Living things or organisms provide each other with substances necessary for life, and a proper balance between plants and animals is needed to maintain life (1, p.246d).
AEcology is the study of interrelationships of organisms to one another and to the environment@ (2, p.121). AThe word AEcology@ comes from the Greek words Oikos - house, and Logos - the way a subject is spoken about or treated. Ecology is a subject that tells about the Ahouses@ of living things, in other words the study of how organisms interact with the various living and nonliving parts of the environment in which they live@ (3, p.14).
ABiosphere is the portion of the earth and its atmosphere that is capable of supporting life@ (2, p.53).
All ecosystems are Aopen,@ which means that energy and matter continually escape from the ecosystem as they are used by living organisms. Unless they are replaced, the ecosystem will collapse. Usually, the replacement comes from a biotic environment, but sometimes it happens between adjacent ecosystems. Often the pathway is difficult to determine(4, p.9). A Growth and reproduction, mortality, immigration, and emigration are among the numerous and important balancing mechanisms that affect ecosystems. They also influence behavior, physiology, and population numbers@ (4, p.9).
Living things are mixed together, involved in a great variety of ways, including feeding, competition, and cooperation. Energy flows to the community, and the physical environment has profound effects on all plants and animals. The environment of any living thing consists both of other living things and of inanimate materials. The living community and its nonliving environment act together as an