some group or groups of organisms. Ekman's 

 (1953) zoogeographical regional classification of 

 marine areas is an example. 



Coastal biotic province— Delineations of 

 associations based on biotic components, water 

 mass characteristics, and coastal geomorphology, 

 with emphasis on the biotic components (Ray 

 1975). 



Division— Used in the same sense as the word 

 taxon is used in taxonomy; i.e., any one of the 

 categories such as Level I, Level II, etc., into which 

 coastal ecosystems are classified. 



Ecological characterization studies— Studies 

 being performed by the National Coastal Ecosys- 

 tem Team of the U.S. Fish and Wildlife Service 

 which provide a description of the important re- 

 sources and processes comprising a coastal ecosys- 

 tem. They also provide an understanding of the 

 functional and dynamic relationships in coastal 

 ecosystems through integration of existing en- 

 vironmental and socioeconomic resource data 

 into an ecological unit. These studies follow a 

 holistic approach (J.Johnston, NCET, pers. 

 comm. ). 



Ecological land unit (ELU)— 1. "U.S. Forest 

 Service usage. One of the lowest levels of the Eco- 

 class system of classifying ecosystems into sub- 

 divisions for forest description and management. 

 An ELU is a composite of elements from the 

 land subsystem and vegetation subsystem which 

 together define a homogeneous unit (after Corliss 

 1974)." 



2. "U.S. Forest Service Resource Capability Sys- 

 tem (RCS) usage. Units of land having strong uni- 

 formity in slope steepness, aspect, microclimate, 

 rock types and conditions, geomorphology, soil 

 characteristics and productive capabilities, type, 

 density and age of vegetation and ground cover, 

 and drainage characteristics." 



"The basic physical unit of land that scientific 

 disciplines agree must be delineated and examined 

 as a separate entity (for use-evaluation or manage- 

 ment purposes)." 



"The basic unit that is used in the anlaysis of on 

 site potentials, capabilities, and limitations. The 



most significant level of land stratification which 

 best communicates the basic (inherent) capabilities 

 and limitations (Reid 1972)." 



"Land (or water) units which because of their 

 strong uniformity in physical and biological char- 

 acteristics respond similarly to management activ- 

 ities or other stimuli. Sometimes called response 

 units." (Schwartz et al. 1976:64-65). 



Ecological water unit (EWU)— "U.S. Forest Ser- 

 vice usage. One of the lowest levels of the Eco- 

 class system of classifying ecosystems into sub- 

 divisions for forest description and management. 

 An EWU is a composite of elements from the land 

 and aquatic subsystems, where aquatic type and 

 adjacent land types together define a homogeneous 

 unit (after Corliss 1974)" (Schwartz et al. 

 1976:65). 



Ecosystem— 1. "The system formed by the in- 

 teraction of a group of organisms and their en- 

 vironment (Durrcnbcrgcr 1973)." 



2. "A complete, interacting system of organisms 

 considered together with their environment, e.g., 

 a marsh, a watershed, a lake, etc. (after Hanson 

 1962)." 



3. "An ecological community considered together 

 with the nonliving factors of its environment as a 

 unit" (Gove 1963). 



4. "Any spatial unit that includes all of the 

 organisms (i.e., the biotic community) in a given 

 area interacting with the physical environment so 

 that a flow of energy leads to clearly defined food 

 and feeding relationships, biologic diversity and 

 biogeochemical cycles (i.e., exchange of materials 

 between living and nonliving parts) operating as 

 an integrated system." 



"Ecosystem is the preferred term in English while 

 biococnosis or biogeocoenosis is preferred by 

 writers using or familiar with the Germanic and 

 Slavic languages (after Odum 1971)." 



"Some (Ford-Robertson 1971, Hanson 1962) 

 make a distinction between the two terms by 

 using bio(geo)coenosis to refer to actual biologi- 

 cal units (such as a certain bog) and ecosystem 

 when referring to conceptual units. Others (Odum 

 1971) make no such distinction'. We prefer Odum's 



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