new habitats, applicable also to the development of a new 

 community. 



Adaptive Selection 



The evolution of more or less similar forms in separate 

 but ecologically similar areas. 



Additive 



A material added to a fertilizer, or to another substance, 

 to improve its chemical or physical condition. 



Adiabatic 



Refers to an occurrence in which heat is neither gained 

 nor dissipated. 



Adjustment 



Processes by which an organism becomes better fitted to its 

 environment; functional, never structural, cf. Adaptation. 



Adobe 



A fine calcareous clay or silt, may be mixed with water 

 to make bricks for construction purposes, cf. terron. 



Adsorption 



The attachment of molecules or ions to surfaces or inter- 

 faces such as solid-liquid, solid-gas, and liquid-gas boundaries. 



Advance Growth 



Young trees in openings or under the canopy in forests 

 before cutting or regeneration operations are started, syn. 

 Advance reproduction, cf. Second growth. 



Adventicous Species 



Organisms which have invaded from a distance. 



Adventitious 



An organ growing out of its usual location, e.g., root 

 from a stem; a species which has invaded from another area 

 and has become more or less naturalized. 



