biodegradable: When a material is decomposable by soil life forms. Organic material is biodegradable.
compost: "Food" for plants and trees. Compost is made from decomposed plant material, food scraps, and other natural ingredients. It is soil with many nutrients.
decay: The process in which bacteria help to break down a plant or animal decompose. The structure of organic materials breaks down into another form through biological and chemical processes.
decomposer: An organism that helps to break down dead plant material and turn it into soil. Earthworms, pill bugs, centipedes, bacteria, fungus, and mold are decomposers.
depleted: Soil that lacks nutrients and water has been depleted. It is poor for growing, the plants would lack the nutrients as well.
erosion: Wind, rain, or animals can cause soil to wash away, wear down rocks, or change the direction of a stream. It is a natural process that occurs over time, but can be diminished by trees and plants. The roots hold soil in place. People must take caution not to erode areas as well.
food chain: The natural order of animal life and survival. For example: a dead leaf is eaten by an earthworm, that is eaten by a small bird, that is eaten by an owl.
microbe: A decomposer. Microbes are bacteria and are too small to be seen with the naked eye.
minerals: Chemicals that join together and make up rocks, which get broken down into soil. Minerals are found in a variety of foods and are necessary for the growth of living organisms.
mulch: A mixture of material (grass clippings, wood chips, newspaper, straw, leaves, etc.) that is spread around the base of plants and trees to prevent the growth of weeds.
nutrient: Vitamins for plants. Plants get their nutrients from the soil and pass them along to us when we eat the plants.
nutrient cycle: Plants grow in nutrient rich soil and absorb the nutrients. We eat the plants and take in the nutrients. Through composting and decomposition, the soil gets the nutrients back, and the cycle starts again.
root: The part of a tree or plant that grows underground. Roots anchor the plant in the soil and are the way it absorbs water and nutrients.
soil: Broken down rock and organic material that makes up the first few inches to many feet of the earth's top layer. Soil is classified by color, parent material, and particle size.