热带雨林树木的叶子温度调节
Kali B Middleby1,2, Rebecca Jordan3, Alexander W Cheesman1,4
1College of Science and Engineering and Centre for Tropical Environmental and Sustainability Science, James Cook University, Cairns, Queensland, Australia.
Global change biology
|September 4, 2025
概括
热带树木对气候变暖的反应各不相同. 有些物种使用叶子的特征来避免热伤害, 提供气候变化缓冲,
科学领域:
- 生态学
- 植物生理学
- 气候变化生物学
背景情况:
- 热带森林对全球生物多样性和气候调节至关重要,
- 由于表型变化,物种对温度上升的脆弱性可能有所不同,这会影响它们的生存能力.
- 有限的恒温,叶子的特征有助于避免热损伤,是一个潜在的策略,但证据和适应与适应的作用很少.
研究的目的:
- 在热梯度的三个雨林树种中调查叶子特征变化,光合作用热耐受性和热安全边缘.
- 评估有限的同热能力,并区分适应和适应性分歧.
- 识别与气候变量相关的基因组选择信号,并通过受控实验验证结果.
主要方法:
- 在自然温度梯度中测量了树叶的热特性和光合作用耐热性.
- 使用叶子能量平衡模型预测叶子与空气的温度差异 (∆T特征) 和热安全边缘.
- 利用基于个体的全基因组数据来检测适应差异,并进行温室试验来测试适应反应.
主要成果:
- 在三种物种中,两种物种的物种内特征变化减少了∆T特征并提高了热耐受性,这表明有效的缓冲.
- 对于耐热和避热能力较强的物种, 随着温度的增加, 热安全边缘的下降较小.
- 在所有物种中,基因组分析显示了与温度和湿度相关的选择信号,在一种物种中进行了实验验证.
结论:
- 有限的同热性是显而易见的,气候梯度驱动特征组合的选择,降低了适应更温暖的人群的叶子温度.
- 适应可以调整个体特征,但它们的协调反应在不同的条件下保持特定的∆T特征.
- 缺乏强大的适应或适应策略以调整热安全边缘的物种在快速变化的气候中面临更高的灭绝风险.
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