Researchers walking through thick vegetation credit_Michela Mariani

Unprecedented Australian bushfire intensity linked to British colonisation

Wednesday, 16 February 2022

British colonisation of Australia, together with the effects climate change, is likely to have contributed to the recent catastrophic wildfires in southeast Australia, a new study has found.

An international team of researchers, led by the University of Nottingham, have examined the land cover changes that occurred after the British settlement in southeast Australia, which started in 1788.

By extracting tiny fossilised grains of pollen that are laid down in layers of ancient sediment in wetlands and lakebeds, the scientists were able to develop a picture of vegetation in the past.

Platform used to extract lake sediments containing fossil pollen grains in Tasmania, Australia © Michela Mariani

In a world first, they used pollen modelling techniques to find out what the vegetation was like at 52 different sites before and after 1788. The experts discovered evidence of denser vegetation in forests and woodlands following colonial settlement.

They found that forests in the southeast are now much denser than they were before 1788 and have become more flammable due to the amount of woody biomass there. The researchers found an increase of shrub cover by as much as 48%, with an overall average increase of 12% - which the researchers say, considering the vast area covered by the study, the “increase in biomass is massive”.

In the study, published in the academic journal Frontiers in Ecology and the Environment, the scientists say the increase in ‘shrubbiness’ is linked to Indigenous burning practices ceasing.

Dr Mariani collecting vegetation data in southeast Australia_Credit_Simon Connor
We know from historical reports that much of the landscape in early colonial southeast Australia was similar to an open savanna with grassy areas and large gaps between trees. This was described by an early English explorer as ‘a gentleman’s park’, very much reminding him of England.
Dr Michela Mariani, lead author and Assistant Professor in the School of Geography

Painting by Robert Hoddle, Ginninginderry Plains, New South Wales, Australia (1832), depicting the "open savanna" that Indigenous people maintained

The Indigenous people carefully managed this through lighting small fires to prevent flammable vegetation growing back and maintaining this largely open vegetation. After colonial settlement, fire management practices have become more oriented towards fire suppression, disrupting millennia of Indigenous cultural burning.

Dr Mariani explained: “Today, the increase in shrubs provides a connection from the ground to the forest canopy which allows fire to spread with ease, and this has led to the unprecedented fires we have seen in recent years. For example, the Black Summer bushfires (2019-2020) cost the Australian economy over $100 billion (AUD) and burnt a total of 18 million hectares - an area almost twice the size of England. During this event, about 20 per cent of Australian native eucalypt forests burnt down. This proportion of forest burnt is considerably high in comparison what has happened in the past few decades.

Climate change is undoubtedly having an impact on the intensity and scale of these bushfires, but forest management plays a big role too. Our research offers supporting evidence for implementing fire management practices more aligned to Indigenous cultural burning, in order to better manage forests and in turn help to manage fire behaviour in the future.
Dr Michela Mariani

The academics suggest that the Australian fire management agencies should seek to work with Indigenous people to implement new approaches to minimise the accumulation of flammable biomass and limit future risk of extreme wildfires.

High-speed video showing researchers extracting lake sediments using a platform. © Michael-Shawn Fletcher 

Drone footage taken by the researchers shows damage a few months after fire within forests that burnt during the 2019-2020 bushfires. © Michael-Shawn Fletcher

Story credits

More information is available from Dr Michela Mariani, in the Faculty of Social Sciences at the University of Nottingham at 

Katie Andrews - Media Relations Manager for the Faculty of Social Sciences
Phone: 0115 951 5751

Notes to editors:

The University of Nottingham

Our academics can now be interviewed for broadcast via our Media Hub, which offers a Quicklink fixed camera and ISDN line facilities at Jubilee campus. For further information please contact a member of the Press Office on +44 (0)115 951 5798, email

For up to the minute media alerts, follow us on Twitter

The University of Nottingham is a research-intensive university with a proud heritage. Studying at the University of Nottingham is a life-changing experience, and we pride ourselves on unlocking the potential of our students. We have a pioneering spirit, expressed in the vision of our founder Sir Jesse Boot, which has seen us lead the way in establishing campuses in China and Malaysia - part of a globally connected network of education, research and industrial engagement. Ranked 18th in the UK by the QS World University Rankings 2023, the University’s state-of-the-art facilities and inclusive and disability sport provision is reflected in its crowning as The Times and Sunday Times Good University Guide Sports University of the Year twice in three years, most recently in 2021. We are ranked seventh for research power in the UK according to REF 2021. We have six beacons of research excellence helping to transform lives and change the world; we are also a major employer and industry partner - locally and globally. Alongside Nottingham Trent University, we lead the Universities for Nottingham initiative, a pioneering collaboration which brings together the combined strength and civic missions of Nottingham’s two world-class universities and is working with local communities and partners to aid recovery and renewal following the COVID-19 pandemic.

More news…

Media Relations - External Relations

The University of Nottingham
C Floor, Pope Building (Room C4)
University Park
Nottingham, NG7 2RD

telephone: +44 (0) 115 951 5798