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. 2019 Oct;25(10):3267-3281.
doi: 10.1111/gcb.14750. Epub 2019 Aug 1.

Long-term nitrogen addition modifies microbial composition and functions for slow carbon cycling and increased sequestration in tropical forest soil

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Free article

Long-term nitrogen addition modifies microbial composition and functions for slow carbon cycling and increased sequestration in tropical forest soil

Jing Tian et al. Glob Chang Biol. 2019 Oct.
Free article

Abstract

Nitrogen (N) deposition is a component of global change that has considerable impact on belowground carbon (C) dynamics. Plant growth stimulation and alterations of fungal community composition and functions are the main mechanisms driving soil C gains following N deposition in N-limited temperate forests. In N-rich tropical forests, however, N deposition generally has minor effects on plant growth; consequently, C storage in soil may strongly depend on the microbial processes that drive litter and soil organic matter decomposition. Here, we investigated how microbial functions in old-growth tropical forest soil responded to 13 years of N addition at four rates: 0 (Control), 50 (Low-N), 100 (Medium-N), and 150 (High-N) kg N ha-1 year-1 . Soil organic carbon (SOC) content increased under High-N, corresponding to a 33% decrease in CO2 efflux, and reductions in relative abundances of bacteria as well as genes responsible for cellulose and chitin degradation. A 113% increase in N2 O emission was positively correlated with soil acidification and an increase in the relative abundances of denitrification genes (narG and norB). Soil acidification induced by N addition decreased available P concentrations, and was associated with reductions in the relative abundance of phytase. The decreased relative abundance of bacteria and key functional gene groups for C degradation were related to slower SOC decomposition, indicating the key mechanisms driving SOC accumulation in the tropical forest soil subjected to High-N addition. However, changes in microbial functional groups associated with N and P cycling led to coincidentally large increases in N2 O emissions, and exacerbated soil P deficiency. These two factors partially offset the perceived beneficial effects of N addition on SOC storage in tropical forest soils. These findings suggest a potential to incorporate microbial community and functions into Earth system models considering their effects on greenhouse gas emission, biogeochemical processes, and biodiversity of tropical ecosystems.

Keywords: C and N turnover; N deposition; biogeochemical cycling; global climate change; microbial functional community; tropical forest.

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References

REFERENCES

    1. Baccini, A., Walker, W., Carvalho, L., Farina, M., Sulla-Menashe, D., & Houghton, R. A. (2017). Tropical forests are a net carbon source based on aboveground measurements of gain and loss. Science, 358, 230-233. https://doi.org/10.1126/science.aam5962
    1. Beniston, J. W., Shipitalo, M. J., Lal, R., Dayton, E. A., Hopkins, D. W., Jones, F., … Dungait, J. A. J. (2015). Carbon and macronutrient losses during accelerated erosion under different tillage and residue management. European Journal of Soil Science, 66, 218-225. https://doi.org/10.1111/ejss.12205
    1. Boot, C. M., Hall, E. K., Denef, K., & Baron, J. S. (2016). Long-term reactive nitrogen loading alters soil carbon and microbial community properties in a subalpine forest ecosystem. Soil Biology & Biochemistry, 92, 211-220. https://doi.org/10.1016/j.soilbio.2015.10.002
    1. Bossio, D. A., & Scow, K. M. (1998). Impacts of carbon and flooding on soil microbial communities: Phospholipid fatty acid profiles and substrate utilization patterns. Microbial Ecology, 35(3), 265-278. https://doi.org/10.1007/s002489900082
    1. Camenzind, T., Hattenschwiler, S., Treseder, K. K., Lehmann, A., & Rillig, M. C. (2018). Nutrient limitation of soil microbial processes in tropical forests. Ecology Monographs, 88, 4-21. https://doi.org/10.1002/ecm.1279

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