| Title: | Effects of elevated ozone and warming on terpenoid emissions and concentrations of Norway spruce depend on needle phenology and age |
| Author(s): | Kivimaenpaa M; Riikonen J; Valolahti H; Elina H; Holopainen JK; Holopainen T; |
| Address: | "Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 1627, Kuopio 70211, Finland. Natural Resources Institute Finland, Suonenjoki 77600, Finland. Ramboll, Niemenkatu 73, Lahti 15140, Finland. South Savo Centre for Economic Development, Transport and the Environment, PO Box 164, Mikkeli 50101, Finland" |
| ISSN/ISBN: | 1758-4469 (Electronic) 0829-318X (Print) 0829-318X (Linking) |
| Abstract: | "Norway spruce (Picea abies (L.) Karst) trees are affected by ongoing climate change, including warming and exposure to phytotoxic levels of ozone. Non-volatile terpenoids and volatile terpenoids (biogenic organic volatile compounds, BVOCs) protect spruce against biotic and abiotic stresses. BVOCs also affect the atmosphere's oxidative capacity. Four-year-old Norway spruce were exposed to elevated ozone (EO) (1.4 x ambient) and warming (1.1 degrees C + ambient air) alone and in combination on an open-field exposure site in Central Finland. Net photosynthesis, needle terpenoid concentrations and BVOC emissions were measured four times during the experiment's second growing season: after bud opening in May, during the mid-growing season in June, and after needle maturation in August and September. Warming increased terpene concentrations in May due to advanced phenology and decreased them at the end of the growing season in matured current-year needles. Ozone enhanced these effects of warming on several compounds. Warming decreased concentrations of oxygenated sesquiterpenes in previous-year needles. Decreased emissions of oxygenated monoterpenes by warming and ozone alone in May were less prominent when ozone and warming were combined. A similar interactive treatment response in isoprene, camphene, tricyclene and alpha-pinene was observed in August when the temperature and ozone concentration was high. The results suggest long-term warming may reduce the terpenoid-based defence capacity of young spruce, but the defence capacity can be increased during the most sensitive growth phase (after bud break), and when high temperatures or ozone concentrations co-occur. Reduced BVOC emissions from young spruce may decrease the atmosphere's oxidative capacity in the warmer future, but the effect of EO may be marginal because less reactive minor compounds are affected" |
| Keywords: | *Ozone/pharmacology Photosynthesis *Picea/physiology Terpenes Trees/physiology Picea abies Face Norway spruce biogenic organic volatile compound (BVOCs) climate change monoterpene needle age needles open-field exposure ozone seasonal changes sesquiterpene; |
| Notes: | "MedlineKivimaenpaa, Minna Riikonen, Johanna Valolahti, Hanna Elina, Haikio Holopainen, Jarmo K Holopainen, Toini eng Research Support, Non-U.S. Gov't Canada 2022/02/20 Tree Physiol. 2022 Aug 6; 42(8):1570-1586. doi: 10.1093/treephys/tpac019" |
