the vegetation of montauk 77 



Soils. 



It is needless to go into the geology of Montauk*more than to say that 

 all of the surface of the peninsula is made up of glacial till of the Ronkon- 

 koma Moraine, and from this, of course, all the soils of Montauk have 

 been derived. 



This geologically similar material is by no means matched by a similarity 

 of soils. Considering first the mineral soil, which is soil that remains un- 

 modified by the vegetation, — ^the subsoil of the gardeners, — it is at once 

 obvious that this differs in different parts of Montauk and under different 

 vegetative types. 



Disregarding boulders, small stones and coarse gravel, the available 

 subsoil appears to be, under the typical Downs, a mixture of about 85% 

 coarse yellow sand, and 15% of fine sand with sometimes a slight admixture 

 of silt. It is into such a substratum that the deeper rooted perennials, such 

 as Baptisia tinctoria, and all the shrubs, always penetrate (Fig. 26). And 

 of all the Montauk soils these Downs samples are the least favorable for 

 plant growth, being practically wholly lacking in humus (Fig. 27). 



In the wooded kettleholes, in the Hither Woods, or in the Point 

 Woods, the subsoil is very different. A glance at figure 28 shows, that on 

 the average, the subsoils under the forest are higher in fine sand or silt 

 than those under the grassland. In the case of the Hither Woods sample 

 the soil is not far in its mechanical composition from the open Downs, and 

 as the earlier description of that region has shown, the forest there is 

 stunted. It is unquestionably the combination of this poor soil and 

 exposure to the winds which holds back the growth of the oaks in the 

 Hither Woods. How much this is retarded on the windward side of them 

 has already been shown. 



These different subsoilsf appear to have an important influence in 

 controlling the major distribution of the different vegetation types, always, 

 of course, in conjunction with, and subsidiary to, climatic factors. Upon 

 them depend the maintenance of the vegetative status quo. But the es- 

 tablishment and reproduction of either old or aggressively competing types 

 must depend upon the upper layer of the soil, in which all alike must first 

 root or germinate their seeds. 



* For details of this see Fuller, M. L., The geology of Long Island, Prof. Paper 

 U. S. Geological Survey 82: 1-231. 1914. 



t In this, as in other parts of Long Island, my statements are based on many collections 

 under each type of vegetation, so that the remarks about soil possibilities must be under- 

 stood to refer to average conditions, rather than individual cases. 



