Analysis of an Alpine Environment

If plant physiological approaches are to be applied to the solution of ecological problems, it is essential that the field environment and the response of plants to it be described and understood, even to the level of the microenvironment surrounding the responding constituents of the cell. We have studied the environment of the alpine zone on the northern border of Rocky Mountain National Park since 1960, and results of these studies are summarized here. The approach attempts to emphasize the time factor, considering the periods and amplitudes of cyclical changes in environmental parameters at four levels of cycle lengths: short cycles (seconds to hours), diurnal cycles, secular cycles (several days), and annual cycles. In addition to this analysis of change, the usual averages must also be considered in any environmental description. Light intensity, measured continuously with a pyrheliograph, was analyzed primarily from the standpoint of total daily incoming radiation and number of fluctuations (due to...