Seasonality, Rather than Nutrient Addition or Vegetation Types, Influenced Short-Term Temperature Sensitivity of Soil Organic Carbon Decomposition

• Published in: PLOS ONE
• Main Authors: Qian, Yu-Qi, He, Feng-Peng, Wang, Wei
• Other Authors: Wang, W (reprint author), Peking Univ, Coll Urban & Environm Sci, Dept Ecol, Beijing 100871, Peoples R China.; Wang, W (reprint author), Peking Univ, Minist Educ, Key Lab Earth Surface Proc, Beijing 100871, Peoples R China., Peking Univ, Coll Urban & Environm Sci, Dept Ecol, Beijing 100871, Peoples R China., Peking Univ, Minist Educ, Key Lab Earth Surface Proc, Beijing 100871, Peoples R China., Peking Univ, Shenzhen Grad Sch, Shenzhen 518055, Peoples R China., Wang, W (reprint author), Peking Univ, Minist Educ, Key Lab Earth Surface Proc, Beijing 100871, Peoples R China.
• Format: Journal/Newspaper
• Language: English
• Published: PLOS ONE 2016
• Subjects: MICROBIAL COMMUNITY COMPOSITION; CLIMATE-CHANGE; FOREST SOILS; PHOSPHORUS LIMITATION; MATTER DECOMPOSITION; NITROGEN LIMITATION; ROOT RESPIRATION; N FERTILIZATION; TROPICAL FOREST; TUNDRA SOILS; Tundra
• Online Access: https://hdl.handle.net/20.500.11897/434155; https://doi.org/10.1371/journal.pone.0153415

The response of microbial respiration from soil organic carbon (SOC) decomposition to environmental changes plays a key role in predicting future trends of atmospheric CO2 concentration. However, it remains uncertain whether there is a universal trend in the response of microbial respiration to increased temperature and nutrient addition among different vegetation types. In this study, soils were sampled in spring, summer, autumn and winter from five dominant vegetation types, including pine, larch and birch forest, shrubland, and grassland, in the Saihanba area of northern China. Soil samples from each season were incubated at 1, 10, and 20 degrees C for 5 to 7 days. Nitrogen (N; 0.035 mM as NH4NO3) and phosphorus (P; 0.03 mM as P2O5) were added to soil samples, and the responses of soil microbial respiration to increased temperature and nutrient addition were determined. We found a universal trend that soil microbial respiration increased with increased temperature regardless of sampling season or vegetation type. The temperature sensitivity (indicated by Q10, the increase in respiration rate with a 10 degrees C increase in temperature) of microbial respiration was higher in spring and autumn than in summer and winter, irrespective of vegetation type. The Q10 was significantly positively correlated with microbial biomass and the fungal: bacterial ratio. Microbial respiration (or Q10) did not significantly respond to N or P addition. Our results suggest that short-term nutrient input might not change the SOC decomposition rate or its temperature sensitivity, whereas increased temperature might significantly enhance SOC decomposition in spring and autumn, compared with winter and summer. Projects of the National Natural Science Foundation of China [31222011, 31270363, 31321061]; National Basic Research Program of China [2013CB956303]; University Construction Projects from Central Authorities in Beijing and Research Fund of State Key Laboratory of Soil and Sustainable Agriculture, Nanjing Institute of Soil Science, Chinese Academy of Science [Y412201439] SCI(E) PubMed ARTICLE [e-mail] 4 e0153415 11