Dynamics of nitrogen and phosphorus concentrations of fine roots in a mixed forest of Cunninghamia lanceolata and Tsoongiodendron odorum

杉木与观光木混交林中细根的N、P浓度动态研究(英文)

From September 1999 to July 2000, N and P concentrations of fine roots were measured with the method of sequential soil core at bimonthly intervals in a mixed forest of Tsoong's tree (Tsoongiodendron odorum Chun) and Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) in Sanming, Fujian. The results showed that N, P concentration of Chinese fir and Tsoong's tree in fine roots were negatively related to root diameter size. The concentrations of N and P in living roots and dead roots were compared. The order of N concentration in fine roots in different samples was Tsoong's tree>undergrowth>Chinese fir, while that of P was undergrowth>Tsoong's tree>Chinese fir. For Chinese fir, the seasonal change of N, P concentrations in fine roots with various diameter classes showed a single-apex curve with a maximum in September. For Tsoong's tree, maximized concentration of N in fine roots appeared in July or September and maximized P concentration in May.

从1999年9月至2000年7月隔月应用连续土芯法对福建三明莘口林场杉木与观光木的混交林的细根进行取样并测定活、死细根的N、P养分浓度。结果表明，混交林中杉木，观光木和地下植被的细根的N、P浓度均与细根径级呈负相关。混交林中细根的N浓度大小顺序为观光木>林下植被>杉木，而P的浓度则为林下植被>观光木>杉木。混交林中杉木各径级细根的N、P浓度的动态变化表现为单峰型，在9月最高。观光木细根的N、P浓度的动态变化亦表现为单峰型，但N浓度高峰出现在7月或9月，而P浓度则在5月最高。