ECS Overview

The Minnesota Department of Natural Resources has defined an ecosystem as: A dynamic interacting community of organisms (including humans) considered together with their physical environment. Ecosystems are the fundamental units of nature; they are the life support systems for all living things.

Ecosystems occur at multiple geographic scales. They may be small and simple (an isolated prairie pothole wetland) or large and complex (a specific regional forest or the global biosphere). Ecosystems may range from relatively natural through intensively managed to human dominated. 

Ecosystems do not occur randomly. They vary in size across the earth's surface in response to changes in the amount of moisture, nutrients and energy (light and heat) available. The varying amounts of these life-sustaining elements strongly influence nonliving processes, such as nutrient cycling or hydrologic cycles, that occur in an ecosystem and ultimately the abundance, distribution, and vigor of living organisms. Plants and animals occur together because they are adapted to a specific set of conditions and to living with one another.

Ecosystems change with time. At a fundamental level, an ecosystem is defined by the use and movement of essential components (moisture, nutrients, energy and light) in a community through the interaction of the organisms with each other and the physical environment. Ecosystems are characterized by biotic (living) and abiotic (nonliving) components. Abiotic components such as landform, soils, and topography normally change very slowly on a geologic time scale: tens to thousands of years. The biotic components of an ecosystem, however, change on a much shorter time scale. Disturbances such as windstorms, floods, wildfires, harvesting, and insect or disease outbreaks can change vegetation types and animal habitats literally overnight. In a way, a new ecosystem is created after each disturbance. Ecosystems can also change through a process called succession. Succession is defined as a gradual process of change in an ecosystem brought about by the progressive replacement of one community by another. One example of this is a field or grassy opening in a forested landscape. Over time, the opening will subsequently be filled by vegetation, saplings, understory brush, and finally will become a forest. 

                                            go to 'What is an ECS'