Farming News - Agriculture’s role in worrying biodiversity loss

Agriculture’s role in worrying biodiversity loss

15 Jul 2016

New research backed by the European Commission has shown how the intensification of agriculture is driving biodiversity loss. Meanwhile a separate UN study has shown that biodiversity loss is now so great that the ecological systems on which humans rely are suffering. 

The EU-funded research, which appeared in the journal Global Environmental Change, tracks the effects of international food trade on different species, examining species losses linked to 170 crop types across 184 countries. The researchers behind the paper said most biodiversity loss comes from growing crops for domestic consumption, but that industrialised countries can ‘import’ negative impacts from tropical regions.

Biodiversity decline is a major issue; regions with a greater variety of species carry benefits for farmers from more reliable pollination to nutrient cycling, and more biodiverse ecosystems can withstand the effects of climate change better than depleted regions. However, human activity is driving a major extinction event. In the past 500 years, over 300 vertebrate species have become extinct, and many more are now directly threatened or vulnerable.

Agriculture is a major driver of declining biodiversity, and the increasingly globalised trade in agricultural produce, which began in the second half of the 20th Century, has driven declines in both the biodiversity of agricultural species and of farmed crops and varieties.

The EU-funded research paper published this month used the most up-to-date modelling to look at land use change associated with intensification of agriculture, but also examine species’ ability to adapt to these changes, to assess the overall impacts of modern agriculture on plants and wildlife.

The researchers estimate that wheat, rice and maize — which occupy around 40% of global  cropland — contributed a corresponding 40% to global biodiversity impacts. Crops grown in tropical regions, and commonly exported, including palm oil, sugarcane and coffee were associated with higher species losses, even though they occupy smaller areas of cropland.

Major findings include:

  • Produce travelling from Indonesia and Mexico to the USA and China had the highest impacts of any exports, accounting for the extinction of up to 20 species within the produce’s country of origin, though imports to smaller, rich nations including France, Germany and Italy also had significant impacts
  • Even so, the vast majority of species loss (83% or 4,747 species) was due to agricultural land used for domestic consumption
  • the remaining 17% (969 species) of losses were associated with food produced for export markets

According to the researchers, the losses are skewed towards tropical countries, meaning that food produced to supply Germany, for example, is responsible for the extinction of 46 species, though Germany itself only lost three, with 43 species being lost in other global regions as a result of food being produced and imported into the country. The researchers said western countries with ample growing areas could reduce their impact on global biodiversity by improving domestic food production and relying less on imports.

They said interventions in exporting countries can also prove effective, and gave the example of Brazil, where a soy moratorium has reduced deforestation and moves towards greater transparency have helped to reduce the market for beef and soy produced on deforested land.

Biodiversity losses fall below ‘safe’ levels

The EU funded research comes in the same week that environmental scientists at University College London warned that global biodiversity losses have fallen below ‘safe’ levels, and that losses may stop certain ecosystems functioning as they have been for thousands, or even millions of years, and in an alarmingly high number of cases, may not be able to support human societies.  

The UN-backed research, which appears in the journal Science this month, reveals that levels of biodiversity loss  around the world are so high that if left unchecked they could undermine efforts to achieve long-term sustainable development.

"This is the first time we've quantified the effect of habitat loss on biodiversity globally in such detail and we've found that across most of the world biodiversity loss is no longer within the safe limit suggested by ecologists" explained lead researcher, UCL’s Dr Tim Newbold. "We know biodiversity loss affects ecosystem function but how it does this is not entirely clear. What we do know is that in many parts of the world, we are approaching a situation where human intervention might be needed to sustain ecosystem function."

The team found that grasslands, savannas and shrublands were most affected by biodiversity loss, followed closely by many of the world's forests and woodlands. They say the ability of biodiversity in these areas to support key ecosystem functions such as growth of living organisms and nutrient cycling has become increasingly uncertain. For 58.1% of the world's land surface - home to 71.4% of the global population - the level of biodiversity loss is substantial enough to question the ability of ecosystems to support human societies.

This represents one of the nine ‘planetary boundaries’, thresholds which scientists estimate mark fundamental changes in the world’s functioning. Last year, scientists said humans have crossed four of nine planetary boundaries (including the change in biosphere integrity, of which biodiversity is a part).

"It's worrying that land use has already pushed biodiversity below the level proposed as a safe limit," said Professor Andy Purvis of the Natural History Museum, London, who also worked on the study. "Decision-makers worry a lot about economic recessions, but an ecological recession could have even worse consequences - and the biodiversity damage we've had means we're at risk of that happening. Until and unless we can bring biodiversity back up, we're playing ecological roulette."

UCL’s Dr Newbold said all data from the study has been made publicly available and hopes that policy makers will listen and try to enact real change. Pushing for possible remediation work in more built-up countries, Dr Newbold said, “The greatest changes have happened in those places where most people live, which might affect physical and psychological wellbeing. To address this, we would have to preserve the remaining areas of natural vegetation and restore human-used lands.”