Ecosystems and the services they provide are perhaps Earth’s most valuable resources. We depend on ecosystems, and the species within them, in more ways than most people would think. Ecosystems provide many services and products that support life on Earth and are essential to the quality of human life and our economies.

The natural services performed by ecosystems often go unnoticed, but in reality, they are so important, life on Earth could not exist without them. When asked to put a price tag on the value of services provided by ecosystems, scientists came up with an estimate of $33 trillion dollars per year!

Below is a summary of some of the services provided by ecosystems:

Water Purification. Plants and microorganisms in the soil filter out sediments and toxins from water, especially in wetlands. Some organisms, such as aquatic snails and clams, pump water through their bodies to filter out food, while cleaning the water.

Air Purification. In a delicate balance of nature, the Earth’s plants, animals, and microorganisms complement each other’s activities in the exchange of gases needed for their survival. During photosynthesis, plants purify the air by taking in carbon dioxide and releasing oxygen. Animals then use oxygen from the air and release carbon dioxide. This process also helps to remove other pollutants from the air. For example, in cities, trees can help to improve the air by removing some of the toxins from car exhaust.

Pollination. One third of all human food comes from plants that are pollinated by animals such as insects or hummingbirds. Pollination is essential to both wild plants and crops grown on farms. Agriculture is Michigan’s second most important industry, contributing approximately $71 billion (2011) to our economy every year. Some of the major crops produced in Michigan include soybeans, dry beans, blueberries, apples, and tart cherries, all of which depend on wild pollinators.

Seed Dispersal. Plants make seeds in order to reproduce. In order to grow, the seeds need sunlight, water, nutrients, and space, usually found away from the parent plant. Plants depend on wind, water, and other animals to help disperse their seeds. Many kinds of plants depend on animals for their dispersal. Some seeds are packaged in tasty fruits, which are eaten by animals (especially birds) and are often transported to a new location while passing through the animal’s digestive tract. Other seeds are stored or buried by animals such as blue jays, squirrels, and chipmunks. Seeds that are forgotten by the animal have a chance to grow. Other seeds stick to animal fur and travel with the animal until they fall off in a new location. Still other plants depend on the wind or water for seed dispersal.

The Decomposition of Wastes and Recycling of Nutrients. Dead things (and the waste of living things) are recycled into the soil through the work of animal scavengers and microscopic decomposers. Some examples of scavengers include centipedes, pillbugs, catfish, and vultures. Examples of decomposers include fungi, bacteria, and other microorganisms.

Natural Pest and Disease Control. An estimated 99% of all agricultural pests are controlled by natural enemies, such as birds, spiders, wasps, ladybugs, fungi, viral diseases, and flies. These natural predators and diseases save farmers billions of dollars annually, reducing the need for chemical pesticides. Pests that carry diseases that affect humans, wildlife, and wild plants are also controlled by their natural enemies. For example, ticks that cause Lyme disease are controlled by predators, such as birds.

Erosion and Flood Control. Enough rain falls onto the Earth’s land surface every year to cover the land to an average depth of 1 meter. Much of this water is absorbed by plant roots, which hold the soil in place, reducing the likelihood of erosion and mudslides. In places where forests and native vegetation have been cleared, the land is unable to hold the water, increasing the likelihood of erosion, floods, and even drought.

Climate Control. Have you ever visited a forest on a hot day and been surprised to find it was much cooler than in town or especially a parking lot? Forests help control climate by providing shade that is beneficial to all kinds of animals, including people. In the summer, a single tree may transpire as much as several hundred gallons of water into the air every day, providing a cooling effect similar to six window-unit air conditioners. Trees and other plants also help to counteract global warming by taking in and storing carbon dioxide, the gas that is most responsible for global warming.

Nature Appreciation and Recreation. People value natural ecosystems for their beauty, which offers opportunity for quiet reflection, solitude, and inspiration. People also value natural ecosystems as places to visit for recreation and vacations. For example, millions of people visit Michigan’s State Parks and other public areas every year to participate in activities such as hiking, cross-country skiing, camping, wildlife watching, photography, boating, fishing, and hunting. Forest-based tourism brings in around $3 billion to Michigan every year.

Production of Ecosystem Goods. Ecosystem products such as wild plants, fish, and game are used for food; plants are used for medicine; agricultural products and other ecosystem resources such as fuel, timber, and fiber have a variety of uses.

Some examples of products that come from Michigan forests:

• The “leather” (really made of paper) tag on Levi’s (Neenah Paper, Munising)

• Paper for the National Geographic magazine (Verso Paper, Quinnesec)

• Basketball court floors (Homer Flooring, Dollar Bay)

• Guitars (Rossi American Hardwoods, South Range)

• Bowling Pins and Alleys (Brunswick, Muskegon)

• Telephone poles (Hydrolake, McBain)

For more ideas on Michigan forest products, check out the Michigan Forest Forever web site: http://mff.dsisd.net/