Globally, digging animals are increasingly recognised for their ecological importance, performing functions vital to soil health, nutrient cycling and ecosystem resilience. In Australia, a number of these species have been lost, with many others threatened and suffering severe range declines. The southern hairy-nosed wombat, Lasiorhinus latifrons, is one of the world’s largest digging herbivorous mammals, yet its ecological role remains poorly understood. Found across southern South Australia, a region dominated by agriculture, this species is often perceived as a pest and actively removed.
Despite inhabiting semi-arid to arid environments, characterised by nutrient-poor soils, erratic rainfall and limited shelter, L. latifrons has been largely excluded from ecological assessments. These regions are especially vulnerable to climate change, making the ecosystem functions of remaining digging species potentially more critical than ever. Because L. latifrons may be the only significant surviving ecosystem engineer across much of its range, understanding its functional role is essential; not only for its conservation, but for the resilience of the ecosystems it inhabits.
This study began by investigating the initial impacts of L. latifrons on soil properties. Lasiorhinus latifrons activity was found to reduce soil compaction by approximately 78% through the removal of the physical crust and the disruption of compacted layers. This resulted in increased water infiltration rates of 118–295% at L. latifrons disturbed sites. Vertical water infiltration also improved by 119–209%, promoting water percolation to lower levels, reducing water loss through surface evaporation. Additionally, L. latifrons diggings capture organic matter enhancing soil moisture retention, further increasing water availability to other species.
These changes influence vegetation dynamics, including plant density and percent vegetation cover. Within L. latifrons range, plant density increased by an average of 168% compared to areas outside their range, with vegetation cover enhanced by some 50–140%. An indicator species growing over warren systems showed seasonal increases in moisture content ranging from 7% up to 95% and maintained its moisture levels more effectively than plants growing in undisturbed areas even under severe drought conditions. Laboratory analyses also detected mycorrhizal fungi in L. latifrons faeces, suggesting that L. latifrons may act as a vector for fungal dispersal—an important factor in supporting plant health and ecosystem diversity.
Camera trap data revealed that L. latifrons provides critical refugia for other native vertebrates through its subterranean systems. Additionally, areas of L. latifrons digging facilitated increased vertebrate visitations possibly through augmenting the capture of organic matter across the landscape. While this study was conducted during severe drought conditions, it documented a relatively high number of species visiting L. latifrons subterranean systems, indicating their potential role as refuges under environmental stress.
The course of this research also necessitated addressing two additional subjects of concern: (1) the definition of external warren architecture and its implications for population estimates, and (2) the impacts of drought on L. latifrons.
1. Entrances into L. latifrons subterranean system have often been generically referred to as burrows, yet this study found that only one of several tunnel types that were identified by an entrance serves the functions of a true burrow. Differentiating and defining the entrances and tunnel types improves the accuracy of population estimations, which have traditionally relied on active entrances as the primary statistic by acting as a proxy for L. latifrons. Also risking overestimation is the inclusion of abandoned warren systems which are indistinguishable from active systems when viewed in aerial and satellite imagery. These abandoned systems are therefore retained in the count and add to L. latifrons population estimations even though they are not in use. This has dire implications for a species often considered a competitor for agricultural land use.
2. Camera traps observations showing emaciated and unhealthy L. latifrons individuals supported existing literature that drought poses a serious threat to this species. Coupled with habitat loss from climate change and the potential for overestimated population figures that increase the potential for persecution, this research underscores an urgent need for reassessment of management strategies.
This seminal research contributes to establishing L. latifrons as a keystone functional species whose activities provide critical ecosystem services across its range. However, L. latifrons is increasingly threatened by anthropogenic pressures and is in urgent need of recognition as a vital contributor to ecosystem health in semi-arid and arid Australian landscapes.