Autumn foliage change has come early to the Vineyard and much of southeastern New England, not so much because it is September, but because it is dry.

Near-drought conditions have taken their toll. Maple and beetlebung trees, as water-sensitive trees, are stressed and already have turned color. Many of these and other trees are already dropping their leaves.

Island firefighters are at a high level of alert.

“These are extreme conditions,” Tisbury fire chief John Schilling said. “Even a casual toss of a cigarette can have catastrophic results.”

In a stretch of 10 days, the Tisbury fire department has responded to three brush fires. Two of them were set accidentally by children playing with fire.

The Island is in bad need of a good soaking. Lawns are brown, leaves on trees are drooping and some trees may not survive. Although the wet weather earlier this year may have helped the Island’s groundwater, the reserve is getting lower and lower.

“The bottom line is that we’ve had a typical summer pattern,” said meteorologist Bill Babcock of the National Weather Service in Taunton. “The jet stream has been up going across Canada, so all the significant wet weather that passes from West to East has been crossing over Canada. We are down on the edge.”

What has made it so dry for southeastern New England is that there hasn’t been any wet weather coming up from the South to fill the void.

“Most of the action has been north of the Mass Pike,” Mr. Babcock said. “As you get farther south from the jet stream, it gets drier. On top of that we usually get tropical downpours and we have been blocked out of that.”

The National Weather Service cooperative station in Edgartown recorded 1.11 inches for August, well below the 4.43 inch average. July was wet with 2.46 inches, but most of it came early in the month and the rest of the month was dry.

The Martha’s Vineyard Airport automated rain gauge recorded 1.53 inches for August and 1.97 inches for July.

Older trees, particularly the native ones that depend on wet habitat, are suffering, said Tim Boland, executive director of Polly Hill Arboretum.

“You see it in the red maples, the beetlebung and the chokeberry trees,” he said.

“For the homeowner you’ll see trees will drop 25 per cent of their foliage. It is basically the tree trying to protect itself. They shed their leaves so they don’t evaporate their moisture,” Mr. Boland said. “It is not unusual to have this happen on the Vineyard. You can help your trees by watering them.”

John Varkonda, forest superintendent of the Manuel F. Correllus State Forest, said he sees stressed trees all around the Island, but more especially in West Tisbury inside and outside of the State Forest. He said oak trees that were stressed by leaf-eating caterpillars last spring are the hardest hit. “Next year we will see if there is any mortality,” he said.

“The Island’s pine trees are handling it well. They want water, but they have dealt with dry spells for thousands of years,” Mr. Varkonda said.

“We’ve had dry weather plenty times before this,” said Jim Athearn of Morning Glory Farm. “There is never enough water in any season to grow vegetables. In a dry year you do get better at setting up a system for irrigating. The problem with irrigation is that the water doesn’t penetrate as much as you’d like.”

So, when he moves the irrigation equipment around, there is trouble if he missed a spot or didn’t make it wet enough. “It can be so unforgiving,” he said.

William Wilcox, water resource planner for the Martha’s Vineyard Commission, keeps track of the water table which is fed by precipitation. He measures the height of the water table below ground at a number of sites, including one at the State Forest.

“We are still in a range that is somewhat about average for August, if you got back all those years that I’ve measured. At the end of last month it was a half a foot above the average. That being said, from September to December you can usually count on the groundwater levels continuing to drop.”

If the groundwater table does drop more, Mr. Wilcox said it creates problems for those with marginal wells that were dug near the edges of the water table.

“Maybe that will will start to draw in saltier water, or alternatively it starts to suck air,” he said. “Up-Island you get small pocket aquifers that are only fed by recent rainfall. That can be a problem.”

In Tisbury, one of the recent brush fires was in a fire lane off Franklin Terrace. “It was started by kids playing with fireworks. That was a week ago. Fortunately it was a calm day. That fire could have moved quickly,” he said. West Tisbury firefighters provided mutual aid.

A second fire off State Road had been smoldering under ground for a day before it was noticed. The cause was attributed to children playing with a lighter and an aerosol can.

The fire chief urges residents to report anything suspicious, as it doesn’t take long for a fire to take off in these conditions.

“We had a pretty serous brush fire a month ago,” said Aquinnah fire chief Walter Delaney. The fire burned in an area less than an acre, between two houses on Ox Cart Road. “I called for a brush truck from Chilmark and the State forest truck also responded.”

Given the parched conditions in Aquinnah, Chief Delaney said, “We’ve been fortunate.”