Local patchiness of macrobenthic faunal abundance displays homogeneity across the disparate seagrass systems of an estuarine bay
In: Marine Environmental Research. Applied Science Publishers: Barking. ISSN 0141-1136; e-ISSN 1879-0291, meer
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| Trefwoorden |
Aquatic communities > Benthos
Patchiness
Seagrass
Marien/Kust; Brak water; Zoet water |
| Author keywords |
Estuary; Knysna; Self-organisation; Spatial variation |
| Abstract |
Spatial variation in the degree of local patchiness of macrobenthic assemblage abundance was assessed across the 16 km2 warm-temperate Knysna estuarine bay (South Africa) where the seagrass Zostera (Zosterella) capensis grows under a broad spectrum of environmental conditions and supports invertebrate assemblages at a wide range of local density (<2000->320000 ind. M−2). Macrobenthic assemblage abundance at all 27 representative sites examined displayed low-level but highly-significant spatial patchiness (mean Lloyd's index, IP = 1.148). Except at high tidal levels, however, the magnitude of this local patchiness did not vary statistically across the system (CV 4.3%) regardless of assemblage abundance, location or species composition. Patchinesses well within ±1 standard deviation of Knysna's value also characterise an equivalent Z. (Zosterella) capricorni assemblage in subtropical Queensland (IP 1.169) and another, Z. (Zosterella) noltei, assemblage in cool-temperate England (IP 1.135), suggesting that at local scales intertidal dwarf-eelgrass macrobenthic abundance displays a characteristic level of patchiness. |
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