Spatial Variability of Throughfall in a Larch (<i>Larix gmelinii</i>) Forest in Great Kingan Mountain, Northeastern China

Abstract

Larix gmelinii forest is one of the dominant forest types in boreal forest and plays a unique eco-hydrological role in the terrestrial ecosystem. However, the throughfall variability in boreal forest ecosystems, which plays a crucial role in regulating hydrology, remains unclear. Here, we investigated the spatial variability and temporal stability of throughfall within a Larix gmelinii forest in the full leaf stage in Great Kingan Mountain, Northeast China, and the effects of rainfall properties and canopy structure on throughfall variability were systematically evaluated. The results indicate that throughfall represented 81.26% of the gross rainfall in the forest. The throughfall CV (coefficient of variation of throughfall) had a significant and negative correlation with the rainfall amount, rainfall intensity, rainfall duration, and distance from the nearest trunk, whereas it increased with increasing canopy thickness and LAI (leaf area index). The correlation analysis suggested that the throughfall variability was mainly affected by the rainfall amount (R2 = 0.7714) and canopy thickness (R2 = 0.7087). The temporal stability analysis indicated that the spatial distribution of the throughfall was temporally stable. Our findings will facilitate a better understanding of the spatiotemporal heterogeneity of throughfall and help the accurate assessment of throughfall and soil water within boreal forests.

Keywords

• boreal forest
• throughfall variability
• temporal stability
• rainfall properties
• canopy structure
• full leaf stage