Wetlands

 

The term “wetland” encompasses a wide variety of ecological habitat types. All are extremely important to our environment, but some are highly cherished, and others are often considered undesirable wastelands. The latter have been destroyed for centuries in the name of “progress” and “the greater good.”

They include much more than open water and standing water that is partially, or even completely, covered with emergent vegetation. Permanently wet areas, whether open mucky soil or covered with low herbaceous vegetation, shrubs, or trees are included. Even locations where the surface soil may be dry part of the year, but the soil just below the surface is saturated with water, are wetlands.

One of the most important functions of wetlands is that they intercept, store, and slowly release water whether it is from rainfall, snow melt, or natural springs releasing sub-surface water. By slowing the speed of the water flowing through them, they can help filter out soil and other contaminants (such as agricultural fertilizers, herbicides, pesticides, etc.) that are in the water. The slower the water is released, the less is its ability to cause soil erosion. Slowing the water flow can also result in lower water levels down-stream and reduce flooding which causes great damage to agricultural fields, homes, cities, etc. These floods can also do great damage to the environment, wildlife habitat, and other wetlands. Coastal wetlands which help protect shorelines from erosion by the sea are especially vulnerable to damage.

Another extremely important function of wetlands has been the sequestering of carbon for many thousands/millions of years. The carbon dioxide (CO2) levels in our atmosphere used to be much higher. After vast amounts of carbon were sequestered by various means, the CO2 levels in the air became low enough that conditions became suitable for us (and many other modern species) to survive. Much of the information in the rest of this column was obtained from the book “FEN, BOG & SWAMP” by Annie Proulx.

Carbon storage occurs in many situations.

Wetlands, forests, the ocean, and even the soil store large amounts of carbon. The ocean stores CO2 as a gas or through a chemical process as carbonate sediments. The importance of wetlands becomes apparent when considering that mangrove swamps store 10 times the amount of carbon as the same area of land forests and peatlands store twice as much carbon as all the world’s forests.

Other benefits of wetlands are that they provide critical habitat for many wildlife species. Obvious examples are waterfowl, shorebirds, aquatic fur bearers, reptiles, amphibians, and migratory birds. In fact, over half of the approximately 800 species of migratory birds in the U.S. rely on wetlands. A very large bog in Scotland is the major nesting area for most of Europe’s migratory birds. Something rarely thought about is the tremendous abundance and diversity of insects found in wetlands. They are an essential food source for many species (especially birds and bats); also, for fish in wetlands that support fish life.

Underground aquifers often depend on wetlands for their source of water. They are what keep wells flowing for private homes, many towns and cities, and some agricultural irrigation in areas that are not near streams. Over-exploitation of aquifers has caused, or at least contributed to, some of the low-water problems in the western U.S.

As important as wetlands are, they have been drained and destroyed for hundreds of years in the name of progress. The size of wetlands destroyed world-wide has varied from small portions of agricultural fields to wetlands of hundreds of thousands of acres. By the 1980’s about one-half of U.S. wetlands had been destroyed. The loss continues.

In 1849, Congress passed the first of a number of Swampland Laws that turned federal wetlands over to the states to do as they wished; usually this meant drainage. The typical scenario has been that the wetlands were too wet for agriculture and that they must be drained for the public good. However, the lands usually became the property of developers and big agriculturalists or ranchers; so much for the greater good.

Wetland soils are very productive and, when drained, produce very good crops for a few years before becoming depleted. Organic soils disappear when not replenished. Commercial fertilizers are often applied whether or not the field had been a wetland as intensive agriculture can deplete any soil type; all too often this results in fertilizers being washed (or leached) into wetlands and waterways which damages water quality. Also, agricultural fields made from drained wetlands begin releasing the CO2 and methane gas that had been stored in the wetlands.

Tropical swamp forests have also suffered destruction. In Indonesia, the cutting, burning, and converting of them to palm-nut oil plantations has released huge amounts of CO2. The Amazon tropical forest used to be considered (after the ocean) the great storehouse of CO2. However, for decades portions of it have been deforested, burned, plowed, turned into cattle ranches, etc. Now, after a 10-year study measuring the Amazon’s CO2 output, it has been found that the Amazon is now emitting more CO2 than it sequesters.

All is not gloom and doom. There have been actions taken to protect many wetlands. Private organizations such as Duck’s Unlimited, The Nature Conservancy and several others have protected many areas. State and federal conservation agencies have worked for decades acquiring many wetlands. Many private landowners have stepped up and donated their wetland areas or set them up to be protected from drainage. Ireland is in the process of restoring old peatlands; Britain is considering doing so too. A 4,000 square kilometer portion of the large bog in Scotland that I mentioned earlier may become the world’s first bog Natural Heritage site.

“Rights of nature” is a legal concept that is gaining international standing. The U.S. is among dozens of countries that have committed to some “rights of nature” laws that allow citizens to sue on behalf of lakes, streams, ocean reefs, swamps. The movement started in 2020 with the United Nations biodiversity summit.