Influence of rainfall factors and tree structure on rainfall partitioning for typical trees in Linpan settlements, the typical agroforestry ecosystem of the Chengdu Plain

Abstract

Study RegionThis study was conducted in the typical agroforestry ecosystem named Linpan settlements (or simply Linpan) in the Chengdu Plain, located in southwestern China. Study FocusThe aims of this study were: (1) monitoring the seasonal variability in rainfall partitioning for tree plots in Linpan comprised of seven evergreen and four deciduous tree species from April 2018 to April 2019; (2) evaluating the effect of rainfall factors and Linpan tree structure on throughfall (TF), stemflow (SF), and canopy interception (I). New Hydrological Insights for the RegionOnly a few studies have focused on the rainfall partitioning of trees in agroforestry ecosystems. Our results confirm that the mean TF, SF, and I values of Linpan trees, accounted for 57.4 %, 14.3 %, and 28.3 % of the total rainfall volume, respectively. Evergreen trees showed a lower TF% (56.51 %) than that of deciduous trees (59.16 %), but a slightly higher SF% (14.28 %) and I% (29.21 %) than those of deciduous trees (14.21 % and 26.64 %, respectively). The values of TF, SF, and I were very significantly associated with both gross precipitation (GP) and rainfall intensity. However, evergreen trees TF% was only significantly associated with GP, while evergreen trees SF% was only correlated with rainfall intensity. I% values of evergreen trees and deciduous trees exhibited negative non-linear correlations (p ≤ 0.05) with rainfall intensity and GP, respectively. Only SF and SF% were significantly negatively correlated with tree structure. DBH and tree height had opposite effects on SF. Both LAI and tree height showed a negative relationship with SF% of Linpan trees. These results have the potential to inform better regulation of runoff and maintaining a sustainable hydrological cycle of agroforestry ecosystem in the Chengdu Plain.