Alliaria petiolata (garlic mustard) is an herbaceous biennial herb that has been present in the New England landscape for over a century. We investigated the ecological and historical factors affecting A. petiolata's invasion pattern across the New England landscape, including forest community structure, geophysical attributes, and habitat fragmentation. One-hundred-and-seventy-five 25× 100 m roadside, forested plots across two ecoregions were visited in the summers of 2006 and 2007. A. petiolata presence and cover, dominant canopy species, slope, and soil moisture were recorded.

The Chronic Nitrogen Addition Experiment at the Harvard Forest was initiated in 1988 to better understand the process of forest N saturation due to anthropogenic N deposition. Presently, there is great interest in understanding and quantifying impacts of deliberate (forest fertilization) or inadvertent (atmospheric deposition) additions of nitrogen on forest growth as a means to enhance forest uptake of atmospheric C and subsequent storage within biomass and soil.

Climate change, residential development, and timber harvesting are likely to be the primary disturbance agents affecting the forests of Massachusetts in the coming decades. One source of uncertainty is the potential rise of a forest biomass energy industry and the ensuing increases in harvesting to meet demand for feedstock. Under Massachusetts’ Renewable Portfolio Standard, potential future demand for biomass electricity could be around 165 MW, which would require up to 2 million Mg of woody biomass annually.

Ecosystems worldwide are faced with climate change. In the northeastern United States, climate change is coupled with nitrogen deposition from air pollution. The objective of this study is to determine how soil warming and nitrogen deposition influence species richness, diversity, and abundance of vegetation in a northeastern forest. Our study site is the chronic Soil Warming and Nitrogen Fertilization experiment at the Harvard Forest Long Term Ecological Research site.

Relatively little attention has been given to the processes that control the production and subsequent availability of amino acids in temperate forest soils. We examined how differences in soil organic matter chemistry and mycorrhizal association between temperate forest tree species of the Northeastern US lead to variation in amino acid cycling. We measured amino acid cycling throughout the growing season in soils from single tree species plots located in both the Harvard Forest, MA and the Pisgah State Forest, NH.

With recent shifts in public attitudes across the United States concerning the problem of global climate change, momentum is building for aggressive action to mitigate greenhouse gas emissions. At the same time, the ongoing economic recession presents challenges for financing an aggressive climate change abatement campaign; hence, it is imperative that cost-effective strategies for reducing greenhouse gas emissions be identified and pursued. To accomplish this, policy instruments will need to be tailored to a complex range of local and regional conditions.

The temperate forests of eastern North America support high biodiversity and critical ecosystem functions while providing natural resources and cultural benefits to an expanding human population. The region is shaped by a legacy of landscape change: major shifts in climate, vegetation and disturbance at millennial time scales; extensive deforestation for agriculture in the 17th – 19th centuries; and abandonment of farmlands, natural reforestation and increasing urbanization through the mid-21st century.

The objective of this work was to compare estimates of microbial and biogeochemical processes obtained from year round versus field season only data. We also aimed to capture the response of soils to simultaneous warming and nitrogen fertilization in both winter and summer months. Our research took place at the chronic Soil Warming and Nitrogen Fertilization experiment at the Harvard Forest Long Term Ecological Research site. The experiment includes four treatments in a completely randomized design: control, +heat, +N, and +heat +N.

In many parts of the United States, roughly 40% of forest is in non-industrial, private ownership, and in much of the eastern US, as much as 75% of all forest is in this category. Nationally, surveys and participation rates suggest most owners do not participate in traditional management or technical assistance programs, nor do they obtain professional advice prior to a management decision such as the sale of timber.

Woody debris is a recalcitrant carbon pool, storing carbon in complex molecules for extended periods of time. It has been shown that temperature and moisture are major drivers in decomposition from this pool. Additionally, under certain circumstances, both species and size can influence decomposition. It is not known, however, how the woody debris carbon pool in the moist, temperate forests of New England will respond to climate change, specifically soil warming.