Sir

Your News story 'Putting China's wetlands on the map' (Nature 458, 134; 2009) points out that almost 30% of China's natural wetlands vanished between 1990 and 2000. It is time for the country to restore these natural wetlands and, in view of their ecological importance, to construct some artificial wetlands to supplement them.

Wetlands include tidal marshes, mangroves, swamps and flood plains. They contribute the largest sector of total terrestrial ecosystem services — for example, flood mitigation, water-quality improvement, habitat biodiversity and landscape aesthetics. Their alarming rate of disappearance in China can be blamed on conversion to farmland and on pollution from point and non-point sources.

China is putting a massive stimulus package in place to boost the economy, covering the infrastructure of transportation, medical care, education and industrial upgrading. Water regulation is also a vital investment target, and will help to meet the increasing demand for water and create employment. The merits of water-related programmes in Western countries, such as best-management practices and low-impact development, and of small-scale rainfall-collection systems could be useful models for China to study.

Hydroelectric power and the south-to-north water-diversion project will help to alleviate drought in the future, as will China's investment in natural and constructed wetlands, and in additional water resources such as farmland irrigation and drainage.