Influence of clearing ponderosa pine on timing of snowmelt runoff

A 184-ha ponderosa pine forest basin in north-central Arizona was cleared and nonmerchantable material was piled into windrows. Analyses reveal that concentrated runoff during snowmelt periods is extended over a longer period of time following the clearing treatment. There is also a shift in streamflow so that the concentrated snowmelt runoff occurs earlier in the season. These results indicate that the average rate of concentrated runoff during snowmelt is more rapid under forested stands than under open conditions, because the runoff from forested areas, although reduced in quantity, is more concentrated in time. The desynchronization of runoff between forested and open areas could possibly be used to reduce potential spring flood hazard from these headland watersheds.