Height-related changes in leaf photosynthetic traits in diverse Bornean tropical rain forest trees
Height-related changes in leaf photosynthetic traits in diverse Bornean tropical rain forest trees
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DOI：
10.1007/s00442-014-3126-0
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发表时间：
2015-01-01
期刊：
影响因子：
2.7
通讯作者：
Ichie, Tomoaki
中科院分区：
文献类型：
--
作者：
Kenzo, Tanaka;Inoue, Yuta;Ichie, Tomoaki
了解叶子形态生理性状随森林高度的变化对于量化森林生态系统的碳和水通量至关重要。在这里，我们研究了不同树种的叶子性状随森林高度的变化及其在婆罗洲热带雨林中环境适应中的作用，该热带雨林没有经历干旱。对 29 个科 104 个树种从林下到挺水树种的叶片生理和形态特征 [例如最大光合速率 (A (max))、气孔导度 (gs)、暗呼吸速率 (R (d))、碳同位素比 (δ C-13)、氮 (N) 含量和单位面积叶质量 (LMA)] 与高度相关的变化进行了研究。我们发现许多基于叶面积的生理性状（例如，A（最大面积）、R（d）、gs）、N、δ C-13 和 LMA 随树高线性增加，而基于叶质量的生理性状（例如，A（最大质量））仅略有增加。这些模式不同于其他生物群落，例如温带和热带干燥森林，其中树木通常表现出随高度降低的光合能力（例如，A（最大面积）、A（最大质量））。在明亮干燥的上层树冠条件下，光合能力、LMA 和 Delta C-13 的增加有利于光合生产力和耐旱性较高，而较低的 R (d) 和 LMA 可能会提高树冠下部的耐荫性。夜间叶片中午水势迅速恢复至理论重力势支持了大多数树木并未遭受强烈干旱胁迫的观点。总体而言，即使在不同的热带雨林树木中，基于叶面积的光合性状也与树高和叶片干旱胁迫程度相关。
Knowledge of variations in morphophysiological leaf traits with forest height is essential for quantifying carbon and water fluxes from forest ecosystems. Here, we examined changes in leaf traits with forest height in diverse tree species and their role in environmental acclimation in a tropical rain forest in Borneo that does not experience dry spells. Height-related changes in leaf physiological and morphological traits [e.g., maximum photosynthetic rate (A (max)), stomatal conductance (gs), dark respiration rate (R (d)), carbon isotope ratio (delta C-13), nitrogen (N) content, and leaf mass per area (LMA)] from understory to emergent trees were investigated in 104 species in 29 families. We found that many leaf area-based physiological traits (e.g., A (max-area), R (d), gs), N, delta C-13, and LMA increased linearly with tree height, while leaf mass-based physiological traits (e.g., A (max-mass)) only increased slightly. These patterns differed from other biomes such as temperate and tropical dry forests, where trees usually show decreased photosynthetic capacity (e.g., A (max-area), A (max-mass)) with height. Increases in photosynthetic capacity, LMA, and delta C-13 are favored under bright and dry upper canopy conditions with higher photosynthetic productivity and drought tolerance, whereas lower R (d) and LMA may improve shade tolerance in lower canopy trees. Rapid recovery of leaf midday water potential to theoretical gravity potential during the night supports the idea that the majority of trees do not suffer from strong drought stress. Overall, leaf area-based photosynthetic traits were associated with tree height and the degree of leaf drought stress, even in diverse tropical rain forest trees.