Effects of selective defoliation by tent caterpillar on red maple.

Abstract

Species in a community cope differently with natural disturbances. For some, disturbance is harmful. For others disturbance may be beneficial. Red maple is an example of a species that took advantage of the effects of disturbance caused by the tent caterpillar in 1989. This beneficial response was assessed by examining red maple's annual rings. Through a series of statistical tests we were able to investigate red maple's growth response in defoliated versus the non-defoliated sites. Also, we tested whether genotype and/or microsite played a significant role in determining the growth response. Finally, tests were run to see if any long-term effects from the defoliation occurred--specifically, whether there was an effect on subsequent years. In comparing defoliated versus non-defoliated, the results showed no significant difference in the 1989 relative growth response between these two sites, but a trend was seen. Moreover, there was also no significant clump or dbh effect on the growth response. The effect on subsequent years showed that defoliation was beneficial to the red maple's long-term growth. Finally, we also found trees that increased their growth in 1989, continued to increase their growth in subsequent years.