Climate Change & Re-Wilding in New Haven

Arabelle Schoenberg

Pond Lily Nature Preserve is not just a great place for hiking and river views – it also serves as a crucial site for research on ecosystem change, plant systems, and climate change. Due to the removal of the Pond Lily Dam in February 2016, the natural ecosystem at Pond Lily Preserve is regenerating and returning to its natural state. Parts of the land that were previously six feet underwater are newly exposed and revegetating. The West River is forging a new course through the former dam site and the current flows more quickly than before. ‘Re-wilding’ landscapes are critical because they provide ideal locations to study the way natural landscapes recover: at Pond Lily, this means the return of both plants and fish.

Dr. Marlyse Duguid, a research scientist at the Yale School of Forestry & Environmental Studies, uses Pond Lily Preserve to study the influence of anthropogenic (human) disturbance on understory plant communities – the smaller plant species that live closer to the ground. Duguid has a special interest in Pond Lily preserve because it is an ideal location to study the plant succession process – in other words, the steady transition of plants from mosses to brush to small trees to large forest. Duguid and her research team plan to install a series of transects, which are simple pieces of PVC pipe, that divide the land into measurable 10-meter square sections. The research team will visit the site regularly over the span of many years in order to take note of which species are coming up, which are being replaced by new species, and at what rate. Hopefully, this will provide Duguid new insights into the way plant communities recover after centuries of anthropogenic disturbance, like that which was caused by the Pond Lily Dam.

Connecticut Fund for the Environment (CFE) is also heavily involved with the management of the Pond Lily site. CFE served as the project administrator when the dam was taken down in 2015-2016, and now they are in charge of the long-term monitoring of the site. One of their main projects is to evaluate the fish passage through this area of the West River. The stream at Pond Lily is a key site for diadromous fish runs during the spring (diadromous fish are fish species that spend different portions of their life cycles alternating between freshwater and saltwater). During spring fish runs, CFE Green Projects Associate Anna Marshall and her team conduct daily in-stream monitoring of fish presence, identity, abundance, and behavior. Visitors to the preserve may have seen the hot-pink flagging on posts by the river’s edge – CFE uses these markers to help assess fish passage flows, as well as general changes to the river’s morphology.

The research being done at Pond Lily will give scientists a better understanding of how land recovers from human damage – this has important implications for climate change on a national scale. Despite the innovative, widespread federal land conservation system in the United States, almost no American land is truly “wild.” This is particularly true in New England, where agriculture dominated for a century before anyone began to advocate for wilderness conservation – much of the forested land in New England has regrown on top of what used to be farms and pastures. Therefore, many wilderness restoration projects in New England follow the same trajectory as Pond Lily: centuries of human utilization alter land significantly until modern concerns about urbanization, climate degradation, and wildlife disappearance drive ecologists to decide to restore land to a more ‘wild’ or ‘natural’ state.

Protecting ‘re-wilded’ sites like Pond Lily is even more important in urban areas like New Haven. Clearly, urban life causes extra environmental stress for these sites, and thus their protection becomes even more valuable. But protecting urban wilderness is also a crucial opportunity to increase access to wilderness exploration for people of all backgrounds. Visitors can get to the preserve on the city bus, and do not need a car to go for a hike there. The preserve is open to the public from dawn until dusk. We encourage all New Haveners to get outside and visit their local wilderness!

For more information on Pond Lily, site assessments, videos of the dam removal, site maps, and other resources, check out the New Haven Land Trust’s Pond Lily web page:

Many thanks to our donors, CFE/Save the Sound and the Watershed Fund, who have helped make this site a success!

Blog Date: 
Wednesday, April 4, 2018