The macro-invertebrate communities of temporary pools in an intermittent stream in tropical Queensland

Abstract

Nine pools were studied in an intermittent stream. They were close to each other but differed in size, substratum, amount of shade and duration of water presence. Initial conditions were set by wet season flooding, following which each pool developed its own character. Cluster analysis showed that communities changed substantially with time in both species composition and abundance, and that some initially similar communities diverged while some initially dissimilar ones converged.Principal Components Analysis showed that these community changes were due largely to the drying of the pools, and to seasonal effects. Specialised drying communities developed in the pools of longer duration (up to 8 months), but not in the short-lived pools (3-4 months). Apparently similar numerical responses in different pools were often caused by different suites of predominant species.The diversity of the fauna (total of 78 species) was high in comparison with similar habitats in non-tropical regions.The pattern of development of the pools' communities was much as expected from island biogeography theory, except that there was no relationship between species richness and duration and size of pools. The species complements were largely opportunistic, being governed by extreme environmental disturbance.

Are Tropical Streams Ecologically Different from Temperate Streams?

“…Comparisons among detailed studies suggest that diversity in the tropics is greater (e.g. Bishop, 1973;Pearson et al, 1986;Smith and Pearson, 1987;Table II) or lower (Arthington, 1990) but are hindered by lack of standardization of methods used.…”

Effect of Drought Frequency and Other Reach Characteristics on Invertebrate Communities and Litter Breakdown in the Intermittent Mediterranean River Pula (Sardinia, Italy)

“…On the other hand, BOULTON and LAKE (1992b) observed a decreasing species richness in riffles and pools. Such decreases may be attributable to intolerance of deteriorating water quality during drying (BOULTON and LAKE, 1992a, b), and intensified predation (LARIMORE et al, 1959), while increases can be attributable to mobile organisms congregating in ever-diminishing habitats (EXTENCE, 1981;SMITH and PEARSON, 1987).…”

Diversity of aquatic malacofauna of temporary water bodies within the lower Bug River floodplain

“…Development of specialised drought-resistant communities (e.g. WIGGINS et al 1980, SMITH & PEARSON 1987 takes place when the hydroperiod is short (3-4 months). The periodical hydrological connectivity with permanent water bodies or the river channel could enable dispersal of some species, thus increasing the species richness of temporary habitats.…”