Drought‐tolerant grassland species are generally more resistant to competition

作者：Hailey E. Mount, Melinda D. Smith, Alan K. Knapp, Robert J. Griffin‐Nolan, Scott L. Collins, David H. Atkins, Alice E. Stears, Daniel C. Laughlin · 发表于：Journal of Ecology · 年份：2023 · DOI：10.1111/1365-2745.14243 · 被引用次数：17 · 研究领域：Ecology and Vegetation Dynamics Studies、Plant and animal studies、Rangeland and Wildlife Management

Abstract Plant populations are limited by resource availability and exhibit physiological trade‐offs in resource acquisition strategies. These trade‐offs may constrain the ability of populations to exhibit fast growth rates under water limitation and high cover of neighbours. However, traits that confer drought tolerance may also confer resistance to competition. It remains unclear how fitness responses to these abiotic conditions and biotic interactions combine to structure grassland communities and how this relationship may change along a gradient of water availability. To address these knowledge gaps, we estimated the low‐density growth rates of populations in drought conditions with low neighbour cover and in ambient conditions with average neighbour cover for 82 species in six grassland communities across the Central Plains and Southwestern United States. We assessed the relationship between population tolerance to drought and resistance to competition and determined if this relationship was consistent across a precipitation gradient. We also tested whether population growth rates could be predicted using plant functional traits. Across six sites, we observed a positive correlation between low‐density population growth rates in drought and in the presence of interspecific neighbours. This positive relationship was particularly strong in the grasslands of the northern Great Plains but weak in the most xeric grasslands. High leaf dry matter content and a low (more negative...