Australia is dominated by 6 million km² of rangelands that contribute significantly to the livestock industry and carbon market; yet, few studies have quantified the influence of grazing management on woody biomass and carbon stocks across these rangelands. Although grazing exclusion can sometimes facilitate carbon stock accumulation, it is difficult to predict when and where this would occur.

Carbon farming projects in the Australian rangelands routinely use remotely piloted aircraft (drones) to validate vegetation maps. This data collection can be leveraged to provide detailed ecological insights into rangeland ecosystems. Combining drone-derived structural information with ground-based botanical surveys, this paper showcases a method for comprehensive vegetation condition assessment at the property scale. This approach has potential to enhance understanding of ecosystem responses to land management changes across large areas of rangelands.

This article belongs to the collection: Carbon and environmental service markets.

We examined germination conditions for the common Mallee species Eucalyptus costata. Our study found that germination was lowest at high temperatures (35°C/25°C), high salinity (>100 mM), and low water potentials (taking 14 MPa of humidity per day to germinate). Sowing seed deeper than 2 cm reduced emergence. These results suggest that the optimal germination is likely to occur with shallow sowing in low-salinity soils during cool or mild wet conditions. Despite being an arid species, Eucalyptus costata is intolerant of hot and dry conditions, and planting should be focused on mild and wet periods.

Decreased grazing and/or cessation of land clearing are being used across Australian woodlands for sequestration of carbon from regeneration of woody biomass, with estimates of this sequestration being predicted using the empirical carbon accounting model FullCAM. FullCAM predictions were found to be accurate across a wide range of sites, but with further improvements possible in terms of its domain of application, specificity with which it stimulates changed grazing management, and comprehensiveness to account for standing dead pools of woody biomass.