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Harvard Forest REU Symposium Abstract 2016

  • Title: Effects of climate change and invasive species on red maple growth
  • Author: Alexandra Salinas (St. Mary's University)
  • Abstract:

    Acer rubrum (red maple) is a common canopy tree in northeastern American forests and is increasingly dominating the understory and mid-canopy of this region. However, changing climate conditions and invasion by Alliaria petiolata (garlic mustard) potentially threaten the future success of red maple recruitment. Our objectives were thus to examine the interacting effects of soil warming, nitrogen fertilization, and garlic mustard invasion on red maple seedling growth and leaf production. First-year red maple seedlings were planted in 20 plots on the Harvard Forest property under 8 treatments (control, control-invasion, heated, heated-invasion, nitrogen addition, nitrogen-invasion, heated-nitrogen, and heated-nitrogen-invasion) in October 2015. We monitored seedling growth from May to August 2016. Preliminary results suggest that soil warming alone has a strong positive effect on aboveground seedling growth, but in conjunction with nitrogen addition, the positive effects of warming are decreased. Furthermore, seedlings on heated-invasion and heated-nitrogen-invasion treatments had fewer survivors compared to other treatments, suggesting a negative effect of soil warming in conjunction with garlic mustard invasion on early survival. Additionally, garlic mustard invasion on its own appears to positively affect leaf count (though these leaves have smaller surface areas), and in conjunction with nitrogen addition, appears to have a positive effect on stem height compared to nitrogen addition alone. Though growth responses to soil warming are positive, warming is only a single factor of climate change, and our results suggest potential positive growth effects in red maple seedlings from soil warming may be reduced in combination with other climate change factors.

  • Research Category: Invasive Plants, Pests & Pathogens