Dry season water uptake by two dominant canopy tree species in a tropical seasonal rainforest of Xishuangbanna, SW China
Dry season water uptake by two dominant canopy tree species in a tropical seasonal rainforest of Xishuangbanna, SW China
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西双版纳热带季节性雨林中两种主要冠层树种的旱季吸水量
DOI：
10.1016/j.agrformet.2009.12.006
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发表时间：
2010-03
影响因子：
6.2
通讯作者：
li pengju
中科院分区：
文献类型：
--
作者：
liu wen jie;liu wenyao;li hongmei;duan wenping;li pengju
辐射雾被认为是西双版纳热带季节性雨林在每年6个月干旱期间的重要水分来源，但其对栖息在该生态系统中的植物的重要性却几乎未知。研究了西双版纳两种主要季节性雨林冠层树种在2005年和2006年连续两个旱季的水分吸收模式。分析了木质部、土壤、雾、雨和地下水中水分的稳定氧同位素组成，同时测定了土壤含水量和叶片水势，以确定在明显的旱季，成熟树木从浅层土壤中获取水分和幼苗从雾中获取水分的比例。研究结果表明，常绿沙杉主要从土壤剖面的上50cm处获取水分，约有53 ~ 72%的水分来自浅层土壤。相比之下，短落叶柚子树似乎主要从深度大于60厘米或地下水中取水，大约28-46%的水来自浅层土壤，这表明它主要依赖其深层主根吸收水分。在雾最频繁的旱季，毛毛小毛杨幼苗所利用的水分有23-59%来自于叶片滴入土壤的雾水，说明雾水是幼苗生长的重要水源，尤其是在旱季高峰期。由于幼苗和浅根林下物种都需要潮湿和凉爽的条件来再生，因此可以预期其他一些树木幼苗和林下物种在明显的旱季也部分依赖于雾湿度，但需要进一步的研究。
Radiation fog has been suggested as an important source of moisture in tropical seasonal rainforest of Xishuangbanna during 6 months of annual drought, yet its importance for the plants which inhabit this ecosystem is virtually unknown. We assessed patterns of water uptake by two major seasonal rainforest canopy tree species in Xishuangbanna, SW China, during two consecutive dry seasons (2005 and 2006). Stable oxygen isotope compositions of water in xylem, soil, fog, rain, and groundwater were analyzed, and soil water content and leaf water potential were measured concurrently in order to determine the proportion of water deriving from shallow soil by mature trees and from fog water by seedlings during the pronounced dry season. Our results indicated that evergreen Gironniera subaequalis tree appeared to be acquiring water preferentially from the upper 50cm of the soil profile, with around 53–72% of its water from shallow soil. In contrast, brevi-deciduous Pometia tomentosa tree seemed to be tapping water mostly from depths greater than 60cm or from groundwater, with about 28–46% of its water from shallow soil, suggesting that it relies predominantly on its deep taproot for water uptake. During the dry season, when fog was most frequent, 23–59% of the water used by P. tomentosa seedling came from fog water after it had dripped from tree foliage into the soil, indicating that fog water was an important source for seedling growth, especially at the peak of the dry season. Since both seedlings and shallow-rooted understory species require moisture and cool conditions to regenerate, it might be expected that some other tree seedlings and understory species also partially rely on fog moisture during the pronounced dry season, but further research is needed.
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影响因子：
1.7
作者：
Yang Yu;J. Baskin;C. Baskin;Yong Tang;M. Cao
通讯作者：
Yang Yu;J. Baskin;C. Baskin;Yong Tang;M. Cao
影响因子：
4
作者：
A. Ritter;C. Regalado;G. Aschan
通讯作者：
A. Ritter;C. Regalado;G. Aschan
影响因子：
2.7
作者：
Paula C. Jackson;J. Cavelier;Guillermo Goldstein;F. Meinzer;N. Holbrook
通讯作者：
Paula C. Jackson;J. Cavelier;Guillermo Goldstein;F. Meinzer;N. Holbrook
影响因子：
12.8
作者：
W. Liu;Yi -Ping Zhang;H. Li;Yu Hong Liu
通讯作者：
W. Liu;Yi -Ping Zhang;H. Li;Yu Hong Liu
影响因子：
6.4
作者：
Borchert, R;Meyer, SA;Porter-Bolland, L
通讯作者：
Porter-Bolland, L