Assessing The Impact Of Crushed Rock Mining On Biodiversity

Sand,gravel and crushed rock,collectively known as construction aggregates or sand and gravel resources,are the most consumed solid raw materials in the world.However,construction aggregates mining has been shown to lead to habitat loss and biodiversity loss.Mitigating biodiversity loss while meeting the sand and gravel resources needs of the construction industry is a global environmental challenge.China is the world’s largest producer and consumer of construction aggregates.In the past 10 years,China has gradually transformed from extracting sand from rivers to producing crushed rock in quarries.The crushed rock produced by mines has exceeded 75%,becoming the main source of construction aggregates,but the impact of this sand mining transition on terrestrial biodiversity is still unknown.This study takes Guangdong Province as the research area to explore the impact of crushed rock mines on biodiversity and mitigation strategies.Firstly,based on the data of crushed rock mines,analyze the mining status of crushed rock mines in Guangdong Province,and quantify the impact of mining on biodiversity(Biodiversity Factor,BDF)of each grid.Secondly,based on the GIS spatial analysis method,explore the spatial consistency of crushed rock mines,terrestrial nature reserves and Key Biodiversity Area(KBA),and create the null model of mines for comparative analysis;After that,extract the IUCN Red List of Threatened species in batches,and search keyword based on text mining to identify threatened species and habitats threatened by construction mining,and compare them with the spatial coincidence results;Fourthly,use the Max Ent model to predict the suitable habitat of Critically Endangered species Chinese pangolin(Manis pentadactyla),and the biodiversity impact factor of mining on the habitat of the Manis pentadactyla(Biodiversity Factor of Mains Pentadactyla,MPBDF)are used to quantify the impact of mining on the habitat of Chinese pangolin;Finally,respectively sort out the mine restoration policies at home and abroad,and put forward mitigation recommendations on biodiversity protection of mine.The main results are as follows:(1)In 2020,there were a total of 438 crushed rock mines in Guangdong Province,and the mines were concentrated in Northern Guangdong(n=221),which was rich in biodiversity,but the area was dominated by small and scattered mines.In comparison,the Pearl River Delta region had the largest mines scale.And there is a significant positive correlation between mine production scale and mines area.In Guangdong Province,the high impact of mines on biodiversity(BDF)is concentrated in Northern Guangdong.Correlation analysis showed that the production scale,mine area and the impact of mining on biodiversity(BDF)are significantly negatively correlated,which may be related to the spatial distribution of green mines in Guangdong Province.(2)In Guangdong Province,about 2.51% of crushed rock mines directly overlap with terrestrial nature reserves.A total of 42.23% of the mines are located within the boundary range of 1.5km-10 km of the terrestrial nature reserve,and the distance between the mines and nature reserve is significantly closer than the expected result by null model,and the actual impact is greater.A total of 6.15% of mines are located within 10 km buffer of KBA,which is not significant compared with the expected result.Among them,city and county level nature reserves are most vulnerable to the direct threat of crushed rock mines.(3)Based on the IUCN Red List assessment report,about 0.86% and 4.10% of all red-list categories(All categories)and threatened with extinction category are threatened by crushed rock quarries,respectively.About 23.41% of all categories of species have spatial overlap with crushed rock mines,including 51 threatened with extinction category of species.By comparison,it is found that endangered birds and mammals that inhabit forests are most vulnerable to threats from mines.Among them,the Chinese pangolin is the only Critically Endangered(CR)species that is not only reported to be threatened by quarries in the IUCN Red List,but also has the most overlap with crushed rock mines.(4)The high suitable habitats of Chinese pangolin are concentrated in Northern Guangdong,accounting for about 41.18% of the total area of high suitable habitats.In addition,23.96% and90.00% of crushed rock mines overlap with the high suitable habitats and all-level habitats of Chinese pangolins,respectively.The high impact of crushed rock mines on the habitat of Chinese pangolin is concentrated in Northern Guangdong.Correlation analysis found that Chinese pangolin tends to occur in areas with low mine density,and their occurrence records are positively correlated with habitat suitability levels.However,especially in Northern Guangdong,habitats with higher suitability levels are more likely to be threatened by crushed rock mines than other types of habitats.(5)Many foreign countries have established specialized mine restoration management departments,and followed the Mitigation Hierarchy Principles(MHP),that is,avoidance,minimization,restoration and offsetting,which focus on the protection of biodiversity and habitat of species in mining areas.However,China mostly follows the green mine policy,which focuses on the mine production construction and land reclamation,etc.,but pay less and general attention to biodiversity.Therefore,in the future,Guangdong Province,especially in the Northern Guangdong region,should establish a green mine biodiversity management department,learn from the MHP and the IUCN guidelines,and carry out biodiversity-oriented green mine construction from two main management perspectives(government departments and enterprises)and three management stages(before,during and after mining).In conclusion,crushed rock mines in Northern Guangdong have the most concentrated impacts on biodiversity.With crushed rock production expected to continue expanding to satisfy the increasing regional and national aggregates demand,a careful assessment of mining impacts and mitigation measures in mining projects are required to reduce conflicts between crushed rock production and biodiversity.