Forum Flora Germanica

Vegetation
The area contains a wide variety of ecosystems: tropical forests, cliff, summit, cave-mouth and littoral communities, mangrove forests (31 species), seaweeds (140 species), seagrass beds (5 species) and productive coral reefs. Primary tropical forest is found mostly on the larger islands like Ba Mun, sparsely on the steep limestone islands and thicker on the less steep schist and laterite islands. A study by the Institute of Ecology and Biological Resources of Hanoi (IEBR) of the tropical forest ecosystem in Ha Long and the neighboring Bai Tu Long Bay recorded 499 limestone-adapted plants including 12 species of ferns and seven plants endemic to the bay area: Ha Long cycad Cycas tropophylla, Ha Long fan palm Livistona halongensis, Ha Long ginger Alpinia calcicola, Ha Long balsam Impatiens halongensis, violet chirita Chirita halongensis, woolly chirita C. hiepii and Paraboea halongensis; also two sub-species Schefflera heptaphylla halongensis and yellow slipper orchid Paphiopedilum sp. The IEBR study of the wetlands of the Bay and its surroundings distinguished six sub-ecosystems: tidal and mangrove, tidal flats, caves and closed lagoons, hard bottom / coral reefs, soft bottom, and aquatic. Cat Ba National Park to the east is on a large well forested island with 800 vascular plant species, 265 of which are timber trees (sjvietnam 2008). Its primary tropical limestone forest features Spondias lakonensis, Milius flipes, Indospermum sp., and the mangroves Rhizophora mucronata, Bruguiera gymnorhiza, Kandelia candel and Aegiceras mafus (UNESCO, 2008).

....The IEBR (Institute of Ecology and Biological Resources of Hanoi) have catalogued the ecosystems and species of the area

...KNCCN, IEBR & HNU (1997) Ecosystem and Biodiversity of Cat Ba National Park and Ha Long Bay, Vietnam. Seoul: The Korean National Council for Conservation of Nature, the Institute of Ecology and Biological Resources, Hanoi, and Hanoi National University.