Sudbury Valley TrusteesConservation, Collaboration, and Community since 1953
Managing Habitat for Climate Change
Massachusetts' climate has changed dramatically over the past twelve thousand years. Plants and animals that like cold weather pursued the ice sheet northward. As centuries went by, tundra-like conditions warmed, becoming suitable for evergreen forest, then gradually, for the trees we have today. As the vegetation changed, so did the animals that relied on it for food and shelter.
The change was great, but it was slow, which allowed plants time to travel. Plants arrived in post-glacial Massachusetts on legs and wings. Some seeds are built for flight, like maple whirligigs and the wind-catching tufts of poplars, milkweed, and cattails. Plants with tasty fruits, such as raspberries and grapes, disperse their seeds through the digestive tracts of birds. Other plants borrow the legs of mammals. They stick to the fur of passers-by, to be scratched off later, in random locations. Acorns and nuts are carried and buried by rodents too squirrelly to find everything they hide.
Alas, the pace of the modern warming trend is too rapid for such leisurely methods of migration. When experts describe the threats posed to the natural world by climate change, they acknowledge variability from year to year—but they show convincingly that the long term average has become steadily warmer, and that this must be expected to continue. Massachusetts' winters will be rainier, our summers hotter and drier. This is happening, not over millennia, but in decades.
Even if human beings move quickly to reduce emissions of greenhouse gases, our climate, propelled by our past behavior, will come to resemble Maryland's. If we do not reduce our consumption of fossil fuels, by the end of this century Massachusetts will have weather like South Carolina has now, with many summer days over 100˚F and no snow cover in the winter. In that case, perhaps our state bird, the Black-capped Chickadee, will be displaced by its cousin the Carolina Chickadee. Carolina Wrens have already spread across Massachusetts.
As the climate will warms, how will natural communities adjust? Given time, we know they will adapt—they always have—but the changes now in store will be more abrupt than the slow fade of the ice age. As conditions alter, mobile animals such as birds can reach hospitable climates—but what about the specific plants they depend on?
Massachusetts’ conservation leaders gathered recently at Bentley College for a conference called "Responding to Climate Change" to discuss this problem. If rising temperatures hurt the natural communities we have now, will habitat degrade? Will biodiversity suffer because native plants can't move north fast enough? Can conservationists help by bringing plants from the south?
Thoughtful people know that actions can have unintended consequences and sometimes will-intended measures lead to harm. Those responsible for managing wildlife habitat will be forced to make important decisions without models or experience to guide them. All that really seems clear is that that magnitude of the long-term problem depends on the collective choices we make now.
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