Studies On Species Diversity Of Chinese Fir Plantation In South Of Jiangxi Province

Chinese fir (Cunninghamia lanceolata Hook.), native to China, distributes in different provinces of southern drainage area of Changjiang River. It is an important commercial and fast growing in the south of China. The diameter structure, species composition of community, and species diversity of Chinese fire were studied with field investigation in the paper, and some scientific basis for reasonable exploitation and utilization of Chinese fir were supplied. The main results of investigation were given as follows:(1) There was abvious difference in diameter structure of different community. Its distribution range of natural deciduous forest get 6～40cm, Chinese fir plantation mainly concentrated in 6～10cm, accounts for 87.18% of total; Chinese fir pure plantation mainly concentrated in 10～16cm, Chinese fir and broadleaved mixed forest mainly in 10～16cm, accounts for 89.79% of total; upper slopes of Chinese fir pure plantation was mainly in 10～14cm, accounts for 73.91% of total, middle slopes was in 10～16cm, accounts for 91.49%, down slopes was in 12～16cm, accounts for 66.67%.(2) There was abvious difference in species composition of different community. Most species of arbor layer occurred in Chinese fir and broadleaved mixed forest, which belong to 8 families and 10 genera, were mainly Castanopsis rargesn and Cunninghamia lanceolata; Maximal species of shrub layer observed in natural deciduous forest, which belong to 14 families and 20 genera, were mainly Cyclobalanopsis glauca, Castanopsis rargesn, Dendrocalamus membranceus and Fissistigma oldhami; herb layer in Chinese fir and broadleaved mixed forest, belong to 6 families and 7 genera, were Dicranopteris linearis and Adiantum flabellulatum.(3) There was abvious difference in species diversity of different community. The community diversity of natural deciduous forest was highest in different origin stand, followed by Chinese fir and broadleaved mixed forest and Chinese fir pure plantation; The community species richness of upper slopes was highest in different slope positions, next was middle slopes and down slopes, the law of community evenness of shrub layer and herb layer were: upper slopes>down slopes>middle slopes; The sunny slope of community diversity of Chinese fir and broadleaved mixed forest was most abundant in different slope aspect, community species richness of shrub layer was most uniform for shady slopes; the species richness of mature forest was similar to halfmature forest, all more than young growth, the community diversity of herb layer was highest in young growth.(4) There were important significance through keeping community species diversity for forest land quality and ecological restoration. In production practice, closed forest for enhance species diversity; advocated for planting mixed forest; ensure planting trees adapted to soil, selecting as possible in middle slopes, down slopes, shady slopes, half shady slopes for planting Chinese fir; selected scientific mixed planting to avoid allelopathy among plants.