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Chinese Journal of Applied Ecology ›› 2018, Vol. 29 ›› Issue (5): 1635-1644.doi: 10.13287/j.1001-9332.201805.033

• Original Articles • Previous Articles     Next Articles

Dynamics of nutrient concentration and microbial community composition during fine root decomposition in subtropical Mytilaria laosensis and Cunninghamia lanceolata plantations.

CHEN Ya-min1,2, YU Zai-peng1,2, WANG Min-huang1,2, WAN Xiao-hua1,2*, LIU Rui-qiang3, SANG Chang-peng1,2, SONG Meng-ya1,2, XIONG Jia1,2   

  1. 1Cultivation Base of State Key Laboratory of Humid Subtropical Mountain Ecology, Fuzhou 350007, China;
    2School of Geographical Science, Fujian Normal University, Fuzhou 350007, China;
    3School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
  • Received:2017-08-11 Online:2018-05-18 Published:2018-05-18
  • Contact: *E-mail: xiaohuawan2012@foxmail.com
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (31600495, 41371269, 31570604) and the National Key Basic Research and Development Plan (2014CB954003)

Abstract: We conducted a 12-month fine root decomposition experiment under 19-year-old Mytilaria laosensis and Cunninghamia lanceolate plantations to explore the dynamics of nutrient concentration and microbial community composition. The aim of this study was to provide insights into nutrient cycling under plantations with different tree species. Our results showed that the initial concentrations of phosphorus (P) and potassium (K) were significantly higher in the fine root of M. laosensis than those in C. lanceolata, which significantly decreased with decomposition. Nitrogen (N) concentration in fine roots of both species increased with decay time. The variation of N concentration in fine root of C. lanceolata lagged behind that in M. laosensis. During the decomposition, magnesium (Mg) concentration in fine root of C. lanceolata showed no significant changes, but that of M. laosensis decreased at the initial decay stage and increased thereafter and was significantly lower than that of C. lanceolata at the 8th month. The ratio of fungi to bacteria (F/B) of both species decreased at the initial stage and then increased, with significantly higher F/B in fine root of M. laosensis than that of C. lanceolate after one-year decay. Redundancy analysis (RDA) showed that changes in N and K concentrations and C/N ratio explained 37.2%, 14.5% and 14.8% of the variations in microbial community composition of C. lanceolata fine root respectively. However, during the decay of M. laosensis fine root, concentrations of Mg and K were key factors, accounting for 35.9% and 17.6% of the variations in microbial community composition, respectively. We concluded that other nutrients beyond N, such as Mg, might also be an important factor affecting root decomposition in different tree species.

Key words: nitrogen concentration, fine root decomposition, microbial community composition, magnesium concentration