Landscape Pattern Evolution And Ecological Effect Of The Inner Mongolia Wind Farm

Climate warming has become a hot topic of common concern around the world.Approximately 40%of global carbon dioxide emissions are related to electricity and heat production.The development of clean and safe renewable resources is the key to sustainability.The Inner Mongolia Autonomous Region is an important ecological security barrier in northern China,and it is also the region with the most abundant onshore wind energy resources in China.In recent years,wind farm construction has been rapidly developed in Inner Mongolia grasslands,with installed capacity ranking first in the country.With the rapid development of grassland wind farms,the impact of wind farms on the ecological environment has aroused widespread concern.In this study,the landscape pattern evolution of wind farms in Inner Mongolia during the past30 years was dynamically analyzed by remote sensing and field vegetation survey.Taking a typical grassland wind farm as an example,it analyzes the impacts of wind farms on the surrounding grassland communities,community microenvironment,and their emission reduction effects.The main conclusions are as follows:Changes in the temporal and spatial patterns of wind farms in the regions of Inner Mongolia wind farm.The number of wind farms in Inner Mongolia was tiny before2000 and had slow growth before 2008.After that,the construction of wind farms in Inner Mongolia ushered in rapid development.The area of wind farms and the number of patches has increased rapidly,increasing to 10755 km~2 and 226 patches in 2020.The wind farms in Inner Mongolia are concentrated in the center of the province,including six cities:(Bayannaoer,Baotou,Xilin Gol,Ulanqab,Chifeng,and Tongliao).The wind farm area in these cities was all beyond 1000 km~2.Among them,the area of wind farms in Xilin Gol was the largest,reaching 2147km~2,accounting for about 20%of the region’s total area of wind farms.Grassland was occupied the most in this area,with an area of 8639 km~2,accounting for 80%of the total area of wind farms.The second was farmland,which was 1138 km~2,accounting for about 10%of the area.And forest land,construction land,and wetland are all relatively low.Among the grasslands,the typical steppe was occupied the largest area by wind farms,which was 5305km~2,followed by the desert steppe and meadow steppe with areas of 1677km~2 and 1014km~2.The impact of wind farms on the microenvironment of the community.This study focused on the typical grassland,which has the largest area of wind farms.By investigating the microclimate factors and physical and chemical properties of soil in36 sites.For the microclimate,we found that the wind speed would decrease,but the air temperature and humidity had no significant change as the distance from the wind farm increased.For the soil character,as the distance from the wind farm increased,the soil moisture content of 0-30 cm tended to increase.The soil ammonium nitrogen content of 0-10 cm,10-20 cm,and 20-30 cm separately showed increasing,decreasing,and insignificant trends.The trends of soil nitrate-nitrogen and total nitrogen content in 0-30 cm were insignificant.The soil total phosphorus content in 0-20cm and 20-30cm showed an insignificant and decreasing trend,respectively.The soil organic carbon content showed an insignificant trend in the 0-10 cm soil layer and decreasing trend in the 10-30 cm layers with the increase of the distance from the wind farm.The impact of the wind farm on the grassland community.Based on the perspective of functional traits,founding that the wind farms can significantly decrease the species richness,species diversity,functional richness,functional diversity of grassland plant communities,and change the community species composition,by plant community investigation in 36 site.The wind farms had a significant effect on the functional structure of grassland plant community that increasing the plant height,leaf area,leaf dry mass,specific leaf area,leaf carbon content,leaf carbon-to-nitrogen ratio,leaf dry matter content of community weighted trait means,and decreasing the leaf phosphorus content of community weighted trait mean.Meanwhile,this study found that the effect of wind farms on regional productivity of the Inner Mongolia grassland has a threshold effect that the 2 km radius around the wind farm is the largest impact area.Wind farms could cause a 3%-4%decline in plant productivity in this area.The impact of wind farms on carbon emissions.In this study,the carbon footprint of the production,transportation,construction,operation,and disposal stages was evaluated by using the life cycle assessment method in a 49.5 MW wind farm in the typical grassland area of Inner Mongolia,and its carbon emission intensity was explored in further.The results showed the following:The carbon footprint of the wind farm in the grassland area was 18701.29 t,of which the construction stage accounted for the largest proportion at 56.74%,and the other stages,ranging from highest to lowest,were production,disposal,transportation,and operation stages,which were28.18%,12.08%,2.76%,and 0.24%,respectively.The carbon footprint of material recycling was 18726.53 t,and the reduced carbon emissions accounted for 50.03%of the total carbon emissions.The carbon emission intensity of the wind farm was 6.57g/k Wh.It is not only lower than the carbon emission intensity of the four non-renewable energy sources,such as coal,natural gas,oil,and nuclear power,but also lower than the carbon emission intensity of the three renewable energy sources,such as hydropower,biomass,and photovoltaics.Compared with offshore wind farms and non-grassland wind farms,grassland wind farms have the lowest carbon emission intensity.The development of clean energy is the main way to help China’s goal of"carbon peak"and"carbon neutral".In the past three decades,Inner Mongolia has witnessed rapid development of wind power,and wind farms installed capacity ranks first in China.In view of the abundant wind energy resources in the grasslands of Inner Mongolia,it is of great importance to explore the impact of wind farms on grassland ecosystem and their carbon emission efficiency for grassland ecological protection and regional sustainable development.