On the short-term response of soil greenhouse gas emissions in Cunninghamia lanceolata forest to the expansion and eradication of Phyllostachys edulis

Abstract

Objective With an investigation of the effects of expansion and eradication of Phyllostachys edulis (moso bamboo) on soil greenhouse gas emission flux and soil physical and chemical properties in Cunninghamia lanceolata (Chinese fir) forest, this paper is aimed to provide theoretical basis for the scientific management of moso bamboo expansion. Method Short-term in-situ monitoring was carried out of the soil greenhouse gas flux in pure moso bamboo forest (BF), Chinese fir released forest upon the eradication of moso bamboo from the Chinese fir forest mixed with moso bamboo (RF), moso bamboo and Chinese fir mixed forest (MF), and pure Chinese fir forest (CF) using a static chamber gas chromatography method. Result The expansion and eradication of moso bamboo increased the soil CO2 emission flux, which were 827.55, 485.09, 374.33 and 300.44 mg·m−2·h−1 for BF, RF, MF and CF respectively whereas the soil N2O emission flux were 120.86, 98.03, 82.89 and 70.23 µg·m−2·h−1, and the soil CH4 absorption flux were 155.38, 145.77, 135.26 and 119.62 µg·m−2·h−1. The soil temperature decreases from MF (19.77 ℃) to RF (18.72 ℃), BF (18.49 ℃) and CF (18.32 ℃) while the soil moisture content decreases from RF (27.32%) to CF (23.04%), BF (18.67%) and MF (16.36%). In these four different stands, the soil CO2 and N2O emission fluxes and CH4 absorption fluxes were significantly positively correlated with soil temperature and moisture content (P＜0.01) with consistent dynamic changes and had a positive correlation with soil inorganic nitrogen ( \begin{document}$ {\rm{NH}}^{+}_{4}\text{-}{\rm{N}} $\end{document} , \begin{document}$ {\rm{NO}}^{-}_{3}\text{-}{\rm{N}} $\end{document} ) but a negative correlation with soil microbial biomass carbon (MBC). Conclusion The expansion and eradication of moso bamboo resulted in the increase of soil greenhouse gas emission flux in Chinese fir forest, which had a negative impact on the regional atmospheric environment. On the other hand, the soil temperature and soil water content were the main driving factors for the three kinds of greenhouse gas emissions, and could lead to the differences in greenhouse gas emissions among the four stands. [Ch, 5 tab. 50 ref.]