Interspecific variation in leaf water use associated with drought tolerance in four emergent dipterocarp species of a tropical rain forest in Borneo
Interspecific variation in leaf water use associated with drought tolerance in four emergent dipterocarp species of a tropical rain forest in Borneo
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DOI：
10.1007/s10310-011-0303-4
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发表时间：
2012-08
影响因子：
1.5
通讯作者：
Toru Hiromi;T. Ichie;T. Kenzo;I. Ninomiya
中科院分区：
文献类型：
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作者：
Toru Hiromi;T. Ichie;T. Kenzo;I. Ninomiya
通过使用树塔和树冠起重机系统，我们研究了马来西亚沙捞越州非季节性热带雨林中四种挺水龙脑香科植物最上面暴露在阳光下的树冠叶子的水分利用变化，包括蒸腾作用、气孔导度和叶水势。在所有研究的物种中都观察到中午气孔导度和叶水势下降。四种龙脑香科植物的蒸腾速率和气孔导度的最大值以及叶水势的最小值均存在明显的种间差异。这些种间差异与木材密度和影响生态分布模式的因素密切相关。具体来说，小叶望天树（Shorea parvifolia）和 S.对于龙脑香科来说，这两种植物的木材密度相对较低，并且生长在富含粘土的土壤上，白天的蒸腾速率较高，但午间气压较大，叶水势较低。相比之下，木材密度高，生长在沙质土壤地区的Dryobalanopsaroca，即使在白天消耗的水也较少。Dipterocarpuspachyphyllus，木材密度高，生长在富含粘土的土壤上，介于望山树和Dryobalanica之间。芳香叶水的使用。在 1998 年与厄尔尼诺现象相关的严重干旱期间，这两种望天树种的死亡率高于其他树种，因此每种龙脑香树种每日叶水利用模式可能与其对异常干旱事件的敏感性相关。
By use of tree-tower and canopy-crane systems we studied variations in the water use, including transpiration, stomatal conductance, and leaf water potential, of the uppermost sun-exposed canopy leaves of four emergent dipterocarp species in an aseasonal tropical rain forest in Sarawak, Malaysia. Midday depression in stomatal conductance and leaf water potential was observed in all the species studied. Interspecific differences were clearly observed in the maxima of transpiration rates and stomatal conductance and the minima of leaf water potential among the four dipterocarp species. These interspecific variations were closely related to wood density and to factors affecting ecological patterns of distribution. Specifically,Shorea parvifoliaandS. smithiana, both of which have a relatively low wood density for Dipterocarpaceae and are found on clay-rich soil, had a high transpiration rate in the daytime but had a large midday depression and a low leaf water potential. In contrast,Dryobalanops aromatica, which has a high wood density and is found in sandy soil areas, consumed less water even during the daytime.Dipterocarpus pachyphyllus, which has a high wood density and is found on clay-rich soil, stood intermediate betweenShoreaandD. aromaticain leaf water use. The twoShoreaspecies had higher mortality than the others during the severe drought associated with El Niño in 1998, so daily pattern of leaf water use in each dipterocarp species might be correlated with its susceptibility to unusual drought events.