Wang Ai-Ying, Lu Yi-Jun, Cui Han-Xiao, Liu Shen-Si, Li Si-Qi, Hao Guang-You
School of Life Sciences and Engineering, Shenyang University, Shenyang 110044, China.
Liaoning Key Laboratory of Urban Integrated Pest Management and Ecological Security, College of Life Science and Bioengineering, Shenyang University, Shenyang 110044, China.
Plants (Basel). 2024 Dec 21;13(24):3575. doi: 10.3390/plants13243575.
Hydraulic functionality is crucial for tree productivity and stress tolerance. According to the theory of the fast-slow economics spectrum, the adaptive strategies of different tree species diverge along a spectrum defined by coordination and trade-offs of a suite of functional traits. The fast- and slow-growing species are expected to differ in hydraulic efficiency and safety; however, there is still a lack of investigation on the mechanistic association between tree growth rate and tree hydraulic functionality. Here, in a common garden condition, we measured radial growth rate and hydraulic traits in a fast-growing ( L. × Dippel) and a slow-growing tree species ( Bunge), which are both important tree species for afforestation in northern China. In line with the contrasts in radial growth rate and wood anatomical traits at both the tissue and pit levels between the two species, stem hydraulic conductivity of the species was significantly higher than that of the species, but the resistance to drought-induced xylem cavitation was the opposite. A trade-off between hydraulic efficiency and safety was observed across the sampled trees of the two species. Higher water-transport efficiency supports the greater leaf net photosynthetic carbon assimilation capacity of the species and hence facilitates fast growth, while the conservative hydraulic traits of the species result in a slower growth rate but enhanced drought tolerance.
水力功能对于树木生产力和胁迫耐受性至关重要。根据快-慢经济谱理论，不同树种的适应策略沿着由一系列功能性状的协调和权衡所定义的谱线而有所不同。预计速生和慢生树种在水力效率和安全性方面存在差异；然而，对于树木生长速率与树木水力功能之间的机制关联仍缺乏研究。在此，在一个共同园圃条件下，我们测量了速生树种（火炬树）和慢生树种（蒙古栎）的径向生长速率和水力性状，这两种树种都是中国北方造林的重要树种。与这两个树种在组织和纹孔水平上的径向生长速率和木材解剖性状的差异相一致，火炬树的茎水力导度显著高于蒙古栎，但对干旱诱导的木质部空化的抗性则相反。在这两个树种的采样树木中观察到了水力效率和安全性之间的权衡。较高的水分运输效率支持了火炬树更大的叶片净光合碳同化能力，从而促进了快速生长，而蒙古栎保守的水力性状导致生长速率较慢但耐旱性增强。
