Characteristics of stemflow for tall stewartia (Stewartia monadelpha) growing on a hillslope.
Characteristics of stemflow for tall stewartia (Stewartia monadelpha) growing on a hillslope.
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DOI：
10.1016/j.jhydrol.2009.09.027
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发表时间：
2009-11
影响因子：
6.4
通讯作者：
W. Liang;K. Kosugi;T. Mizuyama
中科院分区：
文献类型：
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作者：
W. Liang;K. Kosugi;T. Mizuyama
在日本中部一处山坡上的高大落叶林中观察到了树干径流的特征，揭示了一种以前未报道的落叶林类型的新发现。利用2a的250次降雨观测，分析了几种树木树干径流的季节和空间变化，并应用穿透雨量和植物面积指数(PAI)的附加数据集来粗略估计单个树木的降雨再分配过程和冠层结构的季节变化。与其他落叶树种相比，高斯瓦特落叶树的穿透雨、树干径流和截留量与空地降雨量的比率随着PAI的变化而发生明显的变化。降雨量、降雨强度、风速、风向等气象条件对树干茎流的产生影响不大，主要受树冠结构变化的影响。在几棵高大的斯瓦蒂亚树上发现了三个新的树干流量特征。首先，与山毛榉和橡树林相比，高山毛榉林分水平的年树干流率(12%)较高，这表明高山毛竹具有相当高的产生大量树干径流的潜力。其次，有叶期的茎流量是无叶期的1.3-2.0倍。树干下坡处的树干径流量是上坡处的12-132倍。这可能是由于树冠上坡和下坡之间的面积不均匀，以及由于树干向下倾斜而导致树干上坡和下坡之间的树干径流不对称造成的。
The characteristics of stemflow were observed in a tall stewartia (Stewartia monadelpha) deciduous forest on a hillslope in central Japan, revealing new findings for a previously unreported type of deciduous forest. Using 2-year observations of 250 rainfall events, we analyzed seasonal and spatial variations in stemflow for several trees, and applied additional data sets of throughfall and plant area index (PAI) to produce a rough estimate of seasonal variations in rainfall redistribution processes and canopy architecture for a single tree. Compared to previous findings for other deciduous tree species, the ratios of throughfall, stemflow, and interception to open-area rainfall obviously varied with PAI changes for tall stewartia. Meteorological conditions of rainfall amount, rainfall intensity, wind speed, and wind direction had little effect on stemflow generation, which was mainly affected by variation in canopy architecture. Three novel characteristics of stemflow were identified for several tall stewartia trees. First, the yearly stemflow ratio at the forest-stand level for tall stewartia (12%) was high compared to previous findings on beech and oak stands, indicating tall stewartia has considerably high potential to generate a great amount of stemflow. Second, stemflow tended to be 1.3–2.0 times greater in the leafed period than in the leafless period. Third, the amount of stemflow was 12–132 times greater on the downslope side of the stem than on the upslope side. It likely caused by the uneven area between the upslope and downslope sides of the canopy and by asymmetrical stemflow pathways between the upslope and downslope sides of the trunk due to downslope tilting of the tree trunk.