14 University of Michigan 



let from Thousand Island Lake a large beaver house is located. 



Sphagniiin hog habitat: In a restricted sense the name is 

 here applied to the part of a bog- which is free from trees. It 

 differs from the leather leaf bog in having a greater amount 

 of sphagnum, for while the leather leaf bog when first devel- 

 oped over the water has little or no sphagnum, the sphagnum 

 bog, as here considered, is almost entirely covered by sphag- 

 num. The shrubs found in the two situations are apparently 

 identical, except that the leather leaf is less abundant. A small 

 bog of this type borders the edge of Mud Lake in the Cisco 

 Lake Region, and small parts of many bogs are free from 

 trees. So far as was determined, the mammal fauna is the 

 "same as that for the black spruce — tamarack bog, from which 

 the only difference is the absence of trees. 



Black Spruce — Tamarack Bog habitat: The dominant bog 

 tree in this region is the black spruce (Picca mariana), which 

 is usually small and stunted. With the black spruces are a 

 lesser number of small tamaracks (Larix hrrcina), which in 

 places may be dominant. The ground is heavily covered with 

 sphagnum, which is normally soaked with water. Shrubs are 

 abundant, though usually not forming a closed mat. Of the 

 shrubs the leather leaf is the most abundant, though Kalmia. 

 Andromeda, Ledum, and blueberries are common. A few 

 young white pines and red maples were noted. Sedges occur 

 frequentl}', and the pitcher plant is very characteristic. 



Forests 



Hemlock forest habitat: In the Cisco Lake Region groves 

 of hemlock (Tsuga canadensis) frequently occupy the lower 

 parts of steep slopes adjoining the lakes. One such area studied 

 is made up of practically a pure stand of hemlocks, the trunks 

 being from about 6 to i8 inches in diameter. A few verv old 

 yellow birches are present, and also a few young sugar maples 



