Northeast Public Radio recently interviewed forest ecologist Dave Orwig about the expansion of hemlock woolly adelgid, an invasive insect, into southern Vermont. The adelgid was first found in Virginia in the 1950s, then Massachusetts in 1989, and has continued to move north since then.
As part of a hands-on course in global change research, six science journalists from the Marine Biological Laboratory (MBL) Logan Science Journalism Program spent 3 days at the Harvard Forest in May, working alongside scientists to count Hemlock Woolly Adelgid, measure tree seedlings in herbivore exclosures, quantify carbon dioxide fluxes from a soil warming experiment, and core down to ice-aged sediments in the Black Gum Swamp. Read more > about Journalists Dig into Ecology at the Harvard Forest
A new paleoecology study by Emerson College/HF scientist Wyatt Oswald and HF director David Foster describes multiple episodes of eastern hemlock population decline ~6,000 years ago in New England. These events precede a major and more often-studied hemlock population decline 5,500 years ago. All of the decline events coincide with indicators of abrupt climate change. The sensitivity of hemlock populations, and their ability to recover from these declines, corresponded to geographical differences. Read more > about Middle-Holocene Hemlock Dynamics in Northern New England
New results by Forest Ecologist Dave Orwig and others show that hemlock stands invaded by the hemlock woolly adelgid (HWA) experience dramatic reductions in regeneration of new hemlock seedlings, making the insect's destruction difficult to reverse. In extensive surveys of 141 hemlock stands in southern New England, hemlock seedling density declined 71% between 2007 and 2009, while HWA infestation continued to increase (91% of the study areas were infested by 2009). Read more > about New Harvard Forest Publication: Presence of HWA reduces hemlock regeneration