Conclusion
Our study has emphasized the importance of taking a community-wide approach when quantifying latitudinal variation in herbivore pressure, revealing how community-wide herbivory varies latitude. We also provide new empirical evidence that climate plays a primary role in driving variation in community-wide herbivory, via effects on intraspecific herbivory variability. More broadly, as plant and insect species may undergo range shifts to higher latitudes in response to global warming (Buse et al. 2013; Cavanaugh et al. 2014), the higher latitudes of the Qinghai-Tibetan Plateau are expected to experience greater herbivore pressure. Therefore, field data from latitudinal surveys, together with evidence from experimental temperature treatments, are needed to evaluate the indirect impacts of climate change on plant communities via changing herbivore pressure.
Acknowledgements
We thank Yimin Zhao, Sirui Zhu and Yan Sun for assistance in the field. This study was supported by the National Natural Science Foundation of China (Grants No. 32001116), the Gansu Provincial Science Fund for Distinguished Young Scholars (Grants No. 21JR7RA532), Start-up Funds for Introduced Talent in Lanzhou University (Grants No. 561119211) and the Fundamental Research Fund for Central Universities (Grants No. lzujbky-2021-ct16).