在福建省建瓯万木林自然保护区,选取针叶树种杉木(Cunninghamia lanceolata,CUL)细根和常绿阔叶树种米槠(Castanopsis carlesii,CAC)细根,采用网袋法进行了为期720d细根(分0-1mm、1-2mm两个径级)单独分解(在各自细根的起源林分)和混合分解(分别在杉木林和米槠林)干重损失及其养分释放动态的研究。结果表明:杉木和米槠细根混合分解前期(0-270d)曾对干重损失起促进作用,而之后(270-720d),细根混合起了抑制作用。分解过程中的养分释放与干重损失有所不同,混合分解前期(0-360d)出现过促进作用,分解后期(360-720d),除1-2mm径级混合细根P的释放既没有促进也没有抑制作用外,均表现为养分释放的抑制作用。细根混合分解过程中干重损失和养分释放速率变化与分解者生物群落有很大关系。
In natural reserve of Jianou,Fujian,fine roots of Castanopsis carlesii and Cunninghamia lanceolata were selected and categorized into 0-1mm and 1-2mm size classes in diameter to study their mass loss and nutrient release in decomposition by litterbag experiment with mono-specific and mixed litter in both C.carlesii and C.lanceolata stands for 720 d.At the initial phase(0-270 d) of decomposition,a synergistic effect of root mixtures on the mass loss was observed.However,an antagonistic effect dominated at the late phase(270-720 d) of decomposition.The pattern of nutrient release differed from that of mass loss in the decomposition.In the initial phase(0-360 d) of mixed decomposition,a synergistic effect was shown for the release of N,P and K,while an antagonistic effect for the release of N,K in the later phase(360-720 d) except for P which showed a neutral effect.The effect of fineroot mixture on mass loss and nutrient release could be closely related with the dynamics of soil decomposer community,which necessitates the further investigation.