Soil C:N ratio is the major determinant of soil microbial community structure in subtropical coniferous and broadleaf forest plantations
- 2k Downloads
This study aimed to determine the influence of tree species on soil microbial community structure.
We conducted a litter and root manipulation and a short-term nitrogen (N) addition experiment in 19-year-old broadleaf Mytilaria laosensis (Hamamelidaceae) and coniferous Chinese fir (Cunninghamia lanceolata) plantations in subtropical China. Phospholipid fatty acid (PLFA) analysis was used to examine treatment effects on soil microbial community structure. Redundancy analysis (RDA) was performed to determine the relationships between individual PLFAs and soil properties (soil pH, carbon (C) and N concentration and C:N ratio).
Soil C:N ratio was significantly greater in M. laosensis (17.9) than in C. lanceolata (16.2). Soil C:N ratio was the key factor affecting the soil microbial community regardless of tree species and the litter, root and N treatments at our study site. The fungal biomarkers, 18:1ω9 and 18:2ω6,9 were significantly and positively related to soil C:N ratio and the abundance of bacterial lipid biomarkers was negatively related to soil C:N ratio. N addition for 8 months did not change the biomass and structure of the microbial community in M. laosensis and C. lanceolata soils. Soil nutrient availability before N addition was an important factor in determining the effect of N fertilization on soil microbial biomass and activity. PLFA analysis showed that root exclusion significantly decreased the abundance of the fungal biomarkers and increased the abundance of the Gram-positive bacteria. Rootless plots had a relatively lower Gram-positive to Gram-negative bacteria ratio and a higher fungi to bacteria ratio compared to the plots with roots under both M. laosensis and C. lanceolata. The response of arbuscular mycorrhizal fungi (16:1ω5) to root exclusion was species-specific.
These observations suggest that soil C:N ratio was an important factor in influencing soil microbial community structure. Further studies are required to confirm the long-term effect of tree species on soil microbial community structure.
KeywordsN addition Phospholipid fatty acids (PLFA) Root exclusion Soil properties Tree species
The research was supported by a National Natural Science Foundation of China (41371269), 2011 Program for New Century Excellent Talents in the University of Ministry of Education of China, and the Science Foundation for Excellent Talents of Fujian Province, China.
- Fang Q (1987) Effects of continued planting of Chinese fir on the fertility of soil and the growth of stands. Sci Silvae Sinicae 23:389–397 (In Chinese, Abstract in English).Google Scholar
- Huang Z, Liao L, Wang S, Liu Y (2000b) Dynamics of phenolics content of Chinese fir stump-roots and the rhizosphere soil and it’s allelopathy. Chin J Appl Ecol 11:190–192, In Chinese, Abstract in EnglishGoogle Scholar
- Li Q, Xiao H (2012) The interactions of soil properties and biochemical factors with plant allelopathy. Ecol Envir Sci 21:2031–2036Google Scholar
- Myrold DD (1999) Transformations of nitrogen. In: Sylvia DM, Fuhrmann JJ, Hartel PG, Zuberer DS (eds) Principles and Applications of Soil Microbiology. Prentice-Hall, N.J., pp 259–294Google Scholar
- Siira-Pietikäinen A, Haimi J, Fritze H (2003) Organisms, decomposition, and growth of pine seedlings in boreal forest soil affected by sod cutting and trenching. Biol Fert Soils 37:163–174Google Scholar
- Wan X, Huang Z, He Z, Hu Z, Yu Z, Wang M, Yang Y, Fan S (2014) Effects of tree species transfer on soil dissolved organic matter pools in a reforested Chinese fir (Cunninghamia lanceolata) woodland. Chin J Appl Ecol 25:12–18, In Chinese, Abstract in EnglishGoogle Scholar
- Wu QZ (2005) Study of Mytilaria laosensis Plantation Biomass. J Fujian For Sci Tech 32:125–129, In Chinese, Abstract in EnglishGoogle Scholar