Insects and diseasesThis article is part of a larger document. View the larger document here.
Insects and diseases are a natural part of forested ecosystems. Their activity is partially regulated by biotic factors, e.g., host abundance, host quality; physical factors, e.g., soil, climate; and disturbances (Berryman 1986). Insects and diseases can influence both forest patterns and forest processes by causing, for example, defoliation and mortality. These effects may occur at small scales (gap phase) or large scales (forest development) and at any seral stage (Castello and others 1995). It can be useful to examine population trends for individual insect or pathogen species. However, for broadscale analysis, examining the cumulative effects of insects and pathogens gives a representation of ecosystem stress over time.