Data presented in this paper were obtained during a five year study by the U.S. Forest Service (Ringger, 1972). This study, done in a hardwood stand in Forest County, Wisconsin sought to determine the effect of opening size upon temperature and moisture. Stations were chosen under a complete forest canopy and in openings ranging from single tree size to those large enough to behave as open fields. Hygrothermographs provided continuous records of temperature and humidity.
Ringger, D. and F. Stearns. 1972. Influence of forest openings on climate. Field Station Bulletin 5(2): 8-12.