Ecology of Hong Kong

Geography of Hong Kong
Amusement parks
Areas (Neighbourhoods)
Bays
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Buildings and structures
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Climate
Conservation
Declared monuments
Ecology
Air pollution
Geology
Harbours
Islands and peninsulas
Lakes
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Mountains, peaks, and hills
Urban parks and gardens
Plains
Reservoirs
Rivers
Valleys
Villages
Wetlands
Other Hong Kong topics
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The ecology of Hong Kong is mostly affected by the results of climatic changes. Hong Kong's climate is seasonal due to alternating wind direction between winter and summer.

Hong Kong has been geologically stable for millions of years. Flora and fauna in Hong Kong are altered by climatic change, sea level alternation, and human impact.

Climate

Main article: Climate of Hong Kong

Hong Kong's climate is subtropical but half the year is temperate. The territory is situated South of the tropic of Cancer which is equal to Hawaii in latitude. In winter, strong and cold wind generates from the North to Hong Kong; in summer, the wind reverses in direction and brings the warm and humid air from the South. This climate would support a tropical rainforest.

The map shows the latitude of Hong Kong compared to the major cities in the rest of China and the Asia Pacific area. It can be seen that the latitude of Hong Kong is the same as that of Honolulu (on the right side of the map).

Land

The total land area of Hong Kong is 1,076 square kilometers, but about 75% of this land is open countryside, which contains more than 2600 species of vascular plants, about 450 species of birds, about 200 species of butterflies, about 100 species of dragonflies, 40 species of mammals, 80 species of reptiles and more than 20 species of amphibians, including some species endemic to the territory.

Species richness in Hong Kong

Hong Kong is considered rich in number of species. The number of species of birds in Hong Kong is one third of that in China while the number of butterflies species is also one sixth of the total butterfly species in China according to surveys reported.[1]

Ecosystems in Hong Kong

Mangroves

Mangroves are habitats of enclosed intertidal mud flats with wave action greatly reduced, located near sources of fresh water. Popular mangrove habitats in Hong Kong are located along Deep Bay, such as Pak Nai and Tsim Bei Tsui, where salinity is very low under the influence of fresh water from the Pearl River, and along some mud flats where salinity is lowered by surrounding streams, such as Three Fathoms Cove and Ting Kok. Trees living in this habitat are called mangrove trees.

The following are the sites of mangroves in Hong Kong:

Mangroves in Tai O

Rocky shores

The tidal range of Hong Kong is about 2.5 meters and the distribution of species is situated into this area must be tolerant of both conditions that the shores are covered with sea water during high tide and the shores are exposed to the air directly during low tide, for hours or days. Species which have adapted to these different conditions are described as specialized to successfully exploit narrow vertical zones on the rocky shore.

The species inhabiting Hong Kong rocky shores varies in accordance with the exposure to the wave action from the sea. The sessile filter feeding organisms inhabit the wave exposed shores. They are able to attach on the rock surface and remove food particles in the turbulent water while the mobile herbivores and carnivores inhabit in the sheltered shores. The varieties of the organisms also different from seasons, especially in Hong Kong where oceanic currents change with season: very few erect foliose macro-algae are found in summer because they may suffer from the burning heat; a lot of foliose algae are found on the shores in winter.

The following are the sites of rocky shores in Hong Kong:

Streams

There are two kinds of freshwater habitats: lentic water, such as lakes, ponds, ditches, and lotic water, such as rivers, streams. Streams are an example of a lotic habitat Hong Kong.

There are three main factors to differentiate the habitats in Hong Kong: variability of current, amount of detritus and variable oxygen content. These factors contribute to make the animals adapted in different ways. They have to attach themselves to the surfaces, become predominantly detritus feeders and have a mechanism for obtaining maximum oxygen supply.

The followings are the list of rivers in Hong Kong:

Sandy shores

The following are the site of sandy shores in Hong Kong:

Problems

Pollution

General

Chinese white dolphin
Black-faced spoonbill

In 1989, the Hong Kong government realised that Hong Kong was in danger of becoming a vast, densely populated city. Due to the growth of the economy and business sectors, the water, waste and air pollution cause an adverse effect on the balance of ecology in Hong Kong.

Factories, farms and restaurants in the New Territories dump large amounts of sewage and even untreated waste into the streams and the sea. It makes the New Territories' streams be 'no better than open sewers'. This severe damage is irreversible and the creatures in the sea are the direct victims of the capitalized city’s effort.[3]

The pink dolphin is one of the victims. Under threat from chemical pollution, increased sea traffic and the destruction of much of the natural shoreline for land reclamation, the number of pink dolphins has dramatically declined as the city continues to develop.

The nature reserve and birds in Mai Po Marsh are the other victims. They are threatened by the pig sewage flooding as well as the increased pollution from Shenzhen. Yet according to World Wide Fund for Nature Hong Kong the number of the endangered black-faced spoonbills wintering in Mai Po has risen from roughly 35 in the late 1980s to 152 after 10 years. About 400 are spotted after 2000. Estimates on how many of these birds remain in the wild vary from 2,000 to 1,000.[4]

The oyster farms have been throttled by a mixture of pollution and competition from cheaper oyster cultivation across the border in China.

Air pollution

Air pollution is another serious problem. Smoke-belching factories, ceaseless construction and large numbers of diesel vehicles have made for dangerous levels of particulate matter and nitrogen dioxide. Not only the flora and fauna are affected but also humans. Cases of asthma and bronchial infections have soared in recent years, and doctors place the blame squarely on poor air quality.

Thermal pollution

According to a Baptist University study, daily average minimum temperatures have increased by 0.02 degrees (Celsius) annually between 1965 and 2003, due to the "concrete jungle" which traps heat during the daytime and releases it at night. Average daily maximum temperatures have fallen by 0.014 degrees each year, as air pollution is blocking solar radiation. Resulting increased night time ambient temperatures incite families to use domestic air-conditioning, which further compounds the problem.[5]

Research has shown that the ambient air-temperature in urban areas can be some 5 °C higher than non built-up areas. The Hong Kong Polytechnic University commissioned NASA to take a high-resolution thermal image of urban Hong Kong by satellite at 22:40 on 4 August 2007, which showed at least a 4 degree difference between the coolest areas and the "urban heat islands". The variations are attributable to greater absorbency of man-made materials, and building density which restrict air-flow. The urban heat island had expanded into Hung Hom since January, when the first image was taken.[6]

"Wall effect"

Highly-dense buildings can be seen in Tseung Kwan O.

There has been increasing concern since 2006 over the "wall effect" caused by uniform high-rise developments which adversely impact air circulation. Due to the density of Hong Kong's population and the economies of scale of mass developments, there is the tendency of new private tower block developments with 10 to over 100 towers, ranging from 30-to-70-storeys high. Developers of housing estates are financially motivated to maximise the view, at the expense of the free-flow of air. Huge wall-like estates along the waterfront are often constructed.[7]

In-fill developments will tend to done by smaller developers with less capital. These will be smaller in scale, and less prone to the wall effect.

Environmental group Green Sense expressed concern that their survey on 155 housing estates found 104 have a 'wall-like' design. It cited estates in Tai Kok Tsui and Tseung Kwan O as the "best examples".[7] In May 2007, citing concern over developments in West Kowloon, and near Tai Wai and Yuen Long railway stations, some legislators called for a law to stop developers from constructing tall buildings which adversely affect air flow in densely populated areas, but the bid failed.[8] In 2007, residents of Tai Kok Tsui, increasingly aware of the problem, have been lobbying against further proliferation of such high-rises in their area which threaten the last air corridor.[6]

Threats to flora and fauna

Destruction of habitat

Illegal Hunting of species by mainland Chinese

With increasing affluence of mainland Chinese, some of them become affable to some luxury flora and fauna, like Podocarpus macrophyllus (羅漢松; Cantonese: lo hon chung) and Cuora trifasciata (金錢龜; Cantonese: kam chin kwai). With ever increasing hunting on some luxury species, they're becoming increasingly rare in South China and hunters turn their heads to the last habitat in the area: Hong Kong.

Introduction of non-indigenous species

Most of the introduced species do little harm to the ecology of Hong Kong. However, some species are invasive and cause massive damage to the ecology and/or economy of Hong Kong.[9]

For example, the pinewood nematode from North America and pine-needle scale insect from Taiwan, which together virtually eliminated the native Pinus massoniana in the 1970s and 1980s.[10]

See also

References

  1. ↑ Ecology of Hong Kong, Hong Kong Nature.net
  2. ↑ "Environmental Impact Assessment Report for 132 KV Supply Circuit from Pui O via Chi Ma Wan Peninsula via Sea Crossing towards Cheung Chau. Ecological Impact Assessment. 2001". Epd.gov.hk. 2 February 2001. Retrieved 2012-09-25.
  3. ↑ Reyes, Renato (21 December 1995). "Victoria Harbour to continue choking on sewage". The Standard. Retrieved 2007-05-15.
  4. ↑ Threatened Birds - Black-faced Spoonbill Platalea minor
  5. ↑ Agnes Lam, "Nighttime temperatures creeping ever higher", Page C1, South China Morning Post, 7 June 2007
  6. 1 2 10.40pm, 32°. The future's red hot for HK, pg 1, South China Morning Post, 30 September 2007
  7. 1 2 Yung, Chester (21 December 2006). "`Asia's walled city' leaves - residents longing for air". The Standard. Retrieved 2007-03-21.
  8. ↑ Olga Wong, "Call for law against 'wall effect' fails", South China Morning Post, 10 May 2007
  9. ↑ "Richard Corlett.''Hong Kong's Bad Biodiversity''". Hku.hk. Retrieved 2012-09-25.
  10. ↑ "Porcupine! 23 - Hong Kong's Bad Biodviersity!". Hku.hk. Retrieved 2012-09-25.

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