Studies On Seed Plant Diversity Of Nangun River National Nature Reserve

Nangun River National Nature Resrve (NRNR) is located in Lincang, YunnanProvince, China. The coverage of Nangun River National Nature Resrve isN23°09-23°40and E98°57-99°26. The elevation is rising from510m to2970m. Themain types of forest in Nangun River National Nature Resrve are evergreen broad-leavedforest, Mid-mountain moist evergreen broad-leaved forest, Summit mossy dwarf forest,Alpine meadow etc.. The dominate families of the forest includes Fagaceae, Magnoliaceae,Lauraceae and Theaceae.In order to scientific management and protection of biodiversity in this region, thispaper analyzed the flora of family, genus, species, and analysis of distribution type alongelevational gradient, and floristic equilibrium point. The results are as follows:(1) The total2458species of wild seed plants is recorded belonging to988genera of181family in Nangun River National Nature Resrve, and of these families, genera andspecies, there are4families,4genera and5species in Gymnospermae,177families,984genera and2453species in Angiospermae. So the floristic is abundant.(2)The flora is comprehensive and its geographical ingredient is multiplex. In thisregion, of the total181families can be divided into10types, the total988genera can bedivided into14types and17subtypes, the total2458species can be divided into14types,the total612endemic to China species can be divided into3subtypes and10forms.(3) The flora of Nangun river, which possesses nature of marginal type of the tropicalAsia flora, belongs to Myanmar-Laos-Vietnam zone, India-Malaysia subkingdom, Ancienttropical kingdom in floristic regionalization. Compare between tropical and temperateingredients of family, genus and species are2.73:1,4.02:1,0.87:1.(4) Tropical Asia, East Asia and Endemics of China ingredients are the three originsof the flora. The amount and percentage of each type are as follows:998species (40.60%),627species(25.51%) and613species(24.94%).(5) Based on200m as one section, the number of families, generas, species of seedplants were statisticed with the altitude from510m to2970m. The results indicate that therichness of families, generas and species all presented a unimodal pattern, and the peakvalue appeared in the low altitude. The maximum richness of families distributed from 1101m to1300m and1301m to1500m of elevation, the generas and species appeared withan elevation between1101m and1300m (an average elevation of1740m). This is mainlybecause the water, heat and other conditions in this elevation range were suitable for thegrowth of plants.(6) Aeal-Types proportion of seed plants patterns with altitudinal gradients. Based onthe comparative statistical analysis of seed plant areal-typs in the13sections divided by200m, with increased altitudinal gradients, the proportion of widespread family and genera,the Chinese endemic species tend to go up, but the proportion of tropical family drops from83.72%to70.00%. The appearance of east Asia endemic species proportion is single-peakpattern. The floristic equilibrium point (FEP) do not exist in the family, but appearance to2700m,1300m respectively in the genera and species, which may be affected by origin offamily, genera and species.(7) There are abundant endemic in Nangun River National Nature Resrve.There are4families of East Asia, which are Helwingiaceae, Actinidiaceae, Tetracentraceae andToricelliaceae, accounting for22.22%of the total endemic to east Asia division(18families), this statistics indicates that the NRNR is part of East Asia’ and has consistency ingeological history with East Asia and also makes know that this area has close correlationwith East Asia, it belongs to the south side of East Asia plants. There are5genera endemicto China, which Homocodon, Camptotheca, Tapiscia, Sinoadina, Notoseris. And613species endemics to China which just included only distributed in China, endemic toYunnan Province,12endemic species only in tne area. This indicates the importantsignificance.