Study on ecological restoration countermeasures of abandoned mines in Yunnan Province

CAI Baoxin; LI Qin; KONG Zhigang; YANG Xiaoyan; LI Yanqing; SONG Zenghong

doi:10.11932/karst20240618

Abstract：Ecological restoration of abandoned mines is an important step in practicing ecological civilization and is of great significance in maintaining ecological security in Southwest China.Yunnan Province is abundant in mineral resources and is often referred to as the"Kingdom of Non-ferrous Metals"and the"Province for Phosphorus Chemical Industry".Mining is one of the pillar industries in Yunnan,making significant contributions to the socio-economic development of Yunnan and the rest of China.However,the ecological and environmental issues carried over from mining activities of the past are prominent.The abandoned mines have,to some extent,hindered local socio-economic development;however,they also represent a natural resource that can be re-exploited.Mining activities in the past have excavated and occupied land resources,changed the original topography,destroyed forest and grassland vegetation,disrupted the connectivity of ecological corridors,caused damage or degradation to ecosystems,diminished water conservation functions,and aggravated rocky desertification and soil erosion.There are numerous abandoned mines in Yunnan Province,which are widely distributed and predominantly small in scale.These sites are burdened by significant debt,face complex ecological issues carried over from the past,and possess inadequate natural recovery capacity,resulting in a challenging remediation task.In recent years,there has been a focus on key watersheds and important ecological areas.This focus aligns with the overarching principles of respecting and adapting to nature,following the laws of natural ecosystem succession,prioritizing natural recovery while supplementing it with engineering solutions,and ensuring that all actions are suitable,technically feasible,and financially viable.As a result,ecological restoration methods and measures have been selected based on scientific criteria.Near-natural solutions have been implemented to fully embody the principles of comprehensive management and systematic restoration.These approaches have actively and systematically promoted the ecological restoration of abandoned mines,resulting in positive outcomes.However,the extensive number of abandoned mines and the funding shortfall for restoration efforts have resulted in a critical ecological restoration situation.Currently,over 100,000 acres of abandoned mines in Yunnan Province urgently require ecological restoration,posing significant challenges to the livelihoods and daily lives of local villagers. The diversity of Yunnan's climate presents varying requirements and challenges for environmental protection and ecological restoration.The northwestern cold climate zone of Yunnan experiences long winters with no summers and only short spring and autumn seasons,resulting in slow vegetation growth and significant challenges for ecological restoration.In contrast,the eastern and central temperate climate zones of Yunnan have indistinct seasons,characterized by moderate average annual temperatures and precipitation,which facilitate the recovery and growth of vegetation.The southern and southwestern tropical and subtropical climate zones of Yunnan are abundant in precipitation and biodiversity,creating favorable conditions for vegetation restoration and the protection of biodiversity.Dry and hot river valley regions of the Jinsha river and Yuanjiang river experience a scorching climate characterized by drought and limited rainfall.This results in an imbalance between water and heat,as well as low soil organic matter and nutrient content.Ecological restoration efforts in these areas should prioritize soil and water conservation,along with the protection of water sources. Based on the current situation of ecological and environment damage caused by abandoned mines in Yunnan Province,this paper analyzes the ecological problems of mines.Drawing on the experience gained in the ecological restoration of abandoned mines,it constructs restoration modes such as"natural restoration,ecological carbon sink,transformation and utilization,and ecological restoration+".Fully considering factors such as the natural geography of mining areas,the pattern of ecological restoration,incentive policies,and the requirements of controlling national land space use,it discusses countermeasures and suggestions for the ecological restoration of abandoned mines,focusing on aspects such as restoration direction,engineering measures,and investment mechanisms.The aim is to provide technical support and innovative ideas for the ecological restoration of abandoned mines in the context of the new paradigm of"mountains,rivers,forests,farmlands,lakes,and grasslands as a community of life".In the next step of promoting the restoration of abandoned mines,it is necessary to redefine the concept of ecological restoration of mines.This involves accurately understanding the relationship between natural and artificial restoration.It is crucial to adhere to the principles of ensuring safety,restoring ecological balance,and considering the landscape.Additionally,it is important to scientifically select appropriate models for mine ecological restoration and engineering measures based on the potential value of abandoned land resources,while also complying with regulations of controlling national land space use.Taking into account the current situation of social and economic development in mining areas,as well as factors such as micro-landforms,surrounding vegetation,traffic conditions,and water and soil quality,the ecological restoration of mines has been carried out,and the restoration direction has been determined with careful consideration.Through policy incentives and the strategic allocation of financial funds,we will encourage social capital to engage in the ecological restoration of abandoned mines.Our goal is to revitalize these sites,and establish a new model of self-sustaining and self-cycling ecological restoration of abandoned mines.