Functional Traits Predict Outcomes of Current and Novel Competition Under Warmer Climate

作者：Shengman Lyu, Jake M. Alexander · 发表于：Global Change Biology · 年份：2024 · DOI：10.1111/gcb.17551 · 被引用次数：6 · 研究领域：Species Distribution and Climate Change、Plant and animal studies、Ecology and Vegetation Dynamics Studies

Functional traits offer a potential avenue to generalize and forecast the impacts of changing competition on plant communities, including changing outcomes of competition among species that currently interact (current competition) or that will interact in the future following range shifts (novel competition). However, it remains unclear how well traits explain variation in the outcomes of current and novel competition as well as the underlying processes determining coexistence or competitive exclusion, under changing climate. Here, we interacted pairs of high and low-elevation species in three sites across an elevation gradient in the Swiss Alps. For each species pair, we quantified the population-level outcomes of competition (invasion growth rates), relative fitness differences, and niche overlap and related these to 15 functional traits that were measured in each site. Most traits were significantly associated with invasion growth rates at the low elevation, where species had greater relative fitness differences, but these associations were much weaker towards higher elevations. This appears to be because traits, particularly those associated with light competition, captured species' relative fitness differences at lower elevations, but not at the high elevation site, highlighting that the predictive ability of traits can depend on environmental context. The amplified relative fitness differences towards lower elevations suggest that climate warming may increase the likeli...