106 STABILIZATION AND CLIMAX. 



Nature. — The fundamental nature of the cUmax and its significance in the 

 life-history of a vegetation are indicated by the fact that it is the mature or 

 adult stage of the latter. As stated elsewhere, the climax formation is the 

 ftilly developed community, of which all initial and medial communities are 

 but stages of development. The general behavior of the formation as a com- 

 plex organism resembles very closely that of the simple organism, the indi- 

 vidual. The recognition of the latter is so natural and necessary a prelude to 

 the study of its development and organization that it is taken for granted. 

 In like manner the recognition and limitation of climax formations is indis- 

 pensable to a proper developmental study of vegetation. It is not at all the 

 usual method of approach as yet, because its unique importance has not 

 been generally recognized, but in the future much more attention must be 

 paid to the climax stage if the problems of development and structure are to be 

 clearly foreseen and solved. In fact, the study of succession in any climatic 

 region should be begun by an intensive and extensive study of the adult 

 organism, the development of which is to be traced. This is especially neces- 

 sary in view of the complex nature of succession and the number of adseres 

 and subseres that may occur in the development of any formation. The need 

 of such a method of study is further emphasized by the fact that prisere and 

 subsere are but reproduction processes of the formation and as such can be 

 understood only by an understanding of the formation itself (plate 30, a, b). 



Belation to succession. — ^The explanation of the universal occurrence of a 

 climax in succession lies in the fact that the succession is reproduction. The 

 reproductive process can no more fail to terminate in the adult form in vege- 

 tation than it can in the case of an individual plant. In both instances it 

 may fail under abnormal, i. e., unfavorable, conditions. The lack of light in 

 dense thicket or woodland will prevent the maturing of herb or woody plant, 

 as it will of aquatic and amphibious plants when too deeply submerged. An 

 excess of water will have similar effects, while a deficit often suppresses the 

 vegetative stages in large degree. The action of man or animals may keep 

 the plant in an immature condition throughout its life history. While the 

 response is usually more complex, the behavior of the formation is strictly 

 comparable. Natural or artificial factors may hold it almost indefinitely in 

 an imperfect condition of development, i. e., in practically any initial or 

 medial stage, or may cause reproduction of Httle more than the adult stage 

 alone. Man in particular may cause a developmental stage to become per- 

 manent, or to recur so constantly that it appears to be fixed. 



The imderlying causes of complete development of the formation are to be 

 sought in the habitat, just as they are in the case of the individual. Favorable 

 or normal water and light relations result in normal or complete development; 

 unfavorable or abnormal conditions cause suppression of part of the course. 

 The significant difference Ues in the fact that the reactions of the individuals 

 as a community produce a ciunulative amelioration of the habitat, a progres- 

 sive improvement of the extreme, intrinsic to the continuance of development 

 itself. In the case of heath, the production of "bleisand" and "ortstein" are 

 unfavorable to further development, but such a consequence of reaction is 

 wholly exceptional. Indeed, this hardly constitutes an exception, since the 

 persistence of such conditions produces a climax. The climax is thus a product 

 of reaction operating within the limits of the climatic factors of the region 



