Response Mechanism Of Growth And Biomass Of First-planted Chinese Fir Under Different Site Conditions

The site selection of the young forestland in Chinese fir plantation is a prerequisite for improving the yield and quality of Chinese fir.Therefore,the choice of site conditions for young plantation of Chinese fir plantation must be emphasized.This study was conducted on the Chinese fir seedlings in newly planted forest land in the Sanming Shaxian area of Fujian Province.The growth and development of the planted plants were studied under different site conditions within one year.The difference in seedling growth and biomass was studied.The suitable site conditions for the growth and production of Cunninghamia lanceolata seedlings were provided.A certain reference basis and construction of the seedling biomass estimation model at the same time has important theoretical significance for accurately assessing the biomass of seedlings and their organs,analyzing the effects of biomass allocation on the growth of various organs of seedlings,and quickly judging the quality of seedlings and practical application value.The main findings are as follows:(1)Comparative analysis of soil physical and chemical properties of burned soil under different site conditions in Sanmingsha County,Fujian Province shows that the overall soil structure is poor and acidic.The bulk density of soil under different site conditions varies greatly.The soil structure of the overall test site is poor,and the total phosphorus content is relatively low.(2)The growth process of Chinese fir seedlings under different site conditions was studied.The results showed that,in summary,under the condition of low-elevation shady slopes,the data related to other growth of ground diameter,seedling height,etc.The provenance of Daejeon seedlings was significantly better than container seedlings.Site location factors such as slope position,elevation,etc.also have a certain correlation with the growth of Chinese fir seedlings,and soil conditions also have a certain influence.(3)With the growth of Cunninghamia lanceolata seedlings,the total biomass and biomass of each component showed an increasing trend.The biomass of each organ of Cunninghamia lanceolata seedlings was roughly as follows:leaf>root>stem>branch,biomass of each organ of Chinese fir seedlings.The order of magnitude of change from large to small is:leaf>stem>root>branch.The proportion of leaf biomass was significantly higher than other organs,but the proportions of biomass of roots,stems and branches increased with the growth of seedlings,but the proportion of leaf biomass decreased.The rising trend of dry biomass was greater than that of root biomass,resulting in an upward trend in the ratio of crown to root.(4)As a whole,the quadratic polynomials and cubic polynomial equations of sapling organ and whole plant biomass were based on the R2 value explained by the product of geology diameter,square diameter and plant height,and the plant biomass was in descending order.Stem>branch>leaves>underground section.Through the test results,it was found that the use of the independent diameter diameter,the square diameter of the ground diameter,and the plant height was used to model the young tree organ and whole plant biomass of Cunninghamia lanceolata in Sanming area,and to estimate the diameter of the Chinese fir seedlings and the growth of seedling height at a certain value.Quantity is feasible.In addition to differences in provenance and site conditions,the soil also has an impact on the growth of Chinese fir seedlings.In the later period,it is necessary to supplement the growth of Chinese fir by applying phosphate fertilizer.Low-lying slope areas are suitable for seedlings of Daejeon,and Chinese fir seedlings do not adapt to the sunny slopes with strong sunlight.The underground of high-elevation shady slopes has a large biomass of roots and stems of container seedlings,which can improve the quality of roots and stems and improve the competitiveness of seedlings.