| From Jan to Dec 2007, soil core method was used for estimating seasonal pattern of fine root (D≤2 mm) biomasses, seasonal variation of fine root biomass and distribiution, The relationships of fine root biomass, soil temperature and moisture, rainfall, in Cunninghamia lanceolata, Pinus massoniana, Liquidambar formosana and Cinnamomum camphora main plantation communities in Tianjiling National Forestry Park of Changsha, Hunan, The results show were following:(1) Annual total fine root biomasses are:0.979 t/hm2,1.243 t/hm2,0.919 t/hm2 and 2.143 t/hm2, in C. lanceolata, P. massoniana, L. formosana and C. camphora main plantation communities,2007. respectively. Total fine root biomasses were C. camphora >P. massoniana>C. lanceolata>L. formosana. Live and dead fine root biomass vary among different 4 types forest communities (P<0.05). Annual mean live fine root biomasses were 0.893 t/hm2,1.123 t/hm2,0.826 t/hm2 and 1.958 t/hm2, C. camphora>P. massoniana>C.lanceolata>L. formosana, Annual mean dead fine root biomasses were 0.086 t/hm2,0.119 t/hm2,0.093 t/hm2 and 0.184 t/hm2, C. camphora>P. massoniana>L. formosana> C. lanceolata; Annual mean live fine root biomasses of 4 types community accounts for 91.2%,90.4%,89.9% and 91.4% of total fine root biomasses.(2) Significant seasonal variation of fine s and dead fine root biomasses were found among 4 types community. fine root biomasses were single peak. While peak value and minimum value appear with different months of fine root biomasses in theirs, as a whole change pattern of their live fine root biomasses appear:undulation increase along with air temperature rally from Jan to May, but relative stability, increase range not big; descend trend between P. massoniana and Liquidambar between,has a little increase in C. lanceolata May to June, and that C. camphora had increased 29.6%; Jun to Oct all of the 4 types community had obviously increased, C. camphora is outstanding, compare with the Jun,10 increased to 103.6%. Oct to Nov, obviously reduce. Dead fine root biomasses of 4 types community were irregular curve, crest value and minimum value appear in different month.(3) Live and dead fine root biomasses of 4 types community were distributing in the soil layer of 0-30cm, annual mean live root biomasses account for total live fine root biomasses 67.83%～76.53%, dead fine root biomasses account for total dead fine root biomasses66.01%～76.15%. For the vertical distributions of both the live and dead fine root, the biomasses decreased with soil depth, total fine root biomasses. Therefore total fine root biomasses and soil depth exist an obvious negative relation. In different soil layers, Live and dead fine root biomass vary among different 4 types forest communities (P<0.05, Seasonal dynamics of fine roots had correlativity in different soil layer both live and dead fine root biomasses.(4) The relationships of fine root biomass, soil temperature and moisture had different relativity in 4 types community. Significant exponential relationships were found between fine root biomasses of them with soil temperatures, and between dead fine root biomass of P. massoniana community with soil temperature. Significant line relationships were found among dead fine root of C. lanceolata, L. formosana and C. camphora communities with soil moistures, however, not significant relationships were found between fine root biomasses of 4 types community with soil moistures. Multiple regression analysis showed that variations of fine root biomass were greater with soil temperature than moisture, but variations of dead fine root were greater with soil moisture than temperature.So, research their root biomasses and change rule of space distribution, for understanding ecosystem productivity, output structure and distribution character, and research elements of dominat factors impact on their productivities, Open exhibition science management etc.all includes importance instruction meaning...
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