• 研究报告 •

氮沉降对北亚热带麻栎林土壤呼吸及其温湿度敏感性的影响

1. (1安徽农业大学林学与园林学院， 合肥 230036； 2南京林业大学生物与环境学院， 南京 210037)
• 出版日期:2021-04-10 发布日期:2021-04-12

Effects of nitrogen deposition on soil respiration and its sensitivity to temperature and humidity in a Quercus acutissima forest in northern subtropics.

YU Jing-song1, FU Ruo-xian1, YU Yuan-chun2, LI Chun-tao1, TAO Xiao1*#br#

1. (1College of Forestry and Landscape Architecture, Anhui Agricultural University, Hefei 230036, China; 2College of Biology and Environment, Nanjing Forestry University, Nanjing 210037, China).
• Online:2021-04-10 Published:2021-04-12

Abstract: In recent years, emissions of nitrogenous compounds have increased rapidly, which would continue with population growth and urbanization. Such nitrogen falls into forest ecosystems in the form of deposition, with profound impacts on forest soil carbon fluxes. Nitrogen deposition becomes an important factor affecting forest soil respiration. In this study, a nitrogen deposition simulation experiment was carried out in a Quercus acutissima natural forest in Wanfo Mountain, Anhui Province to explore the shortterm impacts of nitrogen addition on soil respiration and components and their sensitivity to temperature and humidity. The soil respiration rate, soil temperature and moisture were measured by LI-8100. Soil respiration and its components had obvious seasonal variations under all the treatments of N0 (control), N1 (low N) and N2 (high N). Both N1 and N2 treatments slightly increased total soil respiration and its components, but without statistical significance (P<0.05). The average annual total soil respiration rates of N0, N1, and N2 treatments were 2.03, 2.17 and 2.13 μmol·m-2·s-1, with 6.90% and 4.93% higher in N1 and N2 treatments than in N0 treatment, respectively. There was a significant exponential relationship between soil respiration and soil temperature (P<0.001). The Q10 values of the total soil respiration under N0, N1 and N2 treatments were 2.04, 1.99 and 2.10, respectively. N1 treatment increased the Q10 of the autotrophic respiration but decreased the Q10 of the heterotrophic respiration. N2 treatment increased the Q10 of each component of soil respiration. There was a significant correlation between soil moisture and soil respiration (P<0.05), with the R2 value of its correlation being smaller than that between soil temperature and soil respiration. The composite model of soil respiration with soil temperature and soil moisture performed better than the singlefactor models. Our findings provide a new way to predict the changes of soil respiration and its components under the increasing nitrogen deposition scenarios.