A multi-proxy palaeolimnological study in Kings Billabong in the Murray River System, Australia:a test of resilience
A resilient floodplain wetland ecosystem of large rivers reflects how it has evolved as a distinct ecological regime with high biological diversity. The fluvial systems in the River Murray in southeast Australia are some of the most variable flow regimes in the world adapted to natural cycles of flooding and drying maintaining floodplain connectivity. However, the river regulation following the arrival of Europeans in the early 19th century has transformed the hydrology of the River Murray system significantly. Kings Billabong, one of floodplain wetlands of the River Murray system has become permanently inundated following the regulation of this river. We used a multi-proxy palaeolimnological approach to identify whether the impact of anthropogenic and climatic changes in the River Murray altered ecological resilience of Kings Billabong. Carbon and nitrogen isotope ratios in bulk sediment showed a strong shift in their enrichments at a time of regulation. Subfossil assemblages of cladocerans and diatoms also showed shifts between planktonic and littoral assemblages after regulation. The percentage of LOI reflected the period of extreme drought together with effect of regulation. Our results indicate that the multi-proxy palaeolimnological technique is significant to test ecological resilience of the highly regulated river system in southeast Australia. However, given the complex nature of ecosystem with a range of external and internal driving forces and feedback mechanisms involved, a more refined technique on stable isotopes analyses of carbon and nitrogen is required in producers and consumers, including subfossil diatoms and cladocerans for comprehensive understanding of the resilient system.
Australia northwest Victoria Murry River floodplain wetlands Kings Billabong stable isotopes of carbon and nitrogren cladocerans diatoms ecological resilience
G.Kattel P.Gell R.Grundell A.Zawadzki L.Barry
Collaborative Research Network (CRN), University of Ballarat, Mt Helen, Ballarat, Vic 3350, Australi School of Science, Information Technology& Engineering, University of Ballarat, Mt Helen, Ballarat, ANSTO Institute of Environmental Research, Kirrawee DC, NSW 2232, Australia
国际会议
The 3rd Biennial ISRS Symposium Achieving Healthy and Viable Rivers (ISRS)第3届国际河流大会
北京
英文
13-21
2013-08-05（万方平台首次上网日期，不代表论文的发表时间）