Nitrogen

Recent Harvard Forest post-doc Jim Karagatzides has published two papers based on his research with Harvard Forest Senior Ecologist Aaron Ellison. In the first, using stable isotope tracers in the field, Jim showed that Sarracenia purpurea can acquire nitrogen directly from amino acids, bypassing the inorganic nitrogen cycle on which

Forest ecologist David Orwig, along with several former and current Harvard Forest collaborators, examined the magnitude of ecosystem response associated with 3 years of hemlock woolly adelgid (HWA) infestation in southern New England hemlock forests. The study, published in the Canadian Journal of Forest Research, shows that infested forests had significantly higher HWA-induced foliar loss and significantly lower forest floor

Harvard Forest has just acquired a new elemental analyzer for the John G. Torrey Nutrient Laboratory. Purchased with National Science Foundation LTER funding, the Elementar vario MICRO analyzer can be used for measurements of carbon, nitrogen, and sulfur. The new, user-friendly equipment is a nice complement to the Lachat 8500 autoanalyzer in the laboratory and is being used for a

Climate Change affected major forest ecosystems dynamics

The mid-Holocene decline of eastern hemlock is widely viewed as the sole prehistorical example of an insect- or pathogen-mediated collapse of a North American tree species and has been extensively studied for insights into pest–host dynamics and the consequences to terrestrial and aquatic ecosystems of dominant-species removal. We report paleoecological evidence implicating climate as