Three Characteristics of a Sustainable Ecosystem

Nutrient Cycles

• Ecosystems are mostly defined by various organic compounds that must circulate through the ecosystem. Organisms of various types are constantly struggling to acquire these compounds in order to maintain essential biological processes. Important nutrients for an ecosystem include carbon, nitrogen, oxygen and water. These nutrients must cycle through the biosphere and not leave the ecosystem or form compounds that are not usable by the life forms. For example, most organisms need nitrogen in some form. But this nitrogen is not accessible by the majority of these organisms, so they have to rely on microorganisms such as bacteria, which have the ability to fix these nutrients. Also, much of the ecosystem relies on plants and animals passing back and forth oxygen and carbon dioxide, as these organisms consume and release these chemicals as byproducts.

Predators and Prey

• Another important part of the ecosystem are the food chains. These food chains consist of some organisms serving as predators and other organisms serving as prey. Obviously, the prey organisms are beneficial to the predators, and dwindling prey can cause a predator species to die off. But predators also help the prey species by reducing overpopulation so that the prey species does not run out of food. Without predators, many prey species can consume food to the extent that their populations rapidly expand. However, once these populations reach a point where they consume all of the food, these species can rapidly decline until they reach a very small number or even die off. Sustainable ecosystems have the right balance of predators and prey. These organisms must also maintain biodiversity, or else the balances of predator and prey relationships can become disrupted.

Living Soil

• Many of the most crucial nutrients end up in the form of soil. These nutrients come from eroding rock and mountains. While this soil may not look alive, soil usually contains a diverse array of microorganisms, such as bacteria, fungi and soil-dwelling animals. These organisms are often the building blocks of all of the life above the soil. Most of the nitrogen fixation occurs among the bacteria in the soil. Worms poke holes in the soil, aerating it. Plants depend on this soil, which allows them to generate food and oxygen for a vast array of other species. Many areas become barren when soil loses many of its crucial organisms, so soil must be continually replenished for an ecosystem to survive.