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The Environment

Despite its small size, Hong Kong has a great variety of coastal landforms including sea cliffs, sea caves, sea arches, geos, tombolos, wave-built terraces, sea stacks, notches and blowholes.

While most of the hexagonal volcanic rock columns in other regions of the world are composed of basic basaltic lava, those in Sai Kung are made up of acidic silica-rich rhyolitic volcanic rock. Apart from its extraordinary composition, the columns are considered to be unique for their large area (over 100 square kilometres) and size (average diameter of 1.2 metres).

A series of fifteen 1:20,000-scale geological maps and six accompanying geological memoirs have been produced by the Hong Kong Geological Survey. Two summary memoirs and a set of 1:100,000-scale geological and thematic maps have been published, in Chinese and English, synthesising and giving a popular account of Hong Kong's geology. Geological information can be accessed from the website of the Civil Engineering and Development Department.

Flora

Hong Kong is situated near the northern boundary of the distribution of tropical Southeast Asian flora, sharing similar species and structure with the flora of Guangdong Province. Despite its small size, Hong Kong has a rich flora with about 3,300 species of vascular plants, of which 2,100 are native to Hong Kong.

The major types of vegetation cover in Hong Kong currently comprise woodland, shrubland and grassland.

Remnants of the original forest cover can still be found in steep ravines or behind traditional villages in rural areas. They have survived as a result of their location in precipitous topography and the moist micro-climate, or because they are protected for cultural reasons.

Continual afforestation efforts coupled with various conservation measures have transformed formerly bare hillsides and slopes into impressive woodlands. Besides greening and beautifying the countryside, woodlands are important habitats for wildlife and are essential to protect water catchments from soil erosion.

Terrestrial Fauna

Hong Kong's climate and physical environment provide a wide range of habitats and support for a rich and varied fauna which includes around 520 species of birds, over 50 species of mammals, over 100 species of amphibians and reptiles, 236 species of butterflies and 117 species of dragonflies.

Besides having a rich terrestrial fauna biodiversity, a number of species are endemic to Hong Kong, including Romer's Tree Frog, Bogadek's Burrowing Lizard, Hong Kong Tusktail, Hong Kong Clubtail and Hong Kong Bent-winged Firefly. In addition, newly recorded species are discovered from time to time. Globally endangered or threatened species like the Three-banded Box Turtle, Yellow-breasted Bunting, Short-legged Toad, Green Turtle and Chinese Pangolin can also be found in Hong Kong.

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