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以贵州喀斯特石漠化山地退耕还林工程区的刺槐(Robinia pseudoacacia)人工林(RP)、千香柏(Cupressus duclouxiana)人工林(CD)、刺槐千香柏混交林(RD)及未造林地(CK)为研究对象,探讨了土壤物理、化学性质和土壤酶活性的动态变化,并对不同恢复类型的土壤质量进行了综合评价。结果显示:1)各类型人工林的土壤物理特性明显优于未造林地。2)在RP、CD、RD及CK下,土壤养分和pH值存在显著差异,且速效养分在不同月份差异明显(p<0.01)。3)RP、CD、RD及CK下的土壤脲酶的最大活性出现在9月,最小活性出现于1月;不同类型的人工林及CK下土壤蔗糖酶的活性存在显著差异(p<0.01);土壤过氧化氢酶的活性在一年的测定期内的变化趋势一致,呈单峰型分布,而碱性磷酸酶的活性却出现了两次峰值和一次谷值;土壤多酚氧化酶的最小活性均出现在1月,RP在整个研究期间多酚氧化酶的活性最小。RP、CD、RD及CK下,土壤脲酶、蔗糖酶、过氧化氢酶、碱性磷酸酶和多酚氧化酶5种酶的活性在整个研究期间的平均值排序不同。4)土壤质量综合评价的结果表明,土壤质量综合评价指数值(SQI)的大小排序为:RP(0.748)>RD(0.590)>CD(0.406)>CK(0.315)。结果表明,退耕还林后土壤质量得到较明显的改善,其中刺槐纯林和混交林的效果较好。
In this paper, the effects of Robinia pseudoacacia plantations (RP), Cupressus duclouxiana plantation (CD), Acacia fragrans acer sinensis mixed forest (RD) and non-afforestation land (CK) ) As the research object, the dynamic changes of soil physical, chemical properties and soil enzyme activities were discussed, and the soil quality of different restoration types were comprehensively evaluated. The results showed that: 1) The soil physical properties of all types of plantations were significantly better than those of non-afforestation land. 2) Under RP, CD, RD and CK conditions, there was significant difference between soil nutrient and pH, and the available nutrient had significant difference in different months (p <0.01). 3) The maximal soil urease activity at RP, CD, RD and CK appeared in September and the lowest activity appeared in January. There was significant difference (p <0.01) in soil invertase activity under different types of plantations and CK. The changes of soil catalase activity in the same period of one year showed a unimodal distribution, while the activity of alkaline phosphatase appeared two peaks and one trough. The minimum of soil polyphenol oxidase The activity appeared in January and RP was the least active for polyphenol oxidase during the entire study. RP, CD, RD and CK, the activities of soil urease, invertase, catalase, alkaline phosphatase and polyphenol oxidase were different during the whole study period. 4) The results of comprehensive evaluation of soil quality showed that the order of magnitude of soil quality comprehensive evaluation index (SQI) was RP (0.748)> RD (0.590)> CD (0.406)> CK (0.315). The results showed that the soil quality after the conversion of farmland to forestry has been significantly improved, of which the pure locust and mixed forests are better.