煤矸石山植被自然恢复规律及其环境影响

Effects of soil properties on vegetation restoration in coal-gangue pile

采用植物群落数量分类方法研究植被和土壤恢复状况,利用烘干法、环刀法、电位法、凯氏定氮法、钼锑抗比色法、火焰光度法和外加热法测定了土壤的理化性质,并采用TWINSPAN、DCA和DCCA法研究了河南义马矸石植被梯度变化规律及其与环境因子之间的关系。结果表明,煤矸石山大致可以分为三大类:排矸35 a的煤矸石山边坡;排矸30 a和35 a矸石山;排矸45 a和55 a以及有人为干预(排矸20 a)矸石山。DCA排序与TWINSPAN分类结果一致。DCA和DCCA排序图明显反映出排序轴的生态意义。不同类型矸石山自然植被的类型和生长情况差异明显,植物群落的梯度变化主要受土壤阳离子交换量、总孔隙度和土壤养分控制。直接种植具有土壤改良作用的刺槐林能加快矸石山植被的自然恢复和土壤改良进程。研究结果也表明,土壤理化性质改良,有助于自然植被恢复。边坡不稳定,植物难以自然定居,应采取措施稳固边坡;或与工程护坡措施相结合,种植一些抗干旱、耐瘠薄、深根性的植物,以加快边坡的生态恢复。

Waste coal-gangue piles not only occupied and destroyed large fields, but also brought about a series of prob-lems of environment. So it is significant to do the research on restoring vegetation of coal-gangue pile in for local environ-ment. The naturally restored vegetation status were investigated by traditional plot-survey, and soil chemicals and physical properties were analyzed by using standard methodology. The natural vegetation patterns along the environmental gradient and their relationships with ecological factors were analyzed by TWINSPAN, DCA and DCCA. The results showed that the coal-gangue piles could be divided into three groups according to community ordination:the 36° slope of the coal-gangue pile that was discarded for 35 years; the coal-gangue pile was discarded for 30 or 35 years; the coal-gangue pile was discarded for 45 or 55 years and Robinia pseudoacacia forest which was discarded for 20 years. The re-sults of DCA and TWINSPAN for vegetation plots and soil properties were similar. The axes of DCA and DCCA ordina-tion diagram indicated that the variation of vegetation in coal-gangue pile was influenced by physical properties and soil chemicals, such as cation exchange capacity, bulk density and nutrient. Planting trees ( such as R. pseudoacacia) could significantly accelerate the natural recovery of vegetation waste dump and soil improvement process.The results also sug-gest that the improvement of soil chemicals and physical properties was contributed to natural vegetation recovery. Since natural plants are difficult to grow owing to the instability of slope, measures should be taken to make the slope secure, or along with engineering combined with planting some drought-resistant, barrenness-resistant and deep-rooted plants to speed up ecological restoration of the slope.