Rainfall partitioning in a deciduous forest plot in leafed and leafless periods

Abstract

ABSTRACTIn deciduous forests, it is particularly difficult to understand the factors controlling rainfall partitioning because of the seasonal changes of canopy cover. Moreover, under Mediterranean climate conditions, the marked seasonal variability of rainfall produces highly variable event‐based interception losses making comparison of throughfall, stemflow and interception loss in each season difficult. Rainfall partitioning in a downy oak forest plot located in the Eastern Pyrenees Mountains (NE Spain) was measured over 3 years to study the differences in throughfall, stemflow and interception loss between the leafed and leafless periods and to find out the role of canopy cover and rainfall type in rainfall partitioning. Results show small differences in rainfall partitioning between the leafed and leafless periods, although different rainfall patterns were observed in the two periods, and there were significant changes in canopy cover. Throughfall and stemflow were slightly higher during the leafless period (about 3.6% and 1.7% higher, respectively), and therefore, interception loss was lower (about 5.4% in this period). On an event basis, the leafless period was characterized by lower absolute and relative interception losses than the leafed period. Rainfall was classified in four types by intensity and duration to study the influence of rainfall type on rainfall partitioning in leafed and leafless seasons separately. Rainfall duration was apparently important for all rainfall partitioning components in the leafless period, when stemflow and throughfall were lower and interception loss was enhanced during short events, whereas in the leafed period, no single dominating factor could be found. Copyright © 2011 John Wiley & Sons, Ltd.