By LIZ DURKEE
The Vineyard will be a very different place in 100 years, notes Island naturalist Gus Ben David. The changes in his lifetime have been "phenomenal," he says, especially the explosion in population and degradation of natural habitat.
In this century, the biggest threat to the Island's natural world will be the impacts of human-induced global warming. Plants and trees, birds and bees, butterflies and frogs have survived in a fairly fine-tuned Island ecosystem for a long time. Not anymore. Now their interconnectedness is stressed not just by the loss of habitat to development but by hotter summers, warmer winters and more droughts and floods.
Matt Pelikan is the restoration ecologist for the Island office of The Nature Conservancy. The natural system, he says, "has been relatively stable and now climate change is cranking on it. Biologists have two main concerns about how wildlife species will be affected: uncertainty about how species will adapt and how existing relationships are getting out of sync. Plants have specific requirements for particular pollinators, certain bee species, and as a result of climate change bloom periods and flight periods will diversify and plants won't get pollinated effectively."
All plants, he adds, "have temperature and water regimes outside which they can't survive. Some plants need X number of days below freezing for their seeds to germinate, and a lot of wild plants such as blueberries don't flourish in a climate that is too mild. Plants that have water requirements during flowering season may not be able to produce flowers with lengthier and more intense summer droughts. Some plants are vulnerable to decay and rotting roots systems in milder winters."
Some bird species are heading north as their habitats get too warm. Robert Culbert is a local ecological consultant who heads up the annual Island bird count. He reports that several southern bird species that were not on the Island before 1960 are now "common to abundant" here, including the northern cardinal, red-bellied woodpecker, Carolina wren, tufted titmouse, turkey vulture, and American oystercatcher.
The habits, food sources and migration cycles of coastal birds are changing. Mass Audubon reports that sea level rise threatens terns, plovers and saltmarsh sparrows.
According to the Union of Concerned Scientists, 39 butterfly species "are proceeding northward in their range and some are emerging from their cocoons so early that food isn't available."
Some species that would benefit by shifting their range are unable to do so, especially on an island.
"Terrestrial species on isolated islands may be doubly challenged: both sea level rise and climactic changes are reducing the amount of suitable habitat, and range shifts across open water may not be possible." This comes from authors Lara J. Hansen and Jennifer R. Hoffman in their book, Climate Savvy, Adapting Conservation and Resource Management to a Changing World.
Mass Audubon reports that "Plants that are not dispersed widely by wind or birds, as well as animal species with limited dispersal ability that cannot cross barriers like roads and development (e.g., turtles, cold-water fish, and many other small terrestrial and aquatic animals) may not be able to reach ... new habitats and may therefore suffer local or more widespread" extinction.
Chris Kennedy is worried about cold-water fish species, especially the native brook trout population. He is the Vineyard superintendent of The Trustees of Reservations. "Roaring Brook, a fairly small brook that runs through the brickyard in Chilmark, has a neat population of brook trout; it is not stocked. A few temperature degree changes could change the brook habitat dramatically," Mr. Kennedy said.
New England trees will produce less maple syrup and colorful fall foliage. On the Island's outwash plain, oak is the dominant species and it is fairly resilient, according to John Varkonda, superintendent of the Manuel F. Correllus State Forest. He has observed earlier spring blooms and later frosts.
Climate change impacts to local forests include wildfire, storms, pests, disease and invasive species.
Mr. Pelikan describes a caterpillar outbreak that lasted for several years beginning about 2004. "A swath of oak woodland from the back acreage of the Polly Hill Arboretum west to Waskosim's Rock, 200-300 acres of trees, lost almost all their canopies," Mr. Pelikan said. "It was a weird mix of native and exotic caterpillars. One set of moths early in the season hatched at bud break and ate the first flush of leaves. The trees leafed again, and gypsy and tent moilis got to them and defoliated them. The trees ran out of reserves and died. It was localized. This problem will be more prevalent in the future than in the past, although it has always happened."
Mr. Pelikan said invasive species are highly adaptable. "And as we lose native species they are waiting to fill the void," he said. Invasives are defined by the National Invasive Species Council as "species not native to the ecosystem under consideration whose introduction causes or is likely to cause economic or environmental harm or harm to human health." They include plants and animals, including marine species.
All of which begs the question posed in Climate Savvy: "How can we manage populations whose dynamics are shifting under our very eyes? ... We can no longer think in terms of safeguarding and maintaining ... We can no longer plan for the short term ... We need to plan for ranges of possible futures and ranges of acceptable outcomes ... Global warming is hitting us over the head with the message that we need to plan for change."
Our economy could change too. The National Wildlife Federation reports that "Loss of wildlife habitat could mean a loss of tourism dollars. In 2006, more than 2.3 million people spent more than $1.5 billion on hunting, fishing and wildlife viewing in Massachusetts. The industry in turn supported 24,413 jobs in the state."
You can help reduce the impacts of global warming in your own backyard. Lawns are part of the problem. CapeCodOnline last year reported that "the maintenance of lawns - fertilizer production, mowing, leaf blowing, and other lawn maintenance practices - may generate greenhouse gasses that ultimately exceed by four times the carbon they end up storing."
Reduce the use of gas-powered yard tools and the size of the lawn. Plant more trees and a diversity of native plants. Visit the National Wildlife Federation's Web site and read their Gardener's Guide to Global Warming.
Mr. Ben David, who was director of the Mass Audubon Felix Neck Wildlife Sanctuary for 36 years and now runs his World of Reptiles and Bird Park, has his eye on the big picture. He is concerned about food chain disruption, habitat loss, heat, storms, sea level rise and energy consumption. Kids in his day wore sweaters to the August Agricultural Fair. And he is passionate about the biggest of big issues - overpopulation. "Unless we control human population all the other things we do will have no effects. We'll be out of house and home."
How does he cope? He quotes the late and lovely Island resident, Della Hardman: "Savor the moment."
This series of 14 essays about climate change was published in the Vineyard Gazette over a period of seven months in 2011. It appears here with permission. Copyright Vineyard Gazette. All rights reserved.