"Michigan, for instance, has something over 10,000,000 acres of idle land which once grew fine pine, but which is now idle. Wisconsin and Minnesota have twice as much of that land as has Michigan. Georgia has 20,000,000 acres, and a dozen other states have from 5,000,000 to 15,000,000 acres each of idle, cut-over, logged off, nonproductive, “waste” land…. But in the case of Ohio, the removal of the forests was followed promptly by intensive agricultural development; the land went from a lower to a higher kind of use.”
- PS Lovejoy, “Michigan’s Million Idle Acres,” The Detroit News, 1920
Prior to 1619, forested woodland and wetlands covered the United States from the eastern seaboard to west of the Mississippi River into Minnesota, Wisconsin, Missouri, Arkansas, Louisiana, and Eastern Texas. These forested woodlands and wetlands were once an almost continuous ecosystem. The entire states of Wisconsin, Indiana, Michigan, and Ohio were submerged in a mix of hardwood and softwood forests and riverine, lacustrine, and palustrine wetlands.
By 1920, forests in the region sustained just 10% of coverage that existed before US Western Imperial expansion (source: Canadian Wood Council). Wetland destruction has proved harder to measure, as water systems ebb and flow. However, already by 1915 thirty-six states had enacted general drainage laws encouraging conversion of wetlands to agricultural development. In 1984, with the aid of aerial photography, scientists determined that over 54% of all former US wetlands had been drained (NRCS). In Iowa, for example, 90% of the state’s wetlands have been removed (USDA), and 70% of the state’s total land is utilized for agriculture (Source: NLCD).
Historically, Deforestation and wetland destruction went hand in hand—sometimes drainage opened up a forests wetland edge to logging, or logging brought development interest to a newly open territory for agricultural development and wetland drainage. PS Lovejoy’s 1920 article “Michigan’s Million Idle Acres” should be viewed in this context. Lovejoy points to the motivation to transition from once forested land to agricultural use. With further hindsight, we understand that this historical trend also included wetland drainage.
Ohio’s Black Swamp is an exemplary case. The swamp underwent an impressive succession from wealthy ecological wetlands to fertile farmlands. Annie Proulx, in her book titled: Fen, Bog & Swamp: A Short History of Peatland Destruction and its Role in the Climate Crisis (Scribner, 2022), writes that by the 1850s Ohio farmers noticed dry black soil in raised stream banks in parts of Ohio’s Black Swamp. In close vicinity to the swamp, stream-bank trees were cut, land was plowed, planted, and harvested, yielding fertile crops. As Proulx imagines, farmers said what every farmer in newly opened peat land has ever said as they gathered the first harvests: “This is some of the most productive soil on earth.”
The merry relationship between wetlands and farming would not persist without human ingenuity and intervention. A swamp is a finite resource, and exposed river bed soil is limited. Early farmers invented methods and machinery to drain the swamp with ditches and tiles, thereby gaining access to more fertile soil below. (Source: “Swamps can Protect against Climate Change, if We only Let them,” Proulx, New Yorker, 2022.) By the early twentieth century, the Black Swamp was gone, and the rich soil that was dredged, tilled and farmed remained fertile for only a few generations.
Other Ohio wetlands followed a similar order. Almost the entire northern portion of Ohio has been deforested, much of its wetlands drained, and underlying peat exhausted. And yet, Ohio agricultural production persists. Synthetic fertilizers replaced swampland peat and currently underwrite large scale industrial agriculture in the region. Unfortunately, the erasure of wetlands has ruined a vital mechanism to cleanse runoff. Furthermore, woodland forests no longer shield winds that encourage erosion and exacerbate runoff. As a result, fertilizer and other contaminants are a major source of pollution in rivers, streams, and the Great Lakes.
Ecologists suggest that a landscape is a heterogeneous land area consisting of three fundamental elements: patches, corridors, and a matrix. A patch is a plant or animal community that is surrounded by areas with different community structure. A corridor is a linear patch that differs from its surroundings. A matrix is the background within which patches and corridors exist. (Source: Forman, Godron Landscape Ecology 1986)
Historically, in the regions of the United States known as the Midwest, forests and wetlands were the dominant matrix within which wild and plant life flourished. In the Upper Great Lakes region, this is largely still the case, however, in the Lower Great Lakes region, industrial agriculture has become the dominant matrix, relagating forests and wetlands to a series of patches and corridors. Furthermore, suburban settlements expand into remaining forests and wetlands, and onto farms and fields at the periphery of towns and cities.
Human settlements consist of a small fraction of the regions overall land use but play an outsized role in determining the health of wild life habitats and natural ecologies. Housing, urban development, and infrastructure, such energy, transportation, and communication networks connect and integrate every individual place of social and economic life. These networks also fragment and divide numerous wild life habitats and natural ecologies. Current settlement patterns and infrastructures are not well designed to compliment human and wild life habitats and natural ecologies.
The result is a fragmented landscape with human settlement and infrastructure exporting significant quantities of sediment, chemical pollutants, and other externalities into waterways, the air and soil. In deforested and historically much wetter regions like the Lower Great Lakes Region, the landscape capacity to sustain diverse plant, animal, and aquatic species is struggling and shrinking.
Corridors are an ecological conservation and restoration technique that can play a vital role in connecting, repairing and enhancing the fragmented patches of forests and wetlands. The USDA Natural Resources Conservation Service (NRCS) lists ten types of best practices in an ecological corridor toolbox:
- Riparian/ stream buffers,
- Wetland, lake, and reservoir buffers
- Field borders
- Field buffers
- Filter strips
- Grassed waterways
- Vegetated ditches
- Grassed terraces and diversions
- Windbreak/ shelterbelts
- Hedgerows
Corridors perform many important ecological functions, acting as: habitats, conduits, filter or barriers, sinks, and sources. Corridors as habitats can be homes for small species, or a transitional zone for large mammals, during seasonal migrations between patches. Corridors as conduits convey energy, water, nutrients, genes, seeds, organisms, and other elements. Corridors as filters or barriers intercept wind, wind-blown particles, prevent or preserve them in place; filter out sediments and agricultural chemicals from runoff; and act as barriers that reduce wind velocity and decrease erosion. Corridors as sinks receive and retain objects and substances that originate in the matrix, for example: soil water, agricultural chemicals, seeds and animals. Corridors as sources release objects and substances into corridors, patches and an adjacent matrix.
Thousands of acres of potentially high quality habitats exist at roadsides, windbreaks, riparian areas, grassed waterways, and other types of corridors. Opportunities exist in every state to plan, design and manage corridors to optimize multiple environmental, social and economic benefits. A diverse and connected landscape provides opportunity to enhance existing agricultural and urban settlements and create a new, diverse, and a mutually beneficial relationship with wildlife habitats and natural ecologies.
Corridor Investment Opportunities
III.
Corridors as Continuous Ecosystems
Acknowledgement of wide spread deforestation and wetland depletion has encouraged a number of local, state, and federal programs to target conservation and restoration. Numerous local, county, state (Department of Natural Resources) and federal agencies (Army Corps, Fish and Wildlife, Natural Park Service, US Forest Service, Bureau of Land Management) oversee protected woodlands and wetlands known as: “conservation and recreation lands.” The lands are vital wildlife habitats and natural ecologies.
The US Department of Agriculture (USDA) has encouraged wetland restoration at the edges of agricultural development to serve as sponges, filters, and wind breaks. The 1990 Farm Bill Wetlands Reserve Program (WRP) incentivized the restoration of agricultural land to wetland ecosystems. This initiative was renewed in the 2014 Farm Bill, known currently as the Agricultural Conservation Easement Program (AECP). Since 1990, the program has enrolled approximately 2.6 million wetland acres.
Climate resiliency related programs have served as more recent funding sources for woodland and wetland repair. Wetland “sponges” mitigate flooding and sewer overflow events during coastal and rain water storms. These “green” and “blue” infrastructure projects have been theorized in the design disciplines under the moniker “landscape urbanism.” The funding of blue and green infrastructure projects has created opportunities for cities and towns to engage in a regional ecological conversation that requires coordination between multiple political jurisdictions.
Infrastructure, such as energy, communication and mobility networks are also strategically positioned to play a significant role in ecological corridor development in the future. Currently, the physical footprint of these networks do not serve an ecological purpose, but more often divide and fragment. This is due to a lack of design and foresight. Energy, communication and mobility networks are part of a regional infrastructure that have the potential to bridge and connect a patchwork of landscapes and social and political jurisdictions. How could the physical artiface of energy, communication and mobility networks be instrumental to construct a more restorative and reparative relationship between human settlements and wild life and natural ecologies?
© PĀR
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I.
The Once Forested and Wetland Past
Michigan’s “Iron Belle Trail” project is currently being implemented to become a new state-wide public mobility infrastructure. The project ambition, put forth by a Republican Governor and adopted by Democratic Governor, is to construct a continuous bicycle path and hiking trail from the lower Great Lakes Region to the Upper Peninsula. For the project to succeed, local governments will need to implement the strategic vision and create pathways that are safe and complete. Furthermore, discontinuous links that have yet to been constructed are opportunities to create connections between hitherto fragmented and discontinuous patches of wild life habitats and natural ecologies.
Regional mobility networks such as Michigan’s “Iron Belle Trail” exist in other parts of the world and are termed: “bicycle highways.” Bicycle highways and hiking corridors are non-invasive mobility networks and are able to provide access to parts of the landscape that are largely inaccessible via rail or road networks. Bicycle highways and hiking corridors can run along windbreaks. Bike highways can navigate alongside filter strips and vegetated ditches. Bike highways can weave in and out of riparian, wetland and other water buffers. In this way, the Iron Belle Trail” has potential to become a regional mobility network and a green and blue infrastructure. A vision that connects urban settlements and creates a new, diverse, and a mutually beneficial relationships with wildlife habitats and natural ecologies.
