Back to the Future: Understanding Kangaroo Island’s fire and water history to plan for the future

Lashmar's Lagoon, Kangaroo Island

Join us for an evening of 'science in the pub' featuring scientists from the University of Adelaide and Kangaroo Island Landscape Board.

Australian lakes past and future

  • Jonathan Tyler, Senior lecturer in Earth Sciences, University of Adelaide

Lakes are relatively scarce in the Australian landscape, yet they hold tremendous value –as sites of ritual for First Nations people, as economically and culturally important places for recreation, fishing and tourism, and as habitats for threatened ecosystems.

Lakes are also important recorders of environmental change: their sediments retain long histories of climate change, hydrological variability, vegetation and fires, thus contributing to extending our knowledge of the history of Australia’s environment, and the natural causes and frequency of extreme climatic events.

In this talk, with examples from south-eastern Queensland and western Victoria, I’ll give an overview of our research at the University of Adelaide into the way lakes are responding to climate change over recent years and into the future.

I’ll also talk about the ways we use lake sediments to better understand long term droughts, and how our ongoing research on Kangaroo Island can contribute to this bigger picture.

A hot (muddy) mess: piecing together the past 7000 years of fire on KI from ancient lake mud

I’ll be talking about a very hot topic –fire. Unravelling past patterns of fire can help us understand what's happening today and what might happen in the future.

That’s why I’m trying to piece together the past 7000 years of fire on Kangaroo Island using little bits of charcoal trapped in ancient lake mud. Lake mud builds up year after year, so the deeper down we go, the further back in time we travel. The more charcoal in one layer of mud, the more fires there were at that time.I’m also trying to work out what kinds of environments and climates might have led to big fires in the past. For this reason, I've been extracting ancient DNA from the same mud to see what was living in and around the lake before and after big fires. We can also measure chemical signatures in things like shells to give us clues about past droughts and rainfall.

Reading the landscape to secure water for the future

The Board are supporting Kangaroo Island landholders with their water management decisions by developing property water security plans with precision maps. The plans will help landholders read the landscape and forecast how water security changes with climate. The plans use high resolution elevation survey data (Light Detection and Ranging technology), water resource health surveys (water bugs and riparian vegetation) and climate change scenarios. 

The water security plans include waterbody water security ratings, capacity, surface areas at capacity, catchment areas, slope, drainage lines, flow routing, erosion scars, land classes. The maps allow the reading of the landscape to identify optimal dam locations and inform property planning that looks after water dependent ecosystems.

Tagged in For everyone, For industry, Research seminar