From 1999, Chinese government started to make man-made forests to increase natural resources as well as to rehabilitate at degraded crop lands. They chose plantation species as larch and poplar for north regions and ceder for the south. Soil salinization area is estimated to increase due to global warming, especially low precipitation region in the northeastern part of Asia. The distribution of soil salinization in China was wide with many types. Total area is about 99.13 million hectare, accounts for 1.03% of the total land area of China. Due to rapid development of industrialization and urbanization, emissions of ozone (O₃) precursors have been increasing rapidly, which has led to pronounced air pollution of surface O₃.
In this study, we used 2-year-old seedlings of 3 larch species, transplanted in 1-L pot with nutrient poor soil. Seedlings were exposed in open-top chambers (OTCs) for 12hd^-1 for up to 3 months to factorial combination of two levels of salinity (0 and 20 mM NaHCO₃ and NaCl mix solution) and two levels of O₃ (filtered air and 70ppb). We monitored growth and some physiological parameters to elevated O₃, discuss the plausible understanding there eco-physiological function of larch seedlings in relation to future global change.