The Resources And Landscape Utilization Of Styracaceae In Hunan

There are 12 genera, about 150 species worldwide; 11 genera,50 species,9 varieties in China,9 genera,25 species,4 varieties in Hunan. As for the distribution of genera, Hunan is the main distribution area of Styracaceae, which ranks first among provinces in China. Styracaceae is of great ornamental value. Some species have white fragrant flowers or Seyan odd-shaped fruit, which are rare ornamental plants. Currently only Sinojackia xylocarp and Melliodendron xylocarpum used in a few garden, and most of the plants are still in purdah, known by few people.The utilization of Styracaceae needs to be improved.From 2009 to 2010, the author did a field survey on Styracaceae of its planting resources,habitats introduction and cultivation in Hunan province, reviewed the Hunan Styracaceae plant specimens which kept in Herbarium of Central South Forestry University (CSFI) and Life Sciences department of Hunan Normal University (HNNU), and analyzed the ornamental value and landscape potential applications of this plant family. The results are summarized as follows:(1) There are 11 genera,50 species and 9 varieties of the Styracaceae which distribute in China, and 9 genera,25 species, and 4 varieties in Hunan province. According to the distribution of the genera, Hunan is the main distribution area of this family, and ranks first place in China's provinces in number.(2) The Styracaceae plant habitats can be divided into four types:①Growing in the edge of the secondary forest or empty space forest, small canopy density, shape into a loose form, such as the majority of the Styracaceae gerena plants, Sinojackia rehderiana and Sinojackia henryi;②Forming small area communities, which mainly are Alnipyllum and Huodendron.The former one forms the instable pioneer community in the secondary forest; and the latter one is in the middle of the secondary evergreen broad-leaved forest tree species;③Distribution along the water stream, a special community types which grows in a special habitat condition, these mainly are Pterostyrax corymbosus,Changiostyrax dolichocarpa,Melliodendron xylocarpum and Sinojackia sarcocarpa;④Growing in evergreen and deciduous mixed forest, shape into a loose form, such as Rehderodendron and Pterostyrax psilophyllus. In addition, there are some wide ecological amplitude individual species, such as Styrax suberifolius, S. odoratissimus and Halesia macgregorii, which distribute in the forest edge, woodland, jungle and damp valley.(3) The floristicelements of community of Changiostyrax raxdolichocarpa are complex, the tropical geographical elements are strong at family-level and genus-level. Vertical structure of the community is complex, dominated by Mesophanerophytes and Microphanerophytes. The community is rich in plant species, especially the diversity of shrub layer were higher than those of the tree layer and herb layer. Before entering the physiological age of death, there are 2 mortality peaks of Changiostyrax raxdolichocarpa.The first one Produced in young trees stage (II, III age groups),which the main reason is the intraspecific and interspecific competition (mainly caused by light); the other one produced in the stage of the trees growing into big ones(V, VI age groups). The growth in shallow soil, the trees lodging and man-made cutting intensified the peak production, besides intraspecific and interspecific competition.The whole species group presented Gathering distribution type. The changing processes of sapling trees to big trees showed the transformation from the gathered distribution to random distribution.(4) The introduction survival rate of Styracaceae is very high in Hunan. With the exception of Styrax hemsleyanus and Rehderodendron macrocarpum at low altitudes where there is no introduction, others are all introduced in the Botanical Gardens and in the nursery of Central South Forestry University successfully. Some species, such as Pterostyrax psilophyllus and Halesia macgregorii eg, have rigorous requirements for their habitat conditions. Low attitude areas, hot in summer and low humidity of air and soil are the main reasons for their survival in such hard conditions.(5)The flowers of Styracaceae flourish, with aromatic, which enjoy a high ornamental value. The fruits which owe a high ornamental value are the Sinojackia,Melliodendron,Rehderodendron and Halesia. Through the evaluation of AHP, landscape garden recommended species are:Styrax japonicus,S. confusus,S. obassia,S. macrocarpus,Melliodendron xylocarpum,Huodendron tibeticum and Halesia macgregorii.(6) Hunan's Styracaceae plants have great potential landscape applications, which can be used as ornament for courtyards. Some trees can be used for street trees, shelter- forest, scenic forest and to attracting bees and butterflies.(7) The flowers of Styracaceae are mostly white, while pink flower types also exist in nature, such as Styrax japonicus, S. confusa and S. tonkinensis, which can be produced by selecting the pink flower varieties. It is high time that China strengthened the gardening domestication and selection of Styracaceae.