【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。更多还原

【Abstract】 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(P<0.01) 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.更多还原