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Summer Research Project 2017

• Title: Biological invasions, and plant and soil community responses under global climate change
• Group Project Leader: Kristina Stinson
• Mentors: Erin Coates-Connor; Mercedes Harris; Kristina Stinson
• Collaborators: Erin Coates-Connor; Serita Frey; Kristina Stinson
• Project Description:

  Invasive plants can have extensive ecological and economic impacts in invaded landscapes. Ecologically, they can rapidly dominate habitats and outcompete native plant species; economically, domestic losses and eradication efforts cost over thirty billion dollars per year in the US alone. Garlic mustard (Alliaria petiolata) is a highly disruptive invasive plant in North American temperate forests. Garlic mustard grows in high density patches that suppress the growth and recruitment of native understory plants and canopy tree seedlings; further, it can directly invade previously undisturbed forest understories. Previous research indicates that garlic mustard disrupts associations between native plant roots and mycorrhizal fungi, a mutualism critical for nutrient and water uptake, and thus plant performance. This phytochemical inhibitory mechanism is likely key to the invasion success of garlic mustard, as it provides a competitive advantage over native plants key soil resources.
  
  In the temperate hardwood forests of New England, we are conducting research on garlic mustard population dynamics, the impacts of garlic mustard on native plants and soil biota, and potential to control garlic mustard and restore native plant communities under environmental change. Our specific research goals for 2017 are to 1) determine changes in garlic mustard population biology across microhabitats through time using a long-running demography study at the Harvard Forest, 2) test the feasibility of different garlic mustard eradication methods for recovery of plant and soil biological diversity and function, and 3) examine the effects of population density and morphology on garlic mustard phytotoxicity across populations in Massachusetts and New York.
  
  In Summer 2017 we will maintain important long-running field experiments (Objectives 1 and 2). Our work on these experiments will include collecting data on plant community cover and density, sampling plant biomass and soil, and analysis of plant tissues and soil samples. We will be collecting these data mainly at Harvard Forest, Petersham, MA, and other sites across Massachusetts and New York. Soil and plant tissue samples will be used to quantify mycorrhizal fungi diversity and abundance, in association with the Frey lab at UNH. These data will help us to characterize long-term changes in garlic mustard invasion, how patterns of invasion influence soil and plant communities across the landscape, and how different eradication methods impact soil and plant communities across the landscape. We will also establish new field projects (Objective 3), which will include collecting demography and morphological data, sampling plant biomass and soil, and analysis of plant tissues and soil samples from sites in the Harvard Forest, and elsewhere in Massachusetts and New York. These data will help us determine how invasion density and plant structure influence the production of phytotoxic compounds, and thus potential invasion severity. All three projects serve to help characterize patterns and processes of long-term garlic mustard invasion in New England forests, impacts on native communities, and to provide data to help inform best management practices for managing this damaging invasive species.
  
  We are interested in recruiting 1-2 summer students for our projects in 2017. This will be an excellent opportunity to gain hands-on experience in field research and plant ecology. Our students will assist in most or all aspects of our summer fieldwork data collection, as well as data entry and management and statistical analysis. They will also have the opportunity to interpret the data they collected along with previous data from our research group, and to present their findings to Harvard Forest scientists and other student peers in August. The student will use R statistical software for statistical and graphical analyses. Student work will occur both in teams and independently, and a large part of their summer will be spent in the field regardless of weather conditions.
  
  Dr. Kristina Stinson is the principal investigator for the project, and Dr. Stinson and Dr. Serita Frey (UNH) will meet with the student initially to discuss research goals, project design and results. MSc candidate Erin Coates-Connor will provide mentoring at Harvard Forest, including training for data collection, entry and analysis, and supervision of field work. Mercedes Harris will also provide training for data collection, entry and analysis, and supervision.
  

• Readings:

  Barto, E., P. Antunes, K. Stinson, A. Koch, J. Klironomos, and D. Cipollini. 2011. Differences in arbuscular mycorrhizal fungal communities associated with sugar maple seedlings in and outside of invaded garlic mustard forest patches. Biological Invasions 13:2755-2762.
  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 89:1043-1055.
  Dukes, J. S., J. Pontius, D. Orwig, J. R. Garnas, V. L. Rodgers, N. Brazee, B. Cooke, K. A. Theoharides, E. E. Stange, R. Harrington, J. Ehrenfeld, J. Gurevitch, M. Lerdau, K. Stinson, R. Wick, and M. Ayres. 2009. Responses of insect pests, pathogens, and invasive plant species to climate change in the forests of northeastern North America: What can we predict? Canadian Journal of Forest Research 39:231-248.
  Rodgers, V. L., K. A. Stinson, and A. C. Finzi. 2008. Ready or Not, Garlic Mustard Is Moving In: Alliaria petiolata as a Member of Eastern North American Forests. Bioscience 58:426-436.
  Stinson, K., S. Kaufman, L. Durbin, and F. Lowenstein. 2007. Impacts of Garlic Mustard Invasion on a Forest Understory Community. Northeastern Naturalist 14:73-88.
  Stinson, K. A., S. A. Campbell, J. R. Powell, B. E. Wolfe, R. M. Callaway, G. C. Thelen, S. G. Hallett, D. Prati, and J. N. Klironomos. 2006. Invasive plant suppresses the growth of native tree seedlings by disrupting belowground mutualisms. PLoS Biology 4:e140.
  Wolfe, B. E., V. L. Rodgers, K. A. Stinson, and A. Pringle. 2008. The invasive plant Alliaria petiolata (garlic mustard) inhibits ectomycorrhizal fungi in its introduced range. Journal of Ecology 96:777-783.
  

• Research Category: Regional Studies, Physiological Ecology, Population Dynamics, and Species Interactions, Invasive Plants, Pests & Pathogens, Group Projects, Conservation and Management