Logistic Curve 



A graph that represents the growth of an individual or 

 a population, typically S-shaped. 



Long-day Plant 



A plant that blooms under long periods of light and short 

 periods of darkness, e.g., red clover, cf. Photoperiodism. 



Loss-on-ignition 



The loss in weight of a soil (or other material), pre- 

 viously dried at 100C., heated to redness hi a crucible; often 

 used to represent the organic content. 



Lotk 



Refers to running water as in a creek, cf. Lentic, 

 Rheology. 



Lower Austral Life Zone 



See Austral life zone. 



Lower Sonoran Life Zone 



See Sonoran life zone. 



Luminescence 



The emission of light that is not caused by high tempera- 

 ture, cf. Bioluminescence. 



Lunar Periodicity 



The correlation of activities of certain organisms with 

 periods of the moon, e.g., Bioluminescence of the Bermuda 

 fireworm at the time of full moon. 



Lycopod 



A plant in the subphylum Lycopsida (club-mosses) in 

 the phylum Tracheophyta, e.g., Selaginella. 



Lysimeter 



An apparatus used to collect and measure the amount 



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