Wilson, J NSteel, John BGitay, Habiba2015-12-131100-9233http://hdl.handle.net/1885/93724The effect of spatial scale on species evenness has not previously been investigated. As the area of each sample of vegetation (i.e. the spatial grain) increases, evenness could in theory increase, decrease, or stay the same, though the simplest model predicts an increase. We use biomass data from four dune slack sites and two semi-arid grasslands, sampled to allow calculation of evenness at a range of spatial grains. In all six sites, evenness decreases as grain size increases, almost monotonically. It is hypothesized that such a pattern is a result of a general feature of plant species abundance distributions and of vegetation response to environmental microheterogeneity.Keywords: scale effect; spatial resolution; species evenness Abundance distribution; Dune slack; Microheterogeneity; Semi-arid grassland; Spatial grain; Spatial scaleThe effect of spatial scale on evenness19992015-12-12