New Harvard Forest Publications: American Beech Distribution and Disturbance Dynamics

Fagus grandifolia (American Beech) is uncommon along the coast of southern New England, but occasionally forms unusual monodominant stands with higher beech abundance than is typical for inland areas. In this new publication, Posy Busby (former HF MFS student) and HF collaborators document the distribution of beech on Cape Cod and nearby coastal islands, and evaluate environmental and historical factors that influence its distribution. They found beech is most common and abundant on moraines and in areas that are close to water bodies, presumably as a result of reduced drought stress and increased protection from wildfire. The largest monodominant beech forest (approximately 1000 ha) known from the eastern US occurs on Naushon Island, but few stands elsewhere in the region exceed 5 ha. In the six intensively studied forests, increased beech dominance in the 20th century corresponds with episodic beech establishment and growth release after several hurricanes in the 1920s–1950s. Thus, unlike the small-scale gap dynamics characteristic of beech in the extensive northern hardwood forests of northern New England and New York, large-scale wind disturbances apparently contribute to local beech dominance in coastal New England where beech is otherwise uncommon

Busby, P. E., G. Motzkin, and B.R. Hall (2009). Distribution and Dynamics of American Beech in Coastal Southern New England. Northeastern Naturalist 16(2): 159-176.

In a second publication, Posy Busby and collaborators examine 150 years of forest response to frequent hurricane disturbance in coastal Massachusetts. They show that only a single storm (1944 hurricane) over this time period caused dramatic changes in growth and establishment for the dominant species – American beech. This result underscores the importance of individual disturbance events for long-term forest dynamics, even in an area characterized by frequent disturbance. Given the overriding importance of severe disturbances, anticipated increases in the intensity of hurricanes in the North Atlantic may be expected to result in significant impacts on forest conditions and long-term dynamics.

Busby, P. E., Canham, C. D., Motzkin, G., Foster, D. R. 2009. Forest response to chronic hurricane disturbance in coastal New England. Journal of Vegetation Science 20: 487-497.