Fine Root Production And Mortality In Phoebe Bournei Plantation

Generally speaking, in the forest ecology study, the roots of the trees are divided into coarse root and fine root.. Fine root is usually refers to the root of the<2mm, because of its great respiration rate, quick turnover and have high efficiency on make use of the water and nutrients, so fine roots are very dynamic and play a key role in forest ecosystem carbon cycling and accumulation. Fine root production,mortality and biomass in Phoebe bournei forest in Nanpin, Fujian province,were monitored for more than three years by using minirhizotrons. The results show that the annual fine root production in Phoebe bournei was417.3±16.9g·m-2·yr-1. While annual fine root mortality in Phoebe bournei was404.5±20.8g·m-2·yr-1. In this study, the average annual precipitation and the temperature have no significant effect to the fine root production, however, there was no correlation between the average precipitation and the fine root production. Fine root production, mortality, and biomass were all seasonal dynamics, the fine root production was mainly in spring and winter, the mortality was mainly in summer, secondly, in spring and autumn. The fine root production and mortality of Phoebe bournei communities appeared mainly in the top soil layer(0-40cm), accounting for95%of the total production and mortality, respectively. In level of diameter, the fine root production and mortality were mainly in0-1mm, accounting for above90%of the total production and mortality, and first root order was significant higher than that of the higher order. The turnover rate of fine root in Phoebe bournei was2.98yr-1. Root turnover rate was maximum in the second year year(2008-2009) which was higher than the first year(2009-2010). Fine root turnover rate had no tendency with the soil depth increase in Phoebe bournei. The most quickly of fine root turnover rate appeared in surface layer(0-20cm), however, the most slowly fine root turnover rate was appeared in soil depth20-40cm. Among different diameter, root turnover rate in Phoebe bournei was0.6-lmm>0-0.3mm>0.3-0.6mm.