The Influence Of Photovoltaic Power Station On Two Typical Degraded Ecosystems In North Of Shanxi

Energy shortage and environmental pollution are two major problems in the development of the world today.Since the 19 th National Congress of the Communist Party of China,China’s economy has entered a new normal of green development,with the energy structure transforming to green and low-carbon,and promoting large-scale clean energy.Photovoltaic power generation develops rapidly with its great advantages of cleanness,safety and low cost.Photovoltaic power station covers a large area and is mostly built on degraded land such as sand area,desertification and salinization.By the end of November 2018,Shanxi had 2,859 photovoltaic power stations for poverty alleviation in the first batch of the 13 th Five-Year Plan,accounting for a quarter of the country’s total.The north of Shanxi Province is located in the northern farming pastoral area,with dry climate and fragile ecosystem.Therefore,the impact of large-scale photovoltaic power station construction on the ecosystem of the north of Shanxi needs to be studied.The ecosystem functions of fixing carbon and releasing oxygen,maintaining soil nutrient cycling,adjusting microclimate,maintaining biodiversity were selected as indexes in this paper,and the methods of entropy weight,comprehensive index,structural equation model,correlation analysis and redundancy analysis were used to study the ecosystem of two typical degraded lands,desertification land and salinization land in Northern Shanxi Province.The main findings and conclusions are as follows:1.The influence of photovoltaic power station construction on “soil-plant-microorganism” system in the region.(1)For physical and chemical properties of soil,after the construction of photovoltaic power station in desertification land,the contents of moisture,total carbon and rapid available phosphorus in the soil of the photovoltaic park all decreased significantly,while the salinization land shows the opposite trend.However,the conductivity of saline alkali soil is 93.43% lower than that outside the power station.(2)For plant community,plant community diversity and aboveground biomass show different variation trends in different land types,among which,the variation trend of above-ground biomass is more obvious.The construction of power station reduces the biomass in desertification land by more than 86.53%,while significantly increases the biomass of photovoltaic area in salinization land by more than 61.42%.areas.(3)For microbial community,the construction of photovoltaic power station changes the soil microbial structure and composition of two degraded land types.The construction of photovoltaic power station has a certain ecological effect on the two degraded ecosystems with different response trends.(4)For microclimate,the air temperature,soil temperature,photosynthetic effective radiation and wind speed outside the power station are higher than those inside the power station,and the air humidity in the shaded area is higher than that in other2.The influence of photovoltaic power station construction on ecosystem service function.After the establishment of photovoltaic power station,the carbon fixation and oxygen release function of ecosystem,the function of maintaining soil nutrient cycle,the function of regulating microclimate and the function of maintaining biodiversity have changed to some extent.The index of regulating microclimate function of the two land types of desertification and salinization is 35.05% and 72.71% higher in the shaded area of the power station than that outside the power station respectively.The shaded area is the highest,which is 1.339 and 2.085,respectively.The function index of maintaining nutrient cycle in the power station is increased by 45.58% and 16.5%,respectively,compared with that outside the power station.The performance of comprehensive index is more complex.The desertification ecosystem in the power station is lower than that around the power station,while the salinization ecosystem is the opposite.It shows that the construction of photovoltaic power station has a great impact on the service function of the original ecosystem,but has different impact on different types of ecosystems.3.The influence mechanism of photovoltaic power station on ecological environment and service functions.The amount of solar radiation intercepted by photovoltaic panels significantly affected the soil physical and chemical properties of plant diversity and biomass(P<0.05).Environmental factors can account for more than 30% of soil microbial changes.Photosynthetic effective radiation,soil total carbon and soil total nitrogen all have significant effects on the service functions of desertification and salinization ecosystem(P<0.01).The construction of photovoltaic power station affects the ecological environment factors and ecosystem service function.Based on the above research results,suggestions and countermeasures are raised from three aspects of choosing factory site wisely and optimizing land use,promoting the construction of ecological photovoltaic power station,and “agriculture-photovoltaic complementary” power station,and preventing and controlling the environmental impact of photovoltaic power station construction.