Our planet is on the precipice of a sixth mass extinction event so stated no other than the Prince of Wales. But unlike the five previous mass extinctions, this one is man-made. The fundamental driver behind this biodiversity crisis is the unprecedented success of a single species – humans – to manipulate and alter the environment (including moving other species around) to serve its needs. A key cause is agriculture. While it has enabled humans to prosper and occupy all corners of the globe, it has also been the most profound agent of ecological change in the history of life on Earth. The trade-off between conservation and production is rarely clear-cut.
We have to feed an extra 2.5 billion people by 2050.
Simply put, there are two options:
1) convert more land for agriculture;
2) increase yields from existing agricultural land.
(It should be minded that the present food that is produced is mis-distributed and that there exists a large amount of food waste)
“land sparing vs. land sharing”
Should we be encouraging intensification of agriculture, to get the most out of every farmed hectare, and spare as much “natural” habitat as possible (known as “land sparing”)?
Or should we be encouraging “land sharing”: using “wildlife-friendly” farming, despite such methods generally producing smaller yields? (Of course, smaller yields mean more land conversion is needed to produce the same amount of food.)
The researchers found that more species of trees and birds survive under “land sparing” than “land sharing”. There can never be a single, simple answer to the “land sharing vs. land sparing” debate. Can we save all species? Should we try? How much land do we need to protect to conserve species? Where should those reserves be located in the landscape? Is a dichotomy between conservation reserves and agriculture really helpful? Even in “frontier” landscapes where virgin habitat is being converted into farmland, decisions about how much land to spare and where to spare it are more often influenced by economics than ecological considerations.
While shifting from low- to high-intensity farming is generally bad for wildlife, shifting from forest to even low-intensity farming is generally disastrous. As agricultural output increases, there are two possible scenarios. If production intensity is ramped up but forest conversion is minimised, far fewer species decline dramatically. If land is shared, species decline more rapidly.
European agro-ecosystems are fundamentally different from recently converted forests. In Europe, traditional agricultural practices have operated for millennia, and modern conservation goals in Europe are generally entwined with those agroecosystems. On the other side of the equation, there is far greater potential for increased yields such as in Ghanaian farming systems than those in Europe (or Australia). So it seems likely there would be more “winners” from wildlife-friendly farming in Europe than in a region from which most of the forest system has been cleared within the past hundred years.
Intensive agriculture often relies on significant fertiliser use increased fuel use, and chemicals (although some of the “low-intensity” systems they studied involved high chemical use, too). All of these things affect biodiversity well beyond the tilled field, but their impacts are difficult to quantify. And what of the long-term sustainability of the production systems themselves? If we choose intensive farming, will the less-biodiverse system be less resilient and decline in productivity, requiring us to clear more land anyway?
Can we save nature and feed the world? We have no choice but to try but what requires to be recognised is that the best opportunity will only be within system of society that does not prioritise profits.
Adapted by SOYMB from two articles by Martine Maron and Jim Radford
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