The conversion of subtropical forest to tea plantation changes the fungal community and the contribution of fungi to NO production.

The conversion of natural forests to tea plantations largely affects soil nitrous oxide (NO) emissions and soil microbial communities. However, the impacts of this conversion on the contribution of fungi to NO emission and on fungal community structure remain unclear. In this study, we determined the soil NO emission rate, NO production by fungi, associated fungal community diversity, and related ecological factors in chronological changes of tea crop systems (3, 36 and 105 years old tea orchards named T3, T36 and T105, respectively), and in an adjacent soil from a natural forest. The results indicate that the tea plantations significantly enhanced soil NO production compared with the forest soil. Tea plantations significantly decreased soil pH and C/N ratio, but increased soil inorganic nitrogen (N). Furthermore, they increased the fungal contribution to the production of soil NO, but decreased the bacterial counterpart. We also observed that fungal community and functional composition differed distinctly between tea plantations and forest. Additionally, most of the fungal groups in high NO emission soils (T36 and T105) were identified as the genus Fusarium, which were positively correlated with soil NO emissions. The variation in NO emission response could be well explained by NO-N, soil organic carbon (SOC), C/N, and Fusarium, which contributed to up to 97% of the observed variance. Altogether, these findings provide significant direct evidence that the increase of soil NO emissions and fungal communities be attributed to the conversion of natural forest to tea plantations.