黄土丘陵区自然恢复与人工修复流域生态效益对比分析

论文以陕西吴起县柴沟和合家沟为例,通过样地的植被和土壤调查,在小流域尺度上分析了退耕10 a后人工修复和自然恢复方式生物多样性、生物量、群落特征和土壤物理性质的差异。结果表明:两者草本群落结构相近,相似性系数为0.925。人工修复区乔灌草三层的层盖度和为99.03%,三层的物种数和为85,草本层的株均高为0.41 m,还有该层的物种丰富度指数、多样性指数、均匀度指数均高于自然恢复区;而平均生物量、群落密度、土壤含水率、土壤容重和毛管孔隙度分别为5.890 t.hm-2、8.11×105株.hm-2、8.8%、1.251 g.cm-3和48.9%,均低于自然恢复区。两区土壤指标的变异系数变化较为复杂。

Contrast Analysis of Ecological Benefit between Artificial Restoration Areas and Natural Restoration Areas in Loess Hilly Region

Taking Chaigou and Hejiagou watersheds of Wuqi County in Shaanxi Province as example, in the small watershed scale, discrepancy of biodiversity, biomass, community features and soil physical properties under approach of rehabilitation and abandonment were analyzed through vegetation and soil investigation of sample plot in ten years after returning farmland to forestry. The results showed that: in approach of rehabilitation and abandonment, structure of the herbal community is similar and the similarity coefficient is 0.925. In rehabilitation areas, summation cover and species of tree, shrub and herb layer is 99.03% and 85; average plant height of herb layer was 0.41 m, with indexes of species richness, diversity index, evenness of herb layer, were higher than in the natural restoration areas. But in rehabilitation areas, average biomass, community density, soil moisture, soil bulk density, capillary porosity were 5.890 t·hm^-2, 8.11×10⁵ ind·hm^-2, 8.8%, 1.251g·cm^-3 and 48.9%, lower than that in natural restoration areas. Change of coefficient of variation about soil indicators in two areas was complicated.