Environmental heterogeneity dynamics drive plant diversity on oceanic islands

Aim: The General Dynamic Model (GDM) links island biogeographical processes to island geological history. A key premise of the GDM implies that environmental factors shaping the ecology and evolution of insular biota follow a hump-shaped trend over the island’s life span and drive dynamics in carrying capacity, species diversity and endemism. An important component of the GDM is environmental heterogeneity (EH), but its effects on insular diversity remain poorly understood. Here, we first quantified EH, tested whether EH follows the expected hump-shaped trend along island ontogeny and evaluated how EH relates to plant diversity.

Location: 135 oceanic islands of volcanic origin.

Taxon: Vascular plants.

Methods: We calculated 20 alternative EH metrics for focusing on topographic and climatic components of EH, and comparing whole-island metrics (e.g., range) and moving-window metrics (e.g., roughness). Using linear mixed-effects models, we evaluated the trends of EH with island ag...