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Chinese Journal of Applied Ecology ›› 2021, Vol. 32 ›› Issue (4): 1250-1258.doi: 10.13287/j.1001-9332.202104.022

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Effects of soil moisture on priming effect of soil organic carbon in meadow in Wuyi Mountain, China.

LI Jia-yu1,2, LYU Mao-kui1,3*, LI Xiao-jie1,2, JIANG Yong-meng1,2, XIE Jin-sheng1,2   

  1. 1College of Geographical Science, Fujian Normal University, Fuzhou 350007, China;
    2Key Laboratory for Humid Subtropical Eco-geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou 350007, China;
    3Ecology Postdoctoral Research Station, Fujian Normal University, Fuzhou 350007, China
  • Received:2020-08-18 Accepted:2021-01-18 Published:2021-10-25
  • Contact: *E-mail: maokui.lyu@fjnu.edu.cn
  • Supported by:
    National Natural Science Foundation of China (31870604, U1405231) and International Cooperation Project of Fujian, China (2019I0010).

Abstract: Moisture is an important factor affecting the priming effect of soil organic carbon (SOC). However, empirical evidence for its effect in mountain meadows soil is lacking. We conducted a 126-day laboratory incubation experiment with the high altitude (2130 m) mountain meadow soil in Wuyi Mountain, by adding 13C-labelled glucose combined with controlling soil moisture (30% and 60% of field water capacity, FWC). The CO2 concentration and 13C-CO2 abundance were measured regularly to examine the differences of SOC mineralization and priming effects under different water conditions and the driving factors. Our results showed that SOC mineralization rate increased with increasing soil water content. The priming effect of meadow soil with different soil moisture showed a decreasing trend with the increases of incubation time. The priming effect in soils with low FWC soil was significantly greater than that with high FWC. At the end of incubation, the cumulative priming effect of low FWC soil was 61.4% higher than that of high FWC soil. Compared with low FWC soil, high FWC soil released more CO2 from glucose, and the ratio of cumulative primed carbon to glucose mineralization under low FWC was significantly higher than that under high FWC soil, indicating that soil microorganisms under the high FWC condition might preferentially mineralize more glucose than SOC and consequently lower priming effect. Therefore, the priming effect under high FWC was smaller than that under low FWC. There was a significant positive relationship between priming effect and microbial biomass carbon, microbial biomass carbon/microbial biomass nitrogen, and NH4+-N, indicating that soil microbial biomass and composition could be changed under low FWC condition. The improved microbial “nitrogen-mining” would increase priming effect. Consequently, the decline of soil moisture of mountain meadow induced by global climate change may increase the priming effect of carbon, with consequences on carbon loss.

Key words: priming effect, alpine meadow soil, soil organic carbon, mineralization, soil water content