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INTRODUCTION. 



An estimate of the capacity of any region to produce and maintain a 

 virgin forest presupposes a standard of comparison by whicli to judge 

 success in forest growth. 



What is meant by success depends on the investigator's standpoint. 

 Those who critically examine forest growth can, I think, be roughly 

 divided into four classes. These are systematic botanists, ecological bot- 

 anists, lumbermen, and foresters. The systematic botanist would usually 

 consider the most successful forest to be that which contains on a unit 

 of surface the greatest number of species of all kinds from the ground to 

 the tops of the highest trees. On the above idea, variety in species and 

 form are the main points considered. Thus the forest is composed of 

 a great many species assuming in outline a great many forms, such as 

 lichens, mosses, liverworts, herbs, epiphytes, parasites, climbing bamboos 

 and palms and dicotyledonous trees. He usually brings his material 

 together in tlie form of a "flora," associating plants in groups or families. 

 Thus a qualitative analysis is made of the forest. The idea of bulk is 

 expressed in vague terms, associated ^vith different species, like "common" 

 or "abundant," "a large tree," "a liana," etc. A brief description of 

 the region usually precedes the lists of plants. This is the conventional 

 idea of the tropical forests and those people, who disregard value as an 

 element of success would place such a forest as the most successful in 

 the world. 



The ecological botanist will consider habitat as well as vegetation. He 

 will divide the forest into formations or societies, or types, corresponding 

 lo the different habitats, and then describe each forest type in greater or 

 less detail, calling attention qualitatively, and more or less quantitatively, 

 to the composition of the forest. He may or may not niake an attempt 

 to measure, or express in some way, the factors of the habitat. To him 

 the best physical and biotic conditions produce the best or most successful 

 forest which he calls a mesophytic forest. The idea of "succession" may 

 or may not be considered. In the above ideas there is little or no attempt 

 to measure the amount of vegetation per unit of surface, hence they may 

 be designated as qualitative standards in distinction from the quantitative 

 standards, viz, the standard of the lumberman and the forester. 



The lumberman takes into consideration "value" as an element of 

 success in forest growth. Any given forest would be judged by the trees 

 suitable for his needs and the rest would be considered as "weed trees." 

 As the cost of handling a large amount and a few kinds of lumber is 

 less than in handling a small amount and many kinds on any given area, 

 he desires to obtain a great bulk of one or of veiy few kinds of timber 

 per unit of area. To him the most successful forest in the world would 

 be the greatest aniounl of I lie most valuable tinibei's of the most con- 



