Eco-evolutionary processes and community patterns--- novel avenues for studying biodiversity across spatial and temporal scales

Sammanfattning: Understanding biodiversity patterns poses a persistent challenge due to the complex interconnections of ecological and evolutionary processes. The particular difficulty comes from the various processes influencing biodiversity patterns across different spatial scales. This thesis aims to enhance comprehension of community diversity patterns by employing theoretical models that are capable of generating community diversity patterns on local and regional spatial scales, including commonly used diversity metrics such as species, trait, and phylogenetic diversity. These models incorporate eco-evolutionary dynamics encompassing competition, predation, dispersal, environmental gradients, and adaptive radiation. Combining the results from each paper provides nuanced insights into the interconnected mechanisms governing community diversity patterns, summarized as five general conclusions: First, competition is the primary driver for community diversity patterns on the local scale. Second, environmental gradients play a crucial role in driving community diversity patterns on the regional scale. Third, predation interacts with competition, leading to changes in adaptive radiation on the local scale, thus changing diversity patterns. In general, predators hinder competition-induced disruptive selection by reducing prey abundance. Fourth, dispersal and environmental gradients influence adaptive radiation on the regional scale, changing the spatial diversity patterns. High dispersal can reduce the directional selection imposed by the environmental gradient, leading to species that can survive in multiple environments. Finally, there is a dynamic interplay between local and regional processes. Such temporal dynamics may be revealed by patterns that contain both temporal and spatial signals, such as phylogenetic diversity. In conclusion, this thesis not only advances our understanding of the mechanisms shaping community diversity patterns across spatial and temporal scales but also opens new avenues for biodiversity research. Theoretical models integrating local and regional processes in continuous space hold significant promise for advancing our comprehension of community patterns.