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Harvard Forest REU Symposium Abstract 2005
- Title: Understory Vegetation Response Following a Simulated Hurricane
- Author: Mathew A Trumbull (Hampshire College)
- Abstract:
The hurricane experiment at Harvard Forest was designed to monitor long-term changes in vegetation dynamics after simulated windthrow. In 1990, canopy trees were pulled over with a winch in the experimental area (50 x 160 m), to mimic the effects of the 1938 hurricane, resulting in 80% canopy damage. Little is known about the way that the understory vegetation responds following a catastrophic hurricane. This study analyzes the understory vegetation dynamics 15 years after the manipulation.
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 control. Along each transect 24 permanent plots were established for a total of 96, 10m² (5 x 2 meters) plots (shrubs) and nested, 1m² circular sub-plots (herbs).
Several new colonizing species appeared soon after the manipulation. Some are no longer present but a few species have persisted. Among the persistent, Rubus allegheniensis, and Rubus idaeus increased in percent cover dramatically following the manipulation until around 1995 and since have shown a steady decrease (Figure 1). Trientalis borealis and Dennstaedtia punctilobula showed significant increases in percent cover but have also declined since 1995 (Figure 1). Ferb, herb and shrub totals in the manipulation site follow a similar trend. The percent cover of many species that initially increased greatly in the manipulation site have recovered to pre-manipulation conditions, indicating that understory changes are mostly transient following a severe wind disturbance. - Research Category:
