from the fertilized egg to death of the mature plant or 

 animal. 



Life Expectancy 



The average duration of life that a given individual is 

 expected to live after having reached a certain age. cf. 

 Life table. 



Life-form 



The characteristic form or appearance of a species at 

 maturity, e.g., tree, herb, worm, fish. cf. Growth form, 

 Habitat form, Raunkiaer's life-form classification. 



Life-form Class 



One of the groups in Raunkiaer's classification of life- 

 forms, e.g., Geophyte, Therophyte. 



Life-form Dominance 



The condition in which several species of the same Life- 

 form dominate a plant community, cf. Dominance, ecologic. 



Life Span 



The maximum duration of life of an individual of a 

 species. 



Life Table 



A statistical tabulation presenting complete data on the 

 mortality of a population, cf. Ecological longevity, Life 

 Expectancy. 



Life Zone 



An altitudinal or latitudinal biotic region or belt with 

 distinctive faunal and floral characteristics, cf. Alleghenian, 

 Hudsonian life zones. 



Light Intensity 



See Illumination value. 



Light Quality 



The wave-length composition of light. 



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