Acknowledgements
We appreciate the assistant on data analysis From Dr. Xinli Chen, Mr.
Chen Chen and Dr. Eric Searle, and we thank the authors who published
the papers with the time-consuming belowground data in this
meta-analysis. This study was funded by the Natural Sciences and
Engineering Research Council of Canada (RGPIN-2014–04181,
RTI-2017–00358, and STPGP506284).