Effects of Nitrogen Additions on Soil Respiration in an Asian Tropical Montane Rainforest

Forests

Hui Wang¹  Zhihao Liu¹  Weiguo Liu¹  Changhui Peng¹  Fangtao Wu¹  Dexiang Chen²  Yide Li² 

[1] Center for Ecological Forecasting and Global Change, College of Forestry, Northwest A&F University, Yangling 712100, China;Jianfengling National Key Field Observation and Research Station for Forest Ecosystem, Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou 510520, China;

关键词: nitrogen addition;    soil respiration;    temperature sensitivity;    tropical forest;   

DOI  :  10.3390/f12060802

来源: DOAJ

【 摘 要 】

Understanding the impacts of nitrogen (N) addition on soil respiration (R_S) and its temperature sensitivity (Q₁₀) in tropical forests is very important for the global carbon cycle in a changing environment. Here, we investigated how R_S respond to N addition in a tropical montane rainforest in Southern China. Four levels of N treatments (0, 25, 50, and 100 kg N ha⁻¹ a⁻¹ as control (CK), low N (N25), moderate N (N50), and high N (N100), respectively) were established in September 2010. Based on a static chamber-gas chromatography method, R_S was measured from January 2015 to December 2018. R_S exhibited significant seasonal variability, with low R_S rates appeared in the dry season and high rates appeared in the wet season regardless of treatment. R_S was significantly related to the measured soil temperature and moisture. Our results showed that soil R_S increased after N additions, the mean annual R_S was 7% higher in N25 plots, 8% higher in N50 plots, and 11% higher in N100 plots than that in the CK plots. However, the overall impacts of N additions on R_S were statistically insignificant. For the entire study period, the CK, N25, N50, and N100 treatments yielded Q₁₀ values of 2.27, 3.45, 4.11, and 2.94, respectively. N addition increased the temperature sensitivity (Q₁₀) of R_S. Our results suggest that increasing atmospheric N deposition may have a large impact on the stimulation of soil CO₂ emissions from tropical rainforests in China.

【 授权许可】

Unknown