| In the basis of field investigation sampling of Tamarix Community in the middle reaches of Tarim River, the study took samples in 5 plots and got more accurate biomass Construction Data of Tamarix Community in the middle reaches of Tarim River ,using both statistical and Ecological methods. The study used the PCQ sampling method which is the best method in sampling.Then, it was gotten carbon and nitrogen ratio data , through laboratory experiment. Based on the field work and the model of Evangelista, the study built the best-fit linear-regression model of Tamarix species of this area and obtained the distribution rules of Tamarix species of Tarim River's middle reaches. The result indicates that this model fits for the estimation of aboveground biomass of the study area. According to the distribution rules of aboveground biomass, it is clear that underground water is the major element which decided the distribution of aboveground biomass. This study laid a foundation for further accurate assessment of the ecological system and biomass productivity, provided theoretical bases for environmental protection and management.①The result shows that due to differences of the distance from every point to the river and differences of groundwater level, Tamarix plants have differences in hight. Plant height ranged in 0.4-7m. The maximum value of the plants height come forth in spot C, the reason is that majority of Tamarix in sample C composed of mature "Tamarix package " which are well developed. the minimum value appeared in spot B and E.Although spot B is near to the river and groundwater level is high , But most of the seedlings are young and they are two or three years old, so relatively shorter . The spot E is the farthest point from the river, groundwater level is lower, so, height is not very high.②comparing with the plants hight, the crown area of all points of Tamarix have more prominent differences. the highest value of the crown area appeared in spot C, the minimum value in spot B. Crown area of spots can be sorted as spot C> spot E> spot D> spot A> spot B from large to small.③Nearest neighbor distance of the all spots showed a gradual trend of increase from the spot A to spot D . Nearest neighbor distance from spot D to E showed a trend of slightly decrease.④Comparing with the other spots, shrub A and B have a highest shrub density .The highest shrub density appeared in spot A, the lowest value appeared in spot D. the reason is that spot A and B located in the river edge, most of the seedlings are young and they are two or three years old, the distance is very close each other. Shrub density can sorted as spot B> spot A> spot C> spot D> spot E orderly.⑤Plant biomass of Tamarix from the spot A to spot C showed a trend of increase. From the spot C to spot D, it showed a trend of decrease. From spot D to spot E, it was increasing again. Maximum value of plant biomass appeared in spot C, while the minimum appeared in spot D. This is mainly related with the groundwater level.⑥Total biomass from the spot A to spot C showed a trend of increase. From spot C to spot E showed a trend of decrease. The maximum value of total biomass appeared in spot C, while the minimum appeared in spot E. The total biomass can be sorted as follows: spot C> spot A> spot B> spot E> spotD.⑦The relationship between carbon content of plants and the C/N were significantly negative. Correlation between the carbon content and C/N is very strong. The correlation coefficient is 0.9013, the data show that the volume of C/N depends on the carbon content. According to the analysis of the relationship between carbon content with the C/N of plants, the regression between C/N and the carbon content can be obtained. Y = 0.1039e-0.007x (R = 0.9013) total N and C/N have a weak correlation,Correlation coefficient is 0.3266. the regression between C/ N with total N can be obtained by analysis. Y = 4.9459e 0.0007x(R = 0.3266)...
|
PDF Full Text Request