ENG-1988 — Page 365

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THE ENVIRONMENT

significant amounts. Only kaolin is currently worked within the territory. Granites in Hong Kong have long been quarried for building purposes, and are now used as aggregates.

Much of the urban landscape has been modified as a result of the removal of hills, and the material is used as fill for the various extensive reclamation sites to be found throughout the territory.

The undeveloped areas of Hong Kong comprise mostly steeply-sloping rocky ground where soils are thin and nutrient deficient. These soils support only a sparse cover of grass or thin scrub, except in protected valleys or in water catchment areas where a policy of re-afforestation has succeeded in re-establishing pines and deciduous trees.

The most important agricultural area in Hong Kong is the alluvial plain around Yuen Long in the New Territories. These lowlands have been deposited only within the last 33 000 years, and some coastal areas are still prone to flooding when heavy rainfall coincides with high tides. The natural deposition of sediment is continuing around the Deep Bay area, where brackish fish ponds have been successfully established in areas that once were mudflats, mangrove swamp or salt-water rice paddies.

As Hong Kong lacks large rivers, lakes or underground water supplies, reservoirs have been constructed in large valleys such as Tai Lam Chung and at coastal sites such as Plover Cove and High Island, where embayments and channels have been enclosed by large dams. The catchment areas of the reservoirs have been designated as country parks, of which there are now 21.

(Maps depicting the geology of the territory are being produced at a scale of 1 to 20 000 by the Geological Survey of Hong Kong, which is within the Geotechnical Control Office).

Wildlife

The physical and climatic environment of Hong Kong provides woody and grassy habitats for a wide variety of native animal and plant life. Under the pressure of urbanisation, larger animal species are rarely seen, but reptiles and amphibians, birds and many kinds of insects

are common.

Most of Hong Kong's countryside is protected by the Forests and Countryside Ordinance, the Wild Animals Protection Ordinance, the Country Parks Ordinance, and the Animals and Plants (Protection of Endangered Species) Ordinance.

One of the most important sites in Hong Kong for wildlife is the Mai Po Marshes. A restricted area under the Wild Animals Protection Ordinance and managed by the World Wide Fund for Nature (Hong Kong), it is an internationally significant site for migratory and resident birdlife. Its 380 hectares of mudflats, shrimp ponds and dwarf mangroves pro- vide a rich habitat, particularly for ducks and waders. More than 250 species of birds have been observed in this area, and at least 110 of them are rarely seen elsewhere in the territory. Yim Tso Ha, also a restricted area, is the largest egretry in Hong Kong. Five species, the Chinese Pond Heron, Night Heron, Cattle Egret, Little Egret, and the rare Swinhoe's Egret, nest there regularly. More than 1 000 egrets can be found there between April and September, the nesting season. Egretries are also found at Mai Po Village, A Chau, Jim Uk, Tsim Bei Tsui and Wu Shek Kok.

Although traditional fung shui woods near the old villages and temples are increasingly affected by development, they continue to provide a very important habitat for many birds. Sightings in wooded areas include an assortment of warblers, flycatchers, robins and bulbuls.

Of the larger indigenous animals, the Chinese Pangolin (Scaly Anteater) which grows to a length of about one metre and is protected by horny scales, is still seen occasionally. Areas