Biology Lessons Part 2: Population Biology

Lesson 2.3: Glossary: Chaparral Community


biomass - the total dry weight of organic matter present at a particular trophic level in a food chain

carrion - dead and putrefying animal flesh

chaparral community - a biological community characterized by a predominance of chaparral, which consists of thick shrubs and low trees. San Diego State University's (SDSU) Biological Field Stations are located in this kind of environment. In addition to chaparral, the field stations also include coastal sage scrub, oak woodland habitats, and riparian (river) systems.

community - groups of organisms of two or more different species living together within the same geographical area where they are likely to interact with each other. Every community of living things depends upon its producers to convert inorganic carbon (from the carbon dioxide in the air) into organic molecules (such as sugar) through the process of photosynthesis.

consumers - organisms within a biological community which cannot manufacture their own food and therefore depend on other organisms for their nutritional supply; also called "heterotrophs".

decomposer - an organism that obtains energy from dead or waste organic matter. Bacteria and fungi are decomposers that usually secrete enzymes to digest the material and then ingest the smaller molecules that are released by the enzymes. When animals eat the flesh of dead animals, they are also functioning as decomposers.

energy - the capacity to do chemical or mechanical work.

food chain - a producer and a series of animals through which energy is transferred when one individual eats another. Food chains really are snapshots in both space and time since eating habits vary.

food web - summary of known feeding relationships in a biological community. A food web illustrates how each type of organism in a community is typically consumed by or consumes more than one other type of organism, and that different types of organisms compete for the same food sources.

fungi - kingdom of organisms which includes mushrooms. yeast, and molds; fungi obtain energy by secreting digestive enzymes that decompose other biological tissues; singular = fungus.

herbivores - animals which eat only producers, for example, deer on land and zooplankton in the ocean.

inorganic - describes chemical compounds which do not contain both carbon and hydrogen (hydrocarbon groups); chemical compounds that lack the organized physical structure characteristic of living things; for example, water and minerals are inorganic substances.

matter - anything that has mass and occupies space.

niche - includes all of the functional roles of an organism in a biological community; what an organism does in and for a living community.

organic - describes chemical compounds which contain both carbon and hydrogen (hydrocarbon groups) are usually considered organic; organic compounds form the chemical basis of living things. The major categories of organic compounds found in living things are carbohydrates, lipids, proteins and nucleic acids.

photosynthesis - process by which plants and other producers capture the light energy of the sun and transform it into chemical energy. Producers use light energy to convert inorganic carbon dioxide from the air and water into the sugar glucose, an organic molecule. The glucose is used as an energy source and also as a major building block for the structure of the plant, since sugars are combined to form cellulose. Oxygen is a byproduct of photosynthesis and is released into the air. Photosynthesis also produces an energy transfer molecule called ATP that supports many synthetic reactions in the plant. Since consumers rely on food provided by photosynthesis to sustain them, this process is one of the primary processes supporting life. It also produces most of the oxygen in the air.

predator - an organism, usually an animal, that catches and eats other organisms

prey - living organisms that are caught and eaten by other organisms

primary consumers - animals which eat producers

producers - any of various organisms, such as green plants and certain algae, which obtain food by producing organic compounds from inorganic carbon dioxide by means of photosynthesis. Producers are a direct or indirect source of food for other organisms. Also called "autotrophs".

riparian - referring to the bank of a river

role - all of the ways in which organisms interact with the biotic components of their community and the abiotic factors in their environment

terrestrial - living or growing on land, not in air or water.

top predator - animal in a biological community which is not usually caught and eaten by other animals in that community.

transfer of matter and energy - process by which an animal obtains energy when it eats another animal or a plant. Energy captured by eating is a) used to maintain life functions, b) stored in the chemical bonds of the substances making up the organism's body, or c) lost as heat. The amount of energy that is lost in the energy transfer process is much greater than the amount of energy that is transferred, often in the ratio of 90% lost and 10% transferred.

trophic level - a feeding level in a food chain