| In order to solve the serious ecological and environmental problems caused by the sharply increased greenhouse gases in the atmosphere, study on forest-based biomass of terrestrial ecosystems and carbon sink capacity have already become a key and hot topic in the field of ecology.The Carbon Afforestation Project is a newly emerged way of afforestation methods to cut carbon dioxide emission by the means of reforestation.With the forestry carbon sequestration projects ongoing, plantation cultivation and management will be an important means for global carbon balance and carbon trading in the future, so it of great importance for estimating forest biomass and carbon storage accurately.The area of Jatropha curcas L. plantations was chose as the research object, trying to solve the measurement problem of Jatropha curcas plantation biomass and carbon storage for the sake of doing some basic work for carbon sequestration of Jatropha curcas L. afforestation and similar afforestation.The research main include the following contents:Collect data on planting situation and growth of sample trees of Jatropha curcas L. in the study area.Establish biomass models of various components of Jatropha curcas L. by investigating sample trees with different ground diameter, height and age. It is proved that biomass models can be used to estimate biomass through statistical tests and model errors calculation.Fit three-parameter Richards Growth Equation of ground diameter and height of Jatropha curcas L. based on Richards growth equation. The fitting effect is significant and the biological significance of the model can be explained well.In each share of Jatropha curcas L. biomass, the crown is the largest, reaching 40%, followed by the root, is about 31.2% of the whole tree, the smallest is trunk. The shoot ratio was 0.52, the different land use patterns and tree-age affect the shoot ratio. With the increasing of age, its shoot ratio decreases gradually and reach a steady state at a certain age. The shoot ratio of Jatropha curcas L. in cultivated land was higher than that in grassland and bush land.Fit ground diameter distribution by the means of probability density function and conduct a preliminary study to the ground diameter class distribution structure of Jatropha curcas L. in the same aged pure stands, the distribution of study area is typical Weibull distribution, 2-6cm ground diameter class was relative more, 7-14cm ground diameter class was less. With the increasing of age, the ground diameter increases, the skewness is gradually towards the right. It is considerable that there is amount of additional space for biomass, and we can increase the total biomass of the stand as long as the appropriate management measures executed. At the same time, made correlation table of high and ground diameter (integrate ground diameter class) of Jatropha curcas L. plantation and height curve. Estimate the total biomass according to ground diameter class distribution of forest and tree stand height curve.By using method of mean sample tree, estimate the biomass of crown, trunk and root per unit area. The analysis shows that there are significant differences in Jatropha curcas L. plantation biomass with different land use types and different accretion stages. Biomass size is arranged as follow: cultivated land (1253.67kg/hm2) > grassland (293.78kg/hm2) > shrub land (29.78kg/hm2). Meanwhile, calculate the height, ground diameter, current annual increment of biomass and growth rate under different land use types.Based on different land use types of biomass per unit area, figure out that total biomass of Lincang Jatropha curcas L. energy forest is 7933t, and total carbon storage is 3729t, the total truck biomass is 2633.7t, crown biomass is 2569.1t, roots biomass is 2730.3t. In accordance with the terms of land use types, biomass size is as follows: cultivated land (5907t) > grassland (1890t) > shrubs land (136.2t). Finally, gave the recommendations to increase Jatropha curcas L. plantation biomass and carbon stock in the study area. |
PDF Full Text Request