Understory shrub diversity: equally vital as overstory tree diversity to promote forest productivity. - Chen, Chen; Yan, Guoyong; Schmid, Bernhard; Li, Yi; Bongers, Franca J; Bruelheide, Helge; Huang, Yuanyuan; Li, Shan; Oheimb, Goddert von; Tang, Ting; Verheyen, Kris; Yang, Bo; et al. (National Science Review, 2025)