Abstract:

Phalaenopsis lobbii is a rare species with extremely small populations in China. Field investigation covering habitat survey and quadrangular survey in community 1 in Longhushan Nature Reserve, Guangxi, China and community 2 in small nature reserve of Horsfieldia hainanensis and Camellia impressinervis was conducted to study the community characteristics including habitat characteristics, species composition, community floristic characteristics and the structure. P. lobbii lived in an evergreen broad leaved forest with limestone with an altitude 150-330 meters. The vegetation of the habitat was well preserved. There were a total of 50 species of vascular plants in community 1, which belonging to 45 genera and 32 families. The biodiversity of the community was rich, among which Liliaceae was the dominant families. There were 38 species of vascular plants in community 2, which belonging to 35 genera and 26 families, without dominant families. Tropical Asian and pantropical genera played the dominant status at the generic level in the two communities. The floristic composition of the two communities showed tropical and subtropical transition. Both communities were dominated by the phanerophyte plants, making up 64% of the total species in community 1 and 65.79% in community 2, and lianas accounted for the largest proportion, indicating that canopy density increased and P. lobbii had certain requirements for ambient humidity and illumination. Importance values of herb layer species showed that multiple dominant populations were included in the community. Aglaonema modestum, Pilea boniana and Aspidistra fungilliformis were the dominant species in community 1 and Caryota monostachya, Tectaria subtriphylla, Rhaphidophora decursiva were the dominant species in community 2. P. lobbii was the only one orchid plant and just as an accompanying species in plant communities which attached to the trunk of the trees in the two community. At present, there are few systematic studies on the community structure and conservation of wild plant resources of P. lobbii. Further study is recommended about the germplasm resources and conservation of the plant. Taken measures such as strengthening local protection, combining with ex-situ protection, studying endangered mechanism, introducing species back into the wild by artificial cultivation and propagation to alleviate the endangered situation in the wild, and providing technical support for rational development and utilization.

Key words: Phalaenopsis lobbii, wild plant species with extremely small populations, habitat, community characteristics, importance value