MEPS 516:263-266 (2014)  -  DOI: https://doi.org/10.3354/meps11067

ABSTRACT: For all general types of frequency of species occurrence curve, the proportion of the total species in unit samples is significantly uniform if the component species are distributed independently of each other, and the precise constant number of species obtained then depends on the shape of the curve. In respect of the recently demonstrated instances of spatial uniformity of macrofaunal species density in intertidal seagrass and in adjacent unvegetated sediment, the observed proportions of samples containing different total numbers of species do not differ from those expected by chance from the observed overall occurrence frequency distributions. The spatial uniformity of species density observed is therefore no more than an inevitable reflection of the frequency of occurrence distributions of the species concerned under conditions of random assemblage composition, and requires no further biological explanation. What produces the similar frequency of species occurrence patterns in seagrass habitats, however, yielding similar numbers of species per unit area from the cool-temperates to the subtropics, remains to be elucidated.

KEY WORDS: Biodiversity · Macrobenthos · Sandflat · Seagrass · Spatial constancy · Spatial occurrence · Spatial uniformity