WTMA 2020 Revegetation Costs: Ecological tree-planting and pasture conversion costs on the southern Atherton Tablelands
Compiled by Amanda Freeman from contributions by Carla Catterall, Kylie Freebody, David Hudson and Cath Moran.
Summary
The southern Atherton Tablelands has been a focus of rainforest revegetation efforts in the Wet Tropics region for over three decades. Aiming to restore biodiversity and ecological function, most revegetation has used biodiverse tree-planting, the cost of which is an obstacle to larger-scale restoration efforts. Emerging methods to convert disused pasture to forest by catalysing natural regeneration involve suppressing exotic grasses and managing the resulting regenerating vegetation. The "Kickstart Pasture Conversion Trials" and "Cloudland Expanded Kickstart Natural Regeneration Project" demonstrate that vegetation cover can be promoted by these means. However, compared to biodiverse tree-planting, it takes longer to establish cover to the point when maintenance treatment with herbicide can stop. As pasture conversion methods minimise the cost associated with tree-planting, they have potential to significantly expand rainforest revegetation at lower unit cost.
This WTMA report examines the costs of biodiverse tree-planting on the southern Atherton Tablelands through time and compares the direct costs of biodiverse tree-planting versus pasture conversion at one experimental project site. Although there is wide variation depending on scale and site-specific factors, the cost of an "average" biodiverse tree-planting on the Atherton Tablelands has remained essentially the same over 25 years. At $34 - $39K/ha, this method of rainforest revegetation remains costly and therefore relatively small scale. At $7-$9K/ha, emerging pasture conversion techniques show promise as cheaper alternatives, conceivably facilitating vegetation establishment for as little as one quarter of the cost.