As proposed in TR1, each identified habitat type was assigned an indicative ecological value of either high, medium, low or negligible. These ecological values are defined with reference to elements of Annex 8: Criteria for Evaluating Ecological Impact, EPD Technical Memorandum on the Environmental Impact Assessment Process (EIAO TM). The definitions of high, medium, low and negligible ecological value habitats are provided below:

High ecological value habitat is defined as:

• areas which support the highest known biodiversity values for Hong Kong; or

• areas which are documented to function as important breeding, nursery or key foraging habitats; or

• areas which contain habitats that are regionally rare or threatened or provide documented critical habitat for "rare" species; or

• areas which contain unusually large-sized, valuable and generally undisturbed habitat.

• Medium ecological value habitat is defined as:

• areas which support intermediate biodiversity values for Hong Kong; or

• areas which may provide critical habitat for "rare" species but for which such use is not documented; or

• areas which may function as important breeding, nursery or key foraging habitats but for which such use is not documented; or

• areas which contain unusually large-sized and valuable habitats which have been fragmented or otherwise disturbed such that habitat potential has diminished; or

• areas which have potential to develop into high value habitat but do not meet the criteria for high ecological value at present.

Low ecological value habitat is defined as:

• areas which support low biodiversity values for Hong Kong; or

• areas which are not likely to provide critical habitat for "rare" species; or

• areas which are not likely to function as important breeding, nursery or key foraging habitats; or

• areas which contain habitats that have been degraded or modified by human activities such that habitat potential is low but that can be recolonized by the original floral/faunal assemblage; or

• areas which have potential to develop into medium value habitat but do not meet the criteria for medium ecological value at present.

Negligible ecological value habitat is defined as:

• areas which support negligible biodiversity values for Hong Kong; or

• areas which do not provide critical habitat for "rare" species; or

• areas which do not function as important breeding, nursery or key foraging habitats; or

• areas which contain habitats that have been severely degraded or extensively modified by human activities such that habitat potential is negligible and recolonization by the original floral/faunal assemblage is unlikely; or

• areas which do not have potential for developing into high, medium or low value habitat in the foreseeable future.

In assigning each of the habitat categories either high, medium, low or negligible ecological value, a number of criteria (biodiversity, support of rare species, ecological function, rarity, vulnerability, size and potential) were assessed. However, the overall assessment was based on the classification which best represented the habitat type rather than on strict compliance with each of the criteria under a particular classification. It is also acknowledged that specific sites within a given habitat category may vary in ecological value. This variation, within habitat, has been addressed in later stages of mapping performed under this study (ie field surveys and plotting of detailed existing information).

The habitats proposed for an indicative designation as of high value ecological habitat (in the absence of further information) include:

• Fung shui forest

• Montane forest

• Lowland forest

• Mixed shrubland

• Freshwater/brackish wetland

• Natural watercourse

• Mangrove

• Seagrass bed

• Intertidal mudflat

The habitats proposed for an indicative designation as of medium value ecological habitat (in the absence of further information) include:

• Shrubby grassland

• Baeckia shrubland

• Plantation or plantation/mixed forest

• Fishpond/gei wai

• Sandy shore

• Rocky shore

• Cultivation

The habitats proposed for an indicative designation as of low value ecological habitat (in the absence of further information) include:

• Bare rock or soil

• Grassland

• Modified watercourse

• Artificial rocky/hard shoreline

• Golf course/urban park

• Quarry

The habitats proposed for an indicative designation as of negligible value ecological habitat (in the absence of further information) include:

• Rural industrial storage/containers

• Landfill

• Other

The habitat base map resulting from plotting of the 25 categories. Their indicative ecological values were verified through additional, site-specific baseline surveys under this study and through compilation of existing ecological information under the SUSDEV 21 Study and consultation with relevant government departments.