Correlation between the RS rate and temperature.

With the continuous development of urbanization, nitrogen deposition has affected the regeneration capacity of urban forest soil. This study focused on Quercus acutissima Carruth forest in a southern city Hefei in China. The effects of different nitrogen addition rates on both the soil respiration rate and the soil properties of urban forests were studied. In addition, the effects of seasonal changes on soil respiration were also analyzed. The experimental results showed that low nitrogen addition rate (5 g·m-2·yr-1) increased soil respiration rate by about 11% in summer, but decreased it by about 6% in winter, with a range of 5% to 20%. High nitrogen addition (15 g·m-2·yr-1) significantly increased soil temperature by about 12% in summer (p p -2·s-1 in summer and 0.51 ± 0.07 μmol m-2·s-1 in winter. The results indicated that the high nitrogen addition had a significant effect on soil respiration rate, which increased in summer and decreased in winter. Soil moisture content and temperature had significant effects on soil respiration rate, especially in the suburban test site. Nitrogen addition significantly increased soil total nitrogen and nitrate nitrogen contents (p随着城市化进程的持续推进，氮沉降已对城市森林土壤的再生能力造成影响。本研究以中国南方城市合肥的麻栎（Quercus acutissima Carruth）林为研究对象，探究了不同氮添加速率对城市森林土壤呼吸速率及土壤理化性质的影响。此外，本研究还分析了季节变化对土壤呼吸的影响。实验结果表明，低氮添加组（添加速率为5 g·m⁻²·yr⁻¹）可使夏季土壤呼吸速率提升约11%，但会使冬季土壤呼吸速率降低约6%，波动幅度介于5%至20%之间。高氮添加组（添加速率为15 g·m⁻²·yr⁻¹）可使夏季土壤温度显著升高约12%（p < 0.05），夏季土壤呼吸速率为1.82 ± 0.10 μmol·m⁻²·s⁻¹，冬季为0.51 ± 0.07 μmol·m⁻²·s⁻¹。研究结果表明，高氮添加对土壤呼吸速率具有显著影响，夏季呼吸速率升高，冬季则降低。土壤含水量与温度对土壤呼吸速率具有显著影响，这一效应在城郊试验样地中尤为明显。氮添加可显著提升土壤总氮与硝态氮含量（p