I 摘要 经济林的建设是一项同时兼顾生态效益和经济效益的有效措施，对改善三峡 库区消落带生态环境和缓解库区尖锐的人地矛盾有重要理论和实践意义。本研究 选择前期实验筛选出的一种适合消落带生长的速生树种——竹柳为研究对象，以 消落带传统利用（玉米种植）为对照，通过空间代替时间的方法研究对不同林龄 （两年、三年和四年）对消落带生态系统植被群落特征和土壤质量的影响。同时 研究了不同林龄（一年、两年、三年、四年和五年）竹柳生长状况和经济效益， 拟期揭示竹柳林在消落带造林效果及其应用的可行性。 主要的结果和结论如下： 1）竹柳林显著改变了消落带地上植被的群落特征。随着林龄增加，物种丰富 度愈来愈高，对照为 17，而两年、三年和四年竹柳林分别为 23、28 和 30；地上 植被优势种重要值也发生了明显变化，总体而言，优势种由喜阳的植物（如稗和 雾水葛）逐渐转为喜阴的植物（如狼耙草）；竹柳也明显降低了消落带植被群落 的盖度和生物量，且随着竹柳林龄的增加而逐渐降低，可能于林下郁闭度的逐渐 增高有关，同时由于竹柳根系发达，在养分和水分的种间竞争中占有优势，导致 群落盖度和生物量较低。 2）竹柳林对消落带土壤质量有一定的改善作用。其中含水率、总孔隙度、平 均重量直径大小依次为：四年林>三年林>两年林>对照；容重大小依次为：对照> 两年林>三年林>四年林。竹柳造林用地和对照土壤容重均在 1.1-1.4g/cm3 之间， 均为有机质含量较高且适合耕作的土壤，其中对照田土壤容重最大（1.4g/cm3）， 显然耕作使得土壤紧实，通透性性差，土壤的保水能力和抗侵蚀能力较弱。土壤 有机质、全 N、微生物 C 和微生物 N 含量大小依次为：四年林>三年林>两年林> 对照，且随着竹柳生长年限的增加呈递增趋势。随着竹柳生长年份的增加，使得 根系在土壤中镶嵌分布广、根系密度增加，可以改善土壤水分和养分的供应状况、 为土壤微生物的活动提供丰富的能量物质的供应状况。而对照的土壤全 P 和有效 磷含量显著大于竹柳林，可能与传统种植过程中人为的磷肥施肥有关。因此，相 对传统农业种植而言，竹柳林具有较好的水、土和肥的保持能力。 3）竹柳造林效果良好及一定的应用可行性。竹柳平均成活率为 95.9%,年平均 胸径生长量为 2.25cm、基径生长量为 2.93cm、树高生长量达到 2.08m，冠幅生长 量为 2.06m 2 。按 5 年成林计算，每亩直接经济价值为 15384 元，扣除成本与管理 费用，每亩年均收益为 1226 元。因此，竹柳不仅适合消落带水位的周期性淹水和 出露变化，且具有较为可观的经济效益。重庆大学硕士学位报告 中文摘要 II 竹柳改变了三峡库区消落带植被的群落结构、组成及生物多样性，改善了土 壤环境质量。相对传统农业种植，人工构建的竹柳森林生态系统具有较好的维持 生物多样性和保持水土的能力。同时竹柳也是是一种耐水淹、速生性好且具有较 为可观的经济价值的树种，将在三峡库区消落带的保护与利用上具有一定的作用。 因此，竹柳应该作为一种主要的造林物种或物种之一在三峡库区消落带尝试推广 运用。 关键词：三峡库区，竹柳，消落带，土壤质量，应用可行性重庆大学硕士学位报告 英文摘要 III ABSTRACT The construction of the economic forest with ecological and economic benefits is an effective measures to improve the environment and to sharp contradictions between land and people in the Three Gorges Reservoir area. In this study, Bamboo Willow- the fast-growing tree species suitable with riparian zone by preliminary experiment was selected as the research object. The method of space instead of time was used to explore effect of forest age on characteristics and soil quality of riparian ecosystem. Moreover, growth status (1a, 2a, 3a, 4a and 5a) and economic benefits of Bamboo Willow were Studied to explore the afforestation effect and its marketing potential in the Three Gorges Reservoir. The main results and conclusions are as follows: 1 ） Bamboo Willow and contrast on structure and composition of the herb community and biodiversity impact exist significant differences. As the increase of forest age, species richness of contrast is 17, and r two, three and four years bamboo Willow are 23, 28 and 30, The ground herb important value of dominant species are also significant changed In general, the dominant species from light plants （Echinochloacrusgalli and Pouzolziazeylanica）gradually turn into shade plant （Bidenstripartita）. With the increase of bamboo willow growth age，Bamboo willow also significantly reduces the herb coverage and biomass gradually，maybe the canopy density of forest increased gradually, at the same time because of the bamboo willow root developed, with nutrient and moisture of interspecific competition advantage, leading to a lower coverage and biomass. 2）Bamboo willow forest improved the quality of the soil in the draw-down area . The order of magnitude of moisture content, total porosity, average weight diameter was: four years forest > three years forest > two years forest > contrast. The size of bulk density was: contrast >two years forest > three years forest > four years forest. Both of the bulk density of soils in Bamboo willow forest and contrast ware between 1.1to1.4gocm-3.Both of the soils contain high organic matter. They ware suitable for the tillage. The bulk density of soil in the contrast was the highest(1.4gocm-3).Apparently tillage makes soil compaction, permeability, soil water holding capacity and anti erosion ability is weak. The contents of soil organic matter, total N, microbial C and microbial N were as follows: four years forest > three years forest >two years forest >contrast, and重庆大学硕士学位报告 英文摘要 IV the growing age of bamboo willow increased with the trend of increasing. With the increasing of Bamboo willow growing years,Making the root in the soil mosaic distribution wide, increased root density can improve the supply of the soil moisture and nutrient, soil microbial activities to provide rich material and energy supplies. Andtotal P and available P in the soil of contrast was significantly higher than that of bamboo and willow, it caused by the process of traditional planting artificial phosphate fertilization.Therefore, compared with the traditional agricultural planting, the soil and water and fertilizer retention capacity in Bamboo willow forest is better. 3）Bamboo willow afforestation effect is good and has great promotion potential Bamboo willow the average survival rate reached to 95.9%, the annual average DBH growth reached to 2.25 cm, base diameter growth reached to 2.93 cm, tree height growth reached to 2.08 m, the crown growth reached to 2.06 m2. Calculated at 5 years, the direct economic value is 15384 yuan per acre, deduct cost and management cost, average annual income is 1226 yuan per acre. Therefore, bamboo Willow not only suitable for keeping with periodic flooding and change of water level, and has significant economic benefits. Bamboo willow changed the composition, structure and biodiversity of herb community, and improved the quality of soil of riparian zone, in the Three Gorges Reservoir. Compared with the traditional agriculture, Bamboo Willow forest by artificial building have a good ability to maintain biodiversity and conservation of water and soil. Moreover, Bamboo willow with water impoundment resistance ， the characteristic of fast growth and significant economic value, would be regarded as one of important tree species for the conservation and utilization of riparian zone in the Three Gorges Reservoir. Keywords: The Hydro-fluctuation Belt, Bamboo Willow, Plant Communities SoilQuality, Application Feasibility重庆大学硕士学位报告 目 录 V 目 录 中文摘要..........................................................................................................................................I 英文摘要.......................................................................................................................................III 1 绪 论.........................................................................................................................................1 1.1 国内外研究现状 ................................................................................................................... 1 1.1.1 三峡库区消落带植被恢复重建研究现状 ................................................................. 1 1.1.2 造林对地上植被的影响 ............................................................................................. 2 1.1.3 人工造林对土壤质量影响的研究 .......................................