Llgnln 



A complex organic compound in the walls of certain cells, 

 especially in woody tissue. 



Lignification 



The process of impregnating cell walls of a plant with 

 lignin. 



Lignosa 



Woody vegetation. 



Lime Requirement 



The amount of standard ground limestone needed to 

 change the upper 6.6-inch layer of an acre of acid soil to some 

 lesser degree of acidity, usually stated in tons per acre. 



Limiting Factor 



The environmental influence by which the limit of tolera- 

 tion of an organism is first reached and which therefore 

 acts as the immediate restriction to one or more of its func- 

 tions or activities or in its geographic distribution. 



Limnetic 



Refers to the open water of a pond or lake. cf. Benthic. 



Limnology 



The branch of biology that deals with fresh waters and 

 organisms in them. 



Lincoln Index 



The use of marked animals to estimate the size of a 

 population. 



Line-intercept Method 



The sampling of vegetation by recording the plants inter- 

 cepted by a measured line placed close to the ground, or by 

 vertical projection to the line. cf. Transect. 



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