Oral Presentation Australian Society for Limnology Congress 2013

Ecological connectivity and environmental flows: thresholds for reconnection of wetlands and channels (#27)

Kim M Jenkins 1 , Claire Sives 1 , Rachel Blakey 1 , Skye Wassens 2 , Debashish Mazumder 3 , Martin Forest 1 , Luke McPhan 1 , Jordan Iles 1
  1. Australian Wetlands Rivers and Landscapes Centre, School of BEES, University of New South Wales, Sydney, NSW
  2. Institute for Land, Water and Society, Charles Sturt University, Albury, NSW
  3. ANSTO, Kirrawee, NSW

Ecological connectivity is a central concept in ecology that describes the movement of biota or food webs between discrete landscape features. In freshwater ecosystems, water provides the conduit for lateral and longitudinal movement of plants, animals and carbon sources.  This connectivity is pivotal to the function of floodplain rivers; governing genetic dispersal, reproductive cycles and booms in productivity. Establishing connectivity is often a goal of restoration projects, including large scale Commonwealth and State environmental watering actions.  Despite the significance of ecological connectivity, there is scant data confirming that hydrological connectivity leads to ecological connectivity, or the specific hydrological conditions that promote connectivity. In this paper we explore two types of ecological connectivity across a spectrum of flows. Firstly, we present evidence for a flow threshold in the transfer and uptake of allochthonous carbon from floodplains to biota in channel habitats. Secondly, we assess the movement of microinvertebrates between a river channel and associated wetlands following Commonwealth environmental watering actions. While the transfer of carbon sources and movement of fish are ecologically significant, we explore whether the flushing of microinvertebrates from wetlands into channels may provide a short-lived, but significant boost to productivity or is only a trivial food supply. Findings from these studies can be used to adaptively manage environmental water allocations, predicting outcomes for a range of flows.