阜新露天煤矿排土场边坡土壤质量分异特征

以阜新露天煤矿排土场边坡为对象,分析坡向、坡位和恢复年限对土壤物理、化学和生物学性状的影响,并采用土壤质量综合指数法,研究排土场边坡植被恢复过程中土壤质量变化规律.结果表明,排土场边坡土壤含水量、有机质、碱解氮和速效磷含量、pH值以及脲酶、碱性磷酸酶和蔗糖酶活性从坡上到坡下均逐渐增加;恢复10a阴坡土壤含水量、水稳性团聚体含量、碱性磷酸酶、过氧化氢酶和蔗糖酶活性高于阳坡;随着恢复年限增加,土壤水稳性团聚体和速效磷含量及阴坡碱性磷酸酶活性提高,而土壤pH值、阳坡碱解氮含量及脲酶和过氧化氢酶活性下降.排土场边坡土壤质量表现为阴坡>阳坡、坡下>坡中>坡上的变化规律;随着恢复年限增加,阳坡坡上和坡中及阴坡土壤质量增加,而阳坡坡下下降.以上结果说明,坡位和坡向是影响排土场边坡土壤质量的重要因素,应根据具体生境特点,采取不同治理措施,才能完成生态恢复.

Soil quality variability on dump slopes of opencast coalmine in Fuxin

In the present study, the effects of slope aspect, slope position, and succession years on soil physical, chemical and biological properties in opencast coalmine dumps in Fuxin city were analyzed, and changes of soil quality in the progress of vegetation restoration of the dump slopes were explored using the method of soil quality index. The results showed that the soil water, organic matter, available nitrogen and phosphorus content, pH value, and urease, alkaline phosphatase and invertase activities increased from upper part to lower part of slope. The values of soil water content, water-stable aggregates content, alkaline phosphatase, catalase and invertase activities were higher on the shady slope than on the sunny slope after 10 years restoration. With the succession years increase, the soil water-stable aggregates and available phosphorus content, and alkaline phosphatase activity on the shady slope gradually increased, but the soil pH value, and available nitrogen content, urease and catalase activities on the sunny slope gradually declined. The soil quality was higher on the shady than sunny slope, but decreased in the order of lower part> middle part > upper part. With the succession years increase, soil quality increased on the shady slope and at the upper and middle part of sunny slope, while it declined at lower part of sunny slope. These results indicated that slope aspect and slope position played a critical role in soil quality on the slope of coalmine dumps. Therefore, in order to reclaim successfully the slope of coalmine dumps in Fuxin city, different restoration measures should be carried out based on different characteristics of habitat.