| To better understand the response of the photosynthetic characteristics of Chinese Pine (Pinus tabulaeformisCarr.) to elevated nitrogen deposition, we set up a simulated nitrogen deposition experiment in Taiyue Mountiain, Shanxi. Inthis experiment, five treatments were designed, including control (CK), Low N (N1, 15 kg/hm2窑a) , Medium N(N2, 25 kg/hm2窑a),High N(N3, 50 kg/hm2窑a) and Supersaturated N (N4, 150 kg/hm2窑a). The photosynthetic response curves of current-year andone-year conifer needles under different treatments were measured in the mid and late growing seasons. The maximum netphotosynthetic rate (Pmax), apparent quantum yield (AQY), respiratory rate (Rd), light compensation point (LCP) and lightsaturation point (LSP) among different treatments were measured to evaluate the adaptability of Chinese Pine seedlings tothe increase of nitrogen deposition. The results showed that in the mid-growing season, all parameters of photosynthetic response curve in current-year needles were not significantly affected by nitrogen treatments, but the Rd of one-yearneedles was significantly higher under supersaturated nitrogen treatment. The LCP of one-year needles increased underlow, medium and high nitrogen treatments. In the late-growing season, Rd and LCP of current-year needles and one-year needles promoted significantly under supersaturated nitrogen treatment, while other parameters of photosynthetic response curve were not significantly different among treatments. |
