Managing Island forests for invasive beetles

The Martha’s Vineyard Land Bank is working with the Sheriff’s Meadow Foundation to manage some of the Island forests to combat an invasive species known as the southern pine beetle. 

During a Monday afternoon meeting, Land Bank commissioners discussed a proposal from Sheriff’s Meadow Foundation president and licensed forester, Adam Moore, to remove a number of pitch pines in Ripley’s Field Preserve in Tisbury to protect the forest. 

The pine beetle is considered native in southern states and in Mexico, but can lead to widespread tree damage in northern pine forests.

“Adam has arranged for all of the permits; everything is at hand,” Land Bank executive director James Lengyel said. 

Around 30 trees will be removed over two weeks, as part of the plan. 

Land Bank land superintendent Harrison Kisiel said that the current plan is to cut and leave the trees in place in Ripley’s, which he described as a “not preferred but acceptable” method. Better options, like milling the trees into lumber or using a type of portable incinerator, are planned as well. Additionally, a buffer zone will be established around the infested trees. 

Lengyel said, according to Moore, the beetle needs a live tree with moving sap. 

“It’s not the preferred route, but the tree’s no longer living and that makes the difference,” Lengyel said. 

Aquinnah Land Bank commissioner Sarah Thulin said that southern pine beetles target pitch pine rather than red pine or white pine, which are also on the Island. 

Land Bank ecologist Julie Russell said that while there has been some evidence of pine beetles in other Land Bank properties, confirmation was still needed on whether they were southern pine beetles. So far, half of the Land Bank’s pine woodlands have been checked, but the beetles found are not spreading that fast and are on isolated trees.

“It’s early or they’re not the same species,” Russell said, adding it will take a bit more time to really know how extensive the infestation is. 

According to the UMass Extension Landscape, Nursery and Urban Forestry Program, southern pine beetles were caught in traps set by state agencies in 2015 from Southwick to Martha’s Vineyard. While a large number of tree mortalities associated with the beetle have not taken place in Massachusetts, other states, like New York, saw significant damage. 

Moore said this year was the first time these beetles have actually become a problem on the Island.

“It’s a pretty serious situation on the Island,” Moore told The Times. 

He said a larger outbreak was found at Phillips Preserve in Tisbury, a foundation property, which he had been dealing with the past couple of months. 

Of the 70 acres of pitch pine on the preserve, Moore said three acres have been cut down to prevent the spread, likely to be up to four acres. “We’re still working on the buffer to prevent this outbreak from spreading further,” he said. 

Moore said while there was southern pine beetle confirmation in Land Bank and Sheriff’s Meadow Foundation properties, there may be more in other properties including the state forest. 

The tiny beetles, smaller than a grain of rice, bore one-millimeter sized holes into the trees and lay eggs, according to Moore. The larvae eat a fungus that has a symbiotic relationship with the beetle. The invasive beetles also tunnel into the trees, which prevents sap from transporting nutrients within the plants. 

“The tunnels go underneath the bark in an s-shaped manner, and what they do is girdle the tree,” he said. “And girdle is a way of killing the tree by cutting off its circulation.”

Moore said a southern pine beetle outbreak can lead to multiple generations of the insects, breaking out in one tree to the next. 

“When one tree has too many beetles, the beetles give off a scent that says ‘This tree is full, go to the next one,’” he said. “And that’s what they do. And they bore more holes and move on to the next round.” 

On Phillips Preserve, Moore said beetles moved at a rate of around 10 feet per day. 

“That’s not to say that’s happening everywhere,” he said “That’s why we try to get ahead of it because, to us, that seemed pretty fast.”

Forests on Martha’s Vineyard are susceptible to these beetles because the pines are roughly similar in age and are close to one another physically. 

“Essentially, we’re trying to contain those outbreaks to learn to live with it,” he said. “What we’ll need to live with it is to have a regular program of thinning the pines over time, which is cutting some, not letting them be so close together, and then creating spots where we have young pine trees growing and not just old ones.” 

This type of program is being planned for Sheriff’s Meadow Foundation properties, Moore said. 

When asked what can be done to prevent beetles from moving onto another tree, Moore said there is a limit; the methods being deployed on the Vineyard have been used in the southern United States for a long time. Moore said cutting down infested trees and creating a buffer zone interrupts communication between beetles. 

While outbreaks have been detected, Moore said he wouldn’t be surprised if other outbreaks have gone undetected. 

“We’re trying to manage this and address this, and that’s essentially what we’re working on,” he said.

A representative from the Department of Conservation and Recreation was not immediately available to comment on the southern pine beetle situation in Manuel F. Correllus State Forest.

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