关键词: 接近自然, 软埂梯田, 地埂植树, 黄土丘陵区, 景观生态学

Abstract: Based on the analysis of the Pb, Zn, and Cd contents in the soil and plant samples from abandoned Pb-Zn mine tailings in Huize of Yunnan Province, Southwest China, the heavy metals pollution of the reclaimed and abandoned soils in this area was assessed by the methods of single factor pollution index and Nemerow integrated index, respectively. Compared with the Environmental Quality Standard for Soil of China (GB 15618〖KG-*2〗-〖KG-*7〗1995) (EQSSC), the heavy metals contents in the reclaimed and abandoned soils were higher than the Level 3 pollution defined by EQSSC. The total contents of Cd, Zn, and Pb in reclaimed soil were as 350, 280, and 113 times as Level 3 of EQSSC, whereas those in abandoned soil were as 407, 376, and 167 times as Level 3 of EQSSC, respectively. The assessment with single factor pollution index indicated that the severity level of heavy metals pollution was Cd>Zn>Pb, all in the heavy-pollution category, and the assessment with Nemerow integrated index also showed that the study area had been heavily polluted. The main causes of the pollution were the mine tailings and the local heavy metals-extracting techniques. As a result, the reclaimed soil might not be suitable for farming any more. In the polluted soils, there were certain kinds of wild plants still growing well, and some of them had strong capability to absorb and transmit heavy metals, being able to be used for the bioremediation of the polluted soils.

Key words: Near-nature, Soft-ridged bench terrace, Planting trees on field bund, Hilly loess region, Landscape ecology