Construction Of Artifical Plant Communities And The Impact On Substrate Properties Of The Bare Mining Slopes

The breakage of amout of hillsides and the formation of lots of bared slopes without plant covered as a result of the powerful construction of the national infrastructure. Unfortunately, the formation of slope will largely destroy the landscape environment, even urge to the landslide and coast of slope and lead to serious soil and water loss. Therefore it has become the imperative issue that the bared slope was taken ecological restoration.The research area lies in the mines wasteland of the background with phosphorus in Chaohu drainage basin. Lots of bared steep slope area and gradual slope area accumulated by stripping soil have formed because of long-term exploitation, and the landform waves largely. What's more, the slope soil initial character is exposed and the content of grain phosphorus is high, but the content of nitrogen and the natural plant coverage is low and the soil and water loss is severe.The thesis has researched on the bared slope of background area with phosphorus in Chaohu drainage basin. Cynodon dactylon and Lespedeza chinensis and Indigofera pseudotinctoria Mats has regarded as the tool species on the basis of the native vegetating species, and the different model artifical plant communities were constructed in different gradient. The morphological character of artifical plant community and soil physicochemical properties were researched in the thesis, moreover taking some conclusion on this research basis.(1) The field survey indicates that there are 38 section 129 species native plants in the research region, but the gramineous and leguminous and composite plants are the main plants composing native plant communities in the research region, in which the Cynodon dactylon is the primary predominant species. The Imperata cylindrica-Cynodon dactylon community locating east part and assuming zonal or plaquelike distribution and the Imperata cylindrica-Setaria viridis community locating west part and assuming plaquelike distribution and the Prunella vulgaris-Zoysia sinica community locating flat part and assuming zonal distribution comprised the main plant community of the research region. The content of background phosphorus is high(1.62mg/g) and the condition of soil and water loss is serious (0.1 m3/m2)in the research region.(2) Cynodon dactylon is restrained by Lespedeza chinensis and Indigofera pseudotinctoria Mats lied in shrub layer for the different seeding models in both steep slope region and very steep slope region. Moreover, the three-dimensional plant net has little effect on the three plants in steep slope region but is in favor of the growth of Lespedeza chinensis and Indigofera pseudotinctoria Mats and goes against the growth of Cynodon dactylon. Finally, the gradient has influenced on the height and total coverage and biomass aboveground of the three plants in different seeding models, especially in the steep slope region(the average biomass aboveground of Cynodon dactylon and Lespedeza chinensis and Indigofera pseudotinctoria Mats respectively differes 2.5g/m2,23.5g/m2,16g/m2).(3) The restoration region by constructed artificial plant communities is obviously better than the blank contrastive region about improvement in the soil physical properties especially the soil bulk density, and there is a significant correlation between the soil bulk density and the biomass aboveground(R2=0.707).(4) The biomass aboveground has impacted on the soil chemical properties in the gradual slope region and steep slope region after the construction of artificial plant communities. And the soil total nitrogen have significantly increased in contrast with the blank contrastive region(4.7%).(5)The biomass aboveground in different seeding models exist discrepancy, which in the three-dimensional plant net and Cynodon dactylon and Lespedeza chinensis and Indigofera pseudotinctoria Mat model is highest. And there is a significantly correlation between biomass aboveground and soil available phosphorus(R2=0.935) in the gradual slope region, what's more, there is a obvious correlation between biomass aboveground and soil pH(R2=0.745) in the very steep slope region.