Reforestation is one of 127 initiatives launched by Mayor Bloomberg as part of PlaNYC to make New York City greener and more sustainable by 2030. It is also a key component of MillionTreesNYC, providing over one-third of the total trees to be planted in the campaign by 2017. This effort, building on the work that Parks’ Natural Resources Group (NRG) has been conducting since 1984, is transforming landscapes in areas throughout New York City.
View a map of tree plantings at citywide reforestation sites (PDF, 4.4 MB).
Benefits of Forests in the City
- improve air and water quality
- mitigate climate change
- improve neighborhoods
- reduce energy costs
- lower summer temperatures
- preserve wildlife habitat
- increase biodiversity
To create 2,000 acres of forest on City parkland and other public open spaces by establishing new, ecologically healthy, multi-story forests. Multi-story forest plant communities are composed of large canopy trees like oak, sweetgum and tulip, smaller understory trees including dogwood and sassafras, shrubs, and herbaceous plants. New forests help expand canopy cover in New York City, increasing the myriad environmental benefits already provided by our urban forest.
1. Finding the site
New forests can be established on many different types of landscapes. These areas may be covered with grass, exposed soil, or invasive weeds. They may be dry, upland sites or swampy wet areas near freshwater or marine habitats. Suitable locations for new forests include:
- Sites adjacent to existing forests, as larger forests are more resilient to disturbance and provide greater habitat and ecosystem services and benefits.
- Sites along waterways or steep slopes, which help to reduce erosion and improve water quality.
- Sites along highways and roads, which help buffer the adjacent community from airborne particulates, noise pollution and unsightly views.
2. Understanding existing site conditions
Ecological and cultural factors both determine how potential sites are evaluated. Soils, hydrology, topography, existing vegetation patterns, and invasive species inform the site preparation process. Aesthetics, maintenance requirements, and potential human conflicts also influence site selection and preparation.
3. Planning for the new forest
Reforestation sites are designed to mimic natural forest succession, where many trees sprout in woodland openings, competing with each other for the available space and light with fewer trees ultimately establishing the mature forest canopy. In new forest creation, young trees of appropriate species are planted close together to accelerate the process of creating a forest canopy. This will help the trees shade out most invasive weeds and create conditions that allow native forest plants to survive.
4. Preparing the site for planting
Before planting can occur, invasive vines and weeds, debris, structures, or other barriers to forest establishment must removed. With pervasive weeds such as phragmites or knotweed, removal can take several phases of seasonal herbicide application. In some locations where the soil is particularly compacted, planting holes are created mechanically, using tools such as an auger. When necessary the soil is amended to increase the quality of the growing environment.
Trees are planted in the fall and in the spring, when environmental conditions are most favorable. Correct planting is critical to successful forest establishment. Mulch is applied immediately after planting to discourage weeds, and help the soil retain moisture and increase nutrient availability. All trees planted in reforestation sites are native species, and are grown by nurseries within 200 miles of the city. Some of these young trees derive from seeds collected from parent trees growing in the metropolitan area.
How to Plant a Container Tree (PDF, 1 MB)
6. Caring for the new forest
Periodic weeding is critical so that pervasive weeds do not overwhelm the new plantings. As the trees grow, understory shrubs and herbaceous plants will be planted to create the multi-story forest that will sustain the new ecosystem. Watering may also be important depending on site conditions and weather patterns. Maintenance is most intensive in the first few years after planting.