What was wrong with the Black Walnut Park Woodland the way it was?

At the beginning of the project, the Black Walnut Park Woodland was infested with non-native bush honeysuckle (Lonicera spp.) and European buckthorn (Rhamnus cathartica). These understory shrubs are introduced from other parts of the world and have few barriers to their rapid spread and establishment here. Both of these species quickly take over woodlands preventing the regeneration of native trees, smother woodland wildflowers, and can have a detrimental effect on native wildlife. Bush honeysuckle develops buds and leaves earlier than native species, consequently stealing valuable sunlight and resources from native woodland plants, especially spring ephemeral wildflowers. Buckthorn similarly has a negative impact on diversity by emitting chemicals in the soil that prevent the growth of native plants (this is referred to as allelopathy).

Trees are trees, right? Why is diversity important?

Diversity refers to having several different species of plants and animals within an ecosystem, which ultimately makes the system healthier and more functional. Invasive species reduce diversity by spreading aggressively and taking over areas where native species would otherwise thrive. When there are a limited number of species that take over a majority of an area, there is a limited amount of food sources available for pollinators and other wildlife. A variety of native shrubs and herbaceous plants ensures that there are various pollen, nectar and/or fruit sources available throughout the growing season. Homogeneity can be detrimental to bees, butterflies and the other animals that depend on them. Similarly, a variety of tree and shrub species within a woodland stand offer significant protection against incoming tree diseases and pests that may target a single genus or species.

Why are there brush piles left behind?

Smaller debris and mulch left behind from forestry mowing activity will be left to break down and nourish the woodland soil, like fertilizer. A few small piles and logs will be left to provide habitat areas for a variety of wildlife that seek refuge in these areas including various frogs, salamanders, insects and even some birds. A majority of larger debris and piles were removed while the ground was frozen, piles that are remaining will remain in place until frozen conditions are available in Winter. A majority of a tree’s roots are within the top 18” of soil. Only accessing the woodland areas with large equipment during frozen conditions prevents severe soil compaction which can be very damaging to mature trees. While some of the debris may appear very noticeable now in the recent aftermath of clearing operations, in future seasons the understory will fill in with native herbaceous plants and shrubs that will provide beautiful coverage and allow for newer and more mature trees, including some majestic oaks, to thrive.

So what happens now?

Maintenance within the first three years is crucial to the ultimate success of the restoration project. The forestry mowing and woody clearing operations provided thorough control of the existing invasive understory, but seeds for these established species remain in the soil and will germinate at the first given opportunity. The first year following clearing will involve strategic management to control the reemergence of honeysuckle and buckthorn sprouts as well as other opportunistic invaders that will hinder the development of desirable native plants, like garlic mustard (Alliaria petiolata). After being able to see what desirable native species emerge from the seedbank and following a year of intensive management, high-quality native trees, shrubs and woodland seed will be planted in the Fall, followed by an assortment of native woodland and foraging plants after the seed has established. Management and a formal monitoring program will continue throughout the critical three-year period to ensure the areas develop and establish as intended.