C— Continued 



climatic community— A community that is 

 in equilibrium with the general climate, 

 theoretically the climax or final sere. 



climax— The final stage in community 

 succession. See also climatic community. 



clone— A term describing all succeeding 

 generations developed from one parent 

 organism and therefore genetically uni- 

 form. 



colonization — A natural phenomenon 

 where a species invades an area previ- 

 ously unoccupied by that species and 

 becomes established. To be successful 

 the species must be able to reproduce in 

 that area. 



commensalism — A relationship between 

 two interacting species or populations in 



which one benefits while the other 

 remains unaffected. 



community, biotic— See biotic community. 



constancy — The percentage of uniform 

 samples containing the species. Used in 

 determining associations. 



contagious distribution — Nonrandom or 

 clustered distribution of members of 

 same species. 



coprophagic— Animals that eat feces. 



crepusular— Refers to twilight time. 



crude density— See density. 



cryptozoa— Animals that remain hidden. 



--D-- 



decomposers— Usually microconsumer orga- 

 nisms which break down organic matter 

 and thus aid in recycling nutrients. 



decreasers — A species that decreases in 

 density under continued grazing and 

 hence can be used as an index for range 

 management. Opposite of increasers. 



demersal— Organisms (usually fish) that live 

 on or slightly above the bottom. 



density— In an ecological sense density is 

 usually subdivided into two catagories: 

 (1) crude density— the number or bio- 

 mass per unit of total area and (2) 

 specific density— the number or biomass 

 per unit of habitable (colonizable) area. 



detritovores— Detritus feeders. 



detritus— Any fine particulate debris, usu- 

 ally of organic origin, but sometimes 

 defined as organic and inorganic debris. 



diel periodicity — Used in referring to a 

 phenomenon that occurs regularly every 

 24 -hour period. See also circadian 

 rhythm. 



dimictic lake— A lake with two seasonal 

 overturns (periods of free circulation) 

 usually in spring and fall. 



dimorphism— Occurrence of two different 

 forms of the same species. 



dioecious— Male and female reproductive 

 parts in different individuals. 



disclimax— A stable nonclimax community 

 that is maintained by animals or fire. 



