Rainforest clearance for cattle pasture causes far greater biodiversity loss than estimated

The researchers conducted the largest investigation into birds in the world, recording 971 different species living in forests and cattle pastures in the South American country in Colombia. This represents almost 10% of birds around the world.

They combined the results, collected over a decade, with information on the sensitivity of each species to the conversion of the habitat to note that the loss of biodiversity caused by the cleaning of the tropical forest for cattle pastures is on average 60% of worse than what thought before.

Until now, understanding the impact of the biodiversity of the change in land use has generally involved local small -scale local surveys. Researchers say that this approach does not represent the larger -scale damage caused to nature.

When the forests are converted to pasture, some species gain and others lose. Measuring the loss of biodiversity on a local scale does not capture the larger -scale effect of forest conversion, which occurs through the ranges of many different species. Although the same species generally survive Pettureland, a wide range of other species do not do so, overall biodiversity is therefore more seriously reduced on a large scale.

The results are published in Ecology and evolution of nature.

Professor David Edwards of the Department of Vegetable Sciences and Conservation of the University of Cambridge, principal author of the report, said: “This is a really surprising result. We have found that the loss of biodiversity caused by the cleaning of the tropical forest for Pettureland is massively underestimated.”

He added: “When people want to understand the broader impact of deforestation on biodiversity, they tend to make a local survey and to extrapolate the results. But the problem is that the clearance of trees occurs on massive spatial scales, in all kinds of habitats and different elements.

“When we have examined the impact of deforestation biodiversity through 13 different ecoregions in Colombia, we found a loss of biodiversity of 62% more than the results of the local survey.”

The study has also shown that at least six different eco -regions – that is to say the regions containing distinct types of plants and animals – must be considered for a precise evaluation of the overall impact of biodiversity. Indeed, the species of different ecoregions have different sensitivities to the conversion of habitat.

Biodiversity compensation patterns, which aim to compensate for the loss of species caused by developments in one place by stimulating biodiversity in another, are counting on precise biodiversity measures.

The trees are also released on a huge scale in Colombia and other tropical regions to create a growth space for large agricultural crops, including rubber, oil palm, sugar cane and coffee.

Edwards said: “The food we eat has a much higher environmental cost than we thought. We need political decision -makers to think much more about the impact of biodiversity on a larger scale of deforestation.”

Tropical bird song recordings

The team studied the life of the birds of Colombia through its various landscapes for more than seven years, recording the song of hundreds of bird species to help them identify the species present in landscapes across the country, from pasture to the mountain forest. In around 80% of cases, the birds were heard but not seen, forcing the team to make identifications from only sounds.

With information on birds, including their size and diet, the team could predict which other species probably lived in the same regions and how they too would react to deforestation.

A highly biodiversity country

Colombia is home to some of the most beautiful and exotic animal and vegetable lives in the world, with almost a third composed of tropical forest.

The areas in particular biodiversity, including the humid forests of the Caqueta and the humid Napo forests, can have 500 to 600 species of different birds in an area of ten square kilometers, but many of these species have very specific housing needs. The study has shown that if the trees are released from their distribution area, these species are likely to go out.

The change of land use, especially in the highly biodiversity tropics, is one of the main causes of the global biodiversity crisis.