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Harvard Forest REU Symposium Abstract 2006

  • Title: Preferred microenvironments for tree regeneration: pit-mound vs. non-pit-mound
  • Author: ()
  • Abstract:

    When hurricane winds come in contact with forests, the results can appear catastrophic. Hurricanes play a major part in forest successional patterns in New England, causing trees to uproot or snap. In addition, these trees fall on and damage other trees. Uprooted trees create pit and mound microsites. After a hurricane, the forest canopy opens and more light is allowed to enter the forest floor. The extra light, plus the mineral soil exposed on pit and mound microsites, provide plenty of resources for seedlings and saplings to establish and grow. Pit and mound microsites may influence future species composition in hurricane damaged forests. I studied whether the number and species composition of seedlings and saplings found growing on the pit and mound microsites differed from undisturbed microsites.

    In this experiment, pit and mound and undisturbed ground microsites were studied in two sites damaged by the severe 1938 hurricane, and two sites that were pulled down in 1989 and 1990 to simulate the 1938 hurricane. Each damaged site was paired with an undamaged control. Total area of each environment sampled was equal. Seedling and sapling diameter, and height were measured, and substrate was recorded. Fifteen species of saplings and seedlings were found across the study sites. Of the 487 seedlings and saplings measured for this project, 24% were saplings, whereas 76% were seedlings. Of the seedlings, 37% were first year germinants.

    Overall, Birches and Maples preferred pit-mound microenvironments. Pines preferred the non-damaged microenvironments to regnerate (Figure 1).

  • Research Category: Large Experiments and Permanent Plot Studies