The Harvard Forest, in collaboration with the Cary Institute of Ecosystem Studies, has launched a new Science Policy Exchange project on forest pests and pathogens. This project addresses growing concerns about damage to trees, forests, and local economies caused by introduced insects.
Hemlock is a "foundation" tree species in eastern forests and its presence defines the properties of a unique ecosystem that is presently declining due to the introduction and spread of an invasive insect, the hemlock woolly adelgid.
We measure key aspects of forest productivity, species composition and nutrient cycling in the mixed-oak forest at Cary. This long-term monitoring allows us to track trends in the forest ecosystem resulting from air pollution and other stresses.
In deciduous and coniferous forests dominated by mast-producing trees, such as oaks, consumers are confronted with the sporadic production of abundant resources. Mast-consuming animals, such as the white-footed mouse (Peromyscus leucopus) and eastern chipmunk (Tamias striatus), rely on these pulsed resources.
Stabilizing a deer population requires a balance between annual recruitment and mortality. For a population reduction, mortality must exceed recruitment. Using hunting as our primary management tool, our hunters are required to focus their efforts on culling females as well as males.
Presently, hunter observations are used as the technique to assess if Cary controlled hunts are stabilizing local deer numbers. Night spotlight counts of deer have been used to index trends in abundance in the past. The observations of deer by bow hunters, has yielded data that have correlated very well with spotlighting numbers with the observation data easier and less expensive to obtain.
Since 1983, Mr. Winchcombe has been monitoring the intensity of deer browsing on the major tree species on the Cary Institute's grounds. Browsing intensity varies annually, with over-winter browsing linked to total winter snowfall amounts. Browsing studies help govern deer management strategies, with heavy browsing highlighting the need to further reduce local deer numbers.