【摘要】 为了桉树(Eucalyptus)的可持续经营,采用野外设置样地和室内分析方法相结合,对刚果12桉(Eucalyptus.ABL12)、尾叶桉(E.urophylla)、窿缘桉(E.exserta)3种桉树Fe元素的积累、循环进行比较研究。研究结果表明:刚果12桉、尾叶桉、窿缘桉3种桉树Fe元素质量分数平均值为:2438.9354、4618.8535、3858.1288mg·kg-1;林分Fe元素积累量为:16787.4307、73163.4701、16421.537kg·hm-2。年存留量为尾叶桉>刚果12桉>窿缘桉;年归还量为尾叶桉>窿缘桉>刚果12桉;刚果12桉、尾叶桉、窿缘桉循环系数分别为0.56、0.49、0.78。尾叶桉林下有植被的林分和林下无植被的林分Fe元素的质量分数分别为5999.5929、3438.114mg·kg-1;林分Fe元素积累量为:157.0052、90.9261kg·hm-2;Fe元素年存留量分别为31.4011、18.1853kg·hm-2·a-1;年归还量分别为33.4183、13.947kg·hm-2·a-1;年吸收量分别为64.8194、32.1323kg·hm-2·a-1;循环系数分别为0.51、0.43。研究结果表明桉树凋落物的回归,促进林下植被的生长发育,对桉树人工林Fe元素的动态平衡起着重要的作用。更多还原

【Abstract】 To achieve the sustainable managements of Eucalyptus, comparison on the accumulation and cycle of Fe was made among Eucalyptus.ABL12, E.urophylla and E.exserta with field sampling and data analysis methods. Results show that average contents of Fe in Eucalyptus.ABL12, E.urophylla and E.exserta plantations are 2 438.935 4 mg·kg-1, 4 618.853 5 mg·kg-1 and 3 858.128 8 mg·kg-1 respectively,and accumulations of Fe in the three forests are 16 787.430 7 kg·hm-2, 73 163.470 1 kg·hm-2 and 16 421.537 kg·hm-2respectively. Annual retention of Fe is in sequence of E.urophylla>E.ABL12>E.exserta, and annual restitution is in se- quence of E.urophylla.>E.exserta >E.ABL12. The cycling coefficient of Fe in E. ABL12, E. urophylla and E. exserta was 0.56, 0.49 and 0.78 respectively. There are some differences between Eucalyptus urophylla forest with understory vegetation and the one without understory vegetation, for examples, contents, accumulation, annual retention, annual restitution, annual absorption and re- cycling coefficient of Fe are 5 999.592 9 mg·kg-1, 157.005 2 kg·hm-2·a-1, 31.401 1 kg·hm-2·a-1, 33.418 3 kg·hm-2·a-1, 64.819 4 kg·hm-2·a-1 and 0.51 in the former respectively, while 3 438.114 mg·kg-1, 90.926 1 kg·hm-2·a-1, 18.185 3 kg·hm-2·a-1, 13.947 kg·hm-2·a-1, 32.132 3 kg·hm-2·a-1 and 0.43 in the latter respectively. Conclusions can be made that litters makes a difference in de- velopment of understory vegetation and maintaining the dynamic balance of Fe in Eucalyptus forest.更多还原