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Advisory Council on the Environment

A BIODIVERSITY SURVEY OF HONG KONG Executive Summary

ACE Paper (41/99)
For information

1. Abstract

The Biodiversity Survey is coordinated by Associate Professor Richard Corlett and Professor David Dudgeon of the Department of Ecology & Biodiversity at The University of Hong Kong. The major source of funding is a HK$3.8 million grant from the Environment and Conservation Fund (ECF) of Hong Kong Government. The project consists of a systematic survey of terrestrial and freshwater biodiversity in Hong Kong, with the basic aim of identifying sites and species of special conservation value. The results have been incorporated into a computer-based Geographic Information System (GIS) database and mapping facility. The information obtained will be useful to Government planners, conservation managers, environmental consultants and researchers in a variety of fields.

2. Introduction and Context

2.1 Historical Impacts and Conservation Potential

Despite massive human impacts over the last several centuries, Hong Kong still has a diverse flora and fauna. The SAR supports more native species of plants, mammals, reptiles, amphibians, freshwater fishes and insects than United Kingdom. There are also species endemic to Hong Kong, and species new to science are regularly discovered. Nevertheless, wildlife habitats are increasingly under threat. This can be attributed, in part, to increased urbanization of the lowland New Territories and the associated habitat loss.

2.2 Is Current Protection of the Biota Adequate?

Legal protection of biological diversity in Hong Kong is aimed either at areas (such as Mai Po Marshes) or individual species (such as the Leopard Cat, Prionailurus bengalensis). Apart from preserving wildlife, protected areas can also provide for other needs, such as water catchments, education and recreation. The major disadvantage is that protected areas are usually chosen by default - the areas not immediately wanted for anything else - and may thus omit many important habitats and species. Hong Kong's current protected area system illustrates these points.

Protected-species lists are useful supplements to protected area systems, and enable the conservation of species which occur partly or exclusively in unprotected sites. However, listing provides no direct protection for particular species against habitat destruction which is the major threat to wildlife in Hong Kong.

2.2.1 Country Parks

Although almost 40% of Hong Kong is covered by Country Parks, Restricted Areas, and Special Areas, the Country Parks' system is deficient from a conservation viewpoint in at least two respects:

i)
The absence of a clear, long-term conservation management policy. Apart from the control of recreational impact, conservation management is limited to fire prevention and the planting of trees which are mostly exotic.
ii)
Country Parks are unable to protect some of the important habitat types. Wildlife habitats such as fung shui woods and wetlands are found mainly in valley bottoms and on lower hill-slopes but such areas are usually excluded from the Country Parks in order to respect the traditional rights of indigenous villagers to use these lands. Development currently threatens many such wildlife habitats.

2.2.2 Other Protected Areas

Other protected areas such as Sites of Special Scientific Interest (SSSIs), Conservation Areas (under the Town Planning Ordinance), and Restricted Areas (under the Wild Animals Protection Ordinance) have been designated in an ad hoc fashion. In the absence of a systematic survey of the whole of Hong Kong, we cannot simply assume that all sites worthy of protection have been identified already or will be identified before they are committed for development.

2.2.3 Protected Species

A protected animal species list is included in the Wild Animals Protection Ordinance. The list probably includes most of the species that could be threatened by trapping or collecting. However, the list provides no direct protection against the more insidious threats of habitat destruction and, for aquatic species, pollution.

Plant species currently receive protection under the Forestry Regulations of the Forests and Countryside Ordinance. The list of protected plant species is far less effective than the protected animal species list of the Wild Animals Protection Ordinance, because it covers a smaller proportion of the Hong Kong species, and includes largely plants of high-altitude areas which are almost all in Country Parks.

2.2.4 International Obligations

The People's Republic of China and the United Kingdom were among the 153 countries who signed the Convention on Biological Diversity at the United Nations Conference on Environment and Development in June 1992. The Convention came into force 90 days after it had been ratified by 30 countries and, because both PRC and UK are signatories, Hong Kong was required to comply with the Convention both before and after July 1, 1997.

Under Article 6 of the Convention, each contracting party is required to develop national strategies, plans or programmes for the conservation and sustainable use of biodiversity. Articles 8 & 9 highlight the importance of in-situ and ex-situ conservation respectively, while Article 10 places emphasis on the sustainable use of biodiversity. To achieve these goals, Article 7 and Annex I of the Convention requires each contracting party to identify those components of biological diversity that are important with respect to conservation and sustainable use. This requirement is among the top priorities for action set by the Convention, and it is this that the Biodiversity Survey will help Government of the HKSAR to address.

2.3 Conclusion

It is clear that Hong Kong's protected species legislation is out of step with modern Hong Kong, and that the protected area system, whilst very valuable, has some serious deficiencies. These problems are a result of lack of information more than a lack of will. A coherent and effective approach to the conservation of species and their habitats in Hong Kong must be based on a knowledge of local patterns of biodiversity. Currently, this knowledge is lacking for all but a small minority of well-studied groups in a very few, often-visited, habitats.

A comprehensive survey of the biodiversity of Hong Kong is thus an essential first step towards developing a conservation strategy for the SAR. This project, entitled A Biodiversity Survey of Hong Kong and financed by a grant of HK$3.8 million from the ECF of Hong Kong Government, constitutes a systematic survey of terrestrial and freshwater biodiversity in Hong Kong. A biodiversity inventory is needed for the ratification and implementation of the United Nation's Convention on Biological Diversity to which China is a signatory.

3. The Survey

3.1 Aims and Objectives

The aim of this project is to undertake a systematic survey of biodiversity in Hong Kong and to provide data which will underpin future conservation activities in the SAR. The Survey results will allow Government to design more effective and more efficient conservation strategies. The data could be made available to NGOs, private developers, environmental consultants, and other interested parties to allow assessment of the potential ecological damage arising from development proposals. Representative sites in all non-marine habitats (i.e. areas above the high-tide mark) have been included in the survey. The results have been incorporated into a computer-based GIS database and mapping facility.

It has not been feasible to include every group of organisms in the survey. The groups that are being surveyed currently include representatives from a range of phyla: vascular plants, mammals, birds, reptiles, amphibians, freshwater fishes, freshwater invertebrates, spiders, butterflies and moths (i.e. Macrolepidoptera), ants and a variety of other insect groups. We have deliberately chosen groups which contrast in their lifestyles and habits so as to obtain as wide an ecological coverage as possible. In order to supplement information on particular groups of animals, special attention has been paid to threatened habitats (such as freshwater wetlands) and those habitats we believe are likely to contain rare or endemic species (montane forest and larger fung shui woods).

The survey output consists of two parts :

The first part (described in the accompanying documentation and including a CD-ROM) consists of the GIS database, comprising species distribution data for the major groups of organisms in non-marine habitats in Hong Kong. We stress that the current version of the database is Release 1.0 (including information on >3,400 species); collection, collation and curation of specimens and data records is an ongoing process, and we expect to update the database (with Release 2.0 et seq.) in due course.

The second main output will be a comprehensive report in book form which will give an account of the main findings of the study, characterize the patterns of biodiversity in Hong Kong, interpret them in an ecological framework, and place these data in the context of local conservation needs and goals. The book - provisionally titled The Biodiversity of Hong Kong - setting out our analysis of the database and providing a conservation evaluation of the Hong Kong countryside. It will follow a habitat-based approach, and will provide a frame of reference for subsequent investigations of human impacts on the local flora and fauna. In particular, we expect that our analysis of the data will facilitate the ecological element of the EIA process by providing a point of comparison through a set of 'anchor sites' and by identifying a 'predictor set' of taxa (families, etc.) that can indicate the diversity of the overall assemblage of organisms found in non-marine habitats. These findings will make an important contribution to Government's commitment to sustainable development in the context of Sus Dev 21.

3.2 Methods

3.2.1 Data Collection

A considerable amount of data already exists for some of the groups which are being surveyed, but this information is not in a form suitable for direct inclusion into the GIS system. Thus an initial aim of the survey has been to supplement existing or ongoing surveys of the biota, to put such data into a form which can be entered into the GIS, and to initiate new work on species groups which have not been investigated previously. Some of the early stages of this work has involved liaison with local naturalists and conservation groups, including World Wide Fund for Nature (WWF) Hong Kong and the Hong Kong Bird-Watching Society, as well as the Agriculture & Fisheries Department of Hong Kong Government. We have worked particularly closely with the Kadoorie Farm & Botanic Garden, who have provided us with much-needed logistical support. The initial ECF grant for the Biodiversity Survey has been supplemented by Hong Kong University funds used to support graduate students working on various aspects of the survey (currently including moths and mosses, etc.).

Survey methods had to be different for each group of organisms, but some general principles have been followed:

a) The Survey aims to be geographically comprehensive, including the major sections of the New Territories and non-urban Kowloon, all the major islands, and a representative sample of the smaller islands.
b) Within each area, sampling has been habitat-based. Species lists for defined habitats have far more predictive value than lists for areas including several habitats. Where appropriate, the same sites have been used for sampling different groups of organisms so that between-group comparisons are facilitated.
c) Survey efforts have focused upon those local habitats which show the least evidence of recent human impact as it is in these sites that we would expect to find the most diverse communities; e.g. mature secondary forest. Botanical sampling effort has been concentrated in woodlands and closed shrubland because experience has shown that it is these habitats which have both the most diverse floras and the greatest abundance of rare species.

A wide range of standard sampling methods exist for different groups of organisms, and - for brevity - these will not be discussed in any detail here. Not all sampling methods are appropriate for every habitat, and emphasis is being placed on comparability of results within habitat types. This is, to some extent, confounded by seasonal variations in the abundance of many animals (e.g. migratory birds) in the Hong Kong countryside, and thus we place more weight on positive records of fauna than on records of 'absence' (which could reflect seasonal movements, dormancy, or genuine non-occurrence). For this reason also, records are in the form of species occurrences - not absolute abundance of individuals of each species. Between-habitat comparability is difficult to achieve but a consistent standardised approach to sampling in each of the different habitat types should allow sites within the same habitat category to be ranked according to species diversity and conservation value, and thus permit qualitative comparisons between habitats.

3.2.2 Data Analysis and Manipulation

The data arising from the survey have been checked, and stored on CD-ROM which allows manipulation, analysis and presentation using GIS software. Release 1.0 of the database was given to Government in August 1999, and contains information on the distribution of >3,400 species and hundreds of thousands of locality records. Version 2.0 (with additional data - mainly concerning insects) will be released within the next few months. The information can be manipulated by way of the software, and can be overlain over existing digital maps used by Government to examine the implications of changes in land use and development for local biodiversity. Government Departments (and interested parties as the Government sees fit) will be able to interrogate or supplement the database and use it to incorporate conservation or ecological data into planning and development strategies.

3.3 Preliminary Findings

We now have a vast amount of raw data; most of it (including the 'charismatic' vertebrate elements of the local fauna) has been included in Release 1.0. One major result is striking. Hong Kong still supports far more species of plants and animals than would be predicted from its long history of human impact. Who would expect to find, for instance, 390 native tree species or almost 230 types of butterfly?

In all groups of organisms we have studied, Hong Kong supports more species than the whole of the United Kingdom (Table 1). This diversity reflects three main factors: Hong Kong's tropical latitude; the wide range of habitats present; and, the fact that, despite centuries of human impact, no major habitat type has been entirely lost (yet!). Not all groups are doing well, however, and we have confirmed the local extinction of both the Large Indian Civet (Viverra zibetha) and the South China Red Fox (Vulpes vulpes hoole). Although high, the current diversity is undoubtedly less than would have been present in the past. Many species must have been lost as a result of deforestation several centuries ago and our forest fauna, in particular, is impoverished in comparison with the nearest large forest areas in Guangdong. Were it not for human impact, Hong Kong's forests might still support elephants, tigers, rhinoceroses, gibbons, pheasants and woodpeckers. (Some of the missing species, such as the forest pheasants, could probably be reintroduced now that the forest area is increasing and maturing.)

Much of the surviving biodiversity is concentrated in a small proportion of Hong Kong's total areas, and there are some obvious biodiversity 'hotspots' (defined for operational purposes as the 10% most species-rich 1 km2 grids for a taxon): they include montane forests, fung shui woods, freshwater wetlands, some lowland streams, and certain offshore islands. Conversely, there are large areas with relatively low biodiversity, although these are probably essential as buffers and connectors for the 'hotspots', and as habitat for wide-ranging species (such as larger mammals). Unfortunately, the biodiversity 'hotspots' for different groups of organisms do not coincide: the maximum diversities of plants, birds, frogs, fishes, butterflies, dragonflies, ants and all other groups for which we have good data, occur in different places. In the case of some groups, (e.g. rare plants) only 20% of the 'hotspots' lie outside protected areas, but for others (butterflies, for example) the total was over 65%. Clearly, there is a marked difference in current levels of protection provided to different groups. Current and proposed SSSIs and Conservation areas improve the coverage, but these areas are protected only against unauthorised developments and do not receive the active management that is needed to ensure their future. It must be stressed that 'hotspots' draw attention to total species richness only, and are not indicators of conservation value per se. It is possible for a site to have conservation value even if it is not a 'hotspot' because rare species may occur in an otherwise low-diversity habitats. Likewise a 'hotspot' may support an array of common species (leading to high richness), but may contain no organisms of great conservation significance. More sophisticated analysis is needed.

A Ph.D. student in the Department of Ecology & Biodiversity at The Univesity of Hong Kong - Ms Yip Yin (see homepage URL - http://web.hku.hk/~yyipc/biov_ main.htm) - is currently analysing the database in order to identify gaps in the protected areas system so that, where necessary, we can make recommendations for modification of the boundaries. For certain species of amphibians and the freshwater wetland habitat category, for instance, some of the most diverse sites are in the unprotected lowlands, and are thus highly vulnerable to development. Their actual extent is rather small, and we estimate that preservation of these sites would involve extending the existing protected area system by around 1%.

A second point which emerges from a preliminary examination of the database, is the fact that the current lists of species which are legally protected anywhere in Hong Kong (under the Forests & Countryside Ordinance, and the Wild Animals Protection Ordinance) are largely of historical interest and so not reflect current rarity of the degree and type of threat. Many common species are protected while some globally or regionally rare and endangered species are not.

 

Prof. David Dudgeon
Department of Ecology & Biodiversity
The University of Hong Kong
October 1999


Table 1. Numbers of known non-marine species in Hong Kong (including recent mammalian extinctions, but excluding exotics).
Plants       
  Algae     >1000
  Bryophytes     220
  Ferns     215
  Gymnoperms     5
  Angiosperms     2000
             
Animals       
  Invertebrates (total)     c. 30,000
    Moths    >2,000
    Butterflies    225
    Dragonflies    107
    Caddisflies    65
    Mayflies    47
    Staphylinid beetles    >415
    Ants    160
    Termites    40
    Spiders    >409
    Land snails    39
             
  Vertebrates (total)     c. 700
    Freshwater fish    >97
    Amphibia    23
    Reptiles    73
    Birds    450
    Mammals (total)    55
      Chiroptera   23
      Rodentia   10
        Squirrels   1
        Rats   6
        Mice   2
        Porcupines   1
      Insectivora   2
      Pholidota   1
      Artiodactyla   2
        Pigs   1
        Deer   1 (2?)
      Primates   4
      Carnivora   13
        Dogs   2
        Mustelidae   3
        Viverridae   5
        Cats   3

 


 

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