Completed Research Projects

American elms represent some of the most culturally and economically significant urban trees. Their contributions to the urban landscape are numerous and include: carbon sequestration, capture of storm water and airborne particulate matter, reduced heating and cooling costs through wind buffering and shade and enhanced aesthetics with their large, sweeping canopies. Prior to the introduction of Dutch Elm Disease, American elms dominated the urban and suburban landscape because of their beauty, rapid growth rates and ability to tolerate difficult growing conditions.  Despite the devastating effects of the disease, millions of American elms still occupy the urban and forest landscape today. But, after decades of regular injection the costs associated with these treatments are adversely impacting tree heath and this issue must be addressed. The UMass Shade Tree Laboratory, now the Plant Diagnostic Laboratory, was founded in 1935 with the sole purpose of combating the DED epidemic. Now, 80 years later the fight against this destructive disease continues in ways that could never be predicted decades ago.

Global climate change affects every aspect of our life. Global warming increases the intensity of drought, which leads to the increase in frequency and severity of forest fires. Beyond being a source of soot and polyaromatic hydrocarbons (PAHs), severe wildfires/forest fires can damage soils, water quality and quantity, fisheries, plant communities, wildlife habitat, and endangered species; result in economic and property loss; and cause harms to the environment and public health. Forest thinning or prescribed burns reduce the accumulation of hazardous fuels and restore forest health.  The major cause of global warming is the ever-increasing concentration of carbon dioxide (CO2) in the atmosphere from the use of carbon-based fuels. Biochar, the anaerobic pyrolysis productof biomass waste material, has attracted research interest as a soil amendment that may improve soil structure, moisture retention, and buffering capacity, and that helps control plant root diseases and sequester carbon in soils (instead of release to air as CO2), as a result, mitigate greenhouse effect. Therefore, the goal of this proposed project is to utilize wood waste materials to produce biochar which can be used in both forest and agricultural soils to improve soil quality, sequester carbon in soils, and reduce the emission of greenhouse gases (e.g., CO2 and N2O).

This study will examine threats to water security and potential impacts on water quantity and quality in watershed systems. The main goal of the study is to evaluate the effects of land use, extreme precipitation, and climatic stressors on water security (quantity and quality) and potential mitigation opportunities at a river basin scale. Geographic Information Systems (GIS), uncertainty analysis, simulation modeling, and a multi-attribute decision framework will be used to evaluate and advance water security in watershed systems.

It has been hypothesized that climate change will cause plant species ranges to shift northward with plants at the south end of ranges declining in vigor and growth rate. The purpose of this research is to test this hypothesis for red spruce and balsam fir along the southern end of the continuous distribution of these species, in Massachusetts. By measuring the growth patterns of these trees, we can determine if the southern end of the range has been declining, relative to more northern stands of these species.

This research will determine the environmental behavior and process of several types of manufactured nanomaterials. The results of this study are expected to help us understand how these manufactured nanomaterials interact with natural and synthetic molecules, and their fate, mobility, exposure and bioavailability in the environment.

This project will examine the effect of natural diversity on biofuel production efficiency by using a grass energy model organism (Brachypodium distachyon), and treatment with both biological and thermochemical conversion.

Acid rain and atmospheric pollution continue to be regional and national problems. The site's data contributes to the accurate assessment of precipitation chemistry and the effectiveness of the nation's air pollution laws and regulations.

Global climate change and nitrogen deposition are processes that will only increase as industrialization continues. The purpose of this study is to understand the response of the microbially driven soil nitrogen cycle to the combined effects of temperature increase and nitrogen amendments in forest soils of New England.

There is widespread interest in greening municipalities and increasing urban tree canopy cover, largely through local community-based tree planting initiatives. It is generally estimated that newly-installed (i.e. planted) trees require at least 3 or more years before establishment, when they resume pre-transplant growth rates. Most trees installed in the urban environment are dug from the nursery field with a spade, and wrapped in burlap and a metal basket ('balled and burlap' or 'B&B'). There is interest, however, by shade tree committee members and professional urban foresters alike, in planting trees grown using other easier-to-plant systems, including a variety of container-grown (CG, IGF) and bare-root (BR) tree production methods. Trees grown from these production systems, however, must have the potential to grow long-term and reach maturity to offer the numerous values associated with urban trees that include a variety of aesthetic, social, and environmental benefits.This may be a challenge, since urban environments often present very difficult growing conditions that habitually thwart tree growth and survival. Though advances in understanding have been made, empirical data to describe the survival and growth of such trees remains limited, with the preponderance of research considering trees growing in agricultural plots, rather than in urban settings. Since budget constraints are routinely identified as a key limiting factor relative to urban forest management practices, there is also a need for further information concerning the longer term costs associated with planting and maintaining urban trees. Collecting growth and maintenance cost data on established urban oak specimens in Amherst, MA, produced using various nursery systems will 1) add to the overall base of  knowledge concerning urban tree growth and survival 2) enable the quantification and further understanding of the relationship of urban tree growth/survival and nursery production system 3) Enable the quantification and further understanding of the long-term costs associated with planting and maintaining urban trees. The long-term goal of this work is to gather local, empirical data that will help urban forest practitioners consider the appropriate (i.e. most cost-effective, best-performing) nursery production system, when selecting trees for urban planting in Massachusetts communities.

Through this research project a variety of ornamental plants will be grown to assess how production practices can be improved through a series of experiments examining irrigation methods and volume, fertilizer quantity, substrate additives, and substrate components. Plant water needs will be assessed to understand how much irrigation is needed to produce good quality plants. This will provide growers with ways of improving irrigation applications by grouping plants by water needs and reducing irrigation applications when possible. Plant fertilizer needs will be assessed in a similar manner. By reducing fertilizer applications the amount of nutrients in the nursery or greenhouse runoff will be reduced lessening the environmental impact. Substrate components and additives will be assessed to further the body of knowledge on their impact on production with an emphasis on their impact on water applications, retention, and leaching and fertilizer retention and uptake.

The expansive growth of solar photovoltaics (PV) in Massachusetts has helped make the state a leader in renewable energy production, but there have been public concerns regarding the development of agricultural lands for solar PV electricity production. In response to these concerns, the Massachusetts Department of Energy Resources (DOER) included provisions in the new state solar energy program which limit conventional ground-mounted solar arrays on farmland, while encouraging innovative "dual-use" technology. Under the new Solar Massachusetts Renewable Target (SMART) program, there is a significant financial incentive for dual-use systems which limit shading and obstructions, and require continued agricultural production on the land below and around solar arrays.

Current agricultural practices on available arable land will not meet the nutritional needs of a population that will reach nine billion people by the middle of this century (Ray et al. 2013). In parallel, climate change will increase extreme weather events, including drought (Dai, 2011, Trenberth et al., 2014), and continued urbanization of farmland is eliminating arable land (Song et al. 2015). There is a clear need for sustainable agricultural innovations that can increase yields and provide food security without incurring environmental degradation. Soil microbes are known to form associations with plants and affect plant health, and in recent years, interest has grown in exploiting the beneficial associations that plants establish with microbes. The plant microbiome abounds with plant growth-promoting rhizobacteria (PGPR) that can help plants acquire more nutrients from the soil and tolerate stressors like drought (Barnawal et al. 2013, Bresson et al. 2014). PGPR can also control plant pathogens (Chowdhury et al. 2013), promote beneficial mycorrhizal colonization (Labbe et al. 2014), and produce potentially valuable secondary metabolites (Raaijmakers et al. 2012). Finding ways to harness these beneficial microbes to improve crop growth and yield has the potential to ameliorate the challenges imposed by the world's growing population and environmental degradation.

This multidisciplinary project will promote the use of biochar and bio-oil generated from agricultural/forest organic wastes to enhance small farm sustainability through providing renewable fuel, and improving soil quality and crop productivity, and to improve the environment through sequestrating greenhouse gases and reducing the mobility and exposure of contaminants in soils.

Residential solar power is an important technological innovation that holds promise for a cleaner energy future. Out of 2.5 million households in the state of Massachusetts, those who installed solar photovoltaic(PV) systems grew from a mere 14 households to 60,465 households between 2010-2017. Between 2015-2017, the residential installations are growing at an even higher rate of 50% (Data source: Massachusetts Department of Energy Resources). It is crucial to understand what factors are determining the household decisions in the process of adopting the solar PV system.

Global climate change is altering the Earth's natural cycling of water from the ground to the air and back again, what is known as the hydrologic cycle. In New England, climate change is predicted to increase temperatures and increase the frequency and strength of rain events. The increased temperatures will result in less snow accumulation in the winter and an increased need for irrigation in the hotter summer as evapo-transpiration increases. This will alter significantly the recharge/extraction cycle. Will less water enter groundwater aquifers because of reduced snow fall? Will enough water recharge the aquifers to offset the amount extracted in the summer for irrigation? Certainly the timing of recharge will change. These changes will require a better understanding of recharge rates and a better characterization of groundwater aquifers; the volume of water present and its availability. Understanding the seasonal timing and rates of groundwater recharge is critical to maintaining a sustainable water supply. Importantly, how will these changes in the hydrolgical cycle effect sustainable agricultural practices?

Researchers will evaluate the potential use of field indicators of hydric soils to characterize wetland hydroperiods with respect to frequency, depth, and duration of water table fluctuations; test the effectiveness of proposed hydric soil indicators to identify 'problem hydric soils'; test monitoring protocols used to identify reducing conditions to determine if they are effective within a range of soil conditions within the Northeast; and investigate the hydraulic properties of hydromorphic soils with episaturation.

This project will study and numerically model road salt impact on water quality in a typical aquifer in eastern Massachusetts.

This study will provide important information on long-term trends in water demand and supply, aid in the formulation of water policies for water resource development, and offer information to help protect surface and groundwater supplies. This project will also target areas with the best potential for surface augmentation of water supplies based on the relative benefits and costs of water supply augmentation (through spatially explicit policies for runoff mitigation and groundwater recharge). This project will evaluate water resources within a watershed ecosystem framework, and thereby will consider multiple supplies and uses of water resources. This study will address three areas of special interest to the region, namely:
• Water management in the context of forest loss and rapid development and conflict for water supply;
• Improvements in the assessment of water availability, incorporating technological, institutional, cultural and economic factors that   influence water use and water availability and;
• Improved methods of characterizing and quantifying components of the water cycle in forested watersheds.

The incidence and prevalence of many chronic diseases are dramatically increasing in the United States and other countries, making these disorders a serious health problem. It is of practical importance to better understand the roles of food-derived bioactive compounds in development of these chronic diseases, in order to provide optimized dietary recommendations or guidelines, and/or develop safe and effective strategies for disease prevention. In this project, we will focus on two major areas: (1) to better understand the effects and mechanisms of food bioactives on development of chronic diseases such a inflammation, aging, and energy metabolism, and (2) to further understand the factors contributing to the poor bioavailability of food bioactives and develop novel strategies to enhance their metabolic stabilities and health-promoting effects. Together, these efforts will provide the fundamental knowledge which is critical to develop safe and effective diet-based strategies for disease prevention, resulting in significant and positive impact for public health.

House flies are the major vector of numerous food pathogens (e.g., Escherichia coli). It has been suggested that the fly crop is the major reservoir for the pathogen and also that this is where horizontal transmission of antibiotic resistance occurs. The salivary glands of most flies involved in vectoring pathogens are also involved in pathogen transmission and their nutrient and pathogen uptake while feeding. This research focuses on two essential organ systems of house flies, in order to explore non-traditional control strategies for the insects. Control of flies is thought to have a potential strong impact on transmission of food pathogens.

Producing shelf-stable acidified canned foods can help to add value to produce and introduce new markets, extend the agricultural season, and reduce waste. However, to successfully sell and distribute shelf-stable products, such as salsas, sauces, and/or acidified pickled products, processors must comply with the Code of Federal Regulations (21CFR114). This project providesopen-access to the development of 12 shelf-stable acidified canned food recipes that were converted into scale-appropriate product formulations that includes the scheduled process that identifies the appropriate food safety controls that were approved by a Process Authority.

This research focuses on utilizing emulsion technologies to allow omega-3 fatty acid incorporation into foods and to increase the bioavailability of these important dietary fats.