AUTHOR CONTRIBUTIONS
Qingmin Pan, Hao Zhang, and Mengli Zhao conceived the ideas and designed
the study. Mengli Zhao and Guodong Han designed the grazing experiment.
Yang Yang and Hao Zhang conducted the field sampling and laboratory
analysis. Yang Yang, Wei Liu, and Jiamei Sun analyzed the data. Yang
Yang, Hao Zhang, and Qingmin Pan led writing of this manuscript. All
authors contributed to the draft and revision and gave the final
approval for publication.