THE RELATION OF SOILS TO NATURAL VEGETATION 
IN ROSCOMMON AND CRAWFORD COUNTIES, 
MICHIGAN.* 
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY. 
LXVI. 
BURTON EDWARD LIVINGSTON, 
(WITH MAP) 
In a study? of the distribution of vegetation in Kent county, 
Michigan, made by the author several years ago, the tentative con- 
clusion was reached that the controlling factor in the distribution of 
the plant societies on the upland is the amount of water in the soil, 
and that this in turn is determined by two conditions, the nearness 
of the underground water level to the surface and the water-retaining 
or capillary power of the surface layers. This last factor is dependent 
largely upon the size of the soil particles. It was thought well to 
continue this subject farther north, using the same methods. Accord- 
ingly in the summer of 1902 the work here reported was accomplished. 
It covers nearly all of Roscommon county and the southern half of 
Crawford county. 
TOPOGRAPHY AND SOILS. } 
The region consists of a series of ridges and depressions. The 
former are sometimes several miles wide but more often narrow; 
they are always comparatively low, seldom rising more than 50 to 
| oat above the level of Higgins Lake, which lies in the middle of the 
t Published by permission of the U. S. Bureau of Forestry and of the Michigan ae 
Board of Geological Survey. A more detailed account of the investigations here 
t, 
conditions in this region has been published in the Report of the Michigan Forestry 
Commission, 1902. 
2 LIvINGsTON, B. E., The distribution of the plant societies of Kent —— 
Mich. : 81 oe | 
