Loss of Mountain Forests Threatens Biodiversity

Threatened species are coming under increasing pressure as a result of the loss, which was concentrated in tropical biodiversity hotspots.

Loss of Mountain Forests Threatens Biodiversity

Mountains are home to more than 85% of the world’s bird, mammal, and amphibian species, particularly in forest habitats. However, as reported by researchers in the journal One Earth on March 17, these mountain forests are rapidly disappearing.

Since 2000, we have lost mountain forest covering an area larger than Texas of 78.1 million hectares (7.1%). Threatened species are coming under increasing pressure as a result of the loss, which was concentrated in tropical biodiversity hotspots.

Mountain forests were once protected from deforestation by their rugged terrain, but since the turn of the twenty-first century, as lowland areas have become depleted or are under protection, they have been increasingly exploited.

The scope and geographic distribution of mountain forest loss were being studied by a team of scientists led by Xinyue He (@xinyue he), Dominick Spracklen, and Joseph Holden from Leeds University in the United Kingdom, and Zhenzhong Zeng from the Southern University of Science and Technology in China.

The team did this by monitoring annual changes in mountain forests from 2001 to 2018. They estimated the rate at which change is happening, quantified gains and losses in tree cover, compared different elevations and types of mountain forests (boreal, temperate, and tropical), and investigated the effects of this forest loss on biodiversity.

“Knowledge of the dynamics of forest loss along elevation gradients worldwide is crucial for understanding how and where the amount of forested area available for forest species will change as they shift in response to warming,” the authors write.

Although the significance of these various factors varied from region to region, logging was the main cause of mountain forest loss overall (42%), followed by wildfires (29%), shifting or “slash-and-burn” cultivation (15%), and permanent or semi-permanent agriculture (10%). Asia, South America, Africa, Europe, and Australia all experienced significant loss, but North America and Oceania did not.

The loss of mountain forests appears to be accelerating, which is alarming. From 2001 to 2009 to 2010 to 2018, we lost about 5.2 million hectares of mountain forests annually.

According to the authors, this acceleration is likely largely attributable to the rapid agricultural expansion into highland regions of mainland Southeast Asia as well as increased mountain forest logging as a result of either the depletion of lowland forests or the protection of these lowland forests.

Mountain forests in tropical areas suffered the greatest loss (42% of the total global loss) and the fastest acceleration rate, but they also recovered more quickly than mountain forests in temperate and boreal areas. Overall, 23% of the areas that lost their forests showed some signs of regrowing tree cover, according to the researchers.

Less forest was lost in protected areas than in unprotected areas, but the researchers warn that this may not be sufficient to protect threatened species.

The authors state that the crucial issue goes beyond just stopping forest loss when it comes to delicate species in biodiversity hotspots. We also need to keep forests intact in areas with enough space for ranging species and enough room for natural movement.

Additionally, the authors stress the significance of taking human livelihoods and wellbeing into account when formulating forest protection strategies and interventions.

The need for improved forest protection with ensuring food production and human wellbeing must be reconciled in any new measures to protect mountain forests, according to the report. The Southern University of Science and Technology, the University of Leeds, and the Chinese National Natural Science Foundation all provided funding for this study.