基于景观功能评价法(LFA)的5种恢复模式景观功能综合评价:以乌海市典型露天煤矿排土场为例

Comprehensive Evaluation of Landscape Functions of 5 Restoration Modes Based on the LFA Method:A Case Study of the Dumping Site of a Typical Open-pit Coal Mine in the City of Wuhai

对矿区废弃地生态恢复效果的评价通常只考虑植被配置对土壤性质的改良,较少从景观角度对不同人工生态恢复模式进行评价和筛选。以乌海市露天煤矿排土场为研究区,选取5种典型恢复模式并以天然灌草群落的景观功能为恢复目标进行对比,运用并优化景观功能评价法(LFA)评价不同恢复模式下矿区排土场的斑块面积指标(A1)、景观结构指标(A2)及土壤稳定性(Sa)、渗透性(If)、养分循环(Ne)指数,通过最大方差法计算各指标权重得到景观结构功能综合评价指标(Fl)。结果表明:(1)生物结合工程措施的恢复模式比单一模式更好;(2)人工撒播草籽+砖砌框格护坡+土工网恢复模式A1、A2、Sa、If和Ne最高,是人工撒播草籽模式的3.2、1.8、1.8、1.7和2.4倍;(3)人工撒播草籽+砖砌框格护坡+土工网模式Fl最高,是其他恢复模式的1.3~1.9倍,是对照组的1.6倍,人工撒播草籽模式Fl最低,但与对照组相比差异不显著(P>0.05),说明5种恢复模式均能实现该区排土场生态恢复目标,以人工撒播草籽+砖砌框格护坡+土工网修复效果为最佳。研究结果可为筛选西北干旱荒漠区矿区生态恢复模式、促进环境可持续发展提供科学依据。

The evaluation of ecological restoration effects of abandoned land in a mining area usually only considers improvement in soil properties by vegetation allocation while few studies have focused on the evaluation and screening of different artificial ecological restoration models from a landscape perspective.Taking the dumping site of the Wuhai open-pit coal mine as a study area,5 typical recovery modes were selected and the landscape functions of natural shrub communities were used as recovery targets for comparison.The landscape function analysis(LFA)method was adapted and used to evaluate the patch area index(A 1),the landscape structure index(A 2),soil stability(S a),infiltration(I f)and the nutrient cycle(N e)index of the dumping site under different recovery modes,and the weight of each index was calculated by the maximum variance method to obtain the comprehensive evaluation index of the landscape structure function(F l).The results show the following.(1)The recovery mode of bio-integrated engineering measures is superior to a single mode.(2)Under the mode of artificial grass seed application combined with brick sash slope protection and geonet recovery,the A 1,A 2,S a,I f,and N e reached to the highest values that were 3.2,1.8,1.8,1.7,and 2.4 times as high as those values obtained from artificial grass seed application mode.(3)The value of F l was the highest under the recovery mode involving artificial grass seed application combined with brick sash slope protection and geonet which is 1.3-1.9 times as high as the values of other recovery modes and 1.6 times as those of the control group.F l was the lowest under the artificial grass seed application mode,but with no significant difference to that of the control group(P>0.05).Therefore,all the 5 recovery modes can be helpful to achieve the ecological restoration goals of the dump site in this area,and it is best to artificially distribute grass seeds alongside brick sash slope protection and geonet.The results of this research can provide a scientific basis for screening the ecological restoration modes of mining areas in arid desert areas of north-western China and to promote sustainable development.