This book explores four overlapping themes in biogeography among multiple plant and animal groups, across subcontinental to global spatial scales, and over evolutionary time. These four themes include: 1) biogeographic theory and tests of concepts and processes; 2) the regional biogeography of individual taxa; 3) historical and contemporary biogeography of complex landscapes; and 4) the evolutionary biogeography of macrotaxa. In the first chapter of the conceptual biogeography section, Khalid Al Mutairi et al. explore the importance of nestedness among the plant species and plant functional groups in the islands of the Farasan Archipelago in Saudi Arabia
