FOREST SURVEYS ON MICHIGAN STATE FORESTS 571 



(2) in the determination of the best species of trees to be planted on 

 the various areas which require planting. The latter at present is the 

 principal need of the site maps. As a result, the land is divided into 

 its sites in relation to the trees which grow best on the sites. 



The entire region is first divided into two classes — swamp and up- 

 land. These two classes, as a rule, are distinct and easily determined. 

 The swamp is not further subdivided at present. The upland, however, 

 is subdivided into four sites, as follows : White-pine land, or site I ; 

 Norway white-pine land, or site II ; Norway pine land, or site III, and 

 jack-pine land, or site IV. To these four sites all upland areas capable 

 of supporting merchantable tree growth are referenced. 



Although the presence of these four sites in the region is plainly 

 evident after some travel and investigation, the location of their actual 

 boundaries is not easy of determination when working along the strip 

 survey line. The methods usually advocated for the determination of 

 the boundaries of the sites cannot be well used here. The use of the 

 height growth of the trees as the only criterion of site is out of the 

 question, since most of the trees are but sprout hardwoods, seldom over 

 30 feet high and not entirely representative. Soil samples cannot be 

 painstakingly collected during a strip survey, owing to lack of time ; so 

 the site cannot be determined by the mechanical or chemical characters 

 of the soil.^ The composition of the vegetation is to a certain extent a 

 criterion of the site, but determinations of value, it is thought, cannot 

 in this region be based upon it alone.- The use of the volume of the 

 stand is practically out of the question ; not only are the trees too young 

 and small, but the stands are too ragged and disorderly to serve as site 

 determinants. 



Sites are determined not by any one of the methods advocated, but 

 by a combination of all. The compassman mentally judges as to the 

 quality of the soil from observation of it at various places along the 

 strip, looks at the tree heights and rate of growth, notices the compo- 

 sition of the flora on the area, thinks of the topography, and by his own 

 good judgment decides as to the quality of the site for the growth of 

 jack pine, Norway pine, or white pine. 



Crude as may appear to be this method of site determination, it was 

 decided upon after considering the following features of the case: 



* Kenety, W. H. : Preliminary Study of White Spruce in Minnesota. Univ. of 

 Minnesota Agric. Exp. Sta., Bull. 168, June, 1917. 



' Korstian, Clarence F. : The Indicator Significance of Native Vegetation in 

 the Determination of Forest Sites. Plant World, Vol. XX, No. 9, Sept., 1917, 

 pp. 267-287, and Journal of Forestry, Vol. XVI, p. 107. 



