All herbivores, great and small, needed to maintain health of endangered grassy woodlands

by the Queensland University of Technology
3/24/2026

A new QUT-led study has found both grazing mammals and plant-eating insects together play a major role in maintaining the health of Australia’s endangered grassy woodlands.

The three-year study, conducted in lowland grassy woodlands of New South Wales’ Bega Valley, found that removing all herbivores, including insects, caused a shift in plant dominance.  

QUT PhD researcher Nadia Chinn, who led this study jointly with Dr Gabrielle Lebbink (now with DETSI), from QUT’s School of Biology and Environmental Science, said that through repeated defoliation, animal and insect herbivores helped the dominant native Kangaroo grass (Themeda triandra) maintain its vigour, and limit opportunities for the spread of invasive species. 

“Lowland grassy woodlands are listed as endangered in NSW and critically endangered under federal legislation,” Ms Chinn said. 

“The global expansion of agriculture and other human activity has seen the intentional and accidental introduction of non-native pasture plants, which may spread quickly, outcompete native species and alter ecosystem diversity and function. 

“Livestock grazing can further contribute to the success of some invasive pasture grasses, often at the expense of native plant species and particularly in areas with a shorter evolutionary history of non-native grazing animals, like Australia.” 

Keep reading: https://www.qut.edu.au/news?id=203856

Read the Ecology paper: https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecy.70350