Professor David Hannah, who holds the UNESCO Chair in Water Sciences at the University of Birmingham, is a co-author of the paper. He said: “Scientists and policymakers need to work closely to translate scientific knowledge into action. We need to be designing forests and agricultural systems that embrace and enhance diversity. This approach is essential if we are to preserve the natural resilience of our water-dependent ecosystems and provide better stewardship of the Earth’s finite water resources.”
The authors of the paper argue that, while land-use cover change can be well intentioned—whether it is done to increase carbon sequestration or meet food, water, and energy demands—it can have unintended consequences that affect the water cycle.
Plant uniformity in highly managed landscapes that have replaced wetlands, for example, has been linked to increases in the frequency and severity of both floods and droughts, as well as the deterioration of water quality. Elsewhere, the growth of maize monocultures to produce ethanol and biodiesel in the United States are projected to increase areas at risk of groundwater nitrate contamination. And tree plantations grown to meet the demand for wood can reduce or even eliminate streams, leading to soils becoming more acidic or salinated and with increased susceptibility to fire.
In contrast, a more biodiverse system has trees and plant with different architectures, both above and below the ground, leading to a robust, natural system.