三峡库区马尾松人工林细根生产和周转

Fine root production and turnover in Pinus massoniana plantation in Three Gorges Reservoir Area of China

2011年3—12月,采用连续根钻法和分解袋法,研究了三峡库区20年生马尾松人工林细根的季节动态,计算了细根的年生产量和周转率.结果表明:三峡库区马尾松人工林细根(<2mm)年均生物量为146.98g.m-2,其中活细根年均生物量(102.92g.m-2)远大于死细根生物量(44.06g.m-2);不同径级细根现存量的时间动态不同,<1mm根系季节动态较为明显,整体呈单峰型曲线;马尾松人工林细根(<2mm)的年生产量为104.12g.m-2.a-1,年周转率为1.05a-1,其中<1mm和1～2mm的年生产量分别为58.35和45.77g.m-2.a-1,周转率为1.41和0.69a-1.

By the methods of sequential soil cores and buried bags,an investigation was conducted to study the seasonal dynamics of fine roots in a 20-year-old Pinus massoniana plantation in Three Gorges Reservoir Area from March to December 2011,with the annual production and turnover rate of the fine roots calculated.In the plantation,the annual mean biomass of 〈2 mm fine roots was 146.98 g·m-2·a-1,in which,the living root biomass（102.92 g·m-2·a-1） was far greater than that of the dead root biomass（44.06 g·m-2·a-1）.Among the fine roots with different sizes,〈1 mm fine roots had an obvious seasonal dynamics in their biomass,showing a unimodal curve in the sampling period.The annual production and turnover rate of 〈2 mm fine roots were 104.12 g·m-2·a-1 and 1.05 a-1,respectively,in which,the annual production of 〈1 mm and 1-2 mm fine roots was 58.35 and 45.77 g·m-2·a-1,and the turnover rate was 1.41 and 0.69 a-1,respectively.