| In order to solute the current existence of single Casuarina. equisetifolia forest, the paper tried to use native trees to create a mixed type of coastal forest. The experiment transplanted one year old seedlings of Thespesia lampas, Calophyllum inophyllum and Hernandia sonora to the coastal C. equisetifolia plantation, selected 4 plots for each seedling(a total of 12 plots),and there were three treatments in each plot and each dealing with 8 repeats. The coastal sandy soil was treated by adding wood chips(M), bagasse(Z) and the control without adding anything(D) in the planting hole (depth 20cm, width 30cm). The growth index (survival rate, basal diameter, height), physiological (photosynthetic characteristics), the environmental factors (light intensity, soil pH value, soil temperature, moisture, salinity) and soil nutrients (N, P, K) were observed to evaluate these species adaptability to the environment of coastal sand, so as to transform single species of C. equisetifolia plantation, create mixed coastal forest, and to provide more selection of tree species for the construction of coastal windbreak forests.The main results are as follows:1. In two years growth period, the survival rate: T.lampas>H. sonora>C. inophyllum;the net increase of basal diameter: H. sonora>C. inophyllum>T.lampas;the net increase of height: T.lampas>C. inophyllum>H. Sonora. The basal diameter and height of three native tree species had some correlation, and had reached a significant level.2. In the first year, among the 3 tree species ,the diurnal average maximum showed T.lampas>H. sonora >C. inophyllum. the Pn of T.lampas reached the maximum value (7.68μmol·m-2·s-1) in August in one year, the Pn of H. Sonora and C. inophyllum reached the maximum value(3.82μmol·m-2·s-1,4.13μmol·m-2·s-1) in May; the WUE of T.lampas, H. Sonora and C. inophyllum reached the maximum value(9.96 mmol·mol-1,12.43 mmol·mol-1,19.56 mmol·mol-1) in February.3. In two years growth period, the survival rate and net increase of basal diameter of T.lampas had negative correlation with soil temprature, but the survival rate of T.lampas had positive correlation with soil pH value; the survival rate and net increase of basal diameter of C. inophyllum had positive correlation, and the survival rate of C. inophyllum had positive correlation; the survival rate and net increase of basal diameter of H. sonora with soil temprature had negative correlation, the survival rate of H. Sonora with light intensity, soil moisture had negative correlation, and the survival rate of H. Sonora with soil salinity had negative correlation. In the first year, the Cond,Tr of T.lampas with soil moisture and the Ci,Tr of T.lampas with soil pH value had negative correlation, but the Ci of T.lampas with light intensity, soil temperature had positive correlation; the Pn,Cond,Ci,Tr of C. inophyllum with soil temprature had negative correlation, while the Pn with soil pH value had positive correlation, the Ci with soil pH value had negative correlation; the Pn,Cond,Tr of H. Sonora with soil temprature had negative correlation, the Ci of H. Sonora with soil temperature, soil salinity had positive correlation.4. In two years growth period, the survival rate of T.lampas with soil N, P had some correlation, the survival rate of T.lampas with soil K had higer correlation. The Ci of T.lampas, the Pn,Cond,Ci of C. inophyllum, the Ci of H. Sonora with soil K had some correlation, and had reached a significant level. Thus, soil nutrient with the growth and photosynthetic characteristics of the three native tree species have a certain impact.5. Among different soil treatments,in two years growth period, the survival rate of T.lampas, C. inophyllum in the treatment by adding bagasse were higher than the treatment by adding wood chips and the treatment without adding anything. The basal diameter, height of three native tree species in the treatment by adding wood chips, bagasse and the control without adding anything had not significant difference. Among different soil treatments,the diurnal change of Pn, Cond, Ci and Tr of the three species showed the same variation. But the Cond and Tr of T.lampas and H. Sonora in the treatment by adding bagasse were absolutaly higher than the treatment without adding anything in 2009.11, and the Cond and Tr of C. inophyllum in the treatment by adding wood chips were higher than the treatment without adding anything in 2009.08. In two years growth period, the soil N,P,K in the three treatments had not significant difference.The study showed that the three native tree species were suitable to grow in the coastal sand in C. equisetifolia forest. During the two years growth period, the native tree species of T.lampas grew best and it was the most potential forest species mixed with C. equisetifolia.
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