巨桉枯落物持水特性、细根生物量及其关系  

Plantation Hydrological Effects and Their Relationships with Fine Root Biomass in an Age Series of Eucalyptus grandis

作　　者：袁渭阳[1] 李贤伟[1] 张健[1] 

机构地区：[1]四川农业大学生态林业工程省级重点实验室,四川雅安625014

出　　处：《桉树科技》2013年第3期8-16,共9页Eucalypt Science & Technology

基　　金：国家自然基金面上项目(30771717);国家科技支撑计划(2006BAC01A11和2011BAC09B05);四川省科技支撑计划(2010NZ0049);四川农业大学国家级大学生创新性实验计划(101062622);四川农业大学长江上游林木种质资源与培育技术创新团队项目(00370503)

摘　　要：本试验研究了一个林龄序列的巨桉林地枯落物储量、持水量、吸水率、土壤持水性能等与细根生物量关系,结果表明：（1）枯落物现存量在不同林龄林分中表现为5 a〉6 a〉2 a〉4 a〉1 a〉3 a。不同时期变化趋势为,7—10月凋落量（5.581 t·hm-2）〉1—4月凋落量（1.619 t·hm-2）〉10—1月的凋落量（0.152 t·hm-2）;（2）枯落物持水量的变异性较大,同一个季节不同林龄林分的枯落物持水量差异显著,1~6 a平均持水量分别为：9.804 0、12.821 8、7.7508、5.949 8、17.004 2和14.459 6 t·hm-2。枯落物吸水率与浸泡时间呈现极显著的相关性（P〈0.01）,其季节差异在浸泡的前4~6 h表现很明显,一般为秋〉冬〉夏〉春季;林龄差异表现表现为4年生巨桉林枯落物的吸水率最差,1年生的最好;（3）各林龄林分细根生物量在不同季节的基本趋势是：秋〉夏〉春〉冬季（P〈0.01）。林龄趋势为：6年生细根生物量最大（0.906 3 t·hm-2）,3年生最小（0.537 7 t·hm-2）。巨桉幼龄林（1~2 a）细根生物量与枯落物持水量及其浸泡时间显著相关,随着林龄的增长,这种关系不明显。This research studied the biomass, water holding capacity and water absorption of litter and fine roots（2 mm） for an age series of Eucalyptus grandis representing a complete rotation（ages 1 ~ 6 years） in Danling, Meishan city of Sichuan province. The results showed： litter reserves differed significantly with age and descended in the following sequence： 5-years 6-years 2-years 4-years 1-year 3-years old. The dynamic of litter at different survey times showed the following results： Jul. – Oct. 2006（5.581 t·hm-2） Jan. – Apr. 2007（1.619 t·hm-2） Oct. 2006 – Jul. 2007（0.152 t·hm-2）. The water holding capacity of litter was also found to vary with season, as well as at different ages, from 9.804 0 t·hm-2for that of 1-year-old plantation, 12.821 8 t·hm-2for 2-year-old, 7.750 8 t·hm-2for 3-year-old; 5.949 8 t·hm-2for 4-year-old, 17.004 2 t·hm-2for 5-year-old, and 14.459 6 t·hm-2for 6-year-old plantation. It was found that the fastest water absorption occurred during the first 4 hours. After 8 hours water absorption slowed or ceased completely. A significant（P0.01） relationship was observed between rate of water absorption and immersion time. Seasonal differences were also observed in water absorption during the first 4 hour period with seasonal averages descending in the order of autumn winter summer spring. Across different plantation ages, water absorption was lowest at age 4-years and highest at age 1-year. The fine root biomass in the top 0~50 cm of soil depth（soil core method） varied significantly（P 0.01） with season in descending order of autumn summer winter spring. The highest fine root biomass was observed in the 6-year old plantation（0.906 3 t·hm-2） and the lowest in the 3-year old plantation（0.537 7 t·hm-2）. There were significant positive correlations between fine root biomass and water holding capacity of litter at age 1 to 2-years but the significance of the correlation decreased as plantation age increased.

关 键 词：巨桉 枯落物 细根生物量 持水量 

分 类 号：S715.3[农业科学—林学] Q948[生物学—植物学]