Differences in interception storage capacities of undecomposed broad-leaf and needle-leaf litter under simulated rainfall conditions

• Published in: Forest ecology and management Vol. 446; pp. 135 - 142
• Main Authors: Zhao, Longshan, Hou, Rui, Fang, Qian
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.08.2019
• Subjects: Interception storage capacity; Leaf shapes; Litter layer; Runoff; Vegetation cover; Litter layer; Leaf shapes; Vegetation cover; Runoff; Interception storage capacity
• ISSN: 0378-1127; 1872-7042
• DOI: 10.1016/j.foreco.2019.05.043

•Broad-leaf litter intercepted less water than needle-leaf litter on an inclined slope.•Broad-leaf litter provides a short path for rainwater to leave the leaf litter.•A new mechanism of how leaf shapes affect rainwater interception is presented. Leaf litter is an important component of agroforestry ecosystems that plays a key role in soil and water conservation. This study assessed the effect of leaf shape on water interception under controlled laboratory conditions. Two contrasting leaf shapes (needle-leaf, represented by Pinus massoniana; and broad-leaf, represented by Magnolia grandiflora) were placed in a steel box (2 m long and 1 m wide) for separate experiments with different leaf masses per ground area (0.5, 1.0 and 1.5 kg/m2); the steel box was positioned on two different slopes (5° and 20°) corresponding to gentle and steep slopes; the rainfall intensity was 90 mm/h. The results indicated that leaf shapes had specific effects on the interception storage capacity of the leaf litter on a slope. The needle-leaf litter intercepted 2.08 times more rainwater than the broad-leaf litter on average. As the leaf mass increased, the interception storage capacity of the leaf litter successively increased for the needle-leaf litter, while there were no obvious patterns for the broad-leaf litter. This difference occurred because the initially erect broad leaves were easily flattened by raindrop impacts due to their large surface areas and hence formed a horizontal leaf cover (or leaf overlap). This leaf accumulation structure restricted the infiltration of rainwater into the lower leaf litter while providing a short path for rainwater to leave the leaf litter, hence promoting litter flow and leading to less rainwater intercepted by the broad-leaf litter than the needle-leaf litter. Our results provide a better understanding of the effects of leaf shape on leaf litter interception on inclined slopes, which is lacking in the current literature.