Of the estimated 220 million acres of wetlands that existed in the lower 48 states prior to European settlement more than half have been lost through the country’s expansion and use of new technology, often supported by past government programs that advocated the conversion of wetlands to farmland. Also, a significant portion of the remaining intact wetlands have been degraded.
In most instances, especially true in the Midwest, wetland soils are highly productive due to their high carbon and organic contents but are too wet to farm in their natural state, so the wetlands were drained and then plowed under.
The state of Missouri contained about 4.8 million acres of wetlands prior to European settlement. By the 1980s about 87 percent, or 4.18 million acres, of the original wetlands had been lost to other land uses. This map below shows how much all of the 50 states have lost into the 1980s.
The conventional wisdom was that getting rid of the swamps was a good thing providing millions of acres of productive farmland and removing a health hazard. But is that really true or a simplistic generalization that ignores the many benefits that wetlands provide us with?
According to the EPA, “Wetlands are among the most productive ecosystems in the world, comparable to rain forests and coral reefs.”
Conventional wisdom also tells us that replacing wetlands with agriculture has been a huge economic benefit. But digging a little deeper into the subject can lead one to a different conclusion. A large portion of that conclusion is determined by who the economic beneficiaries are.
The benefits received from functioning wetlands are enjoyed by all people within the watershed to varying levels – these are the benefits to the public for common services such as flood storage and improving water quality. The value of the common services are difficult to quantify but estimates far exceed the economic benefit of the conversion to agriculture, especially to row crops that typically degrade or completely eliminate the common services (Source: Costanza, Robert, et al, 1997, The value of the world’s ecosystem services and natural capital, Nature, 387:255). More examples of the common services are listed below.
When a wetland is converted to an agricultural use, especially in a monoculture, row crop system, the benefits associated with raising crops are accrued almost exclusively to the landowner/farmer. The common services benefits to the general public from the wetlands are then almost entirely lost because the wetlands ecosystems are removed.
Unfortunately it was not until after we had destroyed those tens of millions of acres of wetlands that we began to understand that wetlands perform important functions, through which they provide us with immeasurable free services.
|“As human populations increase and progress trudges on, the pressure for converting wetlands to agricultural production, urban development and other uses will increase. One of the best ways to guarantee the protection of our remaining wetlands is to understand how the important values of wetlands serve mankind.” Missouri Department of Conservation