严重侵蚀红壤区生态修复后植物群落组成变化

以强烈干扰马尾松林分为对照,不同修复措施(封育、竹节沟、种草竹节沟、谷坊与无谷坊马尾松和竹节沟湿地松)林分为研究对象,对严重侵蚀红壤地实施生态修复27a后的群落组成和各物种的重要值(IV)特征进行了研究。结果表明:(1)5种坡面林分中,乔木层物种组成单一,均为马尾松或湿地松;灌木层物种种类丰富,重要值分布不均匀,竹节沟湿地松林分修复的效果最为明显。其中,耐半荫常绿野栀子的优势度最大(IV=0.12),喜光落叶的白檀次之(IV=0.11),湿地松的幼苗优势度最小(IV=0.02)。草本层结构较为简单,封育马尾松林分草本盖度最高(40%)。(2)在沟道林分中,谷坊林分乔木层和灌木层植物群落组成种类明显多于无谷坊,各种类重要值差异悬殊,谷坊林分常绿、荫生性物种显著多于无谷坊;而草本层受乔木层、灌木层的影响,总盖度差异悬殊,无谷坊的总盖度达到90%,谷坊的总盖度仅为10%。说明通过改良土壤水肥和光照等小生境,可以明显改善红壤严重侵蚀地植物群落物种组成,加速侵蚀退化地植物群落的演替。

Community Species Composition Changes in Ecological Restorated Area of Serious Eroded Red Soil

Taking Pinus massoniana forest with intense disturbance as control, species composition and important value(I_V) of the ecological restoration community in serious eroded red soil, 27 years after in different types of human induced vegetation were analyzed, such as Pinus massoniana forests without disturbance, Pinus massoniana forests with Bamboo-burl-groove, Pinus massoniana forests with planting grass and Bamboo-burl-groove, check dam and non-check dam Pinus massoniana forest, Pinus elliotti forest with bamboo-burl-groove. The results showed that:(1) Species composition of tree layer was simple in all five kinds of slope forests dominated by Pinus massoniana and Pinus elliotti. Community varieties richly but I_V distribution is not consistent in the shrub layer, especially ecological restoration effect is most obvious in Pinus elliotti forest with bamboo-burl-groove. The dominance of Gardenia jasminoides Ellis with semi-shade tolerance and evergreen leaf is maximum, followed by photophilous and deciduous chamaecereus sylvestri, and Pinus elliotti seedlings dominance is minimum, with I_V of 0.12, 0.11, 0.02, respectively. The herb layer species composition is simple, Pinus massoniana forest without disturbance is the most obvious in restoration, the total herb coverage reaches 40%.(2) In the channel, community species at tree and shrub layers in check dam are more significant than that non-check dam, especially for evergreen and shade species, and each I_V is different. The total coverage in herb layer has great disparity which is affected by the tree layer and shrub layer, with 90% in non-check dam and only 10% in check dam. It indicates that different ecological restoration strategies would facilitate plant species composition and accelerate plant community succession in serious eroded red soil through protecting and improving the soil water and nutrient conditions.