Buffel Grass- fires and biodiversity impacts

Buffel Grass is a weed that has spread across central and northern Australia. It has the potential to massively increase the fire risk in northern Victoria and destroy our natural areas:

Buffel grass destroys habitat

Buffel Grass is a transformer weed. It can change the character of vegetation over substantial areas. The threats from Buffel grass in arid and semi-arid areas of Australia are at least, or greater than, the threat posed by invasive animals. Buffel Grass can also threaten riparian systems, inhibit the abundance of native ground-layer plants, and reduce biodiversity.

The deep-rooted tussock growth forms dense stands and competes with native species including native grasses and wildflowers. This reduces food sources and habitat for native fauna, including reduced habitat patchiness. The cover of Buffel Grass is negatively associated with species richness, including a reduced diversity of invertebrates.

Buffel Grass is a perennial species. As it dries off between periods of growth, a high volume of dry plant material can accumulate, contributing to intense fires. Buffel Grass fueled fires are hotter, larger and more frequent than native grass fires. In Central Australia, the altered fire regimes have transformed woodlands into highly flammable grasslands by killing fire-sensitive woody vegetation.

Recent research documenting the impacts of Buffel Grass is well summarized in Ryan-Colton (2020) The Buffel kerfuffle: how one species quietly destroys native wildlife and cultural sites in arid Australia.

The impacts of Buffel grass are summarised in Read et al. (2020) Ranking Buffel: Comparative risk and mitigation costs of key environmental and socio-cultural threats in central Australia

Buffel Grass and fire

High fuel loads from Buffel Grass are directly linked to increased fire risk. Buffel Grass fuels intense fires and exhibits quick regrowth supporting frequent subsequent fires. Because Buffel Grass is perennial, Buffel-fueled fires occur even in years without significant rainfall. Following high rainfall years, Buffel-fueled fires are particularly intense and extensive. By March 2024, 80% of the Northern Territory is expected to burn in Buffel-fueled bushfires.

There is a significant risk to human life and infrastructure from Buffel-fueled fires. In August 2023, a planned burn near Alice Springs escaped, threatening the town. Northern Territory Parks and Wildlife pointed to the amount of Buffel Grass as a key contributing factor. Buffel Grass has also been implicated in the 2023 Maui wildfires (Hawaii), that claimed 97 lives.

Buffel-fueled fires change the landscape aesthetics and impact tourism infrastructure. For example, almost half of Central Australia’s Tjoritija / West MacDonnel National Park (94,000 ha) was burnt in 2023. This included the closure of and impacts on the world-renowned Larapinta Trail wilderness walk.

There’s a great summary here:

Schlesinger & Judd (2019) “The summer bushfires you didn’t hear about, and the invasive species fuelling them” The Conversation, 12 March 2019