Temporal dynamics of abundance-occupancy relationships

Abundance-occupancy relationships (AOR’s) – where locally abundant species tend to be found in many sites, whereas locally rare species tend to be more narrowly distributed – are one of ecology’s most ubiquitous and oldest macroecological patterns. Several causal mechanisms have been proposed to explain this pattern and are well understood theoretically. However, there is little consensus on the factors important in generating and maintaining the relationship in natural systems. Recent work has suggested that a better understanding of the causes of interspecific AOR’s will come from examining temporal changes in the occupancy and abundance of individual species (intraspecific AOR’s). In this study, we examine the dynamics of inter- and intra-specific AOR’s for vascular plants in tussock grasslands of New Zealand’s South Island. A set of 130 permanently-marked, 100m transects, encompassing nearly 400 species, was established in the 1980’s, remeasured in the 1990’s, and remeasured again between 2005 and 2007. These data show that, surprisingly, despite the substantial turnover in species on these transects, the general form of the interspecific AOR for these plant communities has not changed over time. Here, we show how the temporal dynamics of individual species’ may influence the form of the interspecific AOR.