Sudbury Valley TrusteesConservation, Collaboration, and Community since 1953

Article REVISED December 12, 2008

By Laura Mattei

Never underestimate the fortitude of oriental bittersweet. That’s just one of the many lessons that we have learned over the past three years as we have tirelessly worked to restore shrubland habitat at our Cedar Hill Reservation in Northborough, Massachusetts.

The project centers around a 20-acre patch of former pasture owned by SVT and surrounded by over 2,500 acres of protected mixed forest, wetlands, fields and successional woodlands. The Cedar Hill Reservation presented a perfect opportunity to restore shrubland habitat for wildlife, particularly birds, that depend on these ephemeral habitats for foraging, nesting, and cover. 

Shrubland habitats were historically part of a dynamic landscape of diverse habitats maintained by natural disturbance such as wind, fire and floods and human activities such as farming, logging and grazing. Today, we are rapidly losing shrubland habitats to development and forest succession and as a result, grassland and shrubland species are experiencing more consistent declines than their mature forest counterparts. Six of the ten most rapidly declining bird species in Massachusetts, according to the National Breeding Bird Survey, are early successional species (Brown Thrasher, Eastern Meadowlark, Eastern Towhee, Northern Bobwhite, American Kestrel and Field Sparrow).

SVT’s plan was to restore this 20-acre overgrown pasture in hopes of providing a refuge for shrubland bird species. The site was succeeding to forest and being overtaken by an army of invasive shrubs and vines, such as honeysuckle, multiflora rose, Japanese barberry and oriental bittersweet. Native forbs, grasses and trees were common, but native shrubs were sparse, limited to wetland-affiliated shrubs such as highbush blueberry and arrowwood viburnum.

SVT partnered with Mass Audubon’s Extension Service to conduct an initial plant inventory and management plan. Input was also sought from MassWildlife. In the winter of 2005, a contractor cleared eight acres with a brontosaurus mower. We were astounded the following summer to see that bittersweet had exploded and carpeted over 80% of the cleared area.    Although we had anticipated significant regrowth of invasive plants, this was far beyond expectation and we were concerned about our ability to control the bittersweet.

Based on a recommendation from MassWildlife, we waited a year to apply herbicide. In the meantime, we cleared an additional four acres of brush and collectively treated all twelve acres with herbicide in the fall of 2006. Unfortunately, this herbicide treatment yielded only marginal results. 

Subsequently, we identified a contractor with invasive plant control and habitat restoration experience who offered a guarantee of 90% success within two years. The new contractor applied herbicide in the summer of 2007 and will repeat the application again in 2008. To increase the effectiveness of the 2008  herbicide treatment, we mowed the area this past April and are hopeful for positive results next year.

The restoration area is looking good – we have good regrowth of grasses and native forbs. While there is still significant coverage of invasive plants, their extent has been noticeably reduced. We are optimistic that next year will see even greater improvements. We plan to continue to tweak our management techniques with the hopes of one day supporting the full community of shrubland species at Cedar Hill Reservation.

This project has been supported by the following funders: