Researchers find monocultures negatively impact terrestrial water cycle

In the UK, the global spread of vast forest plantations and agricultural monocultures are turning once diverse landscapes into areas of land supporting single plant species, with profound implications for our terrestrial water cycle, according to new research.

A new paper published in Nature Geoscience, and written by a global collaboration of interdisciplinary researchers studying ecohydrological systems, calls for policymakers and practitioners to consider these water-vegetation interactions in their land management decisions.

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 corn monocultures to produce ethanol 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.