Forest restoration after the storm

Whether or not you own a one-acre or 200-acre wooded lot, you may have experienced significant forest   disturbance as a result of Hurricane Sandy. While catastrophic events such as high winds, ice storms or fire are a natural part of shaping our forests, as a landowner it can be difficult to accept the post-storm forest and the urge to clean up can be overwhelming. To a degree, debris removal, removing partially fallen trees, and filling in big holes in the ground can aid in forest restoration. NJ Audubon suggests considering a combination of clean-up and “hands-off” to achieve a more natural environment that provides new wildlife habitat and encourages vegetation re-growth.

Recommendation 1: Retain Some Coarse Woody Debris

Coarse woody debris (CWD) includes fallen trees and large branches that are on the forest floor as a result of Hurricane Sandy. Some amount of CWD should be left as is in the forest as it has both wildlife and nutritive value in terms of organic matter inputs and energy/nutrient flows. CWD has habitat benefits for a wide variety of wildlife from insects to large mammals by serving as nesting, denning, foraging or cover habitat. Accordingly, CWD of various sizes (diameter and length) and at various stages of decay are an important part of the forest component and supporting a variety of wildlife.

The exact amount of retained woody debris is difficult to quantify and not well understood. In natural landscapes, CWD may be clumped or randomly distributed, typical of forests impacted by a range of events from isolated disease to catastrophic disturbances such as wind throw. Leaving a small amount of CWD in each storm impacted area would be a good way to mimic the natural presentation of CWD in the forest.

Recommendation 2: Retain Some Brush Piles

Where CWD would be individual logs and large branches lying on the forest floor, brush piles would be areas of smaller branches and storm debris that are piled or clumped together. Brush piles are important wildlife habitat providing nesting and cover, particularly to small mammals and birds. In a natural forest environment “brush piles” may be the result of variable sized branches fallen from trees. Like CWD, they may be randomly distributed about the forest. Creating small brush piles creates microhabitat that is not only important to wildlife, but provides some level of protection for new vegetation.

Recommendation 3: Retention of Pit and Mound topography

A hallmark of old, natural forests is the presence of pit and mound topography. This type of typography is the result of uprooted trees, creating both a pit where the root system formerly was, and a mound where the root system is now exposed. Similar to CWD, important wildlife habitat can be created as a result of uprooted trees. The pit, depending on soil conditions, may retain water, creating a vernal pool, ideal for amphibians and macroinvertebrates. Additionally, the mounds are important sites for tree regeneration. Small seedlings may begin to appear on the mound and, given the elevation off the forest floor, these seedlings are somewhat protected from predation thus allowing this new age class of trees to develop in the forest. Rather than cutting all trees such that the root mass falls back, pit and mound topography can be retained in combination with retention of CWD.

Recommendation 4: Replanting with Compatible Native Species

Looking to the benefit of a catastrophic event such as Hurricane Sandy, we now have an opportunity to create some diversity of age classes in the forest. A diverse age class is important not only for overall forest health, but provides a more heterogeneous habitat that can support a wider diversity of wildlife dependent on trees of different densities and sizes. A forest with this structure also encourages growth of native saplings. Perhaps consider increasing forest diversity with compatible native vegetation of various sizes to assist in forest restoration. If planting in small canopy gaps (two or three trees in size) tree species that are at least tolerant of partial shade should be used. Soil and moisture conditions are also important when evaluating what species are appropriate to replant. For example, in small gaps with moist soils, black gum and swamp white oak might be good choices, while hickory and white oak could be planted in drier locations. For larger openings where more light is available, tulip poplar, red oak, black or pin oak might be added into the mix. In addition understory vegetation, such as maple-leaf viburnum, spice bush or witch-hazel may be nice additions to the forest. Plantings can be done in conjunction with retention of CWD, brush piles and pit and mound topography to help provide some level of protection from browse.

Recommendation 5: Maintaining Important Ecological Components

Some of the trees that Sandy affected the most in NJ forests were coniferous, many of which served an important role for a variety of wildlife. In southern New Jersey, pockets of the already rare Atlantic White Cedar (AWC) were toppled during the storm. AWC is considered a globally rare forest type that harbors some very particular wildlife. Ensuring that these forests regenerate with cedar, and not other species such as red maple, will be critical to the continued existence of the animals and insects that depend on AWC for some part of their life cycle. In the hardwood dominated forests of northern New Jersey, hundreds of acres of evergreens were affected by the storm. While the evergreens here only compromise a small percentage of the overall forest, they do provide an element of diversity that would otherwise be lacking. Many of the affected trees are within plantations of non-indigenous species that were established during the days of the Civilian Conservation Corps. While some might argue that a species such as Norway spruce is not native to New Jersey, and is therefore no great loss because it wasn’t supposed to be here, it is important to remember that these evergreens still provide critical habitat for some wildlife species. For example, Norway spruce stands many be the last stronghold for red squirrel populations in north jersey, and many owls prefer nesting in spruce in lieu of nearby hardwoods. Given the fact that for a variety of reasons we continue to see declines in the presence of native conifers that have historically been part of the northern NJ forests, it is extremely important that we work to restore some of these losses. In the case of some non-native plantations blown over in the storm, we are presented with an opportunity to restore them with an evergreen species that is better suited to our area and still maintain that diversity.