Source:http://linkedlifedata.com/resource/umls/id/C0013546
MSH: The branch of science concerned with the interrelationship of organisms and their ENVIRONMENT, especially as manifested by natural cycles and rhythms, community development and structure, interactions between different kinds of organisms, geographic distributions, and population alterations. (Webster's, 3d ed),CSP: relationship of organisms to their environment and their interaction with other organisms.,NCI: The branch of biology concerned with the relations between organisms and their environment.