Yang Yun-Yun, Yan Bin, Xu Qin-Qin, Qin Chu-Qiao, Hu Ya-Lin
Forest Ecology & Stable Isotope Center, College of Juncao Science and Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Ying Yong Sheng Tai Xue Bao. 2025 Feb 18;36(2):461-472. doi: 10.13287/j.1001-9332.202502.007.
Insect herbivory can influence tree growth, community structure and ecological processes in forest ecosystems. We investigated the effects of insect herbivory and leaf defoliation on the emission of biogenic volatile organic compounds (BVOCs), isoprene (ISO) and monoterpenes (MTs) in (broad-leaf tree) and (coniferous tree), and explored the underlying mechanisms by measuring leaf phy-siological characteristics such as photosynthetic parameters and chlorophyll fluorescence. The results showed that insect herbivory and leaf defoliation increased the emission of BVOCs from the leaves of both species compared to the control. Three days after the completion of insect herbivory treatment, the emission flux of ISO in and increased by 4.9 and 3.1 times, respectively, while leaf defoliation increased the ISO emission flux of by 4.6 times. Insect herbivory increased photosynthetic rate, stomatal conductance, intercellular CO concentration, and transpiration rate in , but did not affect the photosynthetic parameters of . In contrast, leaf defoliation significantly reduced chlorophyll fluorescence parameters in . The Pearson correlation analysis and structural equation modeling showed that the emission of ISO and MTs from leaves significantly correlated with photosynthetic and chlorophyll fluorescence parameters. Compared to chlorophyll fluorescence parameters, photosynthetic parameters had a greater influence on the emission of ISO and MTs. For , ISO emission was significantly correlated with chlorophyll fluorescence parameters, and chemical induction due to insect herbivory having a more pronounced effect on ISO emission. In conclusion, our results indicated that insect herbivory could enhance the emission of BVOCs, but the response mechanism varied with tree species. For , the increase in BVOC emission was due to the enhanced photosynthetic rates. The chemical induction resulting from insect herbivory played a more important role in increasing BVOC release from .
昆虫取食会影响森林生态系统中树木的生长、群落结构和生态过程。我们研究了昆虫取食和叶片落叶对阔叶树和针叶树中生物源挥发性有机化合物（BVOCs）、异戊二烯（ISO）和单萜（MTs）排放的影响，并通过测量叶片生理特征（如光合参数和叶绿素荧光）来探究其潜在机制。结果表明，与对照相比，昆虫取食和叶片落叶增加了两个树种叶片中BVOCs的排放。昆虫取食处理完成三天后，阔叶树和针叶树中ISO的排放通量分别增加了4.9倍和3.1倍，而叶片落叶使阔叶树中ISO排放通量增加了4.6倍。昆虫取食增加了阔叶树的光合速率、气孔导度、细胞间CO浓度和蒸腾速率，但对针叶树的光合参数没有影响。相反，叶片落叶显著降低了针叶树的叶绿素荧光参数。Pearson相关分析和结构方程模型表明，阔叶树叶片中ISO和MTs的排放与光合和叶绿素荧光参数显著相关。与叶绿素荧光参数相比，光合参数对ISO和MTs的排放影响更大。对于针叶树，ISO排放与叶绿素荧光参数显著相关，昆虫取食引起的化学诱导对ISO排放的影响更为显著。总之，我们的结果表明昆虫取食可以增强BVOCs的排放，但响应机制因树种而异。对于阔叶树，BVOC排放增加是由于光合速率提高。昆虫取食引起的化学诱导在增加针叶树BVOC释放方面发挥了更重要的作用。
