Providence Water: Planting Future-Adapted Forests

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Action

Providence Water is managing forests to be better-adapted to future conditions, which includes experimenting with planting tree species from farther south on a small number of sites.

Providence Water is managing forests to be better-adapted to future conditions, which includes experimenting with planting tree species from farther south on a small number of sites.

Project Area

Providence Water supplies drinking water to about 600,000 people, or two-thirds of all Rhode Islanders. The main Scituate Reservoir (the state’s largest fresh waterbody) and five smaller tributary reservoirs are surrounded by 13,000 acres of mostly forested public land. These lands serve as “green infrastructure” that essentially performs the first step in the treatment process, filtering surface runoff and preventing the City-owned public utility from having to invest in additional expensive treatment facilities.

Management Goals

Providence Water has actively managed the land for nearly a century since the creation of the reservoir system. The overarching goal is to maintain a forest that is resilient to disturbances that could negatively impact water quality. The desired condition is a mosaic of forest stands with trees of different species and ages

Climate Change Impacts

For this project, the most important anticipated climate change impacts include:
Climate models suggest that temperatures will increase 3 to 10°F by the end of the century in the region, which will also increase the growing season.
Precipitation patterns will continue to change, with less winter snow and the potential for drier conditions later in the growing season.
Many “northern” tree species will face increasing stress from climate change, while those that have more southerly distributions and can tolerate hotter and drier conditions may be favored.
Climate change is likely increase threats from many forest stressors, including insect pests, forest diseases, invasive plant species, and deer.

Adaptation Actions

One of the most significant forest health issues affecting the woodlands surrounding the reservoirs (and much of the southern New England region) is lack of hardwood regeneration due to deer browse and related issues. Because of so many challenges to regeneration, Providence Water is experimenting with actions that promote the “transition” adaptation option in some areas in order to improve regeneration conditions. This includes seedling and planting a variety of species thate are expected to be better adapted to future conditions, including some species that are not currently found in native Rhode Island forests. These efforts have been focused on the upland oak cover type since 2015, where this issue is most pronounced. These stands are characterized by black, white and scarlet oaks growing at a relatively low stocking with a dense shrub layer on sandy and rocky soils.

Area/TopicApproachTactics
Oak forest with regeneration failure (5 acres of a larger stand)
9.3. Guide changes in species composition at early stages of stand development.
9.7. Introduce species that are expected to be adapted to future conditions.
Plant tree species expected to be better-adapted to future conditions: black oak, black locust, white oak, pin oak, persimmon, sweetgum, eastern red cedar, sassafras, and loblolly, pitch, and shortleaf pines.
Follow-up measurements, tending, and treatments as needed.
Nearby oak forest with deer exclosure fence
2.3. Manage herbivory to promote regeneration of desired species.
9.3. Guide changes in species composition at early stages of stand development.
9.4. Protect future-adapted seedlings and saplings.
9.7. Introduce species that are expected to be adapted to future conditions.
Plant tree species expected to be better-adapted to future conditions: black oak, black locust, white oak, pin oak, persimmon, sweetgum, eastern red cedar, sassafras, and loblolly, pitch, and shortleaf pines.
Follow-up measurements, tending, and treatments as needed.
38-acre upland oak stand
9.1. Favor or restore native species that are expected to be adapted to future conditions.
9.7. Introduce species that are expected to be adapted to future conditions.
Harvest declining and poor-quality trees to improve the growth of the residual stand.
Enrichment planting and seeding of tree species that are expected to be better-adapted to future conditions: black locust, black oak, chestnut oak, persimmon, shortleaf pine, sweetgum, Virginia pine, and white oak.

Monitoring

Monitoring occurs across the entire land base through periodic forest inventories, as well as more intensive vegetation monitoring to assess deer impacts using a network of plots and transects . The growth and survival of the planted trees is also being monitored to evaluate the success of the adaptation actions.

Project Photos

Click to enlarge photos

a group of students planting trees in a forest
two students planting trees in a forest
two students planting trees in a forest
two students planting trees in a forest

Learn More

To learn more about this project, contact Maria

Keywords

Forest threats, Drought, Insect pests, Oak, Upland hardwoods, Planting, Regeneration, Water resources

Last Updated

Tuesday, December 13, 2016