Study On Species Diversity Of Plants In The Plot Of Important Forest Species Resources In Longgang Natural Reserve

The species composition of vascular plant, the floristic analysis of families and genera, classify table of plant, and classifying the important plant species (rare or endangered species,the national key protected wild plants, important species, endemic species, the species with important economic value) in the plot of important forest species resources (short for"plot") in Longgang Natural Reserve were studied on the base of a lot of document literature collected, field investigation, specimens collected, reviewed and identified. The major results as follows:1. The vascular plants 336 species belonging to 244 genera in 99 families in the plot, in which, there are fern plants of 30 species belonging to 20 genera and 13 families, there are 2 gymnosperm species belonging to 2 genera in 2 families, there are 304 angiosperm species belonging to 222 genera and 84 families, and there are 2 suspected new species and 2 new recorded species from Guangxi.2. There are 30 species belonging to 20 genera and 13 families in plot, the dominant families are Aspleniaceae and Polypodiaceae, each of them has 6 species, with the proportion of 40%; The dominant genera are Asplenium, Selaginella and Lygodium, they have 10 species with the proportion of 33%. In summary, the spern species are relative scarce in the plot, but the floristic composition of pern species show tropical nature, which coincides with the floral element of Longgang Natural Reserve.3. There are 306 species of seed plant belonging to 224 genera and 86 families in the plot, but the gymnosperm contain just 2 species (Cycas spiniformis and Gnetum montanum) belonging to 2 genera and 2 families, they are not important role of the floristic. There are 304 species of angiosperm belonging to 222 genera and 84 families, the dominant families are Euphorbiaceae, Moraceae, Papilionaceae, Rubiaceae, Orchidaceae, Annonaceae, Vitaceae, Myrsinaceae, Gesneriaceae, Araceae atc., most of them are tropical and sub-tropical, and the proportion of tropical and sub-tropical is about 89%. There are 222 genera angiosperm in the plot, the genera number which each has only one specie is 173, with the proportion of 77%, and 3 genera which each has only one specie in the world, with the proportion is about 1%, Hainania, Pteroceltis and delavaya;The genera which has most species is ficus(11), secondly is Tetrastigma(7), Chirita(5), piper(4); The genera which contain 3 species are clematis, capparis, zanthoxylum, diospyros, ardisia, dioscorea, litsea and clausena; The rests of 39 genera which each has 2 species.4. According to the List of Wild Plants Under State Key Protection (Vol. 1, 1999), 6 species were considered as protection plants in the plot, Alsophila gigantean(II), Cycas spiniformis(I), Excentrodendron tonkinense(II), Diplodiscus trichosperma(II), Madhuca pasquieri(II) and Caryota obtusa(II); The plant endemism is very obvious, according to Plants Endemic to Guangxi Province,A Checklist of Vascular Plants of Guangxi, Flora of Guangxi and correlational research, there are 28 species which endemic to Guangxi in the plot. To a great degree, the exist of the wild plants under state key protection or the plants endemic to Guangxi province affect the floristic composition or vegetation type.5. About 300 vascular plants have certain application, they include medicinal plant, viewing and greening plant, bee plant, textile plant, starch plant, fragrant plant, timber plant, oil plant, food plant, tannic plant, hazardous and noxious plant ect..6. The dominant species are Excentrodendron tonkinense, Cleistanthus sumatranus, Drypetes perreticulata, Walsura robusta, Garcinia paucinervis, Ficus microcarpa, Diplodiscus trichosperma, Sterculia monosperma, Delavaya toxocarpa ect. Cleistanthus sumatranus, Walsura robusta and Drypetes perreticulata widely distributed, and the number of them is large, but Excentrodendron tonkinense, Garcinia paucinervis, Ficus microcarpa, Diplodiscus trichosperma, Sterculia monosperma and Delavaya toxocarpa are non-uniform distribution. The dominant species of the eastern slope are Excentrodendron tonkinense, Cleistanthus sumatranus, Drypetes perreticulata and Walsura robusta, the dominant species of the western slope are Excentrodendron tonkinense, Garcinia paucinervis and Cleistanthus sumatranus, the dominant species of the southern slope are Excentrodendron tonkinense, Diplodiscus trichosperma, Cleistanthus sumatranus, Walsura robusta and Drypetes perreticulata, and the dominant species of the northern slope are Sterculia monosperma, Delavaya toxocarpa and Cleistanthus sumatranus. The plot also contains a vally, which the microhabitat is large different from all sides of slopes, because it was usally underwater during the rainy season, the soil layer is much thicker, and the vally was covered by the vegetation of all sides of slopes. The dominant species of the wally is Ficus hispida var. Hispida, and lots of liana plants grown in it. Because of the characteristic of karst landform, thin soil, high expose rate of stone, and long-term drought, even the vally , underwood plants are relatively scarce in the plot, and the diversity of herbaceous plant is not high, the major plants are some plantlet and small trees of overwood in the shrub layer.