16 Forest Club Annual 



dated by many workers. Under artificial (incubatorial) condi- 

 tions, for example, the seed of some species is known to germin- 

 ate very poorly and in the case of some species practically not at 

 all. For normal germination, on the contrary, there seems to be 

 certain inherent tendencies requiring the conditions of tempera- 

 ture and other factors of the habitat to act on the seed during 

 the period between its maturity up to and including the vernal 

 and possibly other germination periods. By doing the seed test- 

 ing under denuded conditions in the natural habitat, where the 

 germination per cent will be virtually the same as in the case of 

 the seed naturally disseminated over the area, germination poten- 

 tialities of the season's seed crop scattered over the habitat are 

 pretty definitely known. Thus the denuded plot has a value in 

 germination work as well as in the study of invasion and suc- 

 cession. 



While, as stated, conditions of depopulation and denudation 

 brought about as a result of utilization, as well as from fires or 

 other causes, when suitably located and physiographically desira- 

 ble are often directly useful in general investigative work, experi- 

 ence has shown that it is often advantageous artificially to thin, 

 clear cut, and denude. When artificially depopulated, the per- 

 sonnel of the plot may be definitely known and timber areas of 

 the desired age of stand and herbaceous association of a partic- 

 ular composition may be selected. A former record of the per- 

 sonnel is often of great importance in the interpretation of re- 

 sults, especially if the vegetation stand is noted or mapped more 

 or less in detail prior to depopulating. From such records it is 

 often possible to explain the reversion to a type, the stages of 

 temporary vegetation which characteristically forerun the per- 

 manent type or the immediate return to the permanent type, the 

 reasons for which are often not clear without historic data. 



From the viewpoint of light, the size of the cleared plot 

 within a timbered area has an important bearing upon results. 

 In order to avoid flecking from surrounding trees, for example, 

 from one-half to one acre of square area is usually sufficiently 

 large, provided the detailed vegetative plots upon which results 

 are to be based are located near the center. 



Establishment of Plots. 



The charting, when on a minute and detailed scale, is done 

 much as described by Clements in the case of the permanent 

 quadrat. a In some investigations, as in the case of timbered 



a Research methods. ,,,,. 172-186, Clements, F. E., 1905. 



