Describing assemblages and biodiversity of sediment-living organisms
This chapter provides insight into the biodiversity of soft sediments, and how it can be measured using a range of univariate, bivariate and multivariate techniques. It highlights that biodiversity can be described across a range of organisational scales and includes the extension of diversity to cover habitats, behavioural characteristics (biological traits) and functional traits. Scale is an important characterisation of biodiversity and the chapter discusses scale both in its effect on the measurement of biodiversity and also for how it links the components of α-, β- and γ-diversity. These linkages are crucial to help us understand the roles of heterogeneity, species turnover and the ecological connections between local species richness and regional species pools. Most species are rare and thus any description of biodiversity would not be complete without consideration of rarity and its contribution to community structure and dynamics.