There are few areas in the world that haven’t been impacted by humans to some degree. As soon as we were able to move around, the impact on the environment was profound as people sought natural resources for food, shelter, clothing, and other material goods. Eventually, as modern societies built cities, transportation networks, and industrial complexes, the human footprint became the dominant feature in most developed regions of the planet.
Although tremendous progress was made during the 20th century to recognize and protect the value of undisturbed habitat, including the formation of the National Park system in the United States in 1916, it has only been recently that efforts have been taken to repair historical damage to the environment. Over the past 30 to 40 years, the practice of ecosystem restoration has evolved to the extent that, today, significant expenditures of public and private resources are being committed to thousands of restoration initiatives around the world.
Typically, ecosystem restoration projects seek to restore the naturally occurring physical, chemical, and biological components of degraded habitats and reestablish processes leading to ecological sustainability. In some cases, this involves controlling or removing damaging non-native invasive species from sensitive habitats. Other projects focus on reintroducing keystone native species, such as the American bison or timber wolf, into habitats where they have been extirpated.
Many other types of restoration projects are aimed at allowing natural processes to occur in places where they have been eliminated. At many national parks, including Cape Cod National Seashore, prescribed fire is a key tool for ecosystem restoration. Many upland habitats are dependent on naturally occurring fire for maintaining species composition, structure, and productivity. In some locations, especially those near human populations, natural wildfires were historically suppressed. Without periodic fires, habitats changed as fire-dependent vegetation died out in favor other plant species. With the careful reintroduction of prescribed fires, land managers are able to restore the historic conditions that evolved over centuries and bring these degraded habitats back to life.
On Cape Cod, significant investments have been made over the past ten years to restore natural tidal flow to degraded salt marshes. In 2001, the Cape Cod Commission and Massachusetts Wetland Restoration Program released the Cape Cod Tidal Restriction Atlas. This landmark report inventoried road crossings over tidal streams and identified undersized culverts, which choked off tidal exchange to upstream marshes. Since then, Cape Cod towns, the Commonwealth, and several federal agencies have partnered together and marshaled the resources to replace many of these poorly functioning road culverts. So far, approximately 20 culverts have been replaced, restoring natural tidal exchange to more than 300 acres of coastal wetland habitat. Currently, plans are underway for additional tidal restoration throughout Cape Cod, including the Herring River Restoration Project in Wellfleet. Involving almost 1,000 acres of former salt marsh, the Herring River is the most ambitious and largest tidal restoration project in New England.