Co-existence in a species-rich grassland: competition, facilitation and niche structure over a soil depth gradient

摘要

QuestionNiche differentiation may promote species co-existence because it precludes competitive exclusion. However, in stressful environments, facilitation may predominate, and large niche overlaps may result from niche widening and positive spatial associations. We analysed the niche structure of a species-rich system over a soil depth gradient (a niche axis positively correlated with water availability) and tested for various patterns expected from competition or facilitation.