Excessive reliance on afforestation in China's arid and semi-arid regions: Lessons in ecological restoration

Abstract

Afforestation is a primary tool for controlling desertification and soil erosion in China. Large-scale afforestation, however, has complex and poorly understood consequences for the structure and composition of future ecosystems. Here, we discuss the potential links between China's historical large-scale afforestation practices and the program's effects on environmental restoration in arid and semi-arid regions in northern China based on a review of data from published papers, and offer recommendations to overcome the shortcomings of current environmental policy. Although afforestation is potentially an important approach for environmental restoration, current Chinese policy has not been tailored to local environmental conditions, leading to the use of inappropriate species and an overemphasis on tree and shrub planting, thereby compromising the ability to achieve environmental policy goals. China's huge investment to increase forest cover seems likely to exacerbate environmental degradation in environmentally fragile areas because it has ignored climate, pedological, hydrological, and landscape factors that would make a site unsuitable for afforestation. This has, in many cases, led to the deterioration of soil ecosystems and decreased vegetation cover, and has exacerbated water shortages. Large-scale and long-term research is urgently needed to provide information that supports a more effective and flexible environmental restoration policy.

Introduction

China's government has invested huge amounts of money to alleviate severe land degradation problems (Li, 2004, Wang et al., 2007). This includes its Six Key Forestry Programs, which are described in Table 1 and shown in Fig. 1. During the most recent decade (2000 to 2009), China has invested 725 billion RMB (US$100 billion) in these programs, covering more than 97% of China's counties and targeting 76 million ha of land for afforestation (Wang et al., 2007). Under these programs, there has been significant progress in afforestation, with 28 million ha of plantations established from 2000 to 2005 (Chazdon, 2008). The total forest cover since 2000 has increased from 16.6% to 18.2% of China's land area. China's goal is to increase forest cover to 26% by 2050 by means of the largest tree-planting program in the world (Wang et al., 2007). At the U.N. Climate Summit on 22 September 2009, China's President Hu committed to expanding the country's forest area by 40 million ha from 2006 to 2020.

China has aggressively implemented its new forest policies (Table 1). For example, the Natural Forest Conservation Program plans to reforest 4.4 million ha from 2000 to 2010 by means of planting and aerial seeding (State Forestry Administration, 2009). Except for the Wildlife Conservation and Nature Reserves Development Program, the focus of the new policies is how to grow more forests and how to shift from natural vegetation to man-made forests. As a result of these programs, from 1952 to 2008 more than 27.2% of China's area was either artificially planted (230 million ha) or seeded by air (30.7 million ha) (Fig. 2). The area of afforestation has increased rapidly, and the State Forest Administration claims that environmental degradation has begun to reverse (Liu et al., 2008a). However, there is strong evidence that contradicts these claims. First, the overall survival rate of trees in afforestation projects from 1952 to 2005 has been only 24% (Wang et al., 2007). Tree survival across the Three Norths Shelter Forest System Project during this period was only 15% (Li, 2001, Cao, 2008a). Second, serious water-related soil erosion has expanded during the past 30 years to cover an additional 1000 km² of land annually (Wan et al., 2005, Normile, 2007). Third, for arid and semi-arid China as a whole, the desertification rate (the proportion of China's total area that experienced desertification in a given year) increased by 11% in the mid-1950s, 57% in the mid-1980s, and 19% in the early 2000s (Wang et al., 2010). Monitoring data has demonstrated little relationship between the afforestation projects and the frequency and intensity of dust storms in northern China (Wang et al., 2010), and sandstorms continue to sweep northern China and surrounding areas (Fig. 3). In contrast to some official claims, these factors contribute to China's environmental sustainability index remaining among the lowest in the world (Stokstad, 2005, Liu and Diamond, 2008).

Why has China's large-scale afforestation effort failed to achieve the desired goals? In this paper, we discuss the potential links between China's recent large-scale afforestation practices and the program's effects on environmental restoration, and offer recommendations to overcome the shortcomings of the present policy.