Microclimates can vary in many ways, and variation in microclimates can affect an organism’s overall success in its environment. Microclimates in tree cavities are a key ecological factor for many organisms that utilize them. Cavities may protect cavity users from potential predators and may also act to influence thermoregulation. Although it is known that many organisms use cavities in both dead and living trees, the differences between the microclimate produced by each are unknown. Research has been conducted on how the characteristics of cavities or cavity-containing trees affect the cavity microclimate, but the difference in microclimates between live and dead tree cavities has not been addressed. To test the difference between the microclimate in cavities in live trees versus dead trees, I first located a set of cavities in aspen trees at Craters of the Moon National Monument in Arco, Idaho. To measure the temperature of the inside and outside of each cavity, I used IButtons which allowed me to collect temperature readings from the inside and outside of every cavity, every five minutes, for 13 days. I measured microclimate data for 5 cavities in live trees and 5 cavities in dead trees (snags).
Results/Conclusions
I compared the temperature data of live and dead trees, and based on 13 days of information, there is no statistical difference between the average difference of the inside and outside temperature of the two cavity types. For live tree cavities the average difference between the inside of the tree and outside the tree was 1.757 ° C, and the average difference between the inside of the tree and outside of the tree for tree cavities in snags was 1.773 ° C. T-test results indicated that the difference between averages was not statically significant. This information reveals that a cavity in a dead tree provides a similar microclimate as a cavity in a live tree. Since dead trees can still provide a habitable microclimate, managers will know that dead trees are still an important piece of the ecosystem.