Winter's warm worries
By DAN DEWITT
Published January 20, 2007
Virginia Melton decided not to pull the volunteer tomato plants that sprouted in her fall garden, figuring a frost would kill them soon enough.
But the vines not only survived, they have crowded out her winter vegetables. And on Monday, she did something gardeners in this part of Florida usually do in November: harvest ripe, red tomatoes.
"Can you believe that? Tomatoes in January? That's a nice bonus," said Melton, 80, who with her husband, Jack, has been farming in Hernando County since 1950.
Maybe, as the Meltons believe, 2007 will be remembered as just one odd year when winter never arrived - the flip side to 1962, which they recall for their boys' snowball fight in the barnyard.
Or maybe, if some climatologists are right, this winter is a preview of the changes global warming will bring to the region: grasses, bugs and weeds that thrive throughout the winter, dangerously early blossoms on fruit trees and the possible disruption of wading birds' nesting and feeding patterns.
"This year will be very interesting and a lot of us are watching nervously," said Jim Rodgers, a research biologist with the Florida Fish and Wildlife Conservation Commission.
The average temperature in December at Tampa International Airport was 69.5 degrees, the second highest on record, according to the National Weather Service. The median temperature so far this month is 68.9, 7 degrees above normal.
The direct cause of this winter's dramatic weather - hard freezes in California, blizzards in Colorado and the freakishly balmy temperatures through much of the East - has been El Nino, a periodic warming of the southern Pacific that alters the flow of the jet stream, said Dennis Feltgen, a National Weather Service spokesman.
But also consider, Feltgen said, that 2006 was the warmest year in the United States in more than a century, and 2005 was the warmest on record worldwide.
"We know that the rate of warming has accelerated in the past 30 years," he said. "And there's no question that's been linked to the increase of greenhouse gases."
The color of toast
Jack Melton, 82, and his son, Johnny Melton, 55, drove through their Hernando County groves and pastures to show how the warm weather has both helped and hurt their farm.
On a sloping pasture overlooking Interstate 75, beef cattle grazed in knee-high Bermuda grass. Most winters, said Johnny Melton, his family supplements the herd's diet with hay and the Bermuda would be dormant, "the color of toast."
In a nearby field, he saw a black caterpillar clinging to blade of grass. He didn't know the variety, he said, but he did know "you shouldn't have worms this time of year."
A thicket of Spanish needle and other weeds that are typically knocked back by frost had grown up between rows of 3-year-old citrus trees. Controlling the infestation would require an extra application of herbicides.
Though none of the Meltons' trees had begun to bloom, neighboring groves were specked with white orange blossoms, which usually don't appear until late February. If they continue to flower, even a mild freeze could devastate next winter's crop, said Michael Sparks, chief executive officer of Florida Citrus Mutual.
"The trees are reacting like it's early spring," he said. "We are in a very vulnerable situation."
So are Florida's blueberry farmers. But if the warm weather holds, the early harvest could be a boon, allowing them to own the national market for a longer period before fruit is harvested farther north.
The above-normal temperatures have already boosted strawberry production, said Stephen Gran, manager of the Hillsborough County agriculture industry development.
"Assuming we don't get an actual freeze, (the weather) will put all our crops ahead of schedule," Gran said.
The warm weather is bringing lower power bills, green lawns and thriving tropical plants such as mangoes and avocados.
But there are drawbacks, too: The lawn needs to be mowed. Crab grass and other weeds are advancing. And, more subtly, Floridians are losing the markers that define the seasons, said Bob Albanese, an urban horticulturist with the Pinellas County Extension Service.
Crape myrtles, which are famous for blossoming in the summer, "should be completely denuded of leaves and flowers," Albanese said. "But now we have crape myrtles that are actually blooming, which is ridiculous. ... It's just very odd."
Skewed life cycles
Some critters have thrived in the warm weather, most obviously ticks, mosquitoes and fleas that have reproduced unchecked by cold weather.
Among rarer species, adaptable animals such as black bears will probably be fine, said Walt McCown, a research biologist with the Florida Fish and Wildlife Conservation Commission.
The life cycles of other animals, though, are finely tuned to weather patterns and easily disrupted by change. Snail kites, an endangered species, mate earlier in warm weather and could lose eggs or chicks in a late cold snap.
Another endangered bird, wood storks, will nest only in trees growing over standing water, which protects their young from predators. They like to feed in pools of water that grow smaller, trapping prey, as the spring dry season progresses and their hatchlings' demand for food is at its peak.
Many storks may not nest this year because the stretch of warm, sunny days has sped the evaporation in wetlands that are already dry because of less-than-average rainfall, Rodgers said.
Whooping cranes, one of the rarest bird species in the country, also struggle with low water levels, said Marty Folk, another wildlife commission biologist. If the warming trend continues, the state's small flock of migratory whooping cranes may follow the example of some sandhill cranes and not fly to the state at all. Neither species needs warm weather, just feeding ground clear of snow, Folk said.
"Ten years ago, virtually all of the sandhill cranes from the Great Lakes migrated to Florida," he said. "Now, they are short-stopping in Tennessee, and a small number are even staying in Indiana and Wisconsin."
Dan DeWitt can be reached at firstname.lastname@example.org or (352) 754-6116.
CATTLE: Would normally eat mostly grain and hay this time of year. Now they are growing fat on fresh Bermuda grass.
CITRUS: Is blooming early now - which means next year's crop could be devastated by a hard freeze.
BLUEBERRIES: Are also vulnerable to a late winter freeze. But early crops could be a boon to Florida farmers, giving them a corner on the market in early spring, before fruit is harvested in other states.
WEEDS, MOSQUITOES AND TICKS: Are all thriving without the cold weather that normally controls their populations.
WOOD STORKS: Will nest only above stagnant water that protects their nests from predators. If the water surrounding their rookeries dries up, many pairs will not even try to raise young.