Open Birch -Grassland 





I 



SEP OCT NOV DEC JANFEBMARAPRMflrjUNJiJ. AUG SEP OCT NCV DEE JAN FEB MAR APR 



1968 1969 



40 



KEY 



Microtus oeconomus, M pennsylvonicus 



20 - 



o o Clethrionomys rutilus 



* * Zopus hudsonicus 



Closed Spruce Woods 



Closed Birch Woods 



MAY JUN JUL AUG SEP OCT 

 1970 



Figure 44. Demographic data for three samples sites near Fairbanks, Alaska. 



112 



