Study on Biomass Model and Carbon Metrology Parameters of Artificial Cypress Forest in Hilly Areas of Central Sichuan

Artificial cypress forest (Cupressus funebris) is the main forest type in the hilly areas of central Sichuan. Determine its carbon content and biomass model, and provide basic data for accurately estimating vegetation carbon storage in artificial cypress forest ecosystems, and further studying the carbon cycle and carbon sink size of the ecosystem. In this article, the carbon content and biomass of the entire plant and various organs of cypress were obtained through field sample collection and indoor analysis testing in Jintang County and Yanting County (a total of 56 sample plants were collected), and the biomass model was established. The results showed that: (1) The biomass of each organ of cypress was arranged in the order: stem (46.45%)>root (22.87%)>branch (15.80%)>leaf (8.56%)>bark (6.33%). The aboveground biomass accounted for 77.13% of the total biomass, while the belowground biomass accounted for 22.87%. (2) The total average carbon content coefficient of a single cypress tree was 0.4903 ± 0.0197. The carbon content coefficient of each organ was arranged in the order: branch>stem>leaf>bark>root. The carbon content coefficient of the stem was significantly different from that of the root and bark (P<0.05), while that of the root was not significantly different from that of the bark (P>0.05), that of the bark was only not significantly different from that of the root (P>0.05), and that of the branches and leaves was not significantly different from that of the stem (P>0.05). (3) There were slight differences in the carbon content coefficients of various organs of cypress in different places, ranging from 0.44 to 0.57. The carbon content coefficients of the entire plant and organs of cypress in Jintang County were significantly higher than those in Yanting County. (4) Whether it was univariate or binary, the best fitting effects for various organs and the entire plant of cypress were exponential models and power functions, with R² ranging from 0.815 to 0.939. And the fitting effect of the whole plant, aboveground parts, and trunk was significantly better than that of the bark, branches, and leaves.(5) This study can provide basic data for further correction of carbon metrology parameters in IPCC method and accurately estimation of forest carbon storage.