| A | B |
|---|
| Ecosystem | A community of all the living things in an area and the environment in which they live |
| Freshwater | Made up of water that is fresh, not salty. This term is also used to describe creatures that live in fresh water, such as freshwater fish |
| Glaciers | a large mass of ice found near Earth's poles or in a hih, cold mountain valey |
| Watershed | a geographic area that includes all of the land and waterways that drain into a body of water. Also called a drainage basin |
| Food Web | All of the feeding relationships within an ecosystem. Each living thing in a food web provides food energy to other things within that ecosystem |
| Food Chain | a series of plants and animals, each of which depends on the one below it for food. A food chain usually forms part of a much larger food web. |
| Pollution | Damage to the natural environment caused by harmful substances; harmful substances |
| Point-source pollution | water pollution from a single place, such as a discharge pipe at a plant that treats sewage |
| Non-point source pollution | pollution that does not come from a single location, but rather from many sources such as runoff from farms. |
| Pollutants | Something that pollutes, or damages, air, soil, or water |
| Runoff | water from rainfall that is not absorbed into the soil and instead flows into streams or lakes |
| Sediment | bits of soil left in place by moving water |
| Invasive species | nonnative plants and animals, that invade an ecosystem |
| Wetlands | An area where the soil is usually wet or covered with water |
| Habitat | Natural environment in which a plant or animal lives. |
