Acclimation of Biogenic Volatile Organic Compound Emission From Subarctic Heath Under Long‐Term Moderate Warming

Abstract

Biogenic volatile organic compound (BVOC) emissions from subarctic ecosystems have shown to increase drastically in response to a long‐term temperature increase of only 2°C. We assessed whether this increase takes place already after 3 years of warming and how the increase changes over time. To test this, we measured BVOC emissions and CO2 fluxes in a field experiment on a subarctic wet heath, where ecosystem plots were subjected to passive warming by open top chambers for 3 (OTC3) or 13 years (OTC13) or were kept as unmanipulated controls. Already after 3 years of moderate temperature increase of 1–2°C, warming increased the emissions of isoprene (five‐ to sixfold) and monoterpenes (three‐ to fourfold) from the subarctic heath. The several‐fold higher BVOC emissions in the warmed plots are likely a result of increased vegetation biomass and altered vegetation composition as a shift in the species coverage was observed already after 3 years of warming. Warming also increased gross ecosystem production and ecosystem respiration, but the increases were much lower than those for BVOCs. Our results demonstrate that the strong BVOC responses to warming already appeared after 3 years, and the BVOC and CO2 fluxes had acclimated to this warming after 3 years, showing no differences with another 10 years of warming. This finding has important implications for predicting CO2 and BVOC fluxes in subarctic ecosystems.

Volatile organic compound emission in tundra shrubs – Dependence on species characteristics and the near-surface environment

“…Increased air temperature was recently coupled to high VPD and increased terpenoid emission in an evergreen tree species ( Duan et al, 2019 ). Furthermore, high air temperature and water deficit have been observed in earlier studies to strongly stimulate VOC emission of tundra plants ( Kramshøj et al, 2016 ; Lindwall et al, 2016 ; Tang et al, 2018 ).…”

Plant volatiles as cues and signals in plant communication

“…(Cofer, Engelberth, & Engelberth, 2018;Landi et al, 2020). Frequent changes in abiotic conditions provide an important source of variability in plant communication at the community level, as they can trigger plant adaption responses and induce changes in the emission of volatiles (Tang, Valolahti, Kivimäenpää, Michelsen, & Rinnan, 2018) ( Figure 2E-H). In response to cold stress, tea plants release nerolidol, which is absorbed and converted into glucoside and, consequently, improves cold stress tolerance (Figure 2E).…”

“…Volatiles can play multifunctional roles as they have shown in their capacity to affect neighbouring plants and prime them against herbivore attack and abiotic stressors, to promote earlier flowering and to increase reproductive success under stressful situations (Cofer, Engelberth, & Engelberth, 2018; Landi et al, 2020). Frequent changes in abiotic conditions provide an important source of variability in plant communication at the community level, as they can trigger plant adaption responses and induce changes in the emission of volatiles (Tang, Valolahti, Kivimäenpää, Michelsen, & Rinnan, 2018) (Figure 2E–H). In response to cold stress, tea plants release nerolidol, which is absorbed and converted into glucoside and, consequently, improves cold stress tolerance (Zhao, Zhang, et al, 2020) (Figure 2E).…”

Amplification of plant volatile defence against insect herbivory in a warming Arctic tundra

“…Arctic ecosystems have been warming by approximately 1°C per decade for the past 30 years with future temperatures predicted to increase at twice the rate of the global average11. Recent studies suggest that this rapid warming, and the associated changes in vegetation composition and biomass, are transforming the naturally low-emitting Arctic ecosystems to a stronger VOC source3,12–14. For example, warming by only 2-4°C was found to increase biogenic VOC emissions several fold3,14.…”

“…Recent studies suggest that this rapid warming, and the associated changes in vegetation composition and biomass, are transforming the naturally low-emitting Arctic ecosystems to a stronger VOC source3,12–14. For example, warming by only 2-4°C was found to increase biogenic VOC emissions several fold3,14. However, the impacts of biotic factors, such as insect herbivory, are not well studied.…”