Pattern and process in the distribution and abundance of seagrass species in Pulau Tinggi, Malaysia

[Truncated abstract] Knowledge of the distribution patterns of organisms and their links to ecosystem processes is fundamental in biogeographical enquiry. In seagrass ecosystems, however, there are deficiencies in our understanding of species patterns and processes across multiple spatial scales. This is particularly true for seagrasses in Southeast Asia, which has prompted this research. A review of the existing knowledge of seagrasses in Southeast Asia was conducted to provide context for this study. Peer-reviewed papers were limited in number, geographic distribution and habitat types. A critical gap highlighted was the underrepresentation of forereef seagrass systems in the literature. Therefore, this project examined a forereef seagrass system in Pulau Tinggi, Malaysia, which is an ecologically interesting system for its setting in the forereef zone. Variogram modelling was used to quantify the spatial structure of four seagrass species, and to identify potential scale-specific ecological drivers. Halophila ovalis and Halodule uninervis had larger ranges, whereas Cymodocea serrulata and Syringodium isoetifolium were more localised. Within patches, species had a nested distribution. A Linear Model of Coregionalization indicated differences across species both along- and across-shore. Shrimp mounds may be drivers at the micro-scale (<2.5 m). At broaderspatial scales, potential drivers are water depth, physical disturbance, sediment heterogeneity and hydrodynamics. These outcomes were used to construct conceptual models of scale-specific drivers in the seagrass systems of Pulau Tinggi. A burial experiment was performed on four species to test the hypothesis that seagrasses are influenced by micro-scale processes (<2.5 m), while incorporating the moderating effects of clonal integration on each species...