Multivariate pattern analysis of wetland invertebrate communities and environmental variables in Western Australia

Abstract

Macro-invertebrates, zooplankton and water quality variables were sampled at 33 wetlands near Perth, Western Australia, in January-February 1989. Wetlands were classified and ordinated using the invertebrate data. Correlations of environmental variables with the ordination were calculated and the importance of seasonality and geomorphology of the wetlands were investigated. The wetlands were also classified and ordinated using the chemical data. Analysis of variance was used to compare species richness, abundances of all invertebrates, macro-invertebrates, copepods and total phosphorus levels among groups. Six groups of wetlands were identified from the invertebrate data, two of which were outliers on the basis of very low pH and high salinity, respectively. The majority of the wetlands grouped on the basis of their degree of nutrient enrichment and colour. The analyses of chemical data gave similar groups. The coloured wetlands and least nutrient enriched non-coloured wetlands were identified as being closest to the probable state of wetlands prior to European settlement. The greatest numbers of rare species were found in wetlands from these two groups. Species richness was significantly higher in the moderately enriched wetlands than in any other group but decreased in the most enriched wetlands where abundances of invertebrates were highest. Changes in community composition among the groups of wetlands are discussed. The most highly nutrient enriched wetlands were dominated by cosmopolitan species with high abundances, whereas less enriched and coloured wetlands had species with more restricted distributions and lower abundances.

Aquatic invertebrate assemblages of wetlands and rivers in the wheatbelt region of Western Australia

“…Previous analyses suggest that the sampling protocol used here collects around 60% of species present in the wetland at the time of collection but Halse, Pearson et al (2000) and Halse, Cale et al (2002) concluded that this was sufficient to characterise wetland communities using multivariate analysis. Likewise, Growns et al (1992) found that comparable sampling effort was sufficient to produce a useful classification of wetlands on the Swan Coastal Plain. Such characterisations are most easily translated into regional conservation planning when identified community types arc uniquely associated with particular assemblages and occur in distinct and easilv identifiable habitats.…”

“…Most other surveys have been restricted to particular types of wet lands and so are not of comparable scope. For example, the 41 sites on the Swan Coastal Plain surveyed by Growns et al (1992) were all lentic basin wetlands. In that survey, three mildly saline lakes and a secondarily acidic lake were outliers but the remaining wetlands, all freshwater, grouped according to physico-chemistry (nutrients and colour) and seasonality.…”

Macroinvertebrate responses to regime shifts caused by eutrophication in subtropical shallow lakes

“…In contrast, Tubificidae and Chironomidae increase with eutrophication (Brinkhurst and Cook 1974, Wiederholm 1980, Gyorgy and Judit 1983, Wolfram 1996. Increased levels of eutrophication are often accompanied by a decline in macroinvertebrate diversity (Donohue et al 2009), an increase in density, and a decrease in wet biomass (mollusks with shells) (Crowns et al 1992, Wollheim and Lovvorn 1995, Gong and Xie 2001, Xiong et al 2003. However, most previous research has been restricted to local-scale studies, i.e., in a single lake or in a few lakes (Saether 1980, Kerovec et al 1989, Gong et al 2000, Xiong et al 2003, Timm et al 2006, and few studies have covered a complete range of nutrient concentrations (Brauns et al 2007a, Donohue et al 2009).…”

Not really white - again: performing Jewish difference in Hollywood films since the 1980s

“…These orders are both well represented in aquatic systems (Gullan and Cranston 2005) and studies on Western Australian waters have frequently identified them among the most diverse insects. For example, high diversities of coleopterans and dipterans have been recorded from wetlands on the Swan Coastal Plain Growns et al 1992;. The two groups were also identified as the most diverse orders in a study of water bodies in the north-west of the state .…”

“…Monitoring of various parameters provides insight into the functioning of the systems and is of growing importance as water quality issues such as acidification become more prevalent. Previous studies in the south-west including the Swan Coastal Plain (Growns et al 1992;Schmidt and Rosich 1993; and the Wheatbelt region Halse et al 2003;Blinn et al 2004;Cale et al 2004;Pinder et al 2005) …”