Forest Notes, Spring 2021

Cut loose from the suffocating grip of invasive bittersweet vines, apple trees in a once thriving orchard at the Heald Tract will now grow unimpaired again.

Recent Happenings at the Heald Tract, Part 1

Habitat Management in an Overgrown Apple Orchard

By Gabe Roxby

The Heald Tract is one of the Forest Society’s most spectacular properties, and one where landscape-level habitat management is a central focus of our work. Spreading across four towns—Wilton, Temple, Greenville, and Mason—the Heald family’s donation of nearly 1,500 acres to the Forest Society between 1986 and 2016 was one of the most generous gifts of land in our history. Cellar holes and old barn foundations can be found scattered among the property’s tremendously diverse natural features, which include beaver dams, vernal pools, a great blue heron rookery, and a 65-acre pond. The property’s productive and diverse forests are periodically harvested in a responsible manner and yield a variety of wood products that are used for dimensional lumber, flooring, and paper. And an extensive trail network for hiking, snowshoeing, and cross-country skiing make Heald an ideal recreation location throughout the year. The

management of the myriad of natural, cultural, and recreational resources at Heald is not without its challenges, as invasive species are taking over in a couple locations, threatening the forest’s biodiversity and wildlife habitat.

In recent years, the old apple orchards on the Heald Tract have become overgrown with a dense tangle of thorny shrubs, vines, and young trees. Other than the maintained hiking trails that wind through the orchards, this was no longer a pleasant place for people to walk. They were, however, functioning as wildlife habitat for nesting birds and small mammals seeking cover from predators. But there was a problem. The vegetation in this old orchard was being increasingly dominated by invasive species, with oriental bittersweet (Celastrus orbiculatus) the most concerning. Even worse, we were starting to observe this aggressive vine spreading to the rest of the property where it previously had

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Forest Society Field Forester Gabe Roxby (right) provides an overview of the project for Forest Society staff, including Manager of Individual Giving Maria Finnegan (left).

Prior to the Forest Society’s habitat work, the Heald Tract orchards were a tangle of invasive vines and shrubs, with young trees growing throughout.

To re-establish a more open habitat type, workers from Asplundh Tree Experts used a forestry mulcher to cut overgrown vegetation in the orchard.

(OPPOSITE PAGE) RYAN SMITH; (THIS PAGE, CLOCKWISE FROM TOP LEFT) GABE ROXBY (X2), ANNA BERRY

been absent. In the orchard, the vines had already strangled and killed about half of the apple trees and, left unchecked, they would have caused even more damage. So, Forest Society foresters took action and initiated a habitat improvement project, even though we knew it would result in a temporary disruption for local wildlife.

The planning for this project was lengthy. It began in the fall of 2016 with a comprehensive natural resource inventory of the entire Heald Tract. Forest Society forester Steve Junkin and I spent a total of 15 days measuring trees, mapping wetlands, assessing wildlife habitat, and photographing cultural and ecologically sensitive sites. This information was analyzed and used to write a 133-page management plan, a document that outlines how the Forest Society will manage the property for the next 15 years. The inventory revealed about 80 acres of old fields and orchards spread throughout the property, none of which had been cut in decades. Instead of letting these areas grow into forests, Steve and I made the decision to manage these areas as wildlife habitat, cutting them back periodically to encourage the growth of a mixture of shrubs, flowers, grasses, and tree saplings. Wildlife biologists refer to this type of habitat as “early successional.” In New Hampshire, early successional habitat is often scarce, and it can benefit wildlife species in decline, such as New England cottontail, American woodcock, or black racer snakes. Due to the value of early successional habitat in New Hampshire, the Forest Society was awarded a grant to re-open 20 acres of Heald’s old orchards and fields from the Natural Resources Conservation Service through their Environmental Quality Incentives Program. This cost-share program provides private landowners financial and technical assistance to manage their land responsibly.

Managing forests with invasive plants is tricky, and it requires an acknowledgement that complete eradication of invasives is not a realistic goal for areas that are heavily infested. Instead, we try to pick our battles, and focus our efforts in areas where we have the ability, resources, and persistence to make a difference. In many cases, we try to limit the spread of invasives and keep them out of areas that are not currently infested. Prevention, early detection, and treatment are some of the most cost-effective ways of keeping invasives in check. The Heald Tract’s apple orchards were well past the early detection stage, and it was not initially clear to us what the best course of action would be.

Another challenging aspect of wildlife habitat management is balancing the temporary negative impacts your work might have on some animals with the longer-term benefits it can have on sustaining the habitat that local wildlife populations require. In the Heald orchard project, we would remove functional habitat (albeit habitat that was declining in quality due to the bittersweet) in order to improve it over the long run. In order to minimize impacts on wildlife, we scheduled the work to take place during winter, when songbirds aren’t nesting and turtles from the nearby pond aren’t foraging or nesting. There were no known rare, threatened, or endangered species in the project vicinity, according to the Natural Heritage Bureau. Had any of

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From top: Rows of apple trees stand out prominently in this aerial photo after the habitat work was completed. Forest Society Field Forester Gabe Roxby examines an apple tree in the newly re-opened apple orchard at the Heald Tract.

these species been present, our management would have focused on avoiding any impacts to them, as individual animals of rare species can be very important to the success of a population as a whole.

In 2018 and 2019, we invited several groups of natural resource professionals out to the site to provide input. In the end, we decided to act and attempt to knock back the invasives in order to save the living apple trees, to increase the prevalence of native shrubs, and to re-invigorate the shrubland wildlife habitat present.

Finally, after years of planning, the project began on an icy morning in February 2021. The Forest Society hired Asplundh Tree Experts to do the work, and the company’s father-daughter team of John and Jesse Roy operated a forestry mulcher to cut and grind up the unwanted vegetation in the orchards. They nimbly worked around the native shrubs, apple trees, and other wildlife habitat features that I flagged in advance to be left uncut. “Working at Heald Tract was a great opportunity [for us] to participate in the management of habitat and invasive species,” says David Chapman, Asplundh Tree Experts general foreman. “We

enjoyed utilizing our Rayco Mower to show the benefits that mechanical equipment can have on the healthy management of wildlife and lands. It's always gratifying to use our expertise to support the proper management of wildlife habitats.”

By removing the bittersweet and other invasive species, including multiflora rose (Rosa multiflora), we aimed to protect the native shrubs—winterberry holly, arrowwood, dogwood, willow, sumac, and highbush cranberry—and leave a smattering of trees that produce food with a high value to wildlife: apple, cherry, oak, and butternut.

During the project, we hosted a workshop led by the University of New Hampshire (UNH) Cooperative Extension to facilitate a discussion about invasives and habitat management. Interestingly,

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Photo credits: RYAN SMITH, ANNA BERRY; A. GARRETT EVANS

the discussions with our colleagues frequently returned to one topic that might be surprising to some: not all invasives are universally bad for our ecosystems. In New Hampshire, there are currently 35 plant species designated as “invasive” by the state’s Invasive Species Committee. These non-native plants have traits that give them an advantage over native species, including the ability to produce many offspring and grow quickly early in the spring, the adaptability to a broad range of sites, and the lack of natural controls to keep them in check. These traits allow invasives to outcompete our native plants, threatening the health and biodiversity of our landscapes. However, not all invasive species are created equal. Some are worse than others and some even have redeeming characteristics, especially when it comes to wildlife habitat.

We quickly identified the bittersweet taking over the Heald Tract orchards as enemy number one due to its aggressive spread and its penchant for overtopping and strangling vegetation. Left unchecked, bittersweet will dominate an area, reducing wildlife habitat quality and plant biodiversity. The multiflora rose,

WHY HABITATS MATTER

however, was not spreading from the orchard, and it was already providing the dense thicket habitat we were trying to encourage. Because of its chemical similarity to other native rose species, multiflora rose can be a food source for a number of native insect species. “Although most non-native invasive shrubs don’t support as many native caterpillars as do the native shrubs, multiflora rose is an exception,” notes Matt Tarr, a wildlife state specialist at UNH. “Research from UNH has found that multiflora rose supports as many or more caterpillars as the native shrub species that it typically grows in association with.” The plant produces persistent fruit that can be an important food source for birds and small mammals, and its growing habit can provide wildlife habitat. “The structure of multiflora shrubs is effective at holding the snow up above the ground…effectively creating little caverns or igloos that provide great winter cover for white-footed mice, dark-eyed juncos and white-throated sparrows, hares and cottontails, and even denning sites for black bears,” Tarr says. After much discussion and debate with our colleagues, we chose to cut as much of the bittersweet as possible, but left the multiflora rose uncut in a few areas where it was growing on its own and not mixed with the bittersweet.

Habitat management is rarely work that you can do once and then walk away from. It requires follow-up maintenance to guide the trajectory of the habitat and maintain its utility to the species you are attempting to benefit. The work on the Heald Tract this winter was the first step of many. The old apple trees, freed from the vines that once strangled them, could use some pruning to focus their growth and reinvigorate their apple production. The invasives we cut will sprout back vigorously, and we have a targeted selective herbicide application planned for this year or next to give the native plants that are present a head start. And of course, you can’t stop trees from growing here in New Hampshire. If you stop mowing your lawn, nature will run its course; the same is true for this orchard. It will eventually need cutting back again, if our goal is to maintain the early successional habitat we have established here. Managing forestland requires thinking and planning for the long term, and we know that this is a marathon and not a sprint. We look forward to the work in the decades to come that will give this restored orchard the opportunity to thrive.

Gabe Roxby is a Forest Society forester and a member of the New Hampshire Invasive Species Committee, a group of eleven Governorappointed professionals who address invasive species and their impacts.

Stay Tuned: Keep an eye out for part 2 of Gabe’s story about forest management projects at the Heald Tract in the next issue of Forest Notes.

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