四川盆周西缘山地典型人工林下苔藓和凋落物的持水特性

Water Holding Capacities of Bryophyte and Litter Layer under Typical Artificial Stands of Western Sichuan Basin Border

为了解人工林生态系统的持水性特征,采用野外实地观测和室内浸水法对3种主要人工林下苔藓和凋落物层(未分解层、半分解和分解层)的持水特性进行了研究。结果显示:1苔藓层蓄积量以混交林最高(0.52t·hm-2),柳杉林最低(0.10 t·hm-2);凋落物层均以楠木林最高,柳杉林最低。2柳杉和水杉林间、楠木和混交林间苔藓层最大持水性差异均不明显;柳杉和水杉林凋落物半分解层和已分解层最大持水率大于未分解层,而楠木和混交林则是未分解层大于半分解层和已分解层。3各林分苔藓层吸水速率到2 h后均趋于平缓,凋落物半分解层和已分解层与未分解层均在6 h后趋于平缓,苔藓和凋落物层吸水速率与浸泡时间符合V=ktb关系,经检验达显著水平。

In order to study the water holding capacities of artificial stands, the field survey and the water immersion were conducted to study the water holding capacities of bryophyte and litter layer including un-decomposed litter layer and incompletely and completely decomposed under typical artificial stands of western Sichuan basin border. The highest storage amount bryophyte was in mixed forest, and the lowest storage amount bryophyte was in Cryptomeria fortune artificial stands. Phoebe zhennan had the highest storage amount of litter, and C. fortune had the lowest storage amount of litter. There were no significant different water holding capacities between C. fortune and M. glyptostroboides, P. zhennan and mixed forest, respectively. The water holding capacities in F, H layer was higher than that in L layer in both C. fortune and M. glyptostroboides artificial stands, respectively, and F, H layer was lower than that in L layer were in both P. zhennan and mixed forest, respectively. The water holding rate of bryophyte decreased quickly in the first two hours, and litter decreased quickly in the first six hours. Water absorption rates of bryophyte layer under all stands decreased according to V=ktb with time immersed in water in significance level.