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Hong Kong's terrestrial habitats consist of a wide variety of ecological communities which host a surprisingly diverse array of mammals, birds, amphibians, reptiles, fishes, invertebrates and plants. Forests and shrublands are the most extensive vegetation types, comprising about 37% of the total terrestrial area of Hong Kong.
Grasslands, lowland forests and mixed shrublands are the most extensive habitat types, comprising about 23%, 16% and 15% respectively of the total terrestrial area of Hong Kong. Surveys for the SUSDEV 21 habitat map have identified that the most ecologically important terrestrial habitats in Hong Kong are mainly composed of forest and shrubland habitats (including fung shui forest, montane and lowland forests and mixed shrubland), comprising almost 90% of the total area identified as of high ecological value. Other habitats including inland water habitats (freshwater/brackish wetland, natural watercourse and fishpond/gei wai) and coastal habitats (mangrove, intertidal mudflat, seagrass bed, sandy shore and rocky shore) cover less than 4% of the total land area of Hong Kong. Small areas of Cultivation, Plantation or Plantation/Mixed Forest, Shrubby Grassland, Grassland and Urban Park have also been identified as high ecological value habitats. The majority of the forest and shrubland sites surveyed for the habitat mapping survey are relatively intact and subject to little or no human disturbance. However, many of the wetlands surveyed have been subject to degradation from pollution and infilling for development purposes and several authors have reported on the decline in coastal habitats such as mangrove and seagrass beds in recent years.
Winter counts of waterfowl have been undertaken each year at the Mai Po and Inner Deep Bay Ramsar Site since the winter of 1992-93. The data on the total peak winter counts (December to February) and the peak waterbird counts for January (which is the winter month in which highest number of visiting birds are usually observed) show that overall winter counts are currently at around the same levels as when monitoring began in 1992, having declined from a peak of around 80,000 counts during the mid 1990s (Figure 4.1a).
Figure 4.1a: Peak Winter and January Counts of Waterfowl in Mai Po and Inner Deep Bay Ramsar Site, 1992/93 to 1999/2000
A number of important terrestrial species found in Hong Kong are under threat locally or globally including the migratory bird the Black-faced Spoonbill which winters at Mai Po Marsh, several species of freshwater fish as well as some amphibians, reptiles and larger mammals.
Overall the terrestrial ecological resource is under threat from physical clearing for new development, increased disturbance from development encroachment and other effects such as hill fires. Many ecologically diverse habitats such as wetlands occur in low lying areas which are particularly vulnerable to development. Whilst a network of designations exists in Hong Kong, in part to protect areas of nature conservation importance, the coverage afforded is not comprehensive and a number of areas of important habitat remain unprotected from development.
Future sustainability of the terrestrial ecological resource will require protection and management of remaining valuable habitat through implementation of an explicit conservation policy including a comprehensive system of ecological designations. In addition, the effects of pollution on threatened species needs to be better understood and the management of such species should be co-ordinated on a regional basis.
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