5 Mar 2013

The on-going conversion of tropical habitats to cropland could jeopardise global efforts to halt the loss of biodiversity

By Tris Allinson

A new report in the journal PLOS ONE reveals the alarming rate at which tropical habitats are being cleared to make way for crops. The scale of habitat conversion predicted in the biodiversity-rich tropics could seriously undermine society’s capacity to meet internationally-agreed conservation targets.

Member States to the Convention on Biological Diversity have pledged to meet a range of conservation targets by 2020. These include commitments to at least halve, and where feasible bring close to zero, the rate of loss of all natural habitats, to ensure all agricultural lands are managed sustainably and to eliminate all harmful pollution, including those of agricultural origin. Researchers from the Cambridge Conservation Initiative—including scientists from BirdLife International and the RSPB (BirdLife in the UK)—found that cropland had expanded by c. 48,000 km2 per year from 1999–2008, with much new cropland being added in Nigeria, Indonesia, Ethiopia, Sudan and Brazil. The crops that expanded across the largest area during the period were soybeans and maize, whilst other crops with large increases include rice, sorghum, oil palm, beans, sugar cane, cow peas, wheat and cassava. It is estimated that in coming decades, cropland expansion in the tropics could impact an area the size of South Africa.

The report identifies a number of regions with high cultivation potential, including the fringes of the Amazon Basin, northern Australia, the Paraguayan Chaco, and the savanna woodlands of the Sahel and East Africa. It also suggests that places such as Africa’s Congo Basin, that were once thought to have only a low vulnerability to agricultural conversion, are becoming increasingly at risk of cropland expansion. If natural habitats in the tropics continue to be converted to cropland at the rates reported in the study, then the international community’s efforts to achieve biodiversity targets by 2020, as agreed through the Convention on Biological Diversity, could be derailed. It is vital that ways are found to feed growing human populations, while limiting unnecessary cropland expansion and lessening its environmental impacts where it does occur. To read more about the issue click here. To read the report in full click here.