Are Harvard’s Dying Hemlocks a Warning for Trees Everywhere?
Harvard’s forest have seen a recent spike in deaths of hemlock recently due to the invasive hemlock woolly adelgid. The insect is about the size of a sesame seed and can be moved by wind and bird’s feathers and feet. Interestingly enough, while rainforests are still being deforested, the rate of forest growth in northern latitudes has brought the Earth’s total mass of trees to a rate of increase. But this doesn’t mean that things like water stress and pest infestation or disease aren’t seriously damaging forests worldwide. Scientists hope that these forests will be able to bounce back from damages, as tree diversity and forest size and age are important factors in ecosystem function. In Harvard’s forest, the hemlocks are important because their canopy determines when and how quickly snow melts, which further influences spring flooding. The deaths of hemlock will likely dramatically impact the forest species composition as the forest begins to regrow.
Article written by Hillary Rosner, National Geographic, April 2, 2015