Forest Hydrology in China: Introduction to the Featured Collection

Chinese people have long recognized the importance of forests and water in environment, societal development, and civilization. The philosophical thoughts are well reflected in many ancient paintings and stories that picture the harmony of forests, water, and mountains, and in fact, well-respected Chinese rulers are known for their contributions to harnessing large rivers such as the mighty Yellow and the Yangtze Rivers in China’s 5,000 years’ history. Unfortunately, China’s natural forests and water resources have been severely damaged in the past century due to overpopulation, years of wars, mismanagement and exploitative use, and global environmental change. As a result, China has suffered chronic environmental problems at the national scale, notably soil erosion, flooding, and water pollution and shortage in its recent history. While China’s unprecedented socioeconomic growth increasingly stresses forest and water resources, it also provides opportunities to reverse earlier damage. In the past three decades, China has implemented several nationwide forest restoration and protection programs such as the ‘‘Three North Shelterbelts Project,’’ the ‘‘Natural Forest Protection Programme,’’ and the ‘‘Green for Grains Program’’ that aim at reducing soil erosion and flooding, improving water quality, and curbing further ecosystem degradation. Although a full assessment of the projects’ success is not available, it is widely believed that they have resulted in positive effects on water resources and overall ecosystem health of headwaters of major river basins. Thanks to massive forestation campaigns, China has the largest plantation forests (53 million ha, an area larger than California) in the world, and its annual growth in man-made forests accounts for over half of the global total. Last year alone, more than two billion trees were planted in China (http://english.people.com. cn/90001/90776/90882/6371092.html). Forest hydrological research to guide these large ecosystem restoration efforts is urgently needed. Assessments of the effects of forestry policy changes on water resources are well sought by the Chinese government to effectively manage both water and forest resources. Forest hydrology research in China has been limited and western literature was not readily available before the early 1980s when China began economic reform and adopted an ‘‘open-door’’ policy. Since then, large progress has been made in the understanding of forests’ role in regulating the hydrological cycle across the vast landscape of this populous nation. Focus was