Interception and Stemflow in a Pine Plantation

The amount of precipitation reaching the ground under a canopy of vegetation is quite different from the amount recorded in rain-gages in standard exposures in the open. The difference results from interception by the crowns corrected for the amount that flows down the stems. For some purposes, interception is combined with evaporation and transpiration as the total loss of water not recoverable for use. When, however, as is frequently the case, a comparison of run-off or infiltration is to be made between areas with and without or of different vegetative covers, it is essential to know how much of the precipitation reaches the ground as a basis for the comparison. Furthermore, if it is desirable to know the interception, it becomes necessary to measure it with a sufficient number and adequate type of gages so that variations may be evaluated and a representative average figure obtained for an area of land as a whole. The attempt has been made in the following article to analyse the variations of interception and stemflow in relation to characteristics of stand and trees, and to apply the results to specific land areas.