The Flora of the Cayuga Lake Basin 441 



noncalcareous regions are strikingly different, and many plants are distinctly calci- 

 philes or calciphobes. Likewise, the flora of the salt or the brackish marsh is very 

 different from that of ordinary nonsaline regions. Organic matter is important, 

 especially when in the form of peat in peat bogs but also as humus or leaf mold 

 since there are many so-called "humus plants." Peat and humus seem to be greatly 

 influenced by the degree of acidity of the soil as well as by other factors. The 

 formation of peat generally requires acid conditions, but leaf mold appears to be 

 deepest over calcareous soils. The water and the air content o^f the soil are im- 

 portant. They are often dependent on drainage, which in turn is very often related 

 to soil texture. In general, gravelly and sandy soils do not support the same 

 vegetation as does clay. The interrelation of the various factors is often very 

 complex and their effect may be very indirect. The reader is referred to the writ- 

 ings of Fritz Unger, Anton Kerner von Marilaum, Contejean, Hilgard, Fernald, 

 Tansley, Coville, and Wherry, for further information regarding the importance of 

 lime in plant distribution. 



The soils of the Cayuga Lake Basin, except those in Seneca County, have been 

 surveyed by the Bureau of Soils of the United States Department of Agriculture 

 in cooperation with the Cornell University Agricultural Experiment Station. For 

 details of soil distribution, the reader is referred to the bulletins published by that 

 bureau. 40 



The soils of the Cayuga Lake Basin are largely of glacial origin, though stream 

 deltas and alluvial deposits constitute a small proportion. On the hills at the 

 southern end of the basin the glacial drift is thin and the soils are correspondingly 

 shallow, and on the flat plateau summits, as well as in the draws, they are often 

 poorly drained. The underlying rocks are Devonian noncalcareous sandstones and 

 shales. These rocks are the chief source of the overlying soil, much of which is 

 noncalcareous, giving an acid reaction. These plateau soils at the surface are 

 rather light in texture and are filled with angular fragments of stone, and the 

 surface is often thickly strewn with these fragments. Judging from the plant 

 covering, however, these soils are not uniform, for in some localities the forest is 

 composed largely of chestnut with dyer's and scarlet or chestnut oak, and in the 

 early days white pine, while in other localities it is largely made up of sugar maple, 

 beech, and yellow birch, with chestnut and the above-named oaks absent. The 

 associations of trees just mentioned represent two very distinct and contrasting types 

 of forest in the Cayuga Lake Basin, each with its own association of undershrubs 

 and herbs. On the higher plateau the oak-chestnut type is dominant in the south 

 and the southwest, but many small islands of the maple association are scattered 

 about, these becoming larger and more numerous toward Dryden, and from the Mc- 

 Lean region eastward into Cortland County almost entirely replacing the chestnut 

 and oak. The undergrowth in the oak-chestnut forest is chiefly of ericaceous plants, 

 Desmodiums, Lespedezas, and the like, whereas in the maple-beech forest a conspicu- 

 ous growth of herbaceous spring humus plants and a corresponding lack of plants 

 during the summer are characteristic. In this maple-beech forest there is an almost 

 complete absence of ericaceous plants, Desmodiums, and Lespedezas. The leaf mold 

 is generally deeper in this type of wood, and the shade is much denser, two factors 

 which largely determine the extensive development of the spring herbaceous flora 

 on the forest floor of this type of forest, and its lesser development on that of the 

 oak-chestnut type. The contrast between these two types of forest is altogether strik- 

 ing, but the factor or factors determining their occurrence are apparently not known 

 and the problem is an exceedingly interesting one. It would seem that some difference 



40 Soil survey of Cortland County. 

 Soil survey of Tompkins County. (1924 ed.) 

 Scil survey of Cayuga County. (In press.) 

 Soil survey of Auburn District. 

 Soil survey of Wayne County. 



