Floodplain Forest Restoration along the Housatonic River

by Julie Richburg

In the middle of August, staff from The Trustees of Reservations, Project Native, and Helia Land Design, along with a crew of dedicated volunteers, planted more than 1,700 trees along the banks of the Housatonic River at Bartholomew’s Cobble in Sheffield, MA. After several years of planning and preparation, it was finally time for the tree seedlings to get into the ground and begin their development into a major river floodplain forest—a natural community that is now rare throughout the region. 

Volunteers from partnering groups planted over 1,700 trees in a project to redevelop the floodplain forest at Bartholomew’s Cobble, Sheffield, MA.

Volunteers from partnering groups planted over 1,700 trees in a project to redevelop the floodplain forest at Bartholomew’s Cobble, Sheffield, MA.

Although the plantings have been completed, this is just the start for the development of the forest. Over the coming years the trees will grow and survive seasonal flooding. Some will be chewed on by beavers or deer. Some will grow fast and tall, while still others may eventually be shaded out by their neighbors. This is the making of a forest.

Bartholomew’s Cobble, a property owned by The Trustees of the Reservations, is designated as a National Natural Landmark by The National Park Service in recognition of its tremendous diversity of plant species, including over 36 species of ferns. The Floodplain Forest Restoration and Habitat Improvement Project now underway will return 10 acres of floodplain forest to this property by planting floodplain trees on three former hayfields. The project will also improve an additional 70 acres of surrounding habitats through control of non-native invasive plants.

Recovering the Landscape

Floodplain forests were historically cleared for agriculture and other development due to their nutrient rich soils and their relatively level topography. Today, many of the existing floodplain forests in Massachusetts are only small remnants, often heavily impacted by non-native invasive species (such as oriental bittersweet). Although the most recent project has been nearly four years in the making, the work at Bartholomew’s Cobble and the effort to restore additional acres of floodplain forest date back more than a decade.

While Bartholomew’s Cobble has been well known for its native plant life – especially its ferns – non-native invasive plants have expanded their populations over the years, threatening this renowned diversity. In 2003, The Trustees hired a botanist to inventory all of the plant species on the property and then began efforts to control the non-native invasive plants that posed the biggest threat to the Cobble’s unique natural habitats. Control efforts were carefully and slowly implemented, using staff and volunteers to hand-pull, cut, and eventually apply herbicide to knock back the populations of invasive species such as garlic mustard, common buckthorn, Oriental bittersweet, and Japanese barberry. With each year, we learned more about how to control the invasives and were able to spread our efforts from the cobbles, to the floodplain forest, and other habitats in between. The native species have responded wonderfully, quickly filling in holes left by the invasives and once again highlighting the beautiful natural habitats of the property.

With the success of the invasive plant control efforts came a desire to return some of the hayfields closest to the Housatonic River to their previous splendor as floodplain forests. Upon learning about the project, a local farmer recalled his efforts to clear the previous forest to create one of the hayfields and now this project will allow it to become forest once again. The opportunity to fund the restoration came from the Natural Resource Damage Assessment and Restoration Programs of the MA DEP and the US Fish and Wildlife Service, using funding designated for the cleanup of the Housatonic River and enhancing natural habitats within the watershed.

Seedlings collected from elsewhere in Bartholomew’s Cobble or grown locally from seed should help the young trees survive local conditions.

Seedlings collected from elsewhere in Bartholomew’s Cobble or grown locally from seed should help the young trees survive local conditions.

Designing for Restoration

The Trustees of Reservations and Project Native (a native plant farm, nursery, and wildlife sanctuary) collaborated to move the floodplain forest restoration project toward fruition. Project Native brought the expertise of Helia Land Design to aid in the preparation of the fields and in planting floodplain-appropriate trees, with The Trustees taking the lead in overseeing the entire project, including working with Native Habitat Restoration – the local invasive plant control contractor – and an independent botanist on other aspects of the project.

To support the project, Project Native expanded the native plant nursery at its Housatonic location to accommodate and care for the sizeable number of trees used in the restoration. Some of the trees were collected as recently germinated seedlings in 2011 by The Trustees’ Holyoke Youth Conservation Corps and raised for a year in their greenhouse at the Land of Providence Reservation in Holyoke. Once the tree seedlings outgrew the small greenhouse, they were moved to Project Native’s nursery and joined a second set of seedlings collected in 2012. Bridghe McCracken, owner of Helia Land Design, was enlisted by Project Native to oversee the necessary preparation of the fields and tree planting. McCracken says using seedlings collected from Bartholomew’s Cobble “is important because it ensures that we are replanting with local genotypes.” We anticipate that these local genotypes will be very successful in growing under the local conditions that their parents evolved with. Tree species planted include: silver maple, box elder, cottonwood, sycamore, tulip tree, hackberry, and seven varieties of disease-resistant American elms (thanks to a project of The Nature Conservancy focused on elm varieties).

Silver maples dominate the floodplain forests along the Housatonic River.

Silver maples dominate the floodplain forests along the Housatonic River.

As the new trees begin to drop their leaves this fall, The Trustees along with our great partners Project Native, Helia Land Design, Native Habitat Restoration, The Nature Conservancy, and the many volunteers and supporters, will eagerly await the chance to observe the new floodplain forest green up next spring and continue to develop into a mature forest. Of course, we will have some time to wait for the small tree saplings to become a forest, and there is yet more work to be done to get them there. But, we can be confident that many species will take advantage of our efforts and that the Housatonic River will benefit as well.

To visit the restoration project, walk the Spero Trail at Bartholomew’s Cobble (directions available at thetrustees.org). For more information, feel free to contact Julie Richburg, Regional Ecologist for The Trustees of Reservations at jrichburg@ttor.org.

For more information on floodplain forests, check out the following links:

http://www.thetrustees.org/what-we-care-about/the-natural-world/of-forests-and-floodplains.html

http://www.mass.gov/eea/docs/dfg/nhesp/natural-communities-facts/floodplain-forest.pdf

About the Author

Julie Richburg is Regional Ecologist for The Trustees of Reservations, a Massachusetts state-wide land trust.  She works on natural resource inventory and management for the more than 40 properties owned or managed by The Trustees in western MA (approximately totaling 9,000 acres). Julie has a Masters degree and PhD in forest ecology from the University of Massachusetts Amherst where she focused on the impacts and control of invasive plants in natural habitats. She is a member of the Massachusetts Invasive Plant Advisory Group and the current chair of the Westfield River Watershed Invasive Species Partnership.