Albany Pine Bush Preserve Commission: Management

Management of the Albany Pine Bush Preserve involves numerous techniques and methods. There are a number of reasons why the preserve needs to be actively and sometimes intensely managed. Years of fire suppression have allowed many areas in the Preserve to be dominated by either invasive, non-native plants or native plants in unnatural densities. Consequently, beyond the complex and intensive fire management program, a number of other techniques are being used to manage this unique ecosystem. The following is a brief discussion of these techniques, their purpose and the intended goals.

Aspen Girdling – Aspen trees, though native to the Pine Bush, have become a problem in many areas of the preserve. These trees are invasive and fast growing and are out-competing desirable Pine Bush vegetation. Historically, fire maintained the balance between these and the fire adapted species that historically dominated most of the Pine Bush. Because fires have been suppressed for many years, Aspen trees have spread rapidly. The dense shade they create eliminates most of the more typical Pine Bush vegetation, eventually killing many species that require full sunlight to thrive.

Reducing the number of these trees is not an easy task. If the trees are burned or cut down they simply resprout from the roots. A technique referred to as girdling is effective because it allows nutrients and water to be transported to the leaves but does not allow transfer of the sugars to the roots in the fall. Girdling exhausts the energy stored in the roots, effectively reducing potential resprouting and therefore reducing the number of aspen trees found in the Preserve.

Aspen girdling is most easily accomplished during the months of May, June and July on trees that are at least three inches in diameter at waist height. The trees are girdled using a tool called a bark spud. A sharpened metal edge on the end of a wooden handle is inserted under the bark and used to peel off a portion of the bark completely surrounding the trunk of the tree near the base. The tree will be exhausted and die in two or three years allowing the forest canopy to open up. As sunlight again reaches the ground, native Pine Barrens vegetation will be able to reclaim the area. Scrub Oak, blueberry, huckleberry, and grasses like Little bluestem and Indian grass will once again flourish. Wildflowers and shrubs will also grow and once again dominate these newly opened areas.

Because the wood of the Aspen tree is soft, the trees will fall after 3-5 years and will rot quite rapidly. Regular controlled burning by the Commission will prevent aspen trees from dominating these areas again, in addition to maintaining desirable pine barrens vegetation.

Volunteers and students from local schools have girdled thousands of trees in the Preserve over the past 8 years. It is expected that this management technique will be used as a primary restoration technique over the next 5-10 years. To date, there has been little if any resprouting associated with the girdling of these trees. In addition to the root resprouts the trees also produce seeds that sometimes grow once the forest canopy is opened. Prescribed fire will continue to be the primary management technique used to control these seedlings and any resprouts, preventing the Aspen tree from regaining a dominant foothold in the Preserve.

Mechanical Management – Another method being used to manage the Preserve is mechanical vegetation control. Mowing the vegetation is sometimes a necessary and effective way to meet a number of the Commission’s short and long–term objectives.

Since 1995 the Commission, in cooperation with the US Fish and Wildlife Service, has used a machine called a hydro-axe to mow thick scrub-oak thickets, primarily in the more open, barrens areas of the Preserve. Since fire has been suppressed in these areas for 50 to 75 years, mowing is used prior to the first prescribed burn and is an effective method that allows the Commission to continue management in a controlled and ecologically effective manner for years to come.

The hydro-axe is hydraulically operated and uses a blade eight feet long to cut and shred shrubs and smaller trees with stems up to 6 inches in diameter. This method has proved effective at reducing the stature of the scrub oak in areas where prescribed fire would be unmanageable due to the quantity, size and flammability of the vegetation. During restoration of these sites, the areas are mowed and then burned during the summer. Sites will then be managed with fire and some mechanical treatments on a rotating schedule that will not allow the vegetation to become as large or unwieldy and, more importantly, meet objectives that improve the overall health of the Pine Bush.

Mechanical management will probably be used on a limited basis for a number of years until a complete rotation of burning has occurred on these lands in the 3010 acre preserve. As additional lands are added to the preserve, these also may require mechanical treatment.

Chemical Management – Weeds are a major threat to the viability of natural communities, both inside and outside of the Pine Bush. There are a number of weeds that are out-competing the native Pine Bush vegetation. These range from small flowering plants like Garlic Mustard to tall trees like Black Locust. There are various ways to deal with each, and some are more effective than others.

One example of a major weed to both the Northeast and the Pine Bush is the Black Locust tree. Imported from the southeast because of its rot-resistant wood, quick growth habits and soil stabilizing root system, black locust has quickly spread into almost every corner of the Pine Bush. Clonal characteristics and the ability to resprout vigorously have challenged all other methods to eradicate this tree, other than chemical treatments. Research in the Preserve and in other areas of the country has shown that Black Locust will not resprout if the cut stumps are treated chemically. Trees are cut and a small quantity of herbicide is applied to the cut surface. Herbicide is drawn into the root system and kills the tree.

Although chemical control is used as a last resort it is, at least in the case of Black Locust, the only method known to eradicate this invasive tree. Black Locust is found in almost every area of the preserve and is spreading quickly. Cutting, burning or girdling only stimulate the plant to grow and spread faster. After the locust is removed and treated the site will be replanted with native Pine Bush vegetation. Younger stands of Locust trees may still have enough desirable Pine Bush species in the understory so that the increased sunlight may be enough to allow them to dominate once again. Black Locust also often keeps native plants from growing in its understory or only allows other undesirable weeds to grow under its canopy. Often these other weeds will also need to be eliminated before any replanting can begin.

As with the reduction of Aspen trees, it is expected that regular controlled fires will maintain these areas once they are restored and have stabilized with desirable Pine Bush vegetation.

Habitat restoration – In the spring of 1998, pavement on a three-acre parking lot in the Preserve was removed. The site was replanted with native plant species, especially those important to the Karner blue butterfly. Based on this initial experience and the successes of this effort, the Commission has significantly expanded restoration efforts in the Preserve. As of 2005, over 150 acres are actively being restored with plans to restore several hundred more.

On some sites acres of non-native Black Locust trees are removed with heavy land clearing equipment. These sites are cleared to pure sand and then planted with a tractor and seed drill. The seed drill places lupine seed and native grass seed at the proper depth and allows the Commission to plant many acres quickly. Other native flowers are also planted across these sites and include butterfly weed, horsemint and New Jersey Tea. Once established, these plants will multiply on their own, providing quality habitat for not only the Karner blue butterfly but also for many other animals that live in the Pine Bush. These sites will then be managed both mechanically with mowing as well as with fire over the long term.

Management

Albany Pine Bush Preserve Management Techniques