暖温带典型林分不同分解阶段凋落物的持水特征OA

To investigate the water-holding characteristics of litter at different decomposition stages in typical forest stands in the warm temperate zone and their hydrological regulation functions,this study selected four forest stands(Pinus armandii-P.tabuliformis coniferous mixed forest,Quercus wutaishanica conifer-broadleaf mixed forest,P.tabuliformis pure forest,and P.tabuliformis conifer-broadleaf mixed forest)in the Zhongtiao Mountains of Shanxi Province.Litter stock was measured for each stand,and the indoor water immersion method was adopted to analyze the water-holding capacity of litter at different decomposition stages.The results showed that:the total litter stock ranged from 24.46 to 37.93 t·hm-2,and the fully-decomposed layer was dominant in all forest stands(>36%).The total litter stock in the P.armandii-P.tabuliformis coniferous mixed forest and P.tabuliformis pure forest was higher than that in the Q.wutaishanica conifer-broadleaf mixed forest and P.tabuliformis conifer-broadleaf mixed forest(P<0.05).Both the maximum water-holding rate and water absorption rate generally followed the pattern of fresh layer>semi-decomposed layer>fully-decomposed layer.Among the four forest stands,the Q.wutaishanica conifer-broadleaf mixed forest exhibited better overall water-holding performance.Water-holding capacity increased logarithmically with time,whereas water absorption rate decreased as a power function with time.The fitted models showed high goodness of fit(R2>0.91),well describing the dynamic variation processes.Total effective retention of litter ranged from 14.87 to 24.57 t·hm-2,with average retention rates of 57.83%to 77.38%.The total effective retention volume was the highest in the P.tabuliformis pure forest,while the average effective interception rate of Q.wutaishanica conifer-broadleaf mixed forest is the highest.There were differences in overall hydrological regulation performance among different forest stands,with the conifer-broadleaf mixed forest showing better performance.Maintaining a thick and structurally intact litter layer and optimizing the configuration of conifer-broadleaf mixed forests can enhance water conservation and hydrological regulation functions in the Zhongtiao Mountains.