THE REGULARITY OF GEOGRAPHICAL DISTRIBUTIONS OF THE VEGETATION IN HUBEI PROVINCE

Hubei Prvince, 29°05′ 33°20′north latitude and 108°30′ 116°10′east longitude,is situated in the middle reaches of the Changjiang (Yangtze) River.It possesses a total area of 1859000square kilometers and the climate entirely belongs to the subtropic district.The geographycal distribution of the vegetation in Hubei is evidently controlled by the regularity of water and heat factors by the horizontal (latitudinal and longitudinal)and verlical zonalness.The northern part of the province belongs to the north subtropic evergreen and deciduous broad-leaved mixed forest zone,in which the typical vegetation types are the Quercus forest containing cyclobalanopsis, Lithocarpus,Phoebe and Ilex,Platycarya strobilacea forest,Liquidambar,formosana forest,Pinus massoniana forest,Pinus taiwania forest and Pinus henryi forest.The southern part of the province belongs to the central subtropic evergreen broad-leaved forest zone with the typical vegetation types charactering Castanopsis spp.forest,Machilus spp.forest, Cinnamomun camphora forest,Sycopsis sinensis forest,Cunninghmia lanceolata forest and Pinus massoniana forest.The longitudinal zonalness of the vegetation in Hubei Province is decided by drought degree decreasing progressively from east to west, meanwhile the vegetation types present themselves obviously the change of longitudinal zonalness also.The vegetation elements of the province belong basically to the central China elements charactering Taiwania flousiana forest and Pseudolarix amabilis forest,which are closely to the eastern China elements and have a certain relationships to southwestern China and northern China.The vegetation elements of western part of the province,very closely relating to the southwestern China, is the typical elements of central China represented by Pinus henryi forest, Pinus armandii forest and Metasequoia glyptostroboides forest.The vertical distribution of the vegetation in mountinous region is affected by the climate factor changes in various altitude above the sea level; and the phenomenon causes the sere to appear the regular vertical changes.