214 PLANT PHYSIOLOGY AND ECOLOGY 



features. This is most readily done by means of an outline map 

 in which the various zones, consocies, communities, etc., are 

 shown. Sufficiently reliable data for such maps can be obtained 

 by pacing. In securing measurements for the map of a formation 

 or some part of it, it is first necessary to select a base. This may 

 be a road, ravine, ditch, pool, lake, or stream, or the peak or crest 

 of a hill, ridge, or mountain. The width and length of the base 

 are determined, as well as its general direction. The width and 

 length of the various areas, zones, consocies, etc., are then measured, 

 together with the distance and direction of each from the base. 

 These are reduced to the scale desired, viz., 100:1 for small areas, 

 and 1000:1 for larger ones. The base is first outlined upon a 

 meter sheet, usually of plotting paper, and the various areas are 

 then drawn in the proper size and position. Each area is labeled 

 to denote its character, or it may be colored, thus causing the 

 various parts to stand out more distinctly. 



