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Harvard Forest Symposium Abstract 2006
- Title: Understory response over 15 years following simulated hurricane at the Harvard Forest
- Primary Author: Mathew Trumbull (Hampshire College)
- Additional Authors: Audrey Barker Plotkin (Harvard Forest); David Foster (Harvard University)
- Abstract:
The hurricane experiment at Harvard Forest was designed to monitor long-term changes in forest dynamics after simulated windthrow. In 1990, canopy trees were pulled over with a winch in a 0.8 ha experimental area, resulting in 80% canopy damage. We have examined vegetation change and recovery following the manipulation, including the response of understory herb and shrub species. Composition and percent cover of understory vegetation was assessed in 1990 (pre-manipulation), 1991, 1992, 1995, 2000, and 2005. Survey plots were sited along four transects – three in the experimental site, and one in the 0.6 ha un-manipulated control site. Along each transect 24 permanent plots were established for a total of 96, 10m² (5 x 2 meters) plots for shrubs and nested, 1m² circular sub-plots for herbs. Several new species colonized the experimental site soon after the manipulation. Many were transient (e.g., Erechtites hieracifolia and Cirisum spp.) but a few species have persisted (such as Rubus species, though their abundances are decreasing). Two exotic invasive species colonized the site: Celastrus orbiculatus, which continues to occupy a small area of the experimental site, and Lonicera morrowii, which died out between the 2000 and 2005 surveys. Following the manipulation, the understory community in the experimental site shifted substantially (Figure 1). The magnitude of change peaked in 1995 for herbaceous species and in 2000 for shrub species. Thereafter, these suites of species became more similar to pre-manipulation and control conditions. The hurricane manipulation exerted a moderate influence on understory community dynamics, which appears to have peaked 5-10 years after the disturbance. The length of this study (which continues) allows an understanding of the trajectory of understory vegetation recovery in the context of whole-forest response to the manipulation.
- Research Category: Large Experiments and Permanent Plot Studies
