New research has highlighted the importance of strategic land-use planning for achieving goals in bioenergy, climate change mitigation, and biodiversity restoration. While restoration is still the best approach to biodiversity, the study suggests that planting low-cost and low-maintenance crops grown solely for renewable bioenergy production, also known as ‘energy’ crops, on existing agricultural land can reduce biodiversity losses when compared to converting natural habitats. 

The study, published in Journal of Applied Ecology on June 30, 2024, emphasised that prioritising degraded or abandoned agricultural land for energy crops offers the greatest benefit. Planting energy crops in areas with high natural vegetation cover significantly reduces biodiversity, particularly in tropical regions, it said.

However, the study also found that energy crop plantations can, in some cases, be more beneficial for biodiversity than current agricultural practices. This is especially true for plantations with diverse plant mixes and in areas dominated by existing agriculture. This suggests that increasing landscape complexity can have ecological advantages.

The most significant positive impact on biodiversity would come from restoring priority areas for natural vegetation, rather than expanding energy crops. However, the study acknowledges that strategically planting energy crops on existing agricultural land presents a less harmful alternative compared to converting natural habitats.

The most significant positive impact on biodiversity would come from restoring priority areas for natural vegetation, rather than expanding energy crops. However, the study acknowledges that strategically planting energy crops on existing agricultural land presents a less harmful alternative compared to converting natural habitats.

The study looked at Biodiversity Intactness Index (BII) to determine this. BII are estimates how the average abundance of native terrestrial species in a region compares with their abundances before pronounced human impacts.

“Contrasting the spatial effects on BII of planting energy crops compared with restoring natural vegetation highlights places where energy crops could be the least detrimental to BII, such as Central Europe and the east coasts of the USA and China,” said the study. It was also found that plantations that replace existing agricultural land in West Africa could bring some benefits to BII levels, albeit small.

Replacing agricultural land with energy crops in optimal locations can minimize negative impacts on biodiversity, especially in regions like the United States and Europe. This approach could even lead to neutral or slightly positive changes in BII, as it provides additional perennial habitats for various species groups, including invertebrates and birds. 

Therefore, focusing on converting existing agricultural land rather than natural vegetation in these areas would be beneficial for biodiversity conservation, the research said.

Study suggests that, as far as biodiversity is concerned, it is always best to restore farmland to nature rather than re-plant it with energy crops. Yet, we are realists. In the future, more fuel will come from crops, and it is far better to plant them on existing farms than destroy remaining natural habitats. We have shown that where you plant those crops makes a huge difference to how many species continue to thrive.

Sophie Tudge, postgraduate research student, University of Surrey and the lead author