In order to predict and explain the curve shape of the species-area relationship (SAR) it is necessary to understand the patterns and processes that drive it. However, after almost a century, the shapes of species-area curves and the factors and mechanisms that underpin them are still hotly debated and there remains little consensus on anything other than the fact that larger areas contain, on average, more species than smaller ones.
In the chapter we discuss the biologically founded determinants of the SAR.