Effects And Evaluation Of Vegetation Recovery For Limestone Quarry Wasteland In Western Beijing

Damages caused by strip mining give rise to serious ecological problems which become one of major issues needing to be solved. Different vegetative restoration methods were applied in waste land produced by strip mining in Mentougou of Beijing, including pure forest of Cotinus coggygria Scop、 Platycladus orientalis、Rhus typhina、Eucommia ulmoides、Pinus tabuliformis、Ginkgo biloba、Sophora japonica、Forsythia suspensa、Amygdalus persica、Syringa oblata and mixed forest of Platycladus orientalis and Sabina chinensis. Plots were conducted aiming at different restoration methods as well as natural slopes and damaged ones in2012. Investigation including community structure of vegetation and arthropod animals, chemical properties of soil, enzymes and ecological functions was analyzed. Results were as follows:(1) Cotinus coggygria Scop forest, Ginkgo biloba forest, Pinus tabuliformis forest and Rhus typhina forest showed good Environmental adaptation in limestone Quarry Wasteland in West Beijing. There were succession species appeared in all plots forest, the succession species included Robinia pseudoacacia、Ailanthus altissima、Salix matsudana、Populus tomentosa with a low density. Species richness of herb in plots of Ginkgo biloba forest、Sophora japonica forest、Pinus tabuliformis forest was higher and Platycladus orientalis forest had a lower species richness.(2) Pest accounted for a larger proportion among plots of arthropod animal communities. Natural enemy was rich due to large number of pests. Sucking pests are the main groups, playing an important role in regulating predatory natural enemy. The arthropod species are relatively rich, with higher diversity index and scattered species distribution in plots undergone vegetation restoration. These plots had no serious pest communities, performing a better ecological effect. Correlation analysis showed that there was a significant positive relation between the herb diversity index and insects richness. Arthropod diversity index was significantly related with natural enemy richness.(3) Alkali-hydrolysable nitrogen, available phosphorus and available potassium, organic matter content, sucrase, phosphatase, catalase and urease activity in soil with thickness of0～20cm is higher that thickness below20cm. Soil alkaline hydrolysis n, available k, organic matter content in plots with different vegetation restoration measures showed a larger difference. Calculation results showed that natural slope had the strongest soil fertility in all plots. Sucrase in soil of0～20cm was higher than below20cm, catalase activity was similar between both soil layers.(4) The largest Vegetation retaining capacity happened in Rhus typhina forest, followed by Eucommia ulmoides forest and Forsythia suspensa forest. Damaged slope and natural slope had the smaller vegetation retaining capacity. Rhus typhina and Forsythia suspensa had the larger litter water-holding capacity but Platycladus orientalis forest, mixed forest of Platycladus orientalis and Sabina chinensis forest, natural slope and damaged slope had smaller water-holding capacity. Water holding capacity of the natural slope was the largest, followed by damaged slope. Rhus typhina forest had the strongest carbon fixation and oxygen release ability, and smallest in natural slope and damaged slope. Pinus tabuliformis forest had the largest sulfur dioxide absorption capacity followed by Eucommia ulmoides forest、Sophora japonica forest、Ginkgo biloba forest, Forsythia suspensa forest、 Amygdalus persica forest、Cotinus coggygria Scop forest.(5) Selection of Analytic hierarchy process (AHP) and TOPSIS methods were used to analyze and sort the comprehensive ecological function of each plot by selecting a total of18indicators, including water conservation, soil conservation, carbon fixation and oxygen release, biodiversity conservation, nutrient cycle and purification of atmospheric environment. Results showed that plots with higher scores using two methods was as follows:Eucommia ulmoides forest, Sophora japonica forest, Rhus typhina forest, Ginkgo biloba forest, Cotinus coggygria Scop forest, Syringa oblata forest and Amygdalus persica forest. Scores using AHP to calculate the comprehensive function had a higher correlation coefficient R2of0.82with that through the TOPSIS method.