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Harvard Forest REU Symposium Abstract 2017

  • Title: Grassland management practices: preserving biodiversity and preventing ecological invasions
  • Author: Alina S Smithe (Mount Holyoke College)
  • Abstract:

    Vulnerable to infiltration by the ever-expanding New England forests, grassland ecosystems remaining from the footprint of agricultural land use are rapidly decreasing. Without conservation management, loss of many rare species is inevitable. Cattle grazing and mowing are biomass removal management strategies to protect grassland biodiversity through regular disturbance that prevents the growth of woody species. While mowing cuts plants all indiscriminately, cows have specific dietary preferences that may facilitate proliferation of certain invasive plant species. In the third year of a long-term study at Harvard Farm, we examined the impacts of these practices on plant communities by surveying the species in 10m x 10m plots distributed across three experimental treatments (continuous grazing, rotational grazing, and mowing), with two plot types (greens and fairways). Our results indicate that species richness is increasing in all treatment areas; however, the same is true for the abundance of invasive species and woody species. Because changes in plant community structure happen over time, the distinct effects of the treatments will become more interpretable in future years. To understand the spread of the invasive species, Rumex acetosella, we surveyed areas containing a high abundance of the plant and analyzed its potential allelopathic effects. Though we hypothesized that plots containing R. acetosella would contain more bare ground and fewer native species than nearby areas without the invader, we detected no significant trends. Because our results may have been limited by the observational design and small sample size, we also conducted a greenhouse experiment to investigate these effects.

  • Research Category: Biodiversity Studies; Conservation and Management; Invasive Plants, Pests & Pathogens