New Harvard Forest Publications

Land-use History Effect on Forest Ecosystems

We used stable N isotopes in tree rings and lake sediments to demonstrate that N availability in a northeastern forest has declined over the past 75 years, likely because of ecosystem recovery from Euro-American land use. Forest N availability has only recently returned to levels forecast from presettlement trajectories, rendering the trajectory of future forest N cycling uncertain. Our results suggest that chronic disturbance caused by humans, especially logging and agriculture, are major drivers of terrestrial N cycling in forest ecosystems today, even a century after cessation.

McLauchlan, K. K., J. M. Craine, W. W. Oswald, P. R. Leavitt, and G. E. Likens. 2007. Changes in nitrogen cycling during the past century in a northern hardwood forest. PNAS 104:18. pp. 7466–7470.

Wildlife in an urban environment

Harvard University's Arnold Arboretum, located in Jamaica Plain, a historic neighborhood in Boston, Massachusetts provides critical wildlife habitat within an urban landscape. One especially unique area of the Arboretum, Hemlock Hill, is currently undergoing extensive vegetative changes. A very large percentage of the hemlock trees located here have been infested with hemlock woolly adelgid (HWA) and are being removed. This study establishes baseline data on terrestrial salamander species composition, relative abundance, and distribution on Hemlock Hill, and assesses the impact of logging on terrestrial salamander abundance

B. Mathewson. 2007 Salamanders in a Changing Environment on Hemlock Hill. Arnoldia 65/1 pp. 19 - 25.