Within-species relationship of patchiness to both abundance and occupancy, as exemplified by seagrass macrobenthos

Richard Barnes, Apollo-University Of Cambridge Repository
For the first time, intraspecific relationships between the macroecological metrics patchiness (P) and both abundance (A) and occupancy (O) were investigated in a faunal assemblage. As a companion study to recent work on interspecific P, A and O patterns at the same localities, intraspecific patterns were documented within each of the more dominant invertebrates forming the seagrass macrobenthos of warm-temperate Knysna estuarine bay (South Africa) and of sub-tropical Moreton Bay (Australia).
more » ... displayed interspecifically, individual species showed strong A-O patterns (mean scaling coefficient − 0.76 and mean R 2 > 0.8). All P-O relations were negative and most (67%) were statistically significant, although weaker (mean R 2 0.5) than A-O ones; most P-A ones were also negative but fewer (43%) achieved significance, and were even weaker (mean R 2 0.4); 33% of species showed no significant interrelations of either O or A with P. No species showed only a significant P-A relationship. Compared with interspecific P-A-O data from the same assemblages, power-law scaling exponents were equivalent, but R 2 values were larger. Larviparous species comprised 70% of the total studied, but 94% of those displaying significant patchiness interrelationships; 5 of the 9 showing no P-A or P-O relationships, however, were also larviparous. At Knysna, though not in Moreton Bay, larviparous species also showed higher levels of occupancy than non-larviparous ones, whilst non-larviparous species showed higher levels of patchiness. Dominant Moreton Bay species, but not those at Knysna, exhibited homogeneously sloped P-O relationships.
doi:10.17863/cam.72529 fatcat:vvrbdj5cc5gkzhfdo2pb6plcnu