442 Karl M. Wiegand and Arthur J. Eames 



in the soil must be the determining factor, as other environmental factors sometimes 

 are uniform over both types of forest or sometimes seem to fluctuate without 

 reference to them. 



On the lower-level plateau north of Ithaca the soils are more diversified, being 

 derived from drift of differing compositions or from lake sediments. The drift in 

 the region from Union Springs southward to Ludlowville is rather clearly calca- 

 reous, as is much of that up the Fall Creek valley about Freeville and McLean, and 

 to some extent that on the west side of the lake. In the Freeville region the assorted 

 drift is calcareous while the unassorted drift generally is noncalcareous or of 

 neutral reaction. The soils on this plateau are often poorly drained, and swamps 

 and bogs have formed in the pockets. In general these soils support a maple-birch- 

 beech forest, but where the drainage is poor the forest contains much red and silver 

 maple, elm, basswood, and hickory, with some white oak and sour gum. Tulip and 

 cucumber trees are scattered over the region. The undergrowth includes much 

 Cornus (chiefly C. candidissima) and Rubus, and many spring humus plants. Soils 

 transitional to those of the higher plateau are found over considerable areas along 

 the Fall Creek valley. A part of the lower plateau is covered with a sedimentary 

 soil of lake origin, since in the still water of ponds and lakes around the margins of 

 the glaciers a fine sediment was deposited which now forms extensive clay and clay- 

 loam deposits over large tracts. These heavy clay soils are best developed along 

 the east side of Cayuga Lake from Myers southward, in an area which is narrow 

 at the north but broadens markedly at the latitude of Ithaca. Most of the college 

 farm is included, and the area extends east to a point beyond Varna, up the bottom 

 of Six Mile Creek valley north of Brookton, and up the northeast flank of South 

 Hill. Extensive areas of such soils occur also on the west side of the lake and in 

 the Inlet Valley to West Danby or beyond. Other small areas are found near New- 

 field, Waterburg, Danby, and Freeville, and on the Ontario plain. The forest on 

 this heavy soil contains much white and red oak, hickory, and American elm, and 

 some basswood. Some herbaceous plants, as Aster paniculatus and Solidago can- 

 adensis, var. Hargeri, seem to be confined to this soil and may prove to be good clay 

 indicators. However, a definite study of the flora of the clay soils has not yet been 

 made. 



From the region of Esty northward there is an outcrop of limestone along the lake 

 cliffs and in the ravines on both sides of the lake. This gives rise to intermittent 

 areas of limestone cliffs and talus which support many calcicolous plants. The lime- 

 stone strata outcrop also here and there in a zone from Union Springs eastward. 

 Over this latter area the rocks were scoured off by the glacier, and probably were 

 an important source of the lime element in the glacial soils immediately to the south- 

 ward. In this scoured region the effect of the limestone on the vegetation is not so 

 marked as is that of the lime brought out in solution in the various marl springs of 

 the basin. 



Not all of the soil along the lake shore northward is limy talus, however. A not 

 inconsiderable amount of clay soil is found, while north of Aurora there is a curious 

 mixture of light and heavy soil with sandy points jutting into the lake. Due to some 

 factor not yet understood, these soils support a very interesting assemblage of rare 

 plants especially in the region from Aurora to Cayuga. On the crests of the lake 

 cliffs, but more especially on the crests of the ravine banks either about Ithaca or 

 northward, any lime that was originally in the soil has generally leached out, and 

 the soil has become acid and supports the chestnut-vaccinium type of vegetation. 



The section of the Ontario plain from Union Springs and Ovid to Cayuga seems 

 to have been, in part at least, a glacial basin or drainage area, and is covered with 

 alternating areas of sedimentary clays and lighter gravelly soils all of which are 

 generally calcareous. Farther north, where the drumlins occur, the soil is generally 

 of the lighter type and calcareous, though no distinctly sandy areas are found except 

 in the vicinity of Junius. In the last-named region, however, the soil is very sandy, 



