2024-03-28T19:20:06Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/811092022-11-17T02:08:08Zhdl_2115_20046hdl_2115_138Nitrogen loading increases the ozone sensitivity of larch seedlings with higher sensitivity to nitrogen loadingSugai, Tetsuto1000060360939Watanabe, ToshihiroKita, Kazuhito1000010270919Koike, Takayoshiopen access© 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 InternationalOzone sensitivityNitrogen loadingInterspecific differenceHybrid larch F₁Larix kaempferiNitrogen phosphorus ratio470Larch (Larix sp.) tree is a critical species for the future afforestation in Northeast Asia. The impacts of elevated concentrations of ground-level ozone (O₃) and nitrogen (N) deposition are raising concerns. However, knowledge of the combined effects of elevated O₃ and N loading are still limited. We investigated whether nitrogen loading mitigates the negative impacts of ozone on two larch species: the Japanese larch (L. kaempferi) and its hybrid larch F₁ (L. gmelinii var. japonica x L. kaempferi) or not. We used open-top cambers and compared responses of the larch seedlings. Results showed the N loading mitigated the negative effects of O₃ on Japanese larch. However, in hybrid larch F₁, N loading did not mitigate O₃-induced inhibition of growth and photosynthetic capacity. Mitigation effect of N loading on negative O₃ impacts may vary between the two Larix spp., Hybrid larch F₁ could be more affected by the combined effects of O₃ and N loading due to its higher growth response to N loading. Elevated O₃ also reduced leaf nitrogen/phosphorus (N/P) ratio by elevated O₃, with significant effects in hybrid larch F₁, particularly under N loading. In the present study, leaf N/P ratio was utilized to validate the hypothesis that a positive effect of N loading may be observed if O₃ does not induce P limitation in Larix spp. We demonstrated a potential leaf N/P ratio function, which could reflect responses to O₃ and N loading in hybrid larch F₁.Elsevier2019-05-01engjournal articleAMhttp://hdl.handle.net/2115/81109https://doi.org/10.1016/j.scitotenv.2019.01.292307267670048-96971879-1026AA00836666Science of the total environment663587595https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/81109/1/STOTEN%20for%20HUSCAP.pdfapplication/pdf1.2 MB2019-05-01