Study On The Characteristics Of Plant Diversity And Sediment In Najiao River Estuary

Najiao River originated from Sheguang mountain, Bobai county to Dandou Sea,Beibu Gulf. Its estuary does not only have the general characteristics of river wetlands, but it also has the characteristics of mangrove wetlands, which are important ecological resources in the region. This paper chooses cross Najiao River estuary wetland as a research object, research period was from Nov.2010 to Apr.2011.The research is main about the Vegetation composition, plant association, diversity of species, ecological association changing characteristics in associations with time and the soil texture, chemical characteristics and the relationship in this area. Main results are as follows:There were 48 plant quadrat setting in the Najiao River estuary wetland from Nov.2010 to Mar.2011.In Nov.2010, plants there belong to 20 families, 30 genera and 32 species, mainly about Poaceae, Euphorbiaceae, Verbenaceae. In Mar.2011, plants there belong to 22 families, 31 genera and 34 species, mainly about Poaceae, Asteraceae, Polygonaceae.Plant association in Najiao River area was classified by TWINSPAN in Nov. and Mar. According to the result, Najiao River estuary wetland vegetation can be divided into 6 typical groups of plexus in Nov.2010 and 11 typical group s of plexus in Mar.2011.By using richness index, Shannon-Wiener diversity index, evenness index and species dominant species index, this paper analyzed that Najiao River estuary wetland species diversity in different periods. The result showed that the richness index, Shannon-Wiener diversity index, evenness index of Najiao River estuary wetland species diversity in Nov. was higher than Mar.Through the studying about Soil physical and chemical properties of theNajiao River estuary wetland, we can get the conclusion that the soil moisture of the Najiao River estuary is 10.22%~45.10%, PH value is 4.67~6.2, Content of soil organic matter is 3.22~38.57g/kg, CEC is 2.10~24.24coml/kg and Soil fractal dimension is 2.1792~2.3913. So the indicators of soil properties in the area in the vertical stratification did not change significantlyThe analysis of the influence factor the Soil physical and chemical properties of Najiao River to Plant community diversity in this area showed that except the positive correlation between Evenness Index and organic matter and cation exchange capacity, the other Diversity factor do not have the correlation with the Soil physical and chemical properties. So except pH value, organic matter and cation exchange capacity, there are still some other soil factors effecting vegetation form and Richness in this area.