Rehabilitation Lottery

Natural regeneration in arid landscapes is driven by rare wet years often separated by decades.

When the Sprigg family purchased the Arkaroola property in 1968, there had been no regeneration of native pine and mulga for eight decades. A bracket of wet years in the 1970’s triggered a massive regeneration event. With stock removed and grazing pressure reduced, seedlings had a much greater chance of survival. Further regeneration events occurred in 1984 and 1989.

However a single rain is unlikely to initiate a regeneration event. Tropical lows occasionally dump 150 millimetres or more in just a few hours. Seeds germinate, often within days. But without followup rains many seedlings perish. 12 to 15 months of regular rainfall are required to establish new stands of native pine and mulga. The notion of rehabilitation as a condition of approval for mining or mineral exploration, is  fundamentally flawed.

The land surface may be reinstated and seeded. However without suitable rain events,preferably soon after treatment, seed is vulnerable to harvest by birds, ants and other invertebrates, disturbance by wind, may have short-lived viability, or may be lost in a severe storm. Without plants to bind it, soil remains highly erodable. Although mining companies are required to rehabilitate disturbed areas this does not ensure that the sites will be successfully reinstated, especially in steep mountainous terrain in arid areas. Rehabilitation does not guarantee regeneration.

In a region where drought is the norm, wet years the exception, and climate change predicted to deliver wilder storm events but lower annual rainfall, it is less likely that obligatory rehabilitation will result in disturbed ground returning to pre-disturbance condition. Tracks, drill sites and other disturbed areas will probably take decades to repair.

We have a choice – the land could remain undisturbed and natural systems given every chance to adapt to climate shifts.

Extract from Arkaroola Wilderness Sanctuary’s From the ARK e-newsletter – reprinted with permission