Canopy: The uppermost continuous stratum or layer of vegetation in a forest.

Chunam slope: Slope sprayed with concrete on surface to help stabilisation.

Conservation ranking system: A system which incorporates ecological, heritage, recreational and landscape components to provide a composite means by which the conservation values of different areas can be ascribed, mapped and compared.

Conservation value: a reflection of subject's contribution to sustaining features of ecological, heritage, landscape or recreational interests.

Dollo: Reinforced concrete blocks in the shape of an enormous twisted H.

Ecological characteristics: They refer to naturalness, size, structural complexity ( forest, shrubland and plantation), water quality (wetland, watercourse, sandy shore, rocky shore and artificial rock/hard shoreline), nature of substratum ( watercourse, sandy shore, rocky shore and artificial rock/hard shoreline), number and abundance of species groups, presence of "rare" species , presence of known ecologically important areas in the habitat's vicinity, and degree of disturbance and damage.

Ecological function: Ability of an area to support ecosystem component.

Ecological/Habitat value: A reflection of habitat's contribution to sustaining the wildlife communities and essential ecological processes of a wider ecosystem.

Ecosystem: An interacting ecological unit comprising the biotic (living) community and abiotic (non-living) environment within a defined area.

Fauna: The animal life in a particular region, habitat or area.

Flora: The plant life in a particular region, habitat or area.

Habitat mapping category: Habitat types identified for mapping the land area of Hong Kong.

Habitat polygon: The mapping unit identified by habitat type. The smallest size of a polygon is 20 x 20 m

Habitat: The place where an organism normally lives or grows, usually characterised by its physical features or its dominant vegetation.

Heritage function: Ability of an area to serve as a site of unique archaeological, historical or architectural value.

Indicative ecological value: Ecological value assigned to habitat in the absence of further information. it is composed of grades of high, medium, low and negligible.

Low tide mark: The minimum height reached by falling tide, usually measured as metre(s) above Chart Datum.

Landscape function: Ability of an area to serve as a site with distinct landscape character(s) or valued landscape feature(s).

Marsh: A frequently or continually inundated wetland characterised by emergent herbaceous vegetation adapted to saturated soil conditions.

Native: Occurring naturally in a particular area.

Pool: Shallow, intermittently flooded area. May dry out during the dry season.

Preliminary base/habitat map: A map which consists of habitats mapped by supervised classification and existing information but not verified through field surveys.

Rare species: Species which are regionally rare, locally rare, protected and/or confined to specific habitats in Hong Kong.

Recreational function: Ability of an area to serve as a site with valued recreational feature(s).

Reedbed: Marsh dominated by Phragmites (common reed)

Reference site: A site of known surface feature ( and thus habitat type ) which was selected to check the accuracy of a classified image.

Riparian: Growing or occurring along the banks of a stream or river.

Societal functions: Include heritage, recreational and landscape functions.

Supervised (imagery) classification: This classification technique requires the user to define the output classes to which pixel will be assigned by delineating training sites.

Training site: A site of known surface feature ( and thus habitat type ) which was selected to represent a site of a particular spectral property for supervised classification.

Under-storey: Forest plants which are shaded by the taller vegetation or canopy layer; the lowest stratum or layer of vegetation in a forest.

Unsupervised (imagery) classification: This classification technique requires no pre-classification input from the user and pixels are split into a number of groups (to be specified by the user) based on their spectral similarity.

Wasteland: Area formed as a result of human activities and either wholly or partly covered by weedy or ephemeral vegetation.