<正>应用相对生长法和样方收获法对萌芽更新和植苗更新尾巨桉人工林生物量及生产力进行研究。结果表明：相同密度条件下。植苗更新尾巨枝人工林生物量高于萌芽更新人工林；当密度为1097株/hm2时，植苗更新和萌苛更新尾巨桉人工林的生物量分别为79.193t/hm!和68.682t/hm。。年平均净生产量分别为23.9981/hn2和21..163t/hm2.植苗更新和萌芽更新人工林群落净生产量排序由高到低依次为：乔木层、枯枝落叶层、灌木层、草本层。萌芽更新尾巨桉人工林生物量随保留密度的增加而增加。不同更新模式尾巨桉林分干材、干皮、枝、叶、根系的生物量分别占总生物量的60.50%～60.86%、5.62%～5.89%、10.88%～11.23%、4.11%～4.54%和18.1%～18.27%。林分生物量分配的大小排序为：干材、根系、枝、干皮、叶。

Based on the study of hydrogen stable isotope between the high and low altitude watershed in the Heishui valley of the upper Minjiang River, δ D was found to be positive in spring and negative in summer, and show a positive tendency with decreasing of altitude. The results also showed that the spatial and temporal variation of hydrogen stable isotope in the river water reflected the interaction between mechanism of precipitation formation and the terrain patterns. The contributions of different water sources changed in the different periods. During the high-flow period, either in the high ahitude watershed or in the low altitude watershed, contributions of the rainfall to the river water were always more than 20~.