Introduction
China has a population of 1,295 million and an area of 9,600,000km2, about 6.42% of the Earth's land area[1]. This vast area includes forests (16.55%, of which 10% is natural forest), grasslands (41.7%), inland water areas (1.8%), agricultural land (13.5%), and deserts and other lands (26.4%)2. It occupies a range of climatic zones, from humid (32%) and semi-humid (15%) to semi-arid (22%) and arid (31%). China is the world's third richest country in terms of biodiversity[2].
China has a long history of environmental degradation, and the importance of vegetation has been recognised for thousands of years3. However, due to expanding population and rapid development in the past half-century, deforestation, overgrazing and conversion of natural vegetation to farmland have increased. These factors have has led to severe impacts on local patterns of rainfall, water table levels and water holding capacity, and have resulted in increased flooding, drought, and the silting up of lakes and drainage channels. During the floods of 1998 and 1999, the flow in the Yellow River reached the highest recorded in history. Yet outside the rainy season, the river has regularly dried up. Such environmental disasters have drawn increasing attention to the degradation of vegetation.
The Chinese Government has started
six major programmes related to vegetation restoration: (1) the Natural Forests
Protection Programme; (2) the Developing Key Protection Forest System Programme
in the area of "Three Norths" ("Sanbei") and Middle and
Lower Yangtze River; (3) the Returning Farmland to Forests/Grasslands Programme;
(4) the Sandstorm Control Programme around Beijing; (5) the Wildlife Protection
and Natural Reserve System Development Programme; and (6) the Programme of Forestry
Industry Development. These have focused on planting fast-growing and high-productivity
forests in key areas. Meanwhile, the strategy for improving the environmental
situation during the Great Western Development (GWD) has come into effect. It
is expected to achieve over 19% forest cover by 2010 and over 24% during 2011-2030
[57].
The Chinese government will mobilise all available resources to achieve these
goals. Already, China has produced the largest number of artificial forests
in the world, and has been called "the world's greatest restorer of forest".
Forest cover has increased to 16.55%, from 8.6% 50 years ago.
However, these figures are misleading. Most of the afforestation has comprised
artificial forests; ecological "construction" has been promoted rather
than ecological restoration. As a general rule artificial forest systems do
not provide the multitude of ecological services of the natural forests they
replace. Some types of artificial forests bring about declines in the water
table, loss of soil and water, and higher frequencies of diseases, pests and
fires. Replacing diverse vegetation with a monoculture fundamentally changes
the nutrient balance of the soil, while alien species can have devastating impacts
in these simplified ecosystems. Planting trees in natural grasslands can also
bring about adverse effects. Will the large investments of the Government programmes
achieve the expected results? Will these artificial forests restore hydrology
and stabilize the soil?
A natural forest is an immensely
complex, living system, whose ecological processes - the interactions between
soil, air, plants, animals, fungi and microbes - determine its environmental
functions. A plantation without biodiversity is an investment without insurance.
Studies of the service benefits derived from natural vegetation, and evaluation
of the disasters associated with vegetation loss, have revealed the overwhelming
economic value in protecting the remaining forests, restoring their ecological
functions, and re-evaluating the way in which forests and plantations are managed
(see Annex A). These measures will call for investments that are large in relation
to existing forestry budgets, but small compared to the anticipated returns
or to future losses if they are not well implemented.
To achieve environmental stability, China needs to restore healthy ecosystems,
with mixed vegetation of native species. The most important process for achieving
this is natural regeneration itself; to try to work against such natural processes
is both expensive and dangerous. These guidelines present sixteen principles
for restoring China's degraded environment through the use of natural vegetation.
| Box 1. The Sichuan experience
Until the 1960s forest cover in the middle catchments of the Yangtze River remained at about 45%, and harvesting remained modest. However, as the economy grew, the level of forest exploitation increased. Overall forest cover dropped to as low as 16% of the total land area. Much of this clearance took place between 1975 and 1985. Forty percent of the habitat of the giant panda was destroyed in that period [4]. In addition to greatly damaging the hydrological functioning of the river system, this forest loss created severe fragmentation of forests with a concomitant threat to biodiversity. Hunting pressures and pressures for collecting medicinal plants and other forest products all increased, while the area of forests continued to shrink. Damage from natural catastrophes due to the lack of forest in the province is estimated at RMB 10 billion per year 5. Changes in the mode of cutting timber and treating cut forests, together with major efforts to reforest bare slopes, have been in effect since the 1980s, and the forest area is now increasing. Much of this new forest, however, is immature and still lacks full hydrological functionality. |