| In this paper, the seasonal dynamics and spatial distribution of the biomass, the production and turnover rate, nutrient contents and its dynamics, nutrient pools and the dynamic decomposition for the fine root in the different stages of succession have been investigated to discover the relationship between the fine root and the succession of the evergreen broadleaved forest in Tiantong. The main findings as followed:(1) There are distinct seasonal dynamics of the fine root biomass in the series of the succession, the maximum of the biomass occurred in the April and/or July. The peaks of the biomass for the live and the dead fine root in the earlier and later stages demonstrate the seasonal dynamics of the series in the succession. The biomass of the live fine root are 1.013t.hm-2a-1, 1.966 t.hm-2a-1, 0.714 t.hm-2a-1, 1.305 t.hm-2a-1, 2.049 t.hm-2a-1 and 2.513 t.hm-2a-1,respectively, while the dead is 1.380 t.hm-2a-1, 1.320 t.hm-2a-1, 0.352 t.hm-2a-1, 0.226 t.hm-2a-1,0.666 t.hm-2a-1 and 0.688 t.hm-2a-1, respectively. The biomass of the dead fine roots is obvious less than that of the live.(2) The turnover rate of the fine root in the earlier stage is larger than that of the later, the turnover rate in the different series of the succession are 4.065,2.494,2.279, 0.902, 1.092 and 0.695,respectively.(3) The spatial distribution of the fine root is uneven in the soil profile. The biomass of the live and dead fine root is decreased with the depth of the soil. The proportion of the fine root in the upper 0-20cm sum to 80% of the totals. But there is no distinguished difference for the biomass of the fine root in the upper horizon in the series of the succession.(4) There is variance in the N content in the live and dead fine root for the different stages in the succession. The N content in the. live and dead fine root in the D.pe+L.cu comm. is higher than that of L.ch+L.gl comm., the N content increases with the succession processes from L.ch+L.gl comm. to C.fa comm. but there is no significant variance in P content in the fine roots. But there are significant seasonal variance of the N and P content in the fine root, the peak of the P content occurs in theJuly or November, while in the later succession the peak of the N content occurs in the April. The seasonal variance of the N content is similar to that of the P content in the earlier and middle succession. The content of the N and P decreases with the depth in soil profile.and shows no significant variance between the live and dead fine root.(5) In the earlier and later stages, the annual return and release of N and P was higher than that of the intermediate stages.(6) During the initial stages of the fine root decomposition, the percent of mass losing was very high. By the exponential decay model ,the decomposition coefficient in different succession stages was 0.785, 0.504, 0.356., 0.406, 0.617 and 0.796,respectively. In the earlier and later stages, the decomposition rate was faster than that in the intermediate. However, the nutrient content in the fine roots had changed during the decomposition. The N and P in fine roots was enriched in the earlier and middle stage, but was released in the later.(7) It will take three to four years to decompose to that degree of 95% for the fine roots according to the selected 22 sampling plants in Tiantong, the average was 3.74a, which is higher than that of 2.54a for leaf litter. There is difference in the fine root decomposition for individual species; the decomposition rate was rather high in some species in Climax or high-nutrient-content deciduous species, and it correlates positively with the initial nutrient content of N and P in the fine root.(8) The fine root biomass and turnover rate can instead of the characters of fine root. The fine root biomass is affected by many factors, such as soil nutrient, organic matters, the upper floor masses, etc. it is positively correlated with those factors. The community structure and species com...
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