Agricultural expansion could cause widespread biodiversity declines by 2050

                              Journal: Nature Sustainability

     

A Colombian farmer working on his "finca". These patches of forest are given away at a low price by the government to farmers who then clear them up to grow crops. Photo by LAIF.

Almost 90% of terrestrial vertebrate species around the world might lose some of their habitat by 2050 as land is cleared to meet the future demand for food. However, according to a modelling study published in Nature Sustainability, proactive policies focusing on how, where and what food is produced could reduce these threats while also supporting human well-being.

Slashing is a common site on the Canadian prairies. Farmers cut and burn trees and shrubs to make way for more farmland. In this case, it's along the fringes of the Boreal forest in west-central Manitoba. A PinP photo.

Habitat loss driven by agricultural expansion is a major threat to terrestrial vertebrates. Projections based on human population growth and dietary needs estimate that we will need 2–10 million km2 of new agricultural land to be cleared at the expense of natural habitats. 

Conventional conservation approaches — which often focus on a small number of species and/or a specific landscape — may be insufficient to fight these trends. Adequately responding to the impending biodiversity crisis requires location- and species-specific assessments of many thousands of species to identify the species and landscapes most at risk.

David Williams, Michael Clark and colleagues developed a model that increases both the breadth and specificity of current conservation analyses. The authors examined the impacts of likely agricultural expansion on almost 20,000 species. 

Moose in Manitoba, Canada are being described as "imperilled."
The Canadian Parks & Wilderness Society (CPAWS) says they 
need "large, protected areas with healthy forests & wetlands."
Photo Credit - CPAWS.

They found that under current trajectories, 87.7% (17,409) of the terrestrial bird, amphibian, and mammal species in the analysis might lose some habitat by 2050, including around 1,200 species projected to lose more than 25% of their remaining habitat. Projected mean habitat losses were greatest in sub-Saharan Africa with large losses also projected in the Atlantic forest of Brazil, in eastern Argentina and in parts of South and Southeast Asia.

However, the authors also show that proactive policies, such as increasing agricultural yields, transitioning to healthier diets and reducing food waste, may have considerable benefits, with different approaches having bigger impacts in different regions.