Abstract
The species-area relationship (SAR) is often expressed as a power-law, which indicates scale invariance. Although there have been attempts to attribute this feature to the self-similar spatial distribution of individual species, it has been claimed that this is unrealistic because the power law only emerges if distributions for all species have identical fractal dimensions.
Here we show that even if species differ in their fractal dimensions, the resulting SAR can be approximately linear on a log-log scale because observed spatial distributions are inevitably spatially restricted a phenomenon we term the finite area effect. Using distribution atlases, we demonstrate that the apparent power-law of SARs for central European birds can be attributed to this finite-area effect affecting species that indeed reveal self-similar distributions.
We discuss implications of this mechanism producing the SAR