AFRICA'S GREAT GREEN WALL

摘要

Green walls - Historically, 'walls', 'green belts' or 'green walls' have been established to fulfil various purposes, usually for the strategic protection of places, people and wealth. The Great Wall of China for example, was built more than 2,000 years ago to protect the newly unified country from foreign invaders and still stands today. Green belts were proposed to create a new relationship between cities and rural areas and to serve not only as lungs to cities, but also as limits to the expansionof cities. Today green belts are vital to urban harmonious development, contributing to people's well-being. One of the original large scale barrier-plantations, or green walls, was the 'Great Hedge of India'. It was established in 1843 as a customs barrier for salt taxation and was maintained for over 30 years. More recently, in the 1970s, some of the most famous large-scale planting projects include the 'Algerian Green Dam project' started in 1972 which was abandoned 20 years later. The 'Three North Forest Shelterbelt' ongoing programme which began in 1978, also known as the 'Green Great Wall of China', was designed to combat desertification and control dust storms over the capital city. Ecologically, all these large-scale planting projects are designed to reduce the effect of desertification and thereby improve the livelihoods of people.