4.4 Habitat Evaluations

4.4.1 An evaluation of the overall ecological value of each of the main habitat types was carried out and reported in ERM (1999b) and was repeated in the previous EIA Report (BBV 2000). This habitat review was carried out in accordance with the criteria listed in Annex 8 of the EIA Ordinance Technical Memorandum and takes account of the requirements of Clause 3.5.2 (iv) of the Study Brief. The updating of the habitat map undertaken in October 2001 demonstrated that though there were some minor changes in distribution of habitats there were no changes of a scale that required an overall review of habitats’ ecological value. Accordingly, the evaluation contained in ERM (1999b) is repeated below with only minor amendments to reflect changes in the area of habitats, with the exception that evaluation of agricultural habitats has been updated to take into account the revised agricultural habitat categories and an evaluation of the Managed Wetland category has been added. A photographic record of the habitats that will potentially be impacted by the Spur Line (i.e. inactive and active fish ponds at Lok Ma Chau and San Tin and wasteland at Chau Tau) are shown in Plates 4.1 to 4.3.

Fung-shui Forest

4.4.2 Four fung-shui forests have been identified within the Study Area - Ho Sheung Heung, Tsung Pak Long, Chau Tau Village and Pun Uk Tsuen. Given the similarity in habitat attributes between the latter two forests, these have been evaluated together (Table 4.9). It is noted that around 0.5ha of the Pun Uk Tsuen fung-shui forest is within the 200 m study corridor (Table 4.1).

Table 4.9

Ecological Evaluation of Fung-shui Forests within the Study Area

Criteria	Ho Sheung Heung	Tsung Pak Long	Chau Tau/Pun Uk Tsuen
Naturalness	Natural habitat with very little modification	Natural habitat but heavily modified by the villagers	Natural habitat but with some modification as evidenced by the presence of fruit trees and graves
Size	Of moderate size – extending to~6 ha.	Of relatively small size - extending to ~1.6 ha.	Both are of moderate size – extending to over 4 ha.
Diversity	Structurally complex and species diverse	Structurally simple and species poor	Both are structurally complex with moderate species diversity
Rarity	No rare species	No rare species	No rare species
Re-creatability	The habitat characteristics are difficult to recreate	The habitat characteristics are difficult to recreate	The habitat characteristics are difficult to recreate
Fragmentation	Not fragmented	Seriously fragmented in the under-storey	The Chau Tau forest is not fragmented; while the Pun Uk Tsuen forest is slightly fragmented
Ecological Linkage	Functionally linked with Long Valley, providing a movement corridor and shelter for wildlife inhabiting or utilising the area	No direct ecological linkage, although the large Ficus microcarpa could provide foraging opportunities to insectivorous and frugivorousa animals inhabiting the surrounding area	Functionally linked with the agricultural habitat around Chau Tau and Lok Ma Chau, providing shelter and a movement corridor for wildlife utilising the adjacent habitats
Potential Value	Ecological potential is high if the forest remains undisturbed	Limited due to village development in the surrounding area	Ecological potential would be high if disturbance factors are removed and succession is allowed to occur
Nursery/ breeding ground	Not reported, but the sparse forest cover in the surrounding area makes it likely that it is utilised by localised species of birds and mammals	Not reported and not expected	Not reported, but the sparse forest cover in the surrounding area makes it likely that it is utilised by localised species of birds and mammals
Age	The size of the trees indicates an age of over 50 years	The size of the trees indicates an age of over 50 years	The size of the trees indicates an age of over 50 years
Abundance/Rich-ness of Wildlife	High	Low	High
Conclusion	Moderate to High Ecological Value	Low to Moderate Ecological Value	Moderate Ecological Value

Lowland Secondary Forest

4.4.3 The lowland secondary forests within the Study Area are highly fragmented and are mainly found in Lok Ma Chau, Pak Shek Au and the foothills of Ki Lun Shan. With the exception of those patches located in Pak Shek Au and near Ha Wan Tsuen in Lok Ma Chau, each forest area is located beyond the 200 m corridor of the proposed alignment. The ecological value of these forests is evaluated in Table 4.10. For the purposes of the evaluation the patches are combined into two groups according to their habitat characteristics.

Table 4.10

Ecological Evaluation of Lowland Secondary Forest

Criteria	Lok Ma Chau	Pak Shek Au/Ki Lun Shan
Naturalness	Natural habitat, moderately modified by human intervention	Natural habitat, moderately modified by human intervention
Size	The forest next to Ha Wan Tsuen is quite small (~1.2 ha) whereas the other is moderate in size (~4ha)	All are about 2 ha in size and are considered small
Diversity	Both are considered moderate in habitat and species diversity	All of them are moderate in habitat and species diversity
Rarity	Neither the habitat nor the species reported are rare	Neither the habitat nor the species reported are rare
Re-creatability	Re-creatable because of the openness of the forest	Easy to re-create due to the immaturity of the forest
Fragmentation	Both forests are intact	The forests on the foothill of Ki Lun Shan are slightly fragmented; the remaining forest areas are intact
Ecological Linkage	Both are functionally linked with agricultural and fishpond habitats around Chau Tau and Lok Ma Chau, providing shelter and a movement corridor for wildlife utilising adjacent habitats	None of the forest areas are functionally linked to any high value habitat
Potential Value	The ecological potential would be high if disturbance factors are removed and succession is allowed to occur	The ecological potential would be high if disturbance factors are removed and succession is allowed to occur
Nursery/ breeding ground	Not reported, but the sparse forest cover in the surrounding area makes it likely that it is utilised by species of birds and mammals	Not reported, but the sparse forest cover in the surrounding area makes it likely that it is utilised by species of birds and mammals
Age	Tree size indicates that both are relatively old when compared with the other lowland secondary forest in Hong Kong	The size and type of tree species present indicates a relatively young age
Abundance/Rich-ness of Wildlife	Moderate	Moderate
Conclusion	Moderate Ecological Value	Low to Moderate Ecological value

Plantation Forest

4.4.4 Plantation forests within the Study Area are small and fragmented, and are mainly found along roadsides or on cut-slopes; the only sizable area of this habitat is located in the Kwu Tung area, close to Pak Shek Au. The ecological value of this habitat type is evaluated in Table 4.11. For the purposes of the evaluation roadside and cut slope plantations are grouped together. It should be noted that only roadside plantation forests are within the 200m study corridor.

Table 4.11

Ecological Evaluation of Plantation Forest

Criteria	Roadside Plantations	Kwu Tung/Pak Shek Au
Naturalness	Plantation	Plantation - semi-natural due to the establishment of native tree species
Size	They are all small in size	Considered moderate in size (~2ha)
Diversity	Both habitat and species diversity are poor	Low in habitat diversity, moderate in species diversity
Rarity	Neither the habitat nor associated species are rare	Neither the habitat nor associated species are rare
Re-creatability	This habitat type is readily re-creatable	This habitat type is readily re-creatable
Fragmentation	Heavily fragmented	Not fragmented
Ecological Linkage	None	May provide movement corridors for wildlife
Potential Value	Negligible because of the type of species planted and the dimension and location of the habitat	With time it could develop into secondary forest, of higher ecological value than present
Nursery/ breeding ground	None	No wildlife of conservation importance
Age	Young	Young to moderate
Abundance/Rich-ness of Wildlife	Poor	Low to moderate
Conclusion	Low Ecological Value	Low Ecological Value

Orchard

4.4.5 Orchards are a common feature in Kwu Tung and Pak Shek Au and are mostly small in size and highly fragmented. Table 4.12 evaluates the ecological value of this habitat type.

Table 4.12

Ecological Evaluation of Orchard

Criteria	Orchards
Naturalness	Man-made habitats
Size	They are small in size
Diversity	Both the habitat diversity and species diversity are low
Rarity	Neither the habitat nor the species found are rare
Re-creatability	This habitat type is readily re-creatable
Fragmentation	Heavily fragmented
Ecological Linkage	May provide movement corridor for wildlife using the surrounding area
Potential Value	Poor in potential value as they are close to settlements and subject to high levels of disturbance
Nursery/ breeding ground	No wildlife of conservation importance is expected
Age	Varies from relatively recent plantings to mature fruit tree of considerable age
Abundance/Rich-ness of Wildlife	Low
Conclusion	Low Ecological Value

Agricultural Land

4.4.6 Agricultural land is found mainly in Long Valley and around Chau Tau Village. For the purposes of this evaluation, agricultural land has been classified according to the type and status of current land management. Tables 4.13 - 4.17 evaluate the ecological value of each type of agricultural habitat. It is noted that two large patches of wet agricultural land are within the 200m study corridor in Long Valley.

Table 4.13

Ecological Evaluation of Active Wet Agricultural Land

Criteria	Long Valley	Chau Tau	Lok Ma Chau
Naturalness	Man-made habitat actively managed for crop production	Man-made habitat actively managed for crop production	Man-made habitat actively managed for crop production
Size	Although individual units are small, the overall area of wet agriculture is large	Moderate	Small
Diversity	Habitat diversity is low but diverse invertebrate and vertebrate fauna are supported	Habitat diversity is low but diverse invertebrate and vertebrate fauna are supported	Habitat diversity is low but diverse invertebrate and vertebrate fauna are supported
Rarity	The habitat type is not rare in Hong Kong, but is declining rapidly, with few large areas remaining. A number of rare avifauna species utilise this habitat as feeding/roosting site, including Japanese Yellow Bunting and Greater Painted-Snipe	The habitat type is not rare in Hong Kong, but is declining rapidly, with few large areas remaining. A number of rare avifauna species utilise this habitat as feeding/roosting site, including Northern Hobby.	The habitat type is not rare in Hong Kong, but is declining rapidly, with few large areas remaining . It may be utilised by some rare/uncommon avifauna using the adjacent ponds as feeding/roosting site, including Greater Painted-snipe and Bluethroat
Re-creatability	It is readily re-creatable provided that land and fresh water is available	It is readily re-creatable provided that land and fresh water is available	It is readily re-creatable provided that land and fresh water is available
Fragmentation	It is slightly fragmented	It is slightly fragmented	It is slightly fragmented
Ecological Linkage	It is part of a well-known site that supports a number of local and international important avifauna	Ecological linkage is low due to surrounding development, but it could still provide habitats for a range of wildlife	Linked to adjacent fishponds and provides feeding habitat for insectivorous animal
Potential Value	High potential if ecologically sensitive management practices are retained or adopted	High potential if ecologically sensitive management practices are retained or adopted	High potential if ecologically sensitive management practices are retained or adopted
Nursery/ breeding ground	A wide range of resident and migratory wildlife and birds roost and/or feed in Long Valley, including ardeids from the nearby egretry	A wide range of resident and migratory wildlife and birds are known to breed and/or feed in this habitat.	Not confirmed, although the area is likely to serve as a nursery ground for wildlife known to breed and/or feed in the surrounding area
Age	No information is available and this criteria is considered irrelevant to the ecological value of active wet agricultural land	No information is available and this criteria is considered irrelevant to the ecological value of active wet agricultural land	No information is available and this criteria is considered irrelevant to the ecological value of active wet agricultural land
Abundance/Rich-ness of Wildlife	High	High	High
Conclusion	High Ecological Value	Moderate Ecological Value	Low to Moderate Ecological Value

Table 4.14

Ecological Evaluation of Active Dry Agricultural Land

Criteria	Long Valley
Naturalness	Man-made habitat actively management for crop production
Size	Small
Diversity	Moderate in habitat diversity and species diversity due to the diversity of food crops planted.
Rarity	The habitat type is not rare in Hong Kong, but a number of rare avifauna species utilise this habitat as feeding and/or roosting sites.
Re-creatability	Readily re-creatable provided that land is available
Fragmentation	Heavily fragmented, but part of a large unfragmented mosaic of habitats
Ecological Linkage	Functionally linked with the surrounding habitat, providing movement corridors and foraging habitat
Potential Value	Dry agricultural land could be managed to promote wildlife use by adopting some management practice to further enhance the habitat heterogeneity; however, this may conflict with commercially driven crop production
Nursery/ breeding ground	A number of bird species are known to breed in the surrounding areas and this habitat provides nursery grounds to those species
Age	No information is available and this criteria is considered irrelevant to the ecological value of active dry agricultural land
Abundance/Rich-ness of Wildlife	Moderate
Conclusion	Low to Moderate Ecological Value

Table 4.15

Ecological Evaluation of Inactive Wet Agricultural Land

Criteria	Long Valley	Chau Tau Village
Naturalness	Man-made habitat derived from permanent or temporary abandonment of wetland agriculture	Man-made habitat derived from permanent or temporary abandonment of wetland agriculture
Size	Moderate in size	Moderate in size
Diversity	Habitat diversity is moderate and includes many exotic species but supports diverse species	Habitat diversity is moderate and includes many exotic species but supports diverse species
Rarity	The habitat type is not rare in Hong Kong, but a number of rare avifauna species have been reported from these areas	The habitat type is not rare in Hong Kong, but a number of rare avifauna species have been reported from these areas
Re-creatability	Readily re-creatable	Readily re-creatable
Fragmentation	Heavily fragmented within the Long Valley	Slightly fragmented
Ecological Linkage	Functionally linked with the surrounding habitats, providing movement corridor, shelter and roosting sites and foraging habitat. It’s significance in avifaunal terms indicate ecological linkages of international significance	Ecological linkage is lower than previous years because of the surrounding development. Provides important reservoir habitat for a range of wildlife that forage in the surrounding area
Potential Value	The potential ecological value of this habitat type could be enhanced by active management as a wildlife habitat	The potential ecological value of this habitat type could be enhanced by active management as a wildlife habitat
Nursery/breeding ground	A wide array of wildlife including rare resident birds utilise this area as a breeding and nursery habitat, including Greater-Painted-snipe which has been noted breeding in this habitat	A wide array of wildlife including rare resident or migrant birds utilise this area as a breeding and nursery habitat
Age	Varies according to period of inactivity, however areas that are abandoned in the long term will either dry out and revert to grass or shrubland or remain wet and revert to marsh.	Varies according to period of inactivity, however areas that are abandoned in the long term will either dry out and revert to grass or shrubland or remain wet and revert to marsh.
Abundance/Richness of Wildlife	High	Moderate
Conclusion	High Ecological Value	Moderate Ecological Value

Table 4.16

Ecological Evaluation of Inactive Dry Agricultural Land

Criteria	Long Valley	Chau Tau Village
Naturalness	Man-made habitat	Man-made habitat
Size	Moderate in size	Moderate in size
Diversity	Habitat diversity is moderate and contains many exotic species	Habitat diversity is moderate and contains many exotic species
Rarity	The habitat type is not rare in Hong Kong,	The habitat type is not rare in Hong Kong,
Re-creatability	Readily re-creatable	Readily re-creatable
Fragmentation	Heavily fragmented within Long Valley	Slightly fragmented
Ecological Linkage	Functionally linked with the surrounding habitats, providing movement corridor, shelter and roosting sites and foraging habitat.	Functionally linked with the surrounding habitats but ecological linkage is lower than previous years because of the surrounding development
Potential Value	The potential ecological value of this habitat type could be enhanced by active management as a wildlife habitat especially if a water supply permitted conversion to wetland	The potential ecological value of this habitat type could be enhanced by active management as a wildlife habitat but the small area involved would only be suitable for less disturbance sensitive wildlife species
Nursery/ breeding ground	A limited range of species use this habitat but most are common and widespread	A limited range of species use this habitat but most are common and widespread
Age	Varies according to period of inactivity, however areas that are abandoned in the long term revert to shrubland unless they are burnt	Varies according to period of inactivity, however areas that are abandoned in the long term will revert to shrubland unless they are burnt
Abundance/Richness of Wildlife	Low to Moderate	Low
Conclusion	Moderate Ecological Value	Low Ecological Value

Table 4.17

Ecological Evaluation of Managed Wetland

Criteria	Long Valley
Naturalness	Man-made habitat actively managed for nature conservation
Size	Small
Diversity	Moderate in habitat diversity and species diversity
Rarity	Outside of Mai Po Nature Reserve managed wetland is very rare in Hong Kong
Re-creatability	Readily re-creatable provided that land is available
Fragmentation	Heavily fragmented, but part of a large unfragmented mosaic of habitats
Ecological Linkage	Functionally linked with the surrounding habitat, providing movement corridors and foraging habitat
Potential Value	Subject to an appropriate management regime, these habitats will have very high value especially where they are adjacent to wet agricultural
Nursery/ breeding ground	Habitats are not yet mature enough for most species but have the potential to provide undisturbed breeding areas for species utilising the Long Valley habitat mosaic
Age	Habitats have only been created during 2001 and some areas are still under construction
Abundance/Rich-ness of Wildlife	Moderate as not yet mature but considerable potential. Somewhat limited by small size of units
Conclusion	Moderate Ecological Value at present but High Ecological Value when Established

4.4.7 The Managed Wetlands to be formed as compensation for the construction of San Tin Eastern Main Drainage Channel were stated in ERM (1999a) to be of moderate to high value for wetland dependent bird species, though the targeted species are not specified. In addition, this habitat is to be provided on approximately a 1:1 basis in compensation for fish pond loss. The potential ecological value of these wetlands is therefore considered to be equivalent to fishponds and has been taken into account in the assessment for Spur Line.

Fish Pond / Bloodworm Pond

4.4.8 Fish pond and other pond habitats are mainly located in the areas surrounding San Tin and Lok Ma Chau, with much smaller areas near Ho Sheung Heung and in Long Valley. For the purposes of this evaluation, these pond habitats have been categorised into three different types: active fish pond, inactive fish pond and bloodworm ponds. Tables 4.18 - 4.20 provide an evaluation of these three habitat types; those located within the 200 m study corridor are primarily the active fish ponds in San Tin and Lok Ma Chau and the inactive and active fish ponds and bloodworm ponds near Ho Sheung Heung and in Long Valley. Several ponds that were reinstated under the Shenzhen River Regulation Scheme will be impacted by the future Lok Ma Chau Station of Spur Line. These ponds have been returned to pond status, but with riprap along their northern edges and they have been considerably reduced in area. The functional value of these ponds is therefore somewhat limited to large waterbirds because of the proximity to the border road. Their value is considered to be low to moderate.

Table 4.18

Ecological Evaluation of Active Fish Ponds

Criteria	San Tin	Lok Ma Chau	Long Valley
Naturalness	Man-made habitat, actively managed for fish production	Man-made habitat, actively managed for fish production	Man-made habitat, actively managed for fish production
Size	Active fish ponds cover an extensive area within the Study Area	The overall size of active fish ponds in Lok Ma Chau is now moderate as farming has recently ceased on ponds in the proposed station area	Small
Diversity	Low habitat diversity but high in terms of the diversity of wildlife supported	Low habitat diversity but high in terms of the diversity of wildlife supported	Low habitat diversity but moderately high in terms of the diversity of wildlife supported
Rarity	The habitat itself is not rare but some of the species supported are rare locally or globally	The habitat itself is not rare but some of the species supported are rare locally or globally	The habitat itself is not rare but some of the species supported are rare locally or globally
Re-creatability	Readily re-creatable	Readily re-creatable	Readily re-creatable
Fragmentation	Not fragmented	Not fragmented	Not fragmented
Ecological Linkage	Part of the large contiguous area of fish pond habitat in the Deep Bay area, serving a similar function to those at Mai Po Nature Reserve	Part of the large contiguous area of fish pond habitat in the Deep Bay area, serving a similar function to those at Mai Po Nature Reserve	Part of the matrix of wetland habitats in Long Valley which is known to support a diverse array of wildlife
Potential Value	High ecological potential if managed to enhance wildlife use	High ecological potential if managed to enhance wildlife use	High ecological potential if managed to enhance wildlife use
Nursery/ breeding ground	Highly productive system that is particularly important for the high densities of important food resources provided for birds during draw-down for harvest periods	Highly productive system that is particularly important for the high densities of important food resources provided for birds during draw-down for harvest periods	Highly productive system that is particularly important for the high densities of important food resources provided for birds during draw-down for harvest periods. But fairly isolated from similar habitats
Age	No information is available and is considered irrelevant to the ecological value of this habitat type	No information is available and is considered irrelevant to the ecological value of this habitat type	No information is available and is considered irrelevant to the ecological value of this habitat type
Abundance/Richness of Wildlife	High	High	High
Conclusion	High Ecological Value	High Ecological Value	High Ecological Value

Table 4.19

Ecological Evaluation of Inactive Fish Ponds

Criteria	San Tin	Lok Ma Chau	Ho Sheung Heung
Naturalness	Man-made habitat, currently subject to limited human disturbance	Man-made habitat, currently subject to limited human disturbance	Man-made habitat, currently subject to limited human disturbance
Size	Small	Large, as a consequence of the cessation of fish farming in the proposed station area	Small
Diversity	Low habitat diversity but high in terms of wildlife recorded	Low habitat diversity but high in terms of wildlife recorded	Moderate habitat diversity, moderate in terms of wildlife recorded
Rarity	The habitat is not rare but some of the species supported are rare locally or globally, notably some avifauna	The habitat is not rare but some of the species supported are rare locally or globally, notably some avifauna	The habitat is not rare but some of the species supported are rare locally or globally, notably some avifauna
Re-creatability	Readily-re-creatable	Readily-re-creatable	Readily-re-creatable
Fragmentation	Heavily fragmented	Slightly fragmented	Slightly fragmented
Ecological Linkage	Part of the wider fishpond habitat of the Deep Bay area and serves similar function to those located at Mai Po Nature Reserve	Part of the wider fishpond habitat of the Deep Bay area and serves similar function to those located at Mai Po Nature Reserve	Functionally linked to the matrix of wetland habitats in Long Valley known to support a diverse array of wildlife, notably avifauna
Potential Value	High ecological potential if managed properly to enhance wildlife use	High ecological potential if managed properly to enhance wildlife use	High ecological potential if managed properly to enhance wildlife use
Nursery/ breeding ground	Part of the wider Deep Bay fishponds habitats that provide an important breeding/nursery ground for the prey of bird and other mammals, notably the Tilipia and chironomids	Part of the wider Deep Bay fishponds habitats that provide an important breeding/nursery ground for the prey of birds and other wildlife, notably the Tilipia and chironomids	Functionally linked to Long Valley providing an important nursery ground for the prey of birds and other wildlife, notably Tilipia and chironomids
Age	No information is available	No information is available but many ponds have only been abandoned since 2000	No information is available
Abundance/Richness of Wildlife	High	High	High
Conclusion	Moderate to High Ecological Value	Moderate to High Ecological Value	Moderate Ecological Value

Table 4.20

Ecological Evaluation of Bloodworm Ponds

Criteria	Long Valley
Naturalness	Man-made habitat actively managed for aqua-culture produce (bloodworms)
Size	Small in size
Diversity	Low habitat diversity but high in terms of wildlife species supported
Rarity	The habitat is not rare but some of the species found utilising this habitat are rare locally, notably some avifauna
Re-creatability	Readily-re-creatable
Fragmentation	Slightly fragmented
Ecological Linkage	Part of the wetland habitat in Long Valley and provides important feeding and/or breeding habitat for a wide array of wildlife
Potential Value	High ecological potential if managed to enhance wildlife use
Nursery/breeding ground	Part of the wetland habitat of Long Valley and the crop of invertebrate fauna (bloodworms and chironomid) provides an important prey base for insectivorous animals, notably ardeids of the nearby egretries as well as bat species. It also provides breeding sites for amphibian and dragonflies.
Age	No information is available and considered irrelevant
Abundance/Rich-ness of Wildlife	High
Conclusion	Moderate to High Ecological Value

Marsh

4.4.9 Only very limited areas of marshland are present within the Study Area: adjacent to the Lok Ma Chau Boundary Crossing Plaza, to the west of Chau Tau and in Long Valley.. The ecological importance of the main areas of marsh is evaluated in Table 4.21. It should be noted that much of the marshland identified within the study area is within the 200 m study corridor. Intensification of agriculture in Long Valley since the ERM (1999b) study has resulted in a considerable reduction in the area of marsh compared with that shown in the previous EIA Report (Binnie 2000a). Despite this, the marsh continues to fulfil a function as a refuge area for species such as Greater Painted-snipe.

Table 4.21

Ecological Evaluation of Marsh

Criteria	Long Valley	Chau Tau & Lok Ma Chau
Naturalness	The marshes are semi-natural but are subject to some human management associated with agricultural production in the surrounding areas. Habitat may have originated from inactive agricultural fields or ponds	The marsh is natural but may have originated from inactive agricultural fields or ponds
Size	Small in size	Small to moderate in size
Diversity	Both species and habitat diversity are only moderate because of the small area and human activities	Species and habitat diversity are considered moderate and low respectively
Rarity	Not a rare habitat but the site is a known breeding site for the locally rare Greater Painted-snipe	Neither the habitat nor the species found are considered rare
Re-creatability	This habitat is readily re-creatable provided land and appropriate environmental condition is available	This habitat is readily re-creatable provided land is available
Fragmentation	Only slightly fragmented but the remaining area is itself a fragment of the marsh area described in BBV (2000a)	Not fragmented
Ecological Linkage	Part of the wetland system within Long Valley which supports a wide array of wildlife and serves as a shelter, roosting, breeding and feeding site	Part of the wetland systems of San Tin and the Deep Bay area as a whole; invertebrate form an important prey base for insectivorous animal
Potential Value	Moderate potential value - limited by the small size of the remaining area	Moderate potential value - would be higher if actively managed as wildlife habitat
Nursery/breeding ground	Part of the wetland system within Long Valley, providing shelter, breeding and nursery sites for a diverse wildlife, including the rare Greater Painted-snipe	Part of the wetland habitat in the Deep Bay Area and is very important in providing a nursery/breeding ground for the invertebrates which serve as an important food item to avifauna that frequent the Deep Bay area
Age	Evidence from land use divisions and aerial photographs suggests an age of no more than 5-10 years	No information is available, but species diversity and plant age would suggest that this marsh is over 5 years old.
Abundance/Richness of Wildlife	Moderate to High (limited by small size of remaining area)	Moderate
Conclusion	High Ecological Value	Moderate Ecological value

Water Courses

4.4.10 The two major water courses within the Study Area, the River Beas (Sheung Shue River) and the River Sutlej (Shek Sheung River) have been channelised since the ERM (1999b) study was conducted. There is also a minor channelised water course at Chau Tau. Given that the physical conditions of the two rivers (River Beas and Sutlej) are quite similar, they are discussed together in Table 4.22. Though the form of the two rivers has changed significantly their ecological value remains low.

4.4.11 The remaining semi-natural water courses are drainage channels in the San Tin and Lok Ma Chau area and irrigation ditches in Long Valley. The drainage channel regime at Lok Ma Chau and San Tin will shortly be significantly altered by the construction of a major artificial drainage channel, the San Tin Eastern Drainage Channel (Maunsell 2001).

Table 4.22

Ecological Evaluation of Water Courses

Criteria	Rivers	Drainage Channel	Ditches
Naturalness	Channelised with concrete and stone embankments. Water flow controlled by fabri-dams	Man-made habitat but banks of earth and vegetation remain semi-natural	Man-made habitat, some semi-natural earth banks, others formed by artificial materials
Size	Considered inapplicable but the rivers are long and wide	Considered inapplicable but the channels are long and relatively wide	Considered inapplicable but the ditches are long and narrow
Diversity	Very low in habitat and low in species diversity	Low in both habitat and species diversity	Low in both habitat and species diversity
Rarity	Neither the habitat nor species found supported is considered rare	Neither the habitat nor species found supported is considered rare	Neither the habitat nor species found supported is considered rare
Re-creatability	Readily re-creatable	Readily re-creatable	Readily re-creatable
Fragmentation	Not fragmented	Not fragmented	Not fragmented
Ecological Linkage	Ecological linkage to surrounding habitat is considered low because of the poor condition of the water and the extensive artificial embankments and access roads	Ecological linkage to surrounding habitat is considered low because of the poor condition of the water, but the grassy riparian vegetation provides invertebrate prey for insectivorous birds in the surrounding area	Ecological linkage to surrounding habitat is considered low because of the poor condition of the ditches, but the grassy riparian vegetation provides invertebrate prey for insectivorous birds in the surrounding area
Potential Value	The potential of the three rivers could be higher if the water quality improved, but there is no prospect of the naturalness of the rivers being restored	The potential of the channel could be higher if the water quality improved and grasscrete was used in the formation of San Tin Eastern Drainage Channel	The potential of the ditches could be higher if the water quality improved
Nursery/ breeding ground	Not considered significant	Not considered significant	Not considered significant
Age	No information but considered irrelevant	No information but considered irrelevant	No information but considered irrelevant
Abundance/Rich-ness of Wildlife	Poor	Poor	Poor
Conclusion	Low Ecological Value	Low Ecological Value	Low Ecological Value

Grassland-Shrubland Mosaic

4.4.12 This habitat type is found mainly on the hill-slopes behind Chau Tau, Pak Shek Au and on the foothills of Ki Lun Shan. Given the similarity of the habitat attributes of these areas, they are evaluated as a whole in Table 4.23.

Table 4.23

Grassland-Shrubland Mosaic

Criteria	Grassland-Shrubland Mosaic
Naturalness	Natural habitat but subject to frequent hill-fire
Size	Moderate to large in size compared to other habitats within the Study Area
Diversity	Low habitat and species diversity
Rarity	Neither the habitat nor are most of the species known to be present considered rare. However, the habitat is utilised by two rare breeding birds of Conservation Importance (Eurasian Eagle Owl and Northern Hobby) and a third, localised, breeding bird species, the Savanna Nightjar is also present
Re-creatability	Readily re-created but very vulnerable to fire during establishment
Fragmentation	Not fragmented as a whole over the hill-slope
Ecological Linkage	May function as a movement corridor to wildlife foraging over the agricultural habitat within the Study Area, and the fruit of some shrubby plants could provide food sources to fruitivorous wildlife such as civet.
Potential Value	The potential is moderate provided that hill-fire disturbance ceases and succession is allowed. However, both Eurasian Eagle Owl and Savanna Nightjar are dependant upon the habitat created by the fire plagioclimax
Nursery/ breeding ground	Low overall but provides breeding habitat for the three rare or localised breeding species described above
Age	In its present form this habitat is best described as being either in the early stages of the succession gradient or in a plagioclimax imposed and maintained by hill-fires
Abundance/Rich-ness of Wildlife	Poor overall despite the three rare or localised breeding bird species
Conclusion	Low Ecological value

Wasteland

4.4.13 Wasteland is mostly associated with developed areas and is scatter over the Study Area. The ecological value of this habitat is evaluated in Table 4.24.

Table 4.24

Ecological Evaluation of Wasteland

Criteria	Wasteland
Naturalness	Heavily disturbed and disrupted by past and current human activities
Size	Usually small in size
Diversity	Poor in both species and habitat diversity
Rarity	Neither the species present nor the habitat is rare
Re-creatability	Readily re-creatable
Fragmentation	Heavily fragmented within the Study Area
Ecological Linkage	Not functionally linked with any important habitat, although may provide an opportunistic movement corridor for some species
Potential Value	Ecological potential would be moderate if colonisation and succession were allowed to occur
Nursery/ breeding ground	None recorded
Age	Usually young
Abundance/Rich-ness of Wildlife	Poor
Conclusion	Low Ecological Value

Developed Area

4.4.14 Developed Area includes densely populated areas, rural villages, open storage areas, construction sites and other light industrial areas. This habitat covers most of the Study Area in Sheung Shui, Kwu Tung, and part of San Tin, and is also the most common habitat type within the 500m study corridor. The ecological value of this habitat is evaluated in Table 4.25.

Table 4.25

Ecological Evaluation of Developed Area

Criteria	Developed Area
Naturalness	Heavily disrupted and disturbed by human activities
Size	Largest habitat type within the Study Area
Diversity	Poor in both species and habitat diversity
Rarity	Neither the species nor the habitat is rare
Re-creatability	Readily re-creatable
Fragmentation	Heavily fragmented within the Study Area
Ecological Linkage	Not functionally linked with any important habitat
Potential Value	The ecological potential is moderate developed areas pass into wasteland and succession is allowed to proceed
Nursery/ breeding ground	None for Species of Conservation Importance
Age	No information and considered irrelevant
Abundance/Rich-ness of Wildlife	Poor
Conclusion	Low Ecological Value

Conclusion

4.4.15 Most of the habitats occurring within the Study Area are man-made or highly modified and relatively widespread and common in Hong Kong (Table 4.26). Of these, plantation forest, orchard, watercourses, grassland / shrubland mosaics, wasteland and developed areas are of low overall ecological value. However, despite its low overall ecological value, reflected in low habitat and species diversity, one of these habitats (shrubland / grassland mosaic) does support two breeding Species of Conservation Importance, Northern Hobby and Eurasian Eagle Owl.

4.4.16 Several other habitats are of moderate or high ecological value, primarily because they regularly support a number of Species of Conservation Importance as listed in Table 4.2. Of these habitats, the low-lying wet agricultural habitats of Long Valley and the fishponds around San Tin / Lok Ma Chau are of particular ecological value because they support a diverse range of flora and fauna, including large numbers of Species of Conservation Importance.

4.4.17 The fishponds in the San Tin / Lok Ma Chau area are of major importance as this is a large area of habitat that is contiguous with the wetlands of the Deep Bay Ramsar site and because it holds substantial populations of many waterbirds that are Species of Conservation Importance. The conservation importance of the area has been recognised by the Town Planning Board through its designation as a Wetland Conservation Area.

4.4.18 The Long Valley area contains a diverse range of wetland habitats that also support a rich variety of fauna, including a significant number of butterflies, amphibians, reptiles and particularly birds that are Species of Conservation Importance. Such wetland habitats have declined rapidly in Hong Kong in recent years and are under continuing development pressure. Long Valley also contains remnant areas of freshwater marsh, which are now especially threatened in Hong Kong.

Table 4.26

Summary of habitat evaluations

Habitat / location	Overall evaluation
Fung-shui forest
· Ho Sheung Heung	Moderate – High
· Tsung Pak Long	Low – Moderate
· Chau Tau / Pun Uk Tsuen	Moderate
Lowland secondary forest
· Lok Ma Chau	Moderate
· Pak Shek Au / Ki Lun Shan	Low – Moderate
Plantation forest
· Roadside plantation	Low
· Kwu Tung / Pak Shek Au	Low
Orchard	Low
Active wet agricultural land
· Long Valley	High
· Chau Tau	Moderate
· Lok Ma Chau	Low – Moderate
Active dry agricultural land
· Long Valley	Low – Moderate
Inactive wet agricultural land
· Long Valley	High
· Chau Tau	Moderate
Inactive dry agricultural land
· Long Valley	Low – Moderate
· Chau Tau	Low
Managed wetland
· Long Valley	High
Active fish pond
· San Tin	High
· Lok Ma Chau	High
· Long Valley	High
Inactive fish pond
· San Tin	Moderate – high
· Lok Ma Chau	Moderate – high
· Ho Sheung Hung	Moderate
Bloodworm Pond	Moderate – high
· Long Valley	Moderate - high
Marsh
· Long Valley	High
· Chau Tau	Moderate
· Lok Ma Chau	Moderate
Watercourse
· Channelised river	Low
· Drainage channel	Low
· Ditches	Low
Grassland-shrubland mosaic	Low
Wasteland	Low
Developed area	Low

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