4.3 Climatic effects
We investigated the effect of climate on model-plant grassland community traits in reference soil treatments. As indicated by our PCA analysis, species were strongly correlated with the measured traits consistently across sites, whereas climate segregation followed little to no pattern, meaning climate demonstrated minimal correlation with plant traits. Therefore, climate differences in the absence of soil differences did not lead to the restructuring of plant trait hierarchies. This finding was supported by our Random Forest analysis, leading us to reject our hypothesis that climate is the primary driver of trait variability. Instead, our results illustrate consistent responses across species even in the face of high climatic variation. Since our community was selected to minimize functional overlap, a naturally occurring community with higher functional overlap may experience less distinct trait differentiation due to direct competition. This could affect the application of our climate results; however, the effects of soil demonstrated no such role of functional groups in trait responses, rather revealing high stochasticity. While the interactive role of soil and climate on plant traits has been well documented in past community-based studies (Sundert et al. 2021; He and Dijkstra 2014), questions remain about how climate variation alone affects grassland community structures. Overall community diversity and their constituent species have a determinant role in ecosystem responses to climatic changes (Hautier et al. 2015), meaning monoculture-based climate change experiments may not accurately represent plant trait responses. With the consistent species-species trait responses observed in our experiment, a community-based approach may better capture predictive plant-trait responses under a changing climate.