New publication from Cheng et al. in Nature Communications: Biodiversity increases resistance of grasslands against plant invasions under multiple environmental changes

Biodiversity often helps communities resist invasion. However, it is unclear whether this diversity–invasion relationship holds true under environmental changes. Here, we conduct a meta-analysis of 1010 observations from 25 grassland studies in which plant species richness is manipulated together with one or more environmental change factors to test invasibility (measured by biomass or cover of invaders). We find that biodiversity increases resistance to invaders across various environmental conditions. However, the positive biodiversity effect on invasion resistance is strengthened under experimental warming, whereas it is weakened under experimentally imposed drought. When multiple factors are imposed simultaneously, the positive biodiversity effect is strengthened. Overall, we show that biodiversity helps grassland communities resist plant invasions under multiple environmental changes. Therefore, investment in the protection and restoration of native biodiversity is not only important for prevention of invasions under current conditions but also under continued global environmental change.

**Fig. 1: Biodiversity effects on invasion resistance under multiple environmental changes.** The net biodiversity effect (NBE) on invasion resistance (a) and the difference in NBE between ambient and manipulated environmental conditions (∆NBE) (b). Positive values of NBE indicate higher invasion resistance of resident mixtures in comparison with that of resident monocultures, whereas negative values indicate the opposite. Positive values of ∆NBE indicate stronger biodiversity effects under manipulated environmental conditions in comparison with ambient conditions, and vice versa. In panel a, the numbers above the brackets are the p-values of the Q_M tests for the effect of environmental manipulation (ambient vs. manipulated) on NBE. The numbers in brackets show the number of effect sizes. Points with error bars are the estimated means with corrected 95% confidence intervals. Confidence intervals not overlapping with the dashed line (i.e. 0) indicate statistical significance, as indicated by asterisks. Green shading indicates the analysis on all environmental change factors and yellow shading indicates the analysis on different numbers of factors. Symbols of environmental change factors are created by Yue Chen.

Reference:

Cheng, C., Z. Liu, W. Song, X. Chen, Z. Zhang, et al. 2024. Biodiversity increases resistance of grasslands against plant invasions under multiple environmental changes. Nature Communications 15:4506. https://doi.org/10.1038/s41467-024-48876-z.