Mountain forests are disappearing at an alarming rate: study

WASHINGTON — Logging, wildfires and agriculture are causing mountain forests, home to 85 percent of the world’s birds, mammals and amphibians, to disappear at an alarming rate, according to a study released Friday.

Mountain forests covered 1.1 billion hectares (2.71 billion acres) of the planet in 2000, said the authors of the study, published in Cell Press’s One Earth journal.

But at least 78.1 million hectares — an area larger than the US state of Texas — have been lost between 2000 and 2018, with recent losses being 2.7 times greater than at the start of the century.

The main causes of the loss are commercial logging, wildfires, slash-and-burn agriculture and commodity farming, said the authors, from China’s Southern University of Science and Technology and the University of Leeds.

Of particular concern is the severe forest loss in mountainous areas, which are “tropical biodiversity hotspots” – havens for rare and endangered species.

High elevations and steep slopes have historically limited human exploitation of montane forests, the authors said. Since the turn of the century, however, they have increasingly been used specifically for wood and agriculture.

Commercial forestry was responsible for 42 percent of montane forest loss, followed by wildfires (29 percent), shifting cultivation (15 percent), and permanent or semi-permanent commodity agriculture (10 percent), the study found.

In shifting cultivation, a crop is grown on a piece of land for a few years and then left until it becomes fertile again.

“The drivers are different for different regions,” said Zhenzhong Zeng, a co-author of the study, with wildfires being the main cause of loss in high-latitude boreal forests.

“In boreal areas, it is caused by climate change because there is an increase in temperature and a decrease in rainfall,” Zeng told AFP.

“We must reduce fossil fuel use to slow global warming.”

Commodity agriculture is a major reason for the loss of montane forests in Southeast Asia, the authors said.

“People plant more rubber or palm farms to make more products,” Zeng said. “People need more land to grow corn to feed their chickens.”

Shifting cultivation is prevalent in tropical Africa and South America.

– “The effect is enormous” –

The authors said the largest forest loss observed using satellite data during the study period occurred in Asia — 39.8 million hectares — more than half of the world total.

South America, Africa, Europe and Australia also suffered significant casualties.

“Mountain forest loss in the tropical areas is increasing very rapidly, much more than in other regions,” Zeng said. “And the biodiversity is very rich there, so the impact is huge.”

“For tropical areas, we need to get people to live with the forest, not cut down the forest,” he said.

Xinyue He, another co-author, said regrowth has been observed in some areas, but native species are not always involved and have not kept pace with forest loss.

She said there must be better forest management, including stricter enforcement of laws and regulations.

“Protecting areas can help reduce loss,” she said.