THE ENVIRONMENT
298
on various environmental matrices were conducted for monitoring the quality of the environment. In addition, 1 769 tests were conducted for litigation purposes.
Technical support has been given to the Hong Kong Observatory's Environmental Radiation Monitoring Programme and to other government departments in undertaking the Daya Bay Contingency Plan. The Laboratory also provided 24-hour on-site service to render investigatory and advisory support for the handling of any emergency involving spillage of chemicals or suspected emission of noxious and irritating gases.
The Laboratory continued to extend its analytical capabilities in the field of environmental analysis. Extended scope of analysis included the determination of ultra-trace levels of a number of persistent organic pollutants in various environmental matrices. Analysis of vehicular diesel fuel for the content of ultra-low sulphur and the testing of fuel specifications of petroleum fuel for motor vehicles have provided additional information to safeguard the air quality of Hong Kong.
In addition to its routine commitments, the Laboratory has been involved in various environmental impact studies and ad hoc projects including the amendment of the Technical Memorandum for the control of discharge of wastewater under the Water Pollution Control Ordinance.
Flora
Hong Kong is near the northern limit of the distribution of tropical Asian flora and has an estimated 2900 species of vascular plants, both native and introduced. Various conservation measures have transformed the formerly bare hillsides and slopes into areas with trees of local and introduced species. Besides greening and beautifying the countryside, woodlands are important habitats for wildlife and are essential in protecting water catchments from soil erosion and in providing recreational opportunities for the public.
Remnants of the original forest cover, either scrub forest or well-developed woodlands, are still found in steep ravines. They have survived the destructive human influences and hill fires through their location in precipitous topography and the moist winter micro-climate.
Terrestrial Fauna
Hong Kong's physical and climatic environment provides woody and grassy habitats for a wide variety of animals and plants. Owing to urbanisation, larger animal species are rarely seen, but reptiles, amphibians, birds and insects are still common.
The Mai Po Marshes form one of the most important wildlife conservation sites in Hong Kong. Together with the Inner Deep Bay area, the Mai Po Marshes were listed as a 'Wetland of International Importance' under the Ramsar Convention in September 1995. About 1 500 hectares of mudflats, fish ponds, marshes and dwarf mangroves provide a rich habitat for migratory and resident birds, particularly ducks and waders. Some 300 species of birds have been observed in this area, and at least 110 of them are rarely seen elsewhere in Hong Kong. The Agriculture, Fisheries and Conservation Department (AFCD) implements a wetland conservation and management plan for this area.