Redacción Ciencia (EFE).- Mountain forests are disappearing “at an accelerated rate” and since the year 2000 78.1 million hectares (7.1%) have been lost, a large part of them in areas of great tropical diversity , which means increasing pressure on threatened species.
More than 85% of the species of birds, mammals and amphibians live in the mountains, especially in forest habitats, and although their steep location had served as a protection, since the beginning of the century mountain forests have been increasingly exploited, as lowland areas are depleted or protected.
A study published today in One Earth by the Universities of Leeds (UK) and the Southern Universities of Science and Technology (China) investigated the extent and global distribution of montane forest loss.
Tropical montane forests experienced the greatest loss (42% of the global total) and the greatest acceleration, but also a faster rate of regrowth than montane forests in temperate and boreal regions.
Overall, the researchers observed some signs of tree cover regrowth in 23% of the areas that lost forest.
Main factors of the loss of mountain forests
Logging was the main factor in the loss of mountain forests (42%); followed by forest fires (29%); slash and burn crops (15%) and permanent or semi-permanent agriculture (10%).
The importance of these factors varied from region to region, with significant losses occurring in Asia, South America, Africa, Europe and Australia, but not in North America and Oceania.
The authors note that the rate of montane forest loss “appears to be accelerating,” with an annual rate increasing 50 percent from 2001-2009 to 2010-2018, when an estimated 5.2 million hectares of montane forests were lost. mountain per year
This acceleration is likely to be due, in large part, to rapid agricultural expansion into the mountainous areas of mainland Southeast Asia, as well as increased clearing of montane forests due to depletion of lowland forests or because these became protected.
Protected areas suffered less but may not be enough
Protected areas suffered less forest loss, but the researchers caution that this might not be enough to preserve threatened species.
With regard to sensitive species in biodiversity hotspots, the issue goes beyond simply preventing forest loss, as forest integrity must also be maintained over areas large enough to allow natural movements and enough space for species on the move.
The authors also stress the importance of taking human livelihoods and well-being into account when developing forest protection strategies and interventions.
“Any new measure to protect mountain forests – they write – must be adapted to local conditions and contexts and must reconcile the need to improve forest protection with that of guaranteeing food production and human well-being.”
The team tracked changes in montane forests annually between 2001 and 2018, to quantify both tree cover gains and losses.
In addition, they calculated the rate at which the changes occur, compared different elevations and types of montane forests (boreal, temperate, tropical) and explored the impacts of this forest loss on biodiversity.
Knowledge of the dynamics of forest loss along elevational gradients around the world is, according to the team, “crucial to understanding how and where the amount of forest area available to forest species will change as forest species grow.” move in response to warming.