ACKNOWLEDGEMENTS
This study was jointly financed by the State Key and General Programs of
National Natural Science Foundation of China (Nos. 41571130043,
41571251). This study was conducted at the Puding Karst Ecosystem
Station of Chinese Academy of Sciences. We thank the field station staff
for their assistance with sampling. We thank Professor David Powlson of
Rothamsted Research, UK, for helpful scientific discussion and for
improving the English language of this paper.