by FAS faculty. "The intent of the course is to reimburse the Forest for meals and lodging, thereby removing that financial constraint from department budgets so Cambridge-based courses will be encouraged to take advantage of educational opportunities at the Forest. Faculty anticipating activities at the Forest may apply to the fund during preparation of the FY2009 budget." For more information, please contact Edythe Ellin at ellin@fas.harvard.edu

Harvard Forest Publications

Spread and Distribution of Two Invasive Species across Southern New England

Forest ecologist David Orwig along with collaborators Evan Preisser (University of Rhode Island), Alexandra Lodge (Summer 2005 REU student- Kenyon College), and Joe Elkinton (Umass, Amherst) report on the spread and distribution of 2 invasive species (hemlock woolly adelgid-HWA and elongate hemlock scale-EHS) across southern New England. This paper is a follow-up study that resampled 142 eastern hemlock stands originally sampled in the late 1990s (CT stands) or 2002-2004 (MA stands). The number of HWA-infested stands increased but the per-stand HWA density substantially decreased. In contrast, EHS distribution and density increased dramatically since 1997-98. Hemlock mortality was much more strongly related to HWA density than EHS density, and many stands remained relatively healthy despite an overall increase in hemlock mortality. There was a positive correlation between HWA and EHS densities in stands with low mean HWA densities, suggesting the potential for host-plant-mediated facilitation of EHS by HWA. Results suggest that interactions between invasive species may not have outcomes similar to those interactions occurring between native-native or invasive-native species pairs.

Preisser, E.L, A. G. Lodge, D. A. Orwig and J. S. Elkinton. 2008. Range expansion and population dynamics of co-occurring invasive herbivores. Biol Invasions 10:201–213

Water Use by Oak versus Hemlock. Implications for Ecosystem-level Effects of Hemlock Woolly Adelgid

The major significance of this paper is that it shows a red oak-dominated forest, common in many areas of southern New England, uses more water in summer than an old-growth hemlock forest. As a result, if hemlocks that are killed by the hemlock woolly adelgid are eventually replaced by a deciduous forest with oak as the dominant species (or any other species with similarly high water use), forest water use will increase and the amount of water available for streamflow, lakes and reservoirs will be reduced.

The paper also shows that although summer carbon storage in the hemlock forest between July 2004 and June 2006 was much less than in the oak-dominated deciduous forest, the hemlock forest stored enough carbon during relatively mild weather (without freezing nights) in spring and fall, that annual carbon storage in the hemlock forest was comparable to the oak-dominated forest. Climate warming appears likely to increase carbon storage during these spring and fall periods.

Hadley, J.L, P.S. Kuzeja, M.T. Mulcahy and S. Singh. 2008. Water use and carbon exchange of red hemlock dominated forests in the northeastern ecosystem-level effects of hemlock woolly. Tree Physiology 28, 615–627.

February 2008 Highlights

Annual Harvard Forest Ecology Symposium

The nineteenth annual Harvard Forest Ecology Symposium will be held March 18, 2008 from 9:00am - 5:00pm at the Harvard Forest. This year's symposium will feature talks and discussion on: New England Landscape Response to Climate Change and Disturbance: Ecosystem Science Addressing Policy Concerns and The Future of Microbial Ecology at Harvard Forest. Learn more and/or submit abstracts.

Harvard Forest on NPR's Climate Connections

Dan Charles of National Public Radio produced a program aired on December 31, 2007. He captures the work being done here at Harvard forest and helps reveal to the listener the importance of the research. Listen to the story and watch the audio photo show at http://www.npr.org/templates/story/story.php?storyId=17332316

Harvard Forest Schoolyard Students Give Presentation to the Mass. Secretary of Energy and the Environment

Three sixth-grade students who participated in Harvard Forest Schoolyard Ecology projects in 3rd, 4th and 5th grades, gave a presentation to Ian Bowles, Secretary of Executive Office of Environmental Affairs (EOEA. The students from the JR Briggs Elementary School in Ashburnham shared their experiences in the field-based ecological research projects related to Vernal Pools, Leaf Phenology and the Hemlock Woolly Adeldgid. Fifth grade teacher, Kate Bennett, introduced the presentation along with Mary Marro of the Nashua River Watershed Association. All three of HF's protocols were presented in an impressive powerpoint presentation that the students prepared and presented.

Sampling New Hampshire Forest Vegetation

The Harvard Forest is seeking two college students/recent grads with field experience in sampling forest vegetation as part of its 2008 Summer Research Program in Ecology. The two interns will work together with minimal supervision, laying out plots, sampling vegetation (trees, shrubs, herbs), soils and environmental conditions, and entering data into spreadsheets. This summer’s work will serve as the first census of a long-term ecological monitoring program for the more than 4000 acres of forest protected and managed by the Blue Hills Foundation in southern New Hampshire. Learn More.

Harvard Forest Publications

Invasive Species Distribution

Despite the recognized importance of historical factors in controlling many native species distributions, few studies have incorporated historical landscape changes into models of invasive species distribution and abundance. We surveyed 159 currently forested sites for the occurrence and abundance of Berberis thunbergii (Japanese barberry), an invasive, non-native shrub in forests of the northeastern U.S., relative to modern environmental conditions, contemporary logging activity, and two periods of historical land use. Modern edaphic characteristics explained a significant portion of the variation in B. thunbergii occurrence, whereas site history considerably improved predictions of population density and helped evaluate potential invasion mechanisms. Our results indicate that interpretations of both native community composition and modern plant invasions must consider the importance of historical landscape changes and the timing of species introduction along with current environmental conditions.

DeGasperis, B.G. and G. Motzkin. 2007. Windows of Opportunity: Historical and Ecological Controls on Berberis thunbergii invasions. Ecology, 88(12), pp. 3115–3125.

Mangrove Management Activities

In June 2006, Harvard Forest Senior Ecologist Aaron Ellison delivered the keynote address at the 2nd Meeting on the Mangrove Macrobenthos. Selected papers from this meeting have just been published in the Journal of Sea Research. In the lead paper, Ellison addresses mangrove management activities in the broader context of the diversity of animals such as crabs and prawns that depend on mangroves for substrate, food, and shelter and that also are exploited as human food sources. Exploitation of mangrove-associated prawns, crabs, and molluscs has a total economic value exceeding US $4 Billion each year, but world-wide patterns of exploitation fit the process described by economists as "roving banditry". Roving bandits are people and multinational corporations who move from location to location, rapidly exploiting and depleting local resources before moving on to other, as-yet unprotected areas. Ellison argues that to effectively manage mangrove fauna that management for ecosystem services, not immediate profit, is the only way to preserve the total biodiversity of this threatened ecosystem.

Ellison, A. M. 2008. Managing mangroves with benthic biodiversity in mind: moving beyond roving banditry. Journal of Sea Research 59: 2-15.

Read all the papers in this issue

January 2008 Highlights

Harvard Forest Policy Analyst Receives Award from the Society of American Foresters

The New England section of the Society of American Foresters (SAF) has announced that David Kittredge has been elected Fellow to the Society for 2007. SAF recognizes members who have provided outstanding contributions to the Society over a sustained period and have distinguished themselves in the forestry profession with the title Fellow. There are only 38 Fellows in New England (out of a membership of 1,100) and this includes notably Dave’s major professor at Yale University, Dr. David M. Smith.

2008 Harvard Forest Summer Program in Ecology for Undergraduates

We are now accepting applications for the 2008 Summer Program from undergraduates and recent graduates who are interested in an intensive research and education experience in ecology. Deadline: Feb. 1, 2008. Learn more

2008 Charles Bullard Fellowships in Forestry

We are now accepting applications for 6-12 months fellowships for advanced research and study by persons who show promise of making an important contribution, either as scholars or administrators, to forestry defined in its broadest sense as the human use of forested environments. Deadline: Feb. 1, 2008. Learn more

Harvard Forest Schoolyard Ecology Participants win 2007 Teachers of the Year Awards

We are proud to announce that both the Massachusetts Audubon Society's and the Nashua River Watershed Association's 2007 Teacher of the Year awards were given to Harvard Forest Schoolyard Ecology participants!

Tewksbury High School teacher, Elaine Senechal(photo on left) won the Massachusetts Audubon Conservation Teacher of the Year award. Nashua River Watershed Association Education Coordinator, Mary Marro (center) presents the NRWA 2007 Education Award to J.R. Briggs Elementary School Teachers, Mary Gagnon (left) and Kate Bennett (right)

All three of these teachers are involved in their 3rd year of implementing field ecology projects coordinated by the Harvard Forest Schoolyard Ecology program. Elaine Senechal is leading her High School students in a field ecology project called "Buds, Leaves, and Global Warming", which is a phenological study done in coordination with Harvard Forest Ecologist, Dr. John O'Keefe. Mary Gagnon's third grade students are immersed in the "Water in the Landscape: Vernal Pools" project done in coordination with Freshwater Ecologist, Dr. Betsy Colburn. Kate Bennett's 5th grade students are implementing the "Hemlock Trees and the Pesky Pest, the Woolly Adelgid project in cooperation with Forest Ecologist, Dr. David Orwig.

LTER releases Decadal Science Plan

The Long Term Ecological Research (LTER) Network, www.lternet.edu, has released its new Decadal Science Plan, which maps out the Network's science agenda for the next 10 years. Titled "Integrative Science for Society and the Environment(ISSE): A Plan for Research, Education, and Cyberinfrastructure in the U.S. Long-Term Ecological Research Network," the plan makes an ambitious call for research that extends the Network's foundational strength in ecology and environmental biology to also embrace the sociological sciences relevant to human-environment interactions. David Foster, Harvard Forest Director, participated in the writing team for the Plan and the ISSE. Read the entire press release.

New Harvard Forest Publication

Former Harvard Forest Bullard Fellow Elizabeth Farnsworth and Harvard Forest Senior Ecologist Aaron Ellison examine scaling relationships among leaf traits of 10 species of pitcher plants (Sarracenia species) fed different quantities of insect prey. Increased prey availability increased photosystem efficiencey (as expressed by the ratio of Fv/Fm), chlorophyll content, and photosynthetic rate. It also led to a shift from P- to N-limitation in subsequently produced pitchers. Increased prey also shifted leaf-trait scaling relationships, bringing them more in line with those found for a wide range of non-carnivorous plant species. The results support a general hypothesis published in 2006 by Bill Shipley and his colleagues that suggested that observed scaling relationships amongst leaf traits derive from trade-offs in allocation to structural tissues versus liquid-phase (e.g., photosynthetic) processes. These trade-offs appear to be especially constraining for plants growing in extremely nutrient-poor habitats such as bogs and other wetlands.

Farnsworth, E. J., and A. M. Ellison. 2008. Prey availability directly affects physiology, growth, nutrient allocation, and scaling relationships among leaf traits in ten carnivorous plant species. Journal of Ecology 96: 213-221.

December 2007 Highlights

2008 Harvard Forest Summer Program in Ecology for Undergraduates

We are now accepting applications for the 2008 Summer Program from undergraduates and recent graduates who are interested in an intensive research and education experience in ecology. Deadline: Feb. 1, 2008. Learn more

2008 Charles Bullard Fellowships in Forestry

We are now accepting applications for 6-12 months fellowships for advanced research and study by persons who show promise of making an important contribution, either as scholars or administrators, to forestry defined in its broadest sense as the human use of forested environments. Deadline: Feb. 1, 2008. Learn more

Centennial Edition - New England Forests Through Time

The Harvard Forest Centennial Edition (1907-2007) reprinting of New England Forests Through Time: Insights from the Harvard Forest Dioramas is now available. Along with the diorama illustrations and interpretations that made the first printing so popular, this edition contains a new preface, "Forests Past, Present, and Future", and updated "Suggested Further Readings." Copies can be purchased.

New grant for climate change research

The Department of Energy has awarded $3.4 Million to a four-university consortium that includes Harvard University's Harvard Forest, North Carolina State, the University of Tennessee, and the University of Vermont for a four-year study of the effects of climate change on the ecological dynamics of ants and other soil invertebrates. In early 2008, ten 5-meter (16-foot) diameter open-top chambers will be installed at Harvard Forest and in North Carolina. The air and soil in these chambers will be warmed to between 1 and 7 degrees C above current conditions to simulate climatic conditions expected to occur in the eastern United States in the next century. The study will examine changes in the number of species of soil-dwelling invertebrates and changes in the size and activity of ants. We are particularly interested to see if northern species are excluded from our experimental chambers by increasing temperature, and if southern species colonize these "hot-spots" in the landscape.

New Journal Articles

The Analytic Web project, a long-term collaboration between ecologists at Harvard Forest and computer scientists at the University of Massachusetts Amherst, is developing methods to ensure that scientific data analyses are sound and reproducible. This paper considers how such methods might be applied to a complex, real-time system for measuring the movement of water through a small forested watershed at the Harvard Forest.

Boose, E. R., A. M. Ellison, L. J. Osterweil, L. A. Clarke, R. Podorozhny, J. L. Hadley, A. Wise, and D. R. Foster. 2007. Ensuring reliable datasets for environmental models and forecasts. Ecological Informatics 2: 237-247.

What effect do protected lands have on land conservation or development nearby in the surrounding landscape? Using information on land cover and land protection over time for three sites (western North Carolina, central Massachusetts, and central Arizona), this paper aimed to answer this question. At all sites, newly protected conservation areas tended to cluster close to preexisting protected areas. Land protection breeds more land protection. On the other hand, on two of our three sites the development rate was significantly greater in regions with more protected land. Protected lands appear to be an amenity that increases nearby development. These twin trends- increased land protection and increased development nearby previously protected lands- suggest that each conservation action should be justified and valued largely for what is protected on the targeted land, without much hope of broader conservation leverage effects on the surrounding landowners.

McDonald, R.I., C. Yuan-Farrell, C. Fievet, M. Moeller, P. Kareiva, D. Foster, T. Gragson, A. Kinzig, L. Kuby, and C. Redman (2007) Estimating the Effect of Protected Lands on the Development and Conservation of Their Surroundings. Conservation Biology.

Old Growth Publications

Tony D'Amato, former REU and recent Ph.D. graduate, produced an outreach pamphlet with Paul Catanzaro that introduces the habitat features of old-growth forests, outlines management options and resources for restoring these features to woodlands, and discusses the opportunities to obtain economic and ecological benefits from second-growth forests. Management strategies range from hands-off approaches to active management practices and can be implemented in a variety of intensities, stages, and combinations to fit within landowner objectives.

D'Amato, Anthony and P. Catanzaro. 2007. Restoring old-growth characteristics. Outreach pamphlet, Umass Extension, Amherst, MA.

Havard Forest Ecologist David Orwig and Tony D'Amato recently contributed to the New England Society of American Forester's News Quarterly (Oct. 2007). This issues features old growth in the northeastern U.S. as the quarterly theme. They provide an overview of Tony's recently completed Ph.D. work and focus on the old-growth forest remaining in southern New England and how can it help inform management decisions. Findings suggest that relatively frequent, small-scale disturbances were common in the hemlock dominated old-growth forests of western Massachusetts. Structural, compositional, and historical development comparisons between old-growth and second growth hemlock forests are provided as guides to help restore old-growth elements and aid disturbance-based silviculture strategies for forests in this region.

Orwig, D.A. and A. D'Amato. 2007. Southern New England old-growth forests: how much is left and can they help inform management decisions? pp. 10-11 in Old Growth in the Northeast. New England Society of American Foresters Quarterly

November 2007 Highlights

Renewable Energy at Harvard Forest

A new renewable energy source was recently commissioned at Harvard Forest. In mid-July 2007, Moss Hollow, LLC (Lunenburg, MA) completed installation of a 10KW solar array next to the new Facilities Barn. Support for this $100,000 project included grants from the Massachusetts Technology Collaborative Small Renewables Initiative and Harvard University's Faculty of Arts and Sciences Dean's Fund; the balance was covered by the HU Green Campus Loan Fund. In the three months since the array began functioning, the system has generated more than 4,000 kWh of electricity. The solar array is part of the electrical system providing energy for all long-term experiments on the Prospect Hill Tract. These experiments, which explore the impact of global warming on the environment, now receive approximately 8% of their power needs from this renewable energy source. View energy output online.

Richard Hale Goodwin - Memorial Reflection

My first reflection on Dick's accomplishments is that his career and life were so diverse, so wide-reaching and so darn long that few people came to know more than even a small percentage of his greatness. an excerpt by David Foster, Director of Harvard Forest, former student and friend. Read the entire memorial reflection.

Harvard Forest 2007-2008 Charles Bullard Fellows in Forest Research.

Applications for 2008-2009 now being accepted

Harvard Forest is pleased to announce the 2007-2008 Charles Bullard Fellows in Forest Research. The purpose of this fellowship program, established in 1962, is to support advanced research and study by persons who show promise of making important contributions, either as scholars or administrators, to forestry defined in its broadest sense as the human use and study of forested environments.

This year's Bullard Fellows were selected from a large pool of international applicants and cover a broad array of forest-related subjects. These seven distinguished practitioners and academics from across the United States and the globe will spend one to two semesters conducting research based in Cambridge or at the Harvard Forest in Petersham. The breadth of research encompassed by this year's class of scholars is vast, ranging from ecosystem, historical and avian ecology to ant biology and biogeography to social analysis of forest landowners to long-term, continental scale climate patterns.

The Charles Bullard Fellows for the 2007-2008 Academic year are:

Elisabeth Almgren, a paleoecologist and anthropologist at Uppsala University in Sweden, will be collaborating with David Foster, Wyatt Oswald, Matts Lindbladh and other scientists on a comparative study of cultural landscape development and conservation in Scandinavia and the Northeastern U.S. During her 12-month fellowship Almgren will also be developing and implementing interpretive public exhibits based on past, present and future research from the Harvard Forest. The project will expand the present educational options for the general public visiting Harvard Forest by providing additional popular presentations of scientific results and may lead to further collaboration with the Harvard Museum of Natural History.

Charles Cogbill, a forest ecologist at the Hubbard Brook Long Term Ecological Research site in New Hampshire, will incorporate a historical perspective, especially archival data, in investigations of the floristics, development, and biogeography of northeastern forests. His activities will revolve around assembly, organization, and analysis of a comprehensive database of northeastern vegetation before European settlement. He will be extending early surveyors' witness tree records westward across New York and northern Pennsylvania, creating an archived digital database of township witness-tree composition from across the Northeast, analyzing these data using geographic information systems and geo-spatial statistics, and assessing the historical biogeography of dominant trees and background disturbance processes in forests. He will work extensively with scientists at the Harvard Forest, the Harvard University Herbaria, and the Arnold Arboretum.

Todd Crowl, a quantitative ecologist at Utah State University, has worked on research projects dealing with detrital processing and food web dynamics, particularly within streams draining the Luquillo Mountains in Puerto Rico. Crowl is currently part of a large integrated project collecting data on hurricane impacts to forests. The focus of Crowl's six-month work as a Charles Bullard Fellow will be interactions with Aaron Ellison and David Foster to explore ways to analyze and synthesize large experimental data sets; host a number of short analysis and writing sessions with Puerto Rican colleagues; and host a NSF funded National Ecological Observatory Network workshop after site selection.

Rebecca Holberton is an avian ecologist from the biology department at the University of Maine. Holberton's work focuses on the interaction between environmental factors such as weather, food availability and habitat quality and physiological constraints during the migratory period. During her fellowship, she will be conducting a study emphasizing Blackpoll warbler (Dendroica striata) physiological state and key forest community characteristics over time and space during migration. This research will explore how an individual's condition can relate to variation in community structure, particularly during the period of fall migration when communities may be undergoing rapid seasonal changes.

Michael Kaspari studies community ecology and biogeography at the University of Oklahoma. Kaspari's research centers on the behavior, function, and biogeography of soil arthropods in tropical forests, which has prompted the interest of E.O. Wilson, Pellegrino University Professor, emeritus, in collaborative work. As a Charles Bullard Fellow, Kaspari's work will extend to the eastern forests of North America and in collaboration with Aaron Ellison and other researchers, he will explore how metabolic and stoichiometric theories predict patterns of decomposition and abundance in detrital food webs.

Mark Rickenbach investigates social networks and private forest policy at the University of Wisconsin, Madison. During his time as a Charles Bullard Fellow, Rickenbach will study social networks to better understand forest landowners' decisions. This expanded view of forest landowners will lead toward the creation of novel research and meaningful policy and practice change. Through this study, which will complement research undertaken by David Kittredge in the Harvard Forest LTER program, he will formulate new research and outreach objectives that will advance the thoughtful stewardship and conservation of natural and managed ecosystems.

During his six-month Charles Bullard Fellowship, Nicholas Rodenhouse will focus his studies on quantifying the indirect effects of climate change on a forest bird population by using structural equation modeling. He also aims to organize a cross-site comparison of northern temperate forest patterns and processes among three regions: northeastern North America, northeastern Poland (exemplified by the Bialoweiza Forest) and far eastern Russia (represented by Kedrovaya Pad). Rodenhouse teaches and studies population ecology at Wellesley University.

October 2007 Highlights

Fall Foliage - 2007

The photographs below show foliage color at the end of September in 2005, 2006, and 2007 at the edge of the pasture adjacent to the headquarters of the Harvard Forest. The following presentation shows the progression of foliage from 2005 thru 2007.

2005	2006	2007

Based on observations of leaf color and leaf drop on the same trees over the past 18 years by John O'Keefe, 2005 was a rather late fall and 2006 was an early fall, about a week ahead of 2005. It is still to soon to say where 2007 will wind up, but the very dry weather in August and early September led to some drought stress and color/drop of leaves, most noticeable on the birches and maples.

The bright sunny days this September have led to good anthocyanin (red pigment) production. Unlike the yellow carotenoid pigments, which are present through the growing season and then unmasked as chlorophyll breaks down in the fall, these red anthocyanins are produced by sunlight during leaf senescence. Learn more about leaf color.

New Large-scale Experiment at the Harvard Forest:

Early Successional Habitat Dynamics in Former Plantations

The Harvard Forest plans to harvest about 100 acres of mature plantation forests in Winter 2007-2008 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. Learn more about this experiment.

New Journal Articles

The analysis of stomata in lake-sediment cores is increasingly used as a paleoecological tool. Stomata are less likely than pollen grains to be dispersed over long distances, and thus stomate records supplement and enhance interpretations based on pollen data by providing information about patterns and composition of local vegetation. We have conducted the first study of this type in New England, analyzing conifer stomata in the late-glacial and early-Holocene sediments of Berry Pond, Massachusetts. Comparison of the stomate record with pollen data tests the ability of both approaches to reflect the history of vegetation at the study site.

W.W. Oswald, B.C.S. Hansen, D.R. Foster. 2007. New England Note: Comparison of Pollen and Stomata in Late-glacial and early-holocen lake sediments from Eastern Massachusetts. Rhodora, Vol. 109, No. 938, pp. 225–229.

Harvard Forest Senior Research Fellow Aaron Ellison, along with Ph.D. student Sydne Record, 2006 REU student Alex Arguello, and Nick Gotelli (University of Vermont) inventoried the ant assemblage at Black Rock Forest in Cornwall, New York. The inventory was conducted as part of Black Rock's oak removal experiment, which parallels Harvard Forest's Hemlock removal experiment. The study also assessed the utility of different methods of sampling for ant diversity studies in the north temperate zone. Our results suggest that hand sampling and litter collection alone are adequate to identify at least 95% of the ant diversity at the site; that ant species richness in these oak forests ranges at a minimum from 38-58 taxa; and that loss of oak will likely result in an increased aboundance of Camponotus and Lasius species.

Ellison, A.M., S. Record, A. Arguello, and N.J. Gotelli. 2007. Rapid inventory of the ant assemblage in a temperate hardwood forest: species composition and sampling methods. Environmental Entomology 36: 766-775.

Aaron Ellison and his research assistant Jess Butler completed a 2-year study of nitrogen cycling dynamics in the pitcher plant Sarracenia purpurea. Their results show that most nitrogen is stored aboveground (in developing pitchers), and that root storage accounted for < 3% of the plant's overall nitrogen budget. The results suggest why this carnivorous plant has such a low photosynthetic rate, given its tissue nitrogen content. Excess nitrogen is stored for future use rather than being used immediately for enhancing photosynthesis.

Butler, J. L. and A. M. Ellison. 2007. Nitrogen cycling dynamics in the carnivorous northern pitcher plant, Sarracenia purpurea. Functional Ecology 21: 835-843.

September 2007 Highlights

Plant Physiology Lab Renovated

Harvard Forest, with the assistance of the Department of Organismic and Evolutionary Biology and an anonymous donor, recently completed renovation of a plant physiology lab in Shaler Hall. The renovated lab will be used by undergraduates, graduate students, faculty and Harvard Forest and visiting researchers. N. Michelle (Missy) Holbrook, Charles Bullard Professor of Forestry, (OEB) and P. Barry Tomlinson, E. C. Jeffrey Professor of Biology, (Emeritus) both will be using the lab as a core part of their on-going research and education efforts.

Advanced Undergraduate Research Course Offered

David Foster, Missy Holbrook, Kathleen Donohue and Kristina Stinson will offer a new, advanced research course for Harvard undergraduates this fall. This unique peer learning/workshop format provides formal training to students actively engaged in the research process. Students will develop publications, presentations, senior theses, and/or interdisciplinary collaborations from current or recent field research activities. OEB 193 includes focused reading and discussion of student work and relevant literature, plus hands-on training and workshops at the Harvard Forest in scientific writing/presentations, mapping/graphics, and experimental design/analysis. Small class size will allow content to be tailored to the individual research needs of enrollees. Visit the course website for more information.

Harvard Forest Researcher Interviewed

Harvard Forest senior research fellow Aaron Ellison was interviewed for BBC Wildlife Magazine about his research on carnivorous plants. Read the interview.

Harvard Forest Summer Institute for Teachers Attendance Doubles

36 Teachers and Environmental Educators participated in this year's Harvard Forest Summer in Ecology - Summer Institute for Teachers. Thirty-three K-12 teachers from throughout Massachusetts and Southern New Hampshire came to HF to learn directly from Forest Ecologists, Dr. David Orwig and Dr. John O'Keefe. Staff from Massachusetts Audubon Society, Plum Island LTER, the Nashua River Watershed Association, and the Boston Science Museum attended the training in order to find ways to integrate ecological field research into their work with children as well. These participants will in turn lead their students in implementing field research beginning this fall. Research topics include: Buds, Leaves and Global Warming and Hemlock Trees and the Pesky Pest, the Woolly Adelgid.

New publications

Natural History from Rarely Studied Hardwood Trees

Tree-ring research has made significant contributions to the understanding of environmental change and forest stand dynamics. Its application to understanding natural history, however, has been limited. Recent tree-ring data from several rarely studied hardwood species collected by Niel Pederson, Tony D'Amato, and David Orwig has yielded ages well beyond maximum expectations. For example, a sampling of 20 cucumbertrees (Magnolia acuminata) included two individuals 315 and 348 years, respectively, which are nearly two centuries more than the average life expectancy reported for this species. Also, research in recently discovered old-growth stands in western Massachusetts has illustrated the common occurrence of black birch (B. lenta) in eastern hemlock (Tsuga canadensis) dominated old-growth forests with individuals often living beyond 320 years in these systems. These studies have illustrated the importance of utilizing tree-ring research to expand our knowledge of previously overlooked central hardwood species.

Pederson, N., A. W. D’Amato, and D. A. Orwig. 2007. Natural History from Dendrochronology: Maximum Ages and Canopy Persistence of Rarely Studied Hardwood Species. In: Proceedings of the 15th Central Hardwood Forest Conference. Knoxville, TN.

Fire Impact on Ant Communities

Harvard Forest Senior Research Fellow Aaron Ellison and colleagues at the University of Tennessee, University of Vermont, and Humbold State University examined patterns of co-occurrence of ant species in forests and wetlands in the Siskiyou Mountains of Oregon and California that were burned by the Biscuit Fire in 2001. They found that the "assembly rules" acting on these ant communities varied with scale and across years, but there were no long-lasting effects of this large fire.

Sanders, N. J., N. J. Gotelli, S. E. Wittman, J. S. Ratchford, A. M. Ellison, and E. S. Jules. 2007. Assembly rules of ground-foraging ant assemblages are contingent on disturbance, habitat, and spatial scale. Journal of Biogeography 34: 1632-1641.

August 2007 Highlights

Richard Goodwin - Botanist, Conservationist and Friend

Dick Goodwin was many things: a dedicated professor of botany who inspired generations of Connecticut College students and guided them into the world of plants, people and their ecology; a conservation visionary who helped to found The Nature Conservancy and who for more than five decades served as president of the Conservation Research Foundation, which provides "seed monies" for new conservation studies and projects worldwide; and an inspirational individual who lived life fully and gracefully with his wife Esther and committed his energies to applying what he preached.

Among Dick's legacies are two of the most important conservation landscapes in Connecticut: the Burnham Brook Preserve, whose more than 1000 acres were assembled largely by Dick and Esther around their home at Dolbia Farm and are now owned by The Nature Conservancy and the Connecticut College Arboretum , which is now more than 750 acres of natural and research areas, plant collections, and the entire Connecticut College campus in the towns of New London and Waterford. Dick served for many years as Director of the Arboretum, he helped to assemble and document its lands and he oversaw its long-term development with his colleague of four decades Bill Niering.

Dick was also a dedicated friend of the Harvard Forest and botany at Harvard University, where he received his undergraduate and graduate degrees. Inspired by his example and always informed by his advice and perspectives, one of our great pleasures in recent years was to work with Dick to publish his autobiography A Botanist's Window on the Twentieth Century. Dick was 96 years old.

Read his obituary from the New York Times News Service.

65 year-old Fingerprints from 1938 Hurricane found in Remotely-Sensed Data

Analyzing airborne LiDAR (i.e., laser remote sensing) data acquired by NASA in 2003, researchers found differences in measures of canopy structure in stands across the Prospect Hill tract at Harvard Forest. Canopy height and vertical diversity were related to the predominant species present and the intensity of wind disturbance from the 1938 hurricane and associated timber extraction efforts. Given the importance of canopy structure to habitat and ecosystem functions, such as gas exchange, this disturbance legacy probably continues to influence the ecology of impacted New England forests.

Weishampel, J.F., J. B. Drake, A. Cooper, J. B. Blair, M. Hofton. Forest canopy recovery from the 1938 hurricane and subsequent salvage damage measured with airborne LiDAR. 2007. Remote Sensing of Environment 109. pp. 142–153.

July 2007 Highlights

Bob Marshall's Research Plots Recovered and Resampled

In the summer of 1924, Bob Marshall, future founder of the Wilderness Society and career forester and ecologist for the U.S. Forest Service and Department of Indian Affairs came to Petersham to join four other graduate students for studies with Professor Richard Fisher and instructors Albert Cline and Rupe Gast. The group developed a large new experiment on the Tom Swamp tract to examine forest regeneration and dynamics following different logging treatments. Marshall analyzed the land-use history of the tract, extensively sampled tree rings to determine long-term growth trends and established a 80 x 200 foot plot for intensive study. His work is documented in Harvard Forest Bulletin 11: The Growth of Hemlock Before and After Release from Suppression. Following Marshall's departure in 1925, the 1938 hurricane and subsequent harvesting the plot was lost.

This summer, as part of a long-term study of forest dynamics, land use history and conservation coordinated by David Foster, students Alex Ireland (Clarion University) and Ben Mew (Oberlin College) are exploring the experimental tract in detail and reconstructing Marshall's study. Through a painstaking process they have relocated and permanently marked Bob Marshall's plot. Sampling of the current forest on the site confirms Marshall's prediction, based on his own historical work, that hemlock and white pine would predominate across the area, regardless of treatment.

Bird Populations Respond to Climate Change, Land Use and Winter Feeding

Rosemary Balfour completed her Masters of Liberal Arts degree at Harvard in June working with thesis advisors David Foster and Wayne Petersen of the Massachusetts Audubon Society. Rosemary's study utilized Christmas Bird Count data to examine the long-term trends in the abundance and composition of the bird populations that overwinter across the inland regions of Massachusetts. Her research concluded that there were major increases in the ratio of southern to northern ranging bird species and that these could be tied to a number of factors including: warming temperatures, changes in land use, and the greatly increased use of bird feeders. In her work Rosemary received considerable assistance form Harvard Forest scientists: Aaron Ellison, Glenn Motzkin and Brian Hall.

Balfour, R. P. 2007. The Impact of Changes in Average Winter Temperatures and Habitat Modification on Populations of Terrestrial Birds Over-wintering in Inland Areas of Massachusetts. Master's Thesis. Harvard University.

The Connecticut River Boating Guide: Source to Sea

Elizabeth Farnsworth (Bullard Fellow, 2005-6) has published The Connecticut River Boating Guide: Source to Sea, with co-authors, John and Wendy Sinton. The Bullard Fellowship supported much of the research and writing for this book. For all those who enjoy appreciating and recreating on New Englands largest river, this guide is packed with practical information on accessing the river, as well as extensive notes on the history and ecology of the region. Available in bookstores or direct from the web. All royalties benefit the Connecticut River Watershed Council, a regional organization that collaborates, educates, organizes, restores, and intervenes to preserve the health of the whole river for generations to come.

A New Understanding of Subsurface Flow in Headwater Streams

In many headwater streams in stony north-central Massachusetts, much of the water flows below the surface of the ground instead of in an open channel. Harvard Forest researchers, including summer students working through the NSF-funded Summer Research Experiences for Undergraduates (REU) Program, compared water temperatures, chemistry, and aquatic life in surface and subsurface-flowing sections of Bigelow Brook-west, a small, hemlock-dominated headwater stream on the west side of Prospect Hill in Petersham, MA. Subsurface reaches support aquatic insects and other freshwater animals and are similar to surface reaches. Better understanding of so-called "intermittent" streams that actually flow continuously may contribute to changes in state and local regulations affecting these headwater habitats.

Collins, B. M., W. V. Sobczak, and E. A. Colburn. 2007. Subsurface Flowpaths in a Forested Headwater Stream Harbor. A Diverse Macroinvertebrate Community. Wetlands. 27(2): 319-325.

A Guide for Interpreting Historical Materials

Emery Boose, Information Manager at Harvard Forest, co-authored Scholastic Sanskrit: A Manual for Students. This volume gives a complete introduction to the techniques and procedures of Sanskrit commentaries, including detailed information on the overall structure of running commentaries, the standard formulas of analysis of complex grammatical forms, and the most important elements of commentarial style.

June 2007 Highlights

Interns Arrive for Summer Program in Ecology

Twenty-one summer students have arrived as part of the Harvard Forest summer research program in ecology. Students come from all over the United States to participate in on-going research projects investigating atmospheric pollution, global warming, invasive plants, watershed ecology, and insect outbreaks. Researchers come from many disciplines and institutions. Specific projects center on population and community ecology, plant physiology, insect ecology, land-use history, aquatic ecology, biogeochemistry, and atmosphere-biosphere exchanges.

New Elemental Analyzer for John G. Torrey Laboratory

Harvard Forest has just acquired a new elemental analyzer for the John G. Torrey Nutrient Laboratory. Purchased with National Science Foundation LTER funding, the Elementar vario MICRO analyzer can be used for measurements of carbon, nitrogen, and sulfur. The new, user-friendly equipment is a nice complement to the Lachat 8500 autoanalyzer in the laboratory and is being used for a variety of ongoing projects requiring soil, plant tissue and foliar analyses. In addition, this machine will be used by faculty, staff and students from several Harvard University Departments, as well as outside institutions.

New Journal Articles Published

Land-use History Effect on Forest Ecosystems

We used stable N isotopes in tree rings and lake sediments to demonstrate that N availability in a northeastern forest has declined over the past 75 years, likely because of ecosystem recovery from Euro-American land use. Forest N availability has only recently returned to levels forecast from presettlement trajectories, rendering the trajectory of future forest N cycling uncertain. Our results suggest that chronic disturbance caused by humans, especially logging and agriculture, are major drivers of terrestrial N cycling in forest ecosystems today, even a century after cessation.

McLauchlan, K. K., J. M. Craine, W. W. Oswald, P. R. Leavitt, and G. E. Likens. 2007. Changes in nitrogen cycling during the past century in a northern hardwood forest. PNAS 104:18. pp. 7466–7470.

Wildlife in an urban environment

Harvard University’s Arnold Arboretum, located in Jamaica Plain in Boston, Massachusetts provides critical wildlife habitat within an urban landscape. One especially unique area of the Arboretum, Hemlock Hill, is currently undergoing extensive vegetative changes. A very large percentage of the hemlock trees located here have been infested with hemlock woolly adelgid (HWA) and are being removed. This study establishes baseline data on terrestrial salamander species composition, relative abundance, and distribution on Hemlock Hill, and assesses the impact of logging on terrestrial salamander abundance

B. Mathewson. 2007 Salamanders in a Changing Environment on Hemlock Hill. Arnoldia 65/1 pp. 19 - 25.

May 2007 Highlights

2007-2008 Bullard Fellow Recipients Announced

The Charles Bullard fellowship program is to support advanced research and study by individuals who show promise of making an important contribution, either as scholars or administrators, to forestry and forest-related subjects from biology to earth sciences, economics, politics, administration or law. See the complete listing of Bullard Scholars from 1962 - 2006.

Harvard Forest's 100 year old records made available with a Library Digital Initiative grant

For nearly a century, detailed records for all research and forestry operations on the Harvard Forest properties have been maintained in the form of extensive research files, maps, photographs, and other materials. This information allows researchers to interpret the landscape history of research sites, and analyze how past natural and anthropogenic factors influence current ecological patterns. The Harvard Forest is the best documented research forest in the world and is an irreplaceable asset.

Harvard University's Library Digital Initiative (LDI) has provided funding to digitize a number of these archival materials. The LDI grant will provide a great start to populating a central repository for digital resources related to the 3000 acre Harvard Forest lab and classroom. Students, scientists and collaborators have used the land and its associated research facilities to explore topics ranging from conservation and environmental change to land-use history and the ways in which physical, biological and human systems interact to change our earth.

Materials to be digitized as part of the LDI project include:

• 1000 digitally born high resolution images
• 175 historical black and white photographic prints
• 150 Lantern and 35mm slides
• 33,000 pages of stand records and forest inventory from original paper resources
• and the creation of a searchable metadata catalog for all research records stored in the archives.

The first products of this initiative have been digitized and are available for viewing. At the completion of the project a comprehesive webpage will provide a new gateway to the Harvard Forest digital resources.

Fisher Museum Open on Weekends

Starting May 5^th, the Fisher Museum will be open 12 - 4 on Saturdays and Sundays. The Fisher Museum features twenty-three internationally acclaimed models (dioramas) portraying the history, conservation and management of central New England forests. Other exhibits at the museum represent the range of Harvard Forest's research.

Undergraduate Thesis Investigates the Effect of Harvesting on the Carbon-cycle

Harvard College senior Frances C. O'Donnell completed her thesis Carbon Dynamics of a New England Temperate Forest Five Years After Selective Logging. The thesis quantifies how the carbon source-sink dynamics of the forest was modified due to harvesting activities based on field work conducted at the Harvard Forest. Frances' advisor is Professor Steven Wofsy of the Harvard University Department of Earth and Planetary Science. She participated in the 2006 Summer Research Program in Ecology for Undergraduates at the Harvard Forest. Next fall, Frances will begin a masters program at the University of Indiana.

Two New Journal Articles

Oswald, W. W., E. K. Faison, D. R. Foster, E. D. Doughty, B. R. Hall and B. C. S. Hansen. 2007. Post-glacial changes in spatial patterns of vegetation across southern New England. Journal of Biogeography 34, 900–913.

Lindbladh, M., W. W. Oswald, D. R. Foster, E. K. Faison, J. Hou, Y. Huang. 2007. A late-glacial transition from Picea glauca to Picea mariana in southern New England. Quaternary Research. 67 502–508.

April 2007 Highlights

Harvard Forest Nominated as Core Site for NEON

The National Ecological Observatory Network (NEON, Inc.) announced a group of 20 candidate Core Sites across the United States that will be included in the NEON Project Execution Plan. Harvard Forest was identified as the core site for the Northeastern Domain. The NEON Core Sites will be in wildlands (i.e, largely natural vegetation, not intensively managed) and will form the stable, fixed elements of the design, which also includes relocatable gradient sites and mobile (truck mounted) laboratories. The Core Sites will be in place for 30 or more years, have extensive sampling and instrumentation, and serve as a base for staff operating the site and associated gradient and mobile laboratories. The Core Site backbone hopes to observe national-scale impacts of highly “connected” phenomena across the entire country. Examples include impacts of invasion or disease, climate change, large-scale modes of variability such as El Niño, and large-scale transport phenomena, such as inputs of Asiatic dust and pollution.

Summer Institute for Teachers

The Harvard Forest offers a Forest Ecology training institute for teachers of grades 2-12. Learn how to implement field studies related to local ecosystems with your students right in your schoolyard. Registration flyer and forms are now available.

Previous participants have recently posted 4 new Data Analysis lesson plans developed by experienced Schoolyard Ecology teachers: Nichole Ruggles, Kellie Robichaud, Kathleen Bennett, and Mary Gagnon along with support from Harvard Forest Ecologists: Elizabeth Colburn, John O'Keefe, and David Orwig. Lesson plan development was funded by the Massachusetts Environmental Trust.

Harvard Forest in the News

Christian Science Monitor highlights the return of moose to Massachusetts due to landscape change and return of forest. As land was cleared for farms in the Northeast, moose and other wildlife fled. Now that the trees are back, the moose are, too. Read the article.

New Article from Harvard Forest

Coastal sandplain grasslands of New England harbor a number of rare plant species, but few systematic management techniques have been developed to help foster or restore these critical habitats. Farnsworth (2007) applied a comparative, functional group approach to coastal sandplain grassland taxa in order to examine whether rare plant species share certain aspects of rarity and life history characters that are distinct from their more common, co-occurring relatives in these habitats. The paired comparisons revealed that infrequent species are intrinsically rarer range-wide, occupy a narrower range and a more specialized habitat than their common relatives; they also produce larger seeds, are smaller, rely less on vegetative (colonial) reproduction, and tend toward an annual or biennial life history. Management steps to reduce competition from larger-statured, colonial, perennial species are recommended for these infrequent species.

Farnsworth, E.J. 2007. Plant life history traits of rare versus frequent plant taxa of sandplains: Implications for research and management trials. Biological Conservation. 136. pp 44-52

March 2007 Highlights

Annual Harvard Forest Ecology Symposium

The eighteenth annual symposium will be held March 27, 2007 at the Harvard Forest. The symposium will focus on the expanding horizons in long-term ecological research: synthesis across the New England region and disciplinary boundaries. Learn more or submit abstract.

Harvard Forest teams with local land trust and land owners to protect adjacent forest land.

The Harvard Forest has partnered with Mount Grace Land Conservation Trust, Keith Ross of LandVest, state conservation agencies and local land owners to permanently protect nearly 170 acres of forest in two large parcels adjacent to the Prospect Hill tract. This project advances our goal of maintaining the integrity of Harvard Forest studies and contributes significantly to the broader conservation effort in central Massachusetts. The 100-acre Wilson Lot was owned by Don Wilson, a long-time volunteer in the Fisher Museum and his nephew Bill, and the 68-acre Bryant Lot was owned by Richard Bryant, a retired carpenter who worked on many of the buildings at the Harvard Forest.

Both lots were initially purchased by Mount Grace Land Conservation Trust which worked with the Division of Fisheries and Wildlife and the Department of Conservation and Recreation to sell conservation restrictions over each property with funding from the US Forest Service Forest Legacy Program before selling the restricted properties to the Harvard Forest. These were the first of 19 tracts, totaling over 2,000 acres to be protected by a $2.5 million grant from the Forest Legacy Program in the North Quabbin Region. The Harvard Forest received contributions from foundations and individuals to purchase the restricted forest lands.

These parcels are valuable additions to natural open space of the North Quabbin Region as they connect many blocks of protected land in this beautiful, forested part of the region and provide additional protection for the long term climate change research underway at the Harvard Forest.

New Publications from Harvard Forest

Von Holle & Motzkin (2007) examined how previous land use and current biotic and environmental properties influence the abundance and distribution of non-native plant species across coastal upland habitats of southern New England and adjacent New York. They found that the modern distribution of nonnative plants is influenced by multiple, interdependent current and historical factors. Open-canopy communities, such as grasslands, heath barrens and old fields had significantly greater numbers of nonindigenous plants. Additionally, soil calcium levels and native species richness were positively associated with nonnative species richness. Sites that were cultivated historically or experienced other soil disturbance had higher nonnative species richness than areas without soil disturbance. Last, glaciolacustrine landforms had greater nonnative species richness and cover than beach-dune, moraine, and glacial outwash sand plain landforms. Because many rare coastal sandplain plants reach their greatest abundance on extant open-canopied habitats that have historically been disturbed, efforts to restore rare native plants will involve tradeoffs between the benefits of expanded habitat for these species and increased risk of invasion by nonnative species.

Von Holle. B. and G. Motzkin. 2007. Historical land use and environmental determinants of nonnative plant distribution in coastal southern New England. Biological Conservation 136:33-43.

Neill et al. (2007) investigated the role of previous land use, disturbance, and overstory vegetation in controlling soil chemistry and native versus nonnative species composition. They found large differences in soil chemistry and a much higher proportion of nonindigenous species in agricultural grasslands compared with a variety of other sandplain vegetation types that had historically experienced different land uses. This suggests that restoring sandplain shrubland and grassland communities on agricultural lands might be a challenge, given their artificially high levels of soil nutrients and disturbed soils.

Neill, C. M., B. Von Holle, K. Kleese, K. Ivy, A. R. Colllins, C. Treat, and M. Dean. 2007. Historical influences on the vegetation and soils of the Martha’s Vineyard, Massachusetts coastal sandplain: Implications for conservation and restoration. Biological Conservation 136:17-32.

February 2007 Highlights

Harvard Forest Announces New Research Course

In response to a University-wide call to expand small group, experiential study in the sciences, the Harvard Forest will launch a new course and expand its summer research opportunities for Harvard Undergraduates this Spring. The new course, OEB 122 - Field Research in Ecology and Conservation, features hands-on field training and student research activities. Course highlights include:

• Participation in small discussion groups in Ecology and Conservation Biology while developing projects with individual members of the Harvard faculty.
• On-campus classes, field trips, and workshops at the Harvard Forest
• Readings of the scientific literature, formal training in field and lab techniques, and workshops on data analysis, presentation, and scientific writing.
• Multi-disciplinary topics and project in areas as varied as population and community ecology, paleoecology, land-use history, aquatic ecology, biochemistry, soil science, ecophysiology, and atmosphere-biosphere exchanges.
• Participating research mentors include from the Harvard Forest Director Dr. David Foster, researchers Dr. Aaron Ellison and Dr. Kristina Stinson, Faculty in the department of Organismic and Evolutionary Biology: Drs. Missy Holbrook, Kathleen Donohue, and Paul Moorcroft and Earth and Planetary Sciences Dr. Steve Wofsy.
• The course runs both semesters. The spring course, OEB 122a, emphasizes field research methods and the fall course, OEB 122b, provides a formal structure and workshop setting for advanced data analysis, scientific writing, and presentation skills.

2007 Harvard Forest Summer Program in Ecology for Undergraduates

We are now accepting applications for the 2007 Summer Program from undergraduates and recent graduates who are interested in an intensive research and education experience in ecology. Applications Due March 7th. Learn more

Harvard Forest in the Media

WBUR Radio recently visited Petersham and interviewed two Harvard Forest scientists to discus the infestation of hemlock trees by the insect called hemlock woolly adelgid.

Listen to the Report: http://www.wbur.org/news/2007/63760_20070116.asp

The Harvard University Alumni Quarterly Colloquy highlights Harvard Forest as a living laboratory.

Read the article: http://www.gsas.harvard.edu/images/stories/pdfs/colloquy_winter07.pdf

New Journal Articles from the Harvard Forest

Climate Change affected major forest ecosystems dynamics

The mid-Holocene decline of eastern hemlock is widely viewed as the sole prehistorical example of an insect- or pathogen-mediated collapse of a North American tree species and has been extensively studied for insights into pest–host dynamics and the consequences to terrestrial and aquatic ecosystems of dominant-species removal. We report paleoecological evidence implicating climate as a major driver of this episode. Data drawn from sites across a gradient in hemlock abundance from dominant to absent demonstrate: a synchronous, dramatic decline in a contrasting taxon (oak); changes in lake sediments and aquatic taxa indicating low water levels; and one or more intervals of intense drought at regional to continental scales. These results, which accord well with emerging climate reconstructions, challenge the interpretation of a biotically driven hemlock decline and highlight the potential for climate change to generate major, abrupt dynamics in forest ecosystems.

Foster, D.R., W.W. Oswald, E.K. Faison, E.D. Doughty, B.C.S. Hansen. 2006. A Climatic Driver for Abrupt Mid-Holocene Vegetation Dynamics and the Hemlock Decline in New England. Ecology, 87(12), 2959–2966.

Old Growth Estimate in Massachusetts Revised

Old-growth forests are currently identified as core components of regional conservation and forest reserve planning efforts by agencies and organizations across the northeastern United States. Despite the importance of these ecosystems from an ecological and conservation standpoint, major questions remain concerning their actual extent, location, and configuration in many states. This paper reports a substantially revised estimate for individual tracts and the total area of old-growth forests in Massachusetts based on analysis of historical documents and extensive field research and mapping.

D’Amato, A.W., D. A. Orwig, and D. R. Foster. 2006. New Estimates of Massachusetts Old-growth Forests: Useful Data for Regional Conservation and Forest Reserve Planning. New England Naturalist. 13(4):495–506

Limits to Reproductive Success of Pitcher Plants

In this first experimental study of the relative contributions of resource and pollinator availability to reproductive success of the northern pitcher plant, Sarracenia purpurea, 2005 Bullard Fellow Gidi Ne'eman, his wife and high school biology teacher Rina Ne'eman, and Harvard Forest Senior Ecologist Aaron Ellison showed that resource supply dominates reproductive success in this plant. They also provided strong photographic evidence that the fly Fletcherimyia fletcheri pollinates the plant; its larvae is the top predator in the food web that inhabits the plant's water-filled pitchers. The results of this work point to an additional cost of carnivory for plants - reduced reproductive output - that needs to be considered along with reduced photosynthetic activity in determining the evolutionary history of carnivorous plants.

Ne'eman, G., R. Ne'eman, and A. M. Ellison. 2006. Limits to reproductive success of Sarracenia purpurea (Sarraceniaceae). American Journal of Botany 93: 1660-1666.

Cost-benefit model for evolution of carnivorous plants

The cost-benefit model for the evolution of carnivorous plants posits a trade-off between photosynthetic costs associated with carnivorous structures and photosynthetic benefits accrued through additional nutrient acquisition. The model predicts that carnivory is expected to evolve if its marginal benefits exceed its marginal costs. At the 2005 International Botanical Congress, Harvard Forest Senior Ecologist Aaron Ellison reviewed published data and results of ongoing research related to evaluating this cost-benefit model. His analysis shows that nitrogen, phosphorus and potassium often (co)-limit growth of carnivorous plants and that photosynthetic nutrient use efficiency is 20-50% of that of non-carnivorous plants. Assessments of stoichiometric relationships among limiting nutrients, scaling of leaf mass with photosynthesis and nutrient content, and photosynthetic nutrient use efficiency all suggest that carnivorous plants are at an energetic disadvantage relative to non-carnivorous plants in similar habitats. Overall, current data support some of the predictions of the cost-benefit model, fail to support others, and still others remain untested and merit future research. Rather than being an optimal solution to an adaptive problem, botanical carnivory may represent a set of limited responses constrained by both phylogenetic history and environmental stress.

Ellison, A.M. 2006. Nutrient limitation and stoichiometry of carnivorous plants. Plant Biology 8: 740-747.

January 2007 Highlights

New Funding for Global Change and Carbon Dynamics Research

The Terrestrial Carbon Program of the U.S. Department of Energy recently awarded approximately 1.5 million dollars for continued measurements of forest-atmosphere carbon exchange at Harvard Forest. A team of researchers from several departments at Harvard and from the State University of New York at Albany's Atmospheric Sciences Research Center (SUNY-ASRC), led by Bill Munger of Earth and Planetary Sciences (EPS) at Harvard, will conduct the research. The award will support continuation of the world's longest-running continuous eddy flux measurements of carbon exchange (15 years so far) at Harvard Forest's Environmental Measurement Site (EMS). The new funding will also enable researchers to augment the current three-to-four year record of carbon exchange at the Hemlock and Little Prospect Hill tower sites. Continued work at these sites will increase the opportunity to discern influences of climate variability and forest growth on the carbon budgets of a relatively old (100-230 years) coniferous forest and a relatively young (< 60 years) deciduous forest.

The eddy flux technique estimates absorption or release of gases by terrestrial ecosystems, using movements of air between ecosystems and the atmosphere above them. However, the technique can only measure vertical gas exchange, or convection. A long-standing source of uncertainty is movement of gases through horizontal air motion, or advection. In tall-statured ecosystems such as forests, under calm conditions, movement of carbon dioxide (CO₂) through advection can be much greater than CO2 movement via convection.

David Fitzjarrald of SUNY-ASRC will quantify movement of CO₂ through advection, in order to improve carbon exchange estimates for the three flux tower sites. Bill Munger of Harvard EPS and Julian Hadley of Harvard Forest will derive the initial estimates from continuously-collected eddy flux data. Paul Moorcroft of Organismic and Evolutionary Biology at Harvard will incorporate the data into the Ecosystem Demography model, which simulates forest growth and forest-atmosphere carbon exchange over long time intervals. Steve Wofsy of Harvard EPS will help to link forest carbon exchange estimates to changes in the atmosphere using the Regional Atmospheric Modeling System. Through the North American Carbon Program, data from all three sites will contribute to more accurate estimates of current annual carbon storage in North American forests, as well as better models for future forest carbon storage.

Harvard Forest Accepting Applications for Charles Bullard Fellows in Forest Research.

Applications for 2007-2008 now being accepted

The Charles Bullard Fellowship program, established in 1962, is to support advanced research and study by persons who show promise of making an important contribution, either as scholars or administrators, to forestry defined in its broadest sense as the human use of forested environments. Between five to eight distinguished practitioners and academics from across the United States and from around the globe spend one to two semesters based in Cambridge or at the Harvard Forest in Petersham conducting research on a particular field. While in residence at Harvard, Fellows, who are supported by an endowment named after the benefactor Charles Bullard, interact with faculty and students, give seminars, participate in conferences and symposia and avail themselves of the University's great research resources.

2007 Harvard Forest Summer Program in Ecology for Undergraduates

We are now accepting applications for the 2007 Summer Program from undergraduates and recent graduates who are interested in an intensive research and education experience in ecology. Learn more

Harvard Forest New Publication

Soil seed banks are especially important for forest regeneration in stands with few understory species and individuals. The understory of hemlock (Tsuga canadensis)-dominated stands in New England primarily consists of hemlock seedlings and saplings, but all size classes of hemlock are attacked by the hemlock woolly adelgid (Adelges tsugae). Prior to the initiation of the Hemlock Removal Experiment at the Simes Tract, Harvard Extension student Kelley Sullivan (M.L.S. 2005) and Harvard Senior Ecologist Aaron Ellison examined the seed bank composition of all eight 0.81 ha experimental plots. The seed bank samples from the hemlock-dominated plots contained 24 species (95% confidence interval = 20-28), significantly fewer than the 30 found in the hardwood-dominated plots. Seed banks from all plots were dominated by black birch, raspberry, and sedges Among plots, there was little compositional relationship between the forest overstory and its understory on the one hand, and its seed bank on the other hand. Because seeds of hemlock and birch persist for only a few years in the seed bank, and because hemlock seedlings are readily attacked and killed by the adelgid, damaged hemlock stands are more likely to be replaced by stands of black birch and other hardwoods than by hemlock.

Sullivan, K.A., and A.M. Ellison. 2006. The seed bank of hemlock forests: implications for forest regeneration following hemlock decline. Journal of the Torrey Botanical Society 133: 393-402.

December 2006 Highlights

Director Receives New England Wild Flower Society Conservation Award

David Foster, Director of Harvard Forest, received the 2006 New England Wild Flower Society Massachusetts State Conservation Award. He was honored for guiding the development of Harvard Forest from a small academic outpost to a major research site and for changing the way biologists interpret landscape patterns and ecological processes. The award emphasized Dr. Foster's committment to revitalizing Harvard Forest to become a major site of long term ecological research activity, and for promoting conservation of hatibitats through Wildands and Woodlands project.

2007 Harvard Forest Summer Program in Ecology for Undergraduates

We are now accepting applications for the 2007 Summer Program from undergraduates and recent graduates who are interested in an intensive research and education experience in ecology. Learn more

"Green" Garage designed and built at Harvard Forest

The building was designed and built entirely by the Harvard Forest woods crew using Harvard Forest wood products wherever possible. It is also, at the initiative of the crew, a "green building". This includes the composting toilet, a dual fuel wood/oil burner, and reusing materials from previous renovations. They also took the lead in submitting a grant to the state for a solar power system to provide about 8% of the electrical needs for all the Prospect Hill research projects which will be installed in the spring. Finally, the auto repair bay was also moved to this new location removing it from the proximity of the water supply for the Forest. There are many other features such as secured hazardous waste storage and a loft for research materials storage, and numerous others. The integration and understanding of the woods crew for the mission of the Harvard Forest is reflected in the design and intended use of the new building.

Report Outlines Funding to Conserve Half of Massachusetts’s Land

Harvard Forest’s “Wildlands and Woodlands” proposal to conserve roughly half of Massachusetts as protected lands has received a boost from a new report detailing seven strategies to finance the ambitious proposal. The new report is the product of a recent Wildlands and Woodlands Conservation Finance Roundtable. View the full press release. An eight page summary of the report is also available.

New Journal Article from Harvard Forest

The environmental drivers behind abundant ragweed pollen in sediments of four southern New England lakes 10,000-8000 years ago were investigated. They found strong evidence that high levels of ragweed pollen were associated with warmer, drier conditions. This conclusion is corroborated by independent lake level and climate reconstructions. Together, these results have implications for future ragweed distribution and abundance, and suggest that more ragweed pollen could accompany rising temperature and CO₂ levels in New England.

Faison, E.K., D.R. Foster, W.W. Oswald, C.S. Hansen, and E. Doughty. Early Holocene Openlands in Southern New England. Ecology, 87(10), 2006, pp. 2537–2547

November 2006 Highlights

Harvard Forest on the Radio

Dr. David Orwig, Harvard Forest Ecologist, can be heard on WFCR describing the effect the Hemlock Woolly Adelgid is having on New England Forests. Listen to the broadcast.

New Report Outlines Funding to Conserve Half of Massachusetts’s Land

Harvard Forest’s “Wildlands and Woodlands” proposal to conserve roughly half of Massachusetts as protected lands has received a boost from a new report detailing seven strategies to finance the ambitious proposal. The new report is the product of a recent Wildlands and Woodlands Conservation Finance Roundtable. View the full press release. An eight page summary of the report is also available.

Harvard Forest Announces 2006-2007 Charles Bullard Fellows in Forest Research.

Applications for 2007-2008 now being accepted

Harvard Forest is pleased to announce the 2006-2007 incoming Charles Bullard Fellows in Forest Research. The purpose of this fellowship program, established in 1962 is to support advanced research and study by persons who show promise of making an important contribution, either as scholars or administrators, to forestry defined in its broadest sense as the human use of forested environments. Between five to eight distinguished practitioners and academics from across the United States and from around the globe spend one to two semesters based in Cambridge or at the Harvard Forest in Petersham conducting research on a particular field. While in residence at Harvard, Fellows, who are supported by an endowment named after the benefactor Charles Bullard, interact with faculty and students, give seminars, participate in conferences and symposia and avail themselves of the University's great research resources.

The 2006-2007 Fellows were selected from a large pool of international applicants. "The Harvard community benefits immensely from the presence of the outstanding scholars and fellows supported by the Bullard program. The breadth of research encompassed by this year's class of scholars is quite vast, ranging from fine root function to long-term, continental scale climate patterns. In addition, three of our visitors will be based in Cambridge, working with FAS faculty in Organismic and Evolutionary Biology (OEB) and Engineering and Applied Sciences (DEAS)."

The Charles Bullard Fellows for the 2006-2007 Academic year are:

Dr. Hormoz BassiriRad is a plant physiological ecologist who explores the responses of portions of below-ground plants and ecosystems to global climate change. At Harvard, he will work with Missy Holbrook, Professor of Biology and Charles Bullard Professor of Forestry in the Department of Organismic and Evolutionary Biology. This work will focus on the impact of rising atmospheric carbon dioxide on root water and nutrient transport. Dr. BassiriRad is a professor at the University of Illinois at Chicago in the Department of Biological Sciences and received his PhD from the University of Arizona at Tucson. He began his ten month Fellowship in October 2006.

Dr. James Bever has pioneered the study of feedbacks between plants and the soil community which has changed the way ecologist think about maintaining plant diversity. He is a professor at Indiana University at Bloomington in the Department of Biology. Dr. Bever received his PhD from Duke University. At Harvard, he will work with Professor Anne Pringle in the Department of Organismic and Evolutionary Biology on the synthesis and meta-analysis of data relating to mycorrhizal fungi community structure and dynamics in plant invasions. He began his six month Fellowship in September 2006.

Dr. Adrien Finzi's primary research focus is on the response of forest ecosystems to rising concentrations of atmospheric carbon dioxide. During his fellowship, he will focus on the role of N as a constraint to the uptake of atmospheric carbon dioxide in temperate forests. Dr. Finzi is Associate Director of the Stable Isotope Laboratory and an Associate Professor of Biology at Boston University. He received his PhD in Ecology from the University of Connecticut and was formerly a Distinguished Hollaender Fellow for Global Change at the US Dept. of Energy. Dr. Finzi began his six month fellowship in July 2006.

Dr. Sherilyn Fritz investigates long-term environmental change, particularly use of the fossil record to reconstruct natural patterns of climate variation and to evaluate human impacts on ecosystems. She will be in residence at the Harvard Forest working closely with David Foster on the impacts of mid-Holocene and Little Ice Age changes in climate on forest and lake ecosystems and human society. She will also work on a paper comparing Holocene dynamics in North and South America. Dr. Fritz is the Willa Cather Professor at the University of Nebraska, with joint appointments in the Department of Geosciences and School of Biological Sciences. Fritz is a member of the U.S. National Committee of the International Quaternary Union (INQUA), under the auspices of the U.S. National Academy of Sciences, and also serves as a councilor on the Commission for Paleoecology and Human Evolution in INQUA. Dr. Fritz received her PhD in Ecology from the University of Minnesota. Dr. Fritz began her six month fellowship in September 2006.

Jerry Jenkins has spent over 30 years conducting major botanical surveys throughout North America and is the author of several books, including the Adirondack Atlas, a series of volumes on natural resources geography of Vermont, an illustrated history of acid rain research, and a soon to be published guide to the mosses of eastern North America. During his time at Harvard, he will complete ongoing work on the vascular flora of Harvard Forest, inventory the bryophytes of Harvard Forest, and write and illustrate a book on the major forest communities of the northeastern United States. Mr. Jenkins is a researcher with the North American Program of the Wildlife Conservation Society and the Adirondack Nature Conservancy.

Dr. John McDonald has worked as a management-oriented wildlife biologist with state agencies, as an academic researcher, and as a state and federal regulatory administrator. His primary research interest is in wildlife, particularly on how large animals interactive in the Northeast habitat, particularly white-tail deer, black bear, moose and Canada lynx. In 2006, he was elected a Fellow of The Wildlife Society. He currently is a wildlife research specialist with the U.S. Fish and Wildlife Service. He received his PhD from the University of Massachusetts at Amherst. He will work closely with ecologists at the Harvard Forest to investigate the history of white-tailed deer populations in Massachusetts and the limiting factors of distribution of the geographic range of moose in North America during his seven month fellowship beginning November 2006.

Dr. Scott Pearson's research focus is on effect of landscape change on terrestrial biodiversity. During his Bullard Fellowship, he will study the influence of land-use history in New England and the Southern Appalachians on present-day diversity in temperate forest ecosystems and develop methods to model biodiversity responses to future landscape change in these two regions. Dr. Pearson is a Professor and the Chair of the Department of Natural Sciences at Mars Hill College in NC and serves as co-Principal Investigator at the NSF Coweeta Long Term Ecological Site. He received his Ph.D. in Zoology from the University of Georgia-Athens. He will be a Fellow for nine months beginning in September 2006.

October 2006 Highlights

NSF Awards Harvard Forest $4.9 Million to Study Landscape Change

Scientists to examine forest response to natural and human disturbances across northeastern U.S.

The National Science Foundation has awarded Harvard University's Harvard Forest $4.9 million to study drivers, dynamics, and consequences of landscape change in New England. The six-year grant, the largest in the Harvard Forest's 99-year history, will support research on forest responses to natural and human disturbances across the northeastern U.S. Led by Harvard Forest Director David Foster, Harvard researchers and students will collaborate with scientists from the Ecosystems Center at the Marine Biological Laboratory, the Woods Hole Research Center, Brandeis University, Michigan State University, the University of New Hampshire, and the University of Massachusetts.

For more information, read the press release.

Regional Forest Responses to Environmental Change

International Union of Forest Research Organizations, Canopy Processes Working Group

A traveling workshop in Massachusetts, New Hampshire and New York, USA. October 6-13, 2006
Information: http://people.bu.edu/nathan/iufro_info.htm

Sponsors: Bartlett Experimental Forest, Black Rock Forest Consortium, Boston University, Harvard Forest, National Science Foundation, Northeastern Ecosystem Research Cooperative, University of New Hampshire, USDA Forest Service

Within forest ecosystems, forest canopies – defined as the upper layer of forests, including leaves and branches – play a central role in regulating exchanges of carbon, water, and energy between the land surface and atmosphere. Approaches and tools for measuring and translating information from canopy processes to the level of landscapes and regions lack consensus, coordination, and standardization, and hinder our understanding of how and why biogeographic regions show different responses to environmental change. Advances in modeling and monitoring of forest structure and function, including stable isotopes, remote sensing, ecohydrological monitoring, and environmental sensor networks, provide powerful new ways to link canopy processes to regional forest function. The goal of the meeting is to compare, contrast, and synthesize approaches and research findings to assess regional forest responses to environmental change, with a specific focus on emerging tools, methods and standards the international forest canopy science research community uses to measure, model, and translate forest ecosystem information across scales from as small as leaves up to entire landscapes and biomes.

More than 60 contributors to this workshop represent the countries of Australia, Brazil, Canada, Costa Rica, Estonia, Finland, Japan, the Netherlands, New Zealand, Russia, Switzerland, United Kingdom, and the United States.

New Harvard Forest Publication

How to predict species abundance in the face of habitat loss

Plant and animal population sizes inevitably change following habitat loss, but the mechanisms underlying these changes are poorly understood. In a new study published in PLoS Biology, University of Vermont biology professor Nicholas Gotelli and Harvard Forest senior ecologist Aaron Ellison provide the first experimental confirmation that trophic structure can determine species abundances in the face of habitat loss. In a carefully constructed field experiment Gotelli and Ellison altered habitat volume and eliminated top trophic levels of the food web of invertebrates that inhabit rain-filled leaves of the carnivorous pitcher plant Sarracenia purpurea. Path models that incorporated food-web structure better predicted population sizes of food-web constituents than did simple keystone species models, models that included only single-species responses to habitat volume, or models including both food-web structure and habitat volume. In sum, the incorporation of trophic structure into ecological models may yield more accurate predictions of species abundance in a world where available habitats are shrinking and becoming increasingly framented.

Gotelli, N. J. and A. M. Ellison. 2006. Food-web models predict species abundances in response to habitat change. PLoS Biology 4(10): e324.

Open-access link to: PLOS Biology

September 2006 Highlights

Six New Harvard Forest Articles Published

Preemptive and Salvage Harvesting of New England Forest

One unexpected consequence of natural disturbances in forested areas is that managers often initiate activities that may impose greater ecosystem impacts than the disturbances themselves. By salvage logging areas affected by windstorms or other impacts, by harvesting host trees in advance of insect infestation or disease, or by preemptively harvesting forests in an attempt to improve their resilience to future disturbances and stresses, managers initiate substantial changes in the ecosystem structure and function. Much of this activity is undertaken in the absence of information on the qualitative and quantitative differences between disturbance impacts and harvesting. To provide insight for such decisions we evaluated the ecosystem consequences of two major disturbance processes in New England (U.S.A.)—intense windstorms and invasive pests and pathogens—and contrasted them with impacts from preemptive and salvage harvesting. Despite dramatic physical changes in forest structure resulting from hurricane impacts and insect infestation, little disruption of biogeochemical processes or other ecosystem functions typically follows these disturbances. Indeed, the physical and organic structures produced by these disturbances are important natural features providing habitat and landscape heterogeneity that are often missing due to centuries of land use. From an ecosystem perspective there are strong arguments against preemptive and salvage logging or the attempt through silvicultural means to improve the resistance or resilience of forests to disturbance and stress. There are often valid motivations for salvage or preemptive logging including financial considerations, human safety, and a desire to shape the long-term composition and resource-production characteristics of forests. Nonetheless, there are many ecological benefits derived from leaving forests alone when they are affected or threatened by disturbances and pest and pathogen outbreaks.

Foster, D.R. and D.A. Orwig, 2006. Preemptive and Salvage Harvesting of New England Forests: When Doing Nothing Is a Viable Alternative. Conservation Biology Volume 20, No. 4, 959–970.

Modeling Tree Regeneration After an Experimental Hurricane

The hurricane manipulation at Harvard Forest is one of our original LTER (long-term ecological research) experiments contrasting ecosystem response to natural and anthropogenic disturbance. In 1990, canopy trees were pulled over with a winch in a 0.8 ha experimental area, resulting in 80% canopy damage. Detailed height growth measurements of tree seedlings were tracked following the manipulation, and height growth models based on these measurements allow us to understand changes in tree species dominance. After ten years, black and yellow birch, and red maple are the most numerous species and compose the majority of the tallest regeneration. Red oaks, which dominated the original stand, are few and unlikely to emerge to the canopy of the new cohort.

Fajvan, M., A. Barker Plotkin and D.R. Foster. 2006. Modeling tree regeneration height growth after an experimental hurricane. Canadian Journal of Forest Research 36:2003-2014.

Sustaining Long-Term Research through Changing Times

Well-documental permanent plots form a living legacy of research that continues to grow and change, and provide an excellent base to answer new questions. They can be use to answer questions unanticipated when a study began, prompt shifts in scientific thinking and contribute to our understanding that forests are dynamic and constantly responding to a suite of disturbances and stresses. They are a vivid illustration of the concept of forest change over time.

Barker Plotkin, A. and D. Foster. 2006. Sustaining long-term research through changing times at the Harvard Forest. Pages 41-53 in Irland, L.C., A.E. Camp, J.C. Brissette and Z.R. Donohew. Long-term Silvicultural & Ecological Studies: Results for Science and Management. GISF Research Paper 005, Yale University.

Decline of Rare Plants in New England

Recent Bullard Fellow Elizabeth Farnsworth and her colleague Danielle Ogurcak (University of Florida) explore how to detect and accurately document the ever-shifting and contracting ranges of rare plant species in order to identify species most in need of conservation and prioritize protection efforts with limited resources. Using herbarium records and Natural Heritage data, Farnsworth and Ogurcak estimated temporal changes in the town-level distributions of 71 rare plant species in the six New England states. They used three different statistical estimators to determine the probability that a given population of a rare species is still extant, given historical data on their occurrences. These methods account for the lack of precise information on locations and habitats, and targeted searching for rare species that may present a biased picture of biogeographic distributions and presumed habitat preferences. Current ranges of these 71 species were 67% smaller on average than their historical ranges and distances among occurrences decreased. In New England five "hotspots of diversity" contain >35% of known rare plant populations. Extant populations occurred more frequently at the periphery of their historical range than would be expected by chance. This detailed study illustrates that available coarse-grained data on current and historical occurrences can be used to examine large suites of species to prioritize taxa and sites for conservation.

Farnsworth, E. J. and D. E. Ogurcak. 2006. Biogeography and decline of rare plants in New England: historical evidence and contemporary monitoring. Ecological Applications 16: 1327-1337.

Energy and Nutrient Fluxes in Hemlock Forest Invaded by HWA

A recent study by former Bullard Fellow Bernhard Stadler, from the University of Bayreuth in Germany along with collaborators including Harvard Forest Ecologist David Orwig, examined the ecology of energy and nutrient fluxes in hemlock forests invaded by the introduced pest, the hemlock woolly adelgid. This study adds to previous work by the same authors by examining litter microcosms, canopy throughfall and litter lysimeter chemical composition under uninfested and lightly infested trees at a forested site in central Massachusetts. During the early spring, when low densities of adelgid were actively producing wax wool, throughfall fluxes of dissolved organic carbon, dissolved organic nitrogen, potassium, and total organic carbon were significantly higher under infested compared to uninfested trees. Results also suggested that a disturbance to the canopy cascades down to the forest floor, as throughfall fluxes strongly affected litter fluxes. After HWA entered summer aestivation, differences in matter fluxes often became less pronounced. We used results from this study and previous work to construct a nonlinear conceptual model for the temporal and vertical transition of energy and nutrient fluxes associated with chronic HWA infestation. Varying levels of HWA abundance lead to opposing effects on energy and nutrient flows in these systems. Therefore, stands in transition from pure hemlock to pure hardwood stands are likely to contain non-linear nutrient fluxes associated with changes in needle chemistry and progressive needle loss. These findings highlight the need to understand the biology and specific physiological and trophic effects of exotic pests on their hosts and associated ecosystem processes.

Stadler, B, T. Müller and D. Orwig. 2006. The Ecology of Energy and Nutrient Fluxes in Hemlock Forest Invaded by Hemlock Woolly Adelgid. Ecology, 87(7) pp. 1792–1804.

Facilitations between Black Locust and Non-Native Plant Species on Cape Cod

A recent three-year study at Cape Cod National Seashore (Massachusetts) has found that the presence of some invasive species, in this case black locust (Robinia pseudoacacia), appears to support the existence of other nonnative species. Robinia pseudoacacia, a nitrogen-fixing tree to the central Appalachian and Ozark Mountains, is considered to be one of the top 100 worldwide woody plant invaders. This project was initiated to determine the impact of introduced black locust on an upland coastal ecosystem and to estimate the spread of this species within Cape Cod National Seashore. In field research conducted in the summers of 2003 through 2005 Betsy Von Holle and her students in the Harvard Forest Summer Program studied the introduced nitrogen-fixing black locust tree and its understory. They found that black locust had an average of 10 times the number of nonnative species under its canopy as did the native species, primarily pitch pine (Pinus rigida), white oak (Quercus alba) and black oak (Quercus velutina). They also found that nitrogen levels are significantly higher under locust than under native forest approximately 66 feet (20 m) away from the locust stand. Thus, the introduction of a novel functional type (nitrogen-fixing tree) into this sandy, nutrient-poor, upland forested ecosystem resulted in "islands of invasion" within this otherwise invasion-resistant system. However, total land cover of black locust in the outer Cape has significantly declined in this system over the past three decades, as revealed by historical aerial photographs. The authors suggest that managers consider the complex interaction between soil composition, the nonnative species that exist within the invaded ecosystem, and the degree of fragmentation of the landscape when making management decisions regarding this species.

Von Holle, B., K. A. Joseph, E. F. Largay, and R. G. Lohnes. 2006. Facilitations between the introduced nitrogen-fixing tree, Robinia pseudoacacia, and nonnative plant species in the glacial outwash upland ecosystem of Cape Cod, MA. Biodiversity and Conservation 15:2197-2215.

August 2006 Highlights

Donations for The Harvard Forest Ecology K-12 Teacher Training Received

The "Friends of Harvard Forest" and an anonymous donor have provided generous support to our Schoolyard Ecology program. This funding will allow us to provide scientific consultation and training to local K-12 teachers who are implementing field ecology studies related to Harvard Forest ecologist's research. In addition to providing students with hands-on experience using scientific methods this program provides students and teachers with a means of connecting to the natural world. See our schoolyard webpages or contact Pamela Snow, Schoolyard Coordinator at psnow@fas.harvard.edu (978) 724-3302 x246 for more information on this unique program.

New Harvard Forest Publication

One unexpected consequence of natural disturbances in forested areas is that managers often initiate activities that may impose greater ecosystem impacts than the disturbances themselves. By salvage logging areas affected by windstorms or other impacts, by harvesting host trees in advance of insect infestation or disease, or by preemptively harvesting forests in an attempt to improve their resilience to future disturbances and stresses, managers initiate substantial changes in the ecosystem structure and function. Much of this activity is undertaken in the absence of information on the qualitative and quantitative differences between disturbance impacts and harvesting. To provide insight for such decisions we evaluated the ecosystem consequences of two major disturbance processes in New England (U.S.A.)—intense windstorms and invasive pests and pathogens—and contrasted them with impacts from preemptive and salvage harvesting. Despite dramatic physical changes in forest structure resulting from hurricane impacts and insect infestation, little disruption of biogeochemical processes or other ecosystem functions typically follows these disturbances. Indeed, the physical and organic structures produced by these disturbances are important natural features providing habitat and landscape heterogeneity that are often missing due to centuries of land use. From an ecosystem perspective there are strong arguments against preemptive and salvage logging or the attempt through silvicultural means to improve the resistance or resilience of forests to disturbance and stress. There are often valid motivations for salvage or preemptive logging including financial considerations, human safety, and a desire to shape the long-term composition and resource-production characteristics of forests. Nonetheless, there are many ecological benefits derived from leaving forests alone when they are affected or threatened by disturbances and pest and pathogen outbreaks.

Foster, D.R. and D.A. Orwig, 2006. Preemptive and Salvage Harvesting of New England Forests: When Doing Nothing Is a Viable Alternative. Conservation Biology Volume 20, No. 4, 959–970.

July 2006 Highlights

Professor Emeritus Receives Centennial Medallion Award

Harvard Forest Professor Emeritus P. Barry Tomlinson received the Botany Society of America's Centennial Medallion Award. The award honors those who have make significant contributions to the advancement of the botanical sciences as well as contributions to the Botanical Society of America.

Ph.D. student Sydne Record receives Gilgut Fellowship.

Sydne Record, a Ph.D. student in the Plant Biology program at the University of Massachusetts who is doing her dissertation research at the Harvard Forest with Senior Ecologist Aaron Ellison, has received the 2006-2007 Gilgut Fellowship from the Plant Biology program. This fellowship provides a full year of stipend support and release from teaching so that Sydne can focus full-time on her disseration research on understory plants, ants, and ecosystem dynamics.

New Harvard Forest Publications

A.M. Ellison, L.J. Osterweil, L. Clarke, J.L. Hadley, A. Wise, E. Boose, D.R. Foster, A. Hanson, D. Jensen, P. Kuzeja, E. Riseman, and H. Schultz. 2006. Analytic webs support the synthesis of ecological data sets. Ecology 87(6): 1345-1358.

Ecologists are interested in synthesizing a diverse array of complex datasets to address novel ecological questions, but actually synthesizing datasets to produce reliable and reproducible results is a challenging task. A team of ecologists from the Harvard Forest and computer scientists from the University of Massachusetts have developed formal representations, known as analytic webs, that provide both producers and consumers of datasets complete and precise definitions of the scientific processes that are used to process scientific datasets. Analytic webs are created and data can be synthesized with a prototype software tool called SciWalker. We have successfully applied analytic webs to the analysis and synthesis of forest CO₂ exchange data from eddy flux towers located on Prospect Hill. This work was supported by NSF grant CCR-0205575.

Atwater, D.Z., J.L. Butler, and A.M. Ellison. 2006. Spatial distribution and impacts of moth herbivory on northern pitcher plants. Northeastern Naturalist 13: 43-56.

This paper summarizes the independent research project of 2004 REU student Dan Atwater, in which he examined changes in the distribution of two noctuid moths that feed on pitcher plants at Tom Swamp. Large plants were preferentially attacked by larvae of Exyra fax but the pitcher-plant borer Papaipema appassionata was not so selective. We hypothesize that spatial distribution of Exyra larvae results both from selectivity in feeding and from limited flight distances of adults. In contrast, spatial distribution of Papaipema larvae may result from limited larval mobility. The results of this study provided key preliminary data for a successful NSF grant proposal.

Cobb, R.C., D. A. Orwig, and S. Currie. 2006. Decomposition of green foliage in eastern hemlock forests of southern New England impacted by hemlock woolly adelgid infestations. Canadian Journal of Forest Research 36: 1331–1341.

Recent Research Assistant Richard Cobb, working with collaborators including Harvard Forest Ecologist David Orwig and former HF REU summer student Steve Currie, examined the impacts of the introduced insect, the hemlock woolly adelgid (HWA) on green litter decomposition in New England hemlock forests. This study investigated both the direct effects of HWA feeding and indirect changes in microclimate on foliar decomposition. Results suggest that while HWA-feeding did not result in significant changes in foliar percent carbon (C), percent nitrogen (N), or percent lignin at the beginning of the study, decomposing foliage from infested trees had significantly higher N concentrations than uninfested foliage as decomposition progressed. Mass loss of uninfested foliage was lower in infested hemlock stands than uninfested stands (30.9% ±0.7% vs. 34.2% ± 0.1%). Rates of mass loss were significantly correlated with microclimate factors and indicate that organic soil moisture levels are controlling decomposition in HWA-infested forests.

June 2006 Highlights

Spring Leaf Out - 2006

The photographs in the following presentation document the changes in forest trees at the margin of the pasture, adjacent to the headquarters of the Harvard Forest. These photographs were taken during spring of 2006 by John O'Keefe, and show the timing of the leaf out and leaf development this spring.

Despite the very mild and dry winter, leaf out (leaves emerged from 50% of the buds) occurred at the end of the first week in May, about two days later than the average date for the previous 16 years. This date is determined by averaging the date of leaf out of six species, including: red maple, red oak, yellow birch, white oak, striped maple and witch hazel. Due to cool, wet weather in the middle of May, leaf expansion proceeded rather slowly until the last week of May which was very warm. The images show this progression. Learn more about this study of woody species leaf phenology

Undergraduate Research Experience Program Kicks Off

22 summer students have arrived as part of the Harvard Forest summer research program in ecology. Students come from all over the United States to participate in on-going research projects including atmospheric pollution, global warming, hurricanes, treefalls, and insect outbreaks. Researchers come from many