Spatial homogeneity of benthic macrofaunal biodiversity across small spatial scales.

No Thumbnail Available
Change log
Barnes, RSK 

Spatial heterogeneity of biodiversity has been extensively researched, but its spatial homogeneity is virtually unstudied. An intertidal seagrass system at Knysna (South Africa) known to display spatially homogeneous macrobenthic species density at scales ≥0.0275 m2 was re-investigated at four smaller spatial grains (0.0015 m2 - 0.0095 m2) via a lattice of 8 × 8 stations within a 0.2 ha area. The aim was to investigate the null hypothesis that spatial homogeneity of species density is not a fixed emergent assemblage property but breaks down at small spatial grains within given spatial extents. Although assemblage abundance was significantly heterogeneous at all spatial grains investigated, both species density and functional-group density were significantly homogeneous across those same scales; observed densities not departing from those expected on the basis of independent assortment. Spatial homogeneity is therefore an emergent assemblage property within given spatial extents at Knysna and probably at equivalent sites elsewhere. Equivalent species density in South Africa, Australia and the UK at spatial grains <0.03 m2, however, is a scale-related sampling artefact, as may be temporal homogeneity of species density at Knysna over a 3 year period, but close similarity in shape of their species occupancy distributions remains unexplained.

Biodiversity, Macrobenthos, Seagrass, Spatial homogeneity, Spatial scale, Spatial uniformity, Species occupancy distributions, Animals, Aquatic Organisms, Australia, Biodiversity, Ecosystem, Environmental Monitoring, Invertebrates, Population Density, Population Dynamics, South Africa
Journal Title
Mar Environ Res
Conference Name
Journal ISSN
Volume Title
Elsevier BV