The big picture: Prospects for ecological engineering to guide the delivery of ecosystem services in global agriculture

Feeding an estimated nine billion people by the year 2050 will be challenging. Though controversy surrounds the extent to which food production needs to increase, versus a focus on distributional issues and reduced waste, there is a need to reduce the environmental impacts of current farming practices and to avoid further depletion of biodiversity. Over the last century, biodiversity loss has accompanied agricultural intensification so a business-as-usual scenario gives little cause for optimism. In the last decade, studies in many countries have demonstrated the benefits of 'alternative' agricultural systems that can be as productive as conventional agriculture on a per-hectare basis, despite requiring fewer pesticides and fertilizers. These systems employ ecological intensification whereby ecosystem services such as nutrient provisioning, natural pest control, and enhanced pollination replace anthropogenic inputs. Enhancement of biodiversity in these systems is not confined to planned diversity such as multiple crops but includes many other taxa to the extent that farmlands can be important complements to nature reserves and other protected areas. Ecological engineering is one approach that can guide the diversification of farmlands to deliver multiple ecosystem services agricultural intensification based on an ecological evidence base offers significant scope for a win'win scenario whereby future food production needs are more strongly supported by ecosystem services whilst simultaneously motivating farmers to accommodate biodiversity.