Spatial and Temporal Patterns of Natural Disturbance in Old-growth Forests of Northern Maine

EPA Grant Number: U915988
Title: Spatial and Temporal Patterns of Natural Disturbance in Old-growth Forests of Northern Maine
Investigators: Fraver, Shawn
Institution: University of Maine
EPA Project Officer: Graham, Karen
Project Period: January 1, 2001 through January 1, 2004
Project Amount: $93,105
RFA: STAR Graduate Fellowships (2001) RFA Text |  Recipients Lists
Research Category: Fellowship - Forestry , Academic Fellowships , Biology/Life Sciences , Ecological Indicators/Assessment/Restoration


Natural disturbances such as fire, insect outbreaks, and windstorms strongly influence the structure and function of forest communities. The spatial and temporal patterns of natural disturbances that have historically shaped and regenerated our forests provide a standard to which our current management activities can be compared. The objective of this research project is to link methods of dendrochronology (tree-ring analyses) with spatial pattern analyses to reconstruct the history of natural disturbance in an old-growth forest landscape in northern Maine.


I randomly placed a large number of plots in various community types throughout the reserve and reconstructed a history of disturbance (a chronology) for each. The chronologies serve as input for various spatial and temporal analyses. I will: (1) simultaneously evaluate spatial and temporal patterns of disturbance to determine the scale and synchronicity of past disturbances; (2) determine if disturbance rates and patterns vary by forest community type; and (3) determine, by integrating multiple lines of evidence, the timing and severity of specific disturbance agents. Preliminary findings suggest that no large-scale disturbances have occurred during the period covered by this investigation (back to the 1700s); however, small-scale disturbances, caused by wind and insect outbreaks, are common. Species composition best explains the variability in disturbance rates between plots, owing to the prevalence of species-specific disturbance agents. Although disturbance rates are generally low, they vary considerably over time. Disturbance patterns are synchronized to some degree, suggesting landscape-wide pulses of tree recruitment, canopy openness, and deadwood abundance. The low rates of disturbance revealed here have not caused shifts in tree species composition.

Supplemental Keywords:

fellowship, tree species composition, natural disturbances, old-growth forests, northern Maine, ME, dendrochronology, tree-ring analyses.