Rieksta Jolanta, Li Tao, Davie-Martin Cleo L, Aeppli Laurids Christian Brogaard, Høye Toke Thomas, Rinnan Riikka
Terrestrial Ecology Section, Department of Biology University of Copenhagen Copenhagen Denmark.
Center for Permafrost (CENPERM) Department of Geosciences and Natural Resource Management University of Copenhagen Copenhagen K Denmark.
Plant Environ Interact. 2023 Feb 8;4(1):23-35. doi: 10.1002/pei3.10100. eCollection 2023 Feb.
Plants release a complex blend of volatile organic compounds (VOCs) in response to stressors. VOC emissions vary between contrasting environments and increase with insect herbivory and rising temperatures. However, the joint effects of herbivory and warming on plant VOC emissions are understudied, particularly in high latitudes, which are warming fast and facing increasing herbivore pressure. We assessed the individual and combined effects of chemically mimicked insect herbivory, warming, and elevation on dwarf birch () VOC emissions in high-latitude tundra ecosystems in Narsarsuaq, South Greenland. We hypothesized that VOC emissions and compositions would respond synergistically to warming and herbivory, with the magnitude differing between elevations. Warming increased emissions of green leaf volatiles (GLVs) and isoprene. Herbivory increased the homoterpene, (E)-4,8-dimethyl-1,3,7-nonatriene, emissions, and the response was stronger at high elevation. Warming and herbivory had synergistic effects on GLV emissions. Dwarf birch emitted VOCs at similar rates at both elevations, but the VOC blends differed between elevations. Several herbivory-associated VOC groups did not respond to herbivory. Harsher abiotic conditions at high elevations might not limit VOC emissions from dwarf birch, and high-elevation plants might be better at herbivory defense than assumed. The complexity of VOC responses to experimental warming, elevation, and herbivory are challenging our understanding and predictions of future VOC emissions from dwarf birch-dominated ecosystems.
植物会释放出一种复杂的挥发性有机化合物（VOCs）混合物以应对压力源。VOCs的排放因环境差异而有所不同，并随着昆虫取食和气温升高而增加。然而，取食和气候变暖对植物VOCs排放的联合影响尚未得到充分研究，尤其是在高纬度地区，那里气候变暖迅速且面临着不断增加的食草动物压力。我们评估了化学模拟昆虫取食、气候变暖和海拔高度对格陵兰岛南部纳尔萨克高纬度苔原生态系统中矮桦（）VOCs排放的单独和综合影响。我们假设VOCs的排放和组成会对气候变暖和取食产生协同反应，且不同海拔高度的反应程度有所不同。气候变暖增加了绿叶挥发物（GLVs）和异戊二烯的排放。取食增加了倍半萜烯、（E）-4,8-二甲基-1,3,7-壬三烯的排放，且在高海拔地区反应更强。气候变暖和取食对GLVs排放有协同作用。矮桦在两个海拔高度的VOCs排放速率相似，但不同海拔高度的VOCs混合物有所不同。几个与取食相关的VOCs组对取食没有反应。高海拔地区更恶劣的非生物条件可能不会限制矮桦的VOCs排放，而且高海拔植物在防御取食方面可能比我们想象的更好。VOCs对实验性气候变暖、海拔高度和取食反应的复杂性正在挑战我们对矮桦主导生态系统未来VOCs排放的理解和预测。
