In Australia’s logged forests natural regeneration is not enough

In southwestern forests, 19% of cleared areas have not experienced natural regeneration. Poor management practices and climate change are determinants

by Matteo Cavallito

 

The use of poor management practices and the consequences of climate change are making the natural regeneration of forests after logging less and less effective. A phenomenon that appears evident in light of the numbers over the long term. This is according to a research carried out in Australia that looked at the case of forested areas in the state of Victoria, in the southwest of the country. Where, say the authors, about one-fifth of the land affected by logging has not been able to restore itself in 40 years.

“Following the end of native logging in Victoria on January 1 2024, the state’s majestic forests might be expected to regenerate and recover naturally,” the researchers wrote in a subsequent article published in The Conversation. “But our new research shows that’s not always the case.”

Failure to regenerate affects 19 percent of deforested forest.

Victoria, researchers say, “is home to some of the most spectacular forests on the planet.” Its forests are home in particular to mountain ash, the world’s tallest flowering plant, which can reach nearly 100 meters in height. These environments maintain a strong cultural significance for indigenous peoples, support many recreational and tourism activities, and finally provide numerous ecosystem services including carbon sequestration, which, precisely in ash forests, reaches one of the highest concentrations per hectare on a global scale.

For many decades, the researchers recall, these areas have been cleared for timber and pulp, leaving nature to regenerate the plants. But with what effects?

To answer this question, the authors used satellite data and data from official records on logging operations collected over four decades. The results speak for themselves: “We found that 19.2 % of areas logged between 1980 and 2019 in our study area (8030 ha of 41,819 ha cut) were characterized by regeneration failure,” they explain.

The situation has worsened over time

The study, by three scientists from the Australian National University in Canberra and published in the Journal of Environmental Management, found that the phenomenon has been fostered by highly inappropriate forest management choices. Key critical factors include the choice of the problematic clear-cutting, which exposes areas to erosion; logging on steep slopes, where soil loss is greatest; and the lack of remedial interventions such as planting, weed control and protection from grazing.

But that is not all. Particularly serious, in fact, is the temporal progression of failure. “There was strong evidence of a significant increase in the extent of failed regeneration over the 40 years of our study, increasing from an average of <2 ha per cutblock in 1980 (∼7.5%) to an average of >9 ha per cutblock in 2019 (∼85%),” the research states.

Climate change affects forest recovery

Exacerbating the problem in forests, however, is another determining factor: climate change. Indeed, the study shows that regeneration failures have increased in recent years despite a gradual decline in the extent of logging. This suggests that rising temperatures have an increasing influence regardless of the intensity of forest activities.

The problem is most evident in Australian eucalyptus forests in central Victoria. Indeed, these plants are highly dependent on cold, wet climates and regenerate successfully only under very specific conditions and in any case not compatible with those experienced by the region during the period under review: rising temperatures and reduced rainfall. It is no coincidence that failure to regenerate increasingly affects “cutblocks at lower elevations” che “experience warmer temperatures.”

A new strategy is needed

Current post-cutting regeneration methods, in short, are not sufficient to ensure the recovery of forest cover. Therefore, the scientists explain, new large-scale restoration strategies are needed. Among the suggestions in the research are banning logging on too steep terrain, initiating assisted planting in the most vulnerable areas, and integrating restoration into environmental funding mechanisms. Which, the researchers recall, include, for example, the issuance of bonds.

“As part of a coalition of researchers, environmental organisations, and finance sector partners we proposed a A$224 million (almost 130 million euros, ed.) green bond for forest regeneration,” the authors write. “This proposal was put to the Victorian government via the Treasury Corporation of Victoria (the public entity that manages the state’s finances, ed.).”

Green bonds, in particular, would stimulate joint investments by the government and private partners to improve biodiversity monitoring and conservation in native forests. Other investments could include creating tourism initiatives and protecting wildlife by protecting habitats for endangered species.