Plants spread and animals move. They always have. But what’s happening now is an entire ecosystem starting to move.
Plants, animal changes because of heat
Among fauna and flora alterations researchers already have seen:
Movement of ranges farther north.
Changes in seasonal timing of activities.
Behavior changes responding to heat.
Physical make-up changes.
Genetic make-up mutations.
Terry Root, Woods Institute for the Environment senior fellow.
Bit by bit, white shrimp are making up more of the catch than brown shrimp in the Lowcountry, as the browns move farther north. Fewer purple finches are seen. Saw palmetto, which grows berries mostly in Florida, is starting to grow berries more abundantly farther north.
Species after species is moving because the air, land and sea are warming. And the Lowcountry — the farthest north reach of sub-tropical climate on the East Coast — could see changes more quickly and more severe than other areas.
“Right there on the cusp of (species) ranges,” said Elizabeth Fly, National Oceanic and Atmospheric Administration biologist who studies changing climate on economically and ecologically important coastal marine species. “We’re going to see increasing temperatures and shifting species distribution.”
A report released last week on the impacts of climate variability in the Southeast is the latest study to be met with some skepticism in the Lowcountry, where any number of people reject or resist the science indicating climate warming.
Much has been written and debated nationally about the reliability of data from long ago, and how to properly predict the impact of climate change on a local scale.
And then there’s the global argument about what, or who, is causing the planet to warm — a subject sure to heat up any dinner party.
The science, though, increasingly is moving past that. For example, the U.S. Department of Agriculture in 2012 adjusted its growing zones because of warmer winters. A National Audubon Society analysis of more than 300 bird species in 2009 indicated nearly three of every five species significantly shifted their range over 40 years of bird counts. Some species already had moved hundreds of miles farther north and farther inland.
Researchers are studying the potential impact on the Lowcountry and the region — for your lifestyle, economics and especially health.
The regional report, “Climate of the Southeast United States: Variability, Change, Impacts, and Vulnerability,” compiles studies and computer modeling from more than 100 researchers. It concludes that warming will have environmental and economic impacts in the region that disrupt lives and commerce, including little regarded impacts such as damage to the transportation system.
Among the impacts are fewer crops and trees, less water and potentially more “tropical” diseases such as dengue fever — there’s an outbreak now in Florida — not just for people but for food sources like shellfish.
Vibrios are saltwater bacteria that like warm water. They can cause diseases in shellfish and infect people. They recently were linked to a massive outbreak of black gill disease in shrimp in the Southeast, which gets worse the farther south you go. This particular vibrio isn’t harmful to humans.
“Definitely there are species such as lionfish that are changing their range in response to warming, and I fully expect that bacteria will be no different,” said Marie DeLorenzo, a NOAA environmental microbiologist. She’s taking part in a study of vibrios in the Waccamaw River area near Myrtle Beach.
“We’re trying to understand where they are going to go and whether they will be virulent,” she said.
Out of the ordinary
The Southeast as a region is pivotal to species movement, according to a study of 3,000 species by Joshua Lawler, a University of Washington conservation biology professor.
In the Ice Age the Southeast was a place where species gathered when they were pushed out by the glaciers.
“This time our models are showing they will be moving out of there,” Lawler said. On average the region could see a 35 percent change in mammals, birds and amphibians by the end of the century, he said. “As one would expect, there’s more change toward the edge of a species boundary” such as the Lowcountry, he said.
Plants spread and animals move all the time. But “the best evidence that (the current movement) is out of the ordinary is that it isn’t what we’d expect,” Lawler said. The normal movement is to disperse. But now species after species are moving in the same direction, farther north or higher up, following climate gradients, he said.
Species are moving their range and adjusting their seasonal timing with the relatively modest warming of less than 2 degrees Fahrenheit that already has occurred, said Terry Root, Stanford University biology professor who has studied climate change since the early 1980s. More lobsters are moving north to waters off Maine. Birds are growing longer wing feathers to travel farther. Daffodils are blooming earlier, as a few examples.
Changes also are occurring on a genetic level: Insect enzymes are mutating to be more heat tolerant.
“There’s a huge change going on without much change in temperature,” she said. “It’s happening both on land and in the ocean.”
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