摘要
为更好地理解西北风积沙矿区生态环境演变规律,以神东哈拉沟与上湾矿区为例,利用^(137)Cs示踪法分析了未采区、自恢复沉陷区(1、2、4、8 a沉陷区)与植被修复区(13 a沉陷区)的土壤侵蚀与养分特征,研究了矿区土壤侵蚀与养分的演变规律。结果表明:采煤扰动可以导致未采区土壤侵蚀强度增大与有机碳、微生物量碳、全氮、全磷、碱解氮养分明显损失。开采沉陷后,沉陷区土壤侵蚀强度随着时间的推移呈现出先增加后降低的趋势;其中,地表沉陷后的最初2 a是土壤侵蚀急剧增大的时段。采煤扰动下,土壤有机碳、微生物量碳、全氮、全磷、碱解氮养分的演变规律与土壤侵蚀演变密切相关。植被修复可以有效降低沉陷区土壤侵蚀强度与提高土壤养分含量。西北风积沙区采煤沉陷地表的生态恢复应该及时开展地表沉陷后的早起侵蚀防治,兼顾考虑植被修复与土壤微生物联合修复,以此促进土壤、植被正向演替。
Deterioration of the local ecological environment due to coal mining is serious in the aeolian sand area,Northwest China.A better understanding of the evolution of aeolian sandy soil under coal mining disturbance is essential prior to the initiation of restoration of local ecological environment.In this study,the ^137Cs tracing technique was used to investigate the characteristics of soil erosion and nutrients in coal mining disturbed lands of Shendong mining area,Northwest China.A plot without being disturbed by coal mining activities near Shendong mining area was selected as the control plot.As for the mining disturbed lands,an unexploited plot and 5 subsidence plots were selected as the study sites.The 5 subsidence plots include 4 self-recovery subsidence plots and one vegetation restoration plot.The 4 self-recovery subsidence plots（1 ySP,2 ySP,4 ySP,8 ySP） have undergone stabilization for 1,2,4,and 8 years,respectively after surface subsidence.The vegetation restoration plot has experienced a 13-year duration of stabilization after surface subsidence,and has been planted with almond trees for 12 years.It was found that ^137Cs inventories from the unexploited plot,subsidence plots and control plot were 32%-55% lower than local ^137Cs reference inventory（726 Bq/m^2）,which demonstrates the background of severe wind erosion desertification in the study area.In comparison with the control plot,the ^137Cs inventories in the unexploited plot,1 ySP,2 ySP,3 ySP and 4 ySP decreased by 8%,16%,29%,34%,and 10%,respectively.Changes in the nutrients,including soil organic carbon（SOC）,microbial biomass carbon（MBC）,total nitrogen（TN）,available nitrogen（AN） and total phosphorus（TP）,showed a similar trend to the ^137Cs variation.Unlike SOC,MBC,TN,AN,and TP,available phosphorus showed higher concentrations in the unexploited plot and the 4 self-recovery subsidence plots than that in the control plot.In addition,the ^137Cs,SOC and TN concentrations increased in the vegetation restoration plot in comparison with that in the control plot.Overall,there were significant correlations between SOC,MBC,TN,AN,TP and ^137Cs within the mining disturbed lands.It was also found that the coal-mining disturbed lands exhibited smaller ratios of MBC to SOC but greater ratios of SOC to TN（i.e.C/N） than the control plot.These results suggested that the intensity of soil erosion firstly increased and then decreased after surface subsidence in the aeolian sand area.Soil erosion increased sharply in the first 2 years after surface subsidence.The evolution of soil nutrients is closely associated with soil erosion evolution under coal mining disturbance.The present study provides evidences for the acceleration of soil erosion and nutrients depletion in unexploited lands of mining area by coal mining disturbance.As a consequence,there would be a considerable underestimation of the impact of mining subsidence on soil evolution when using unexploited plots as the control.Our study also suggested that vegetation restoration may effectively weaken soil erosion and improve soil nutrients in subsidence lands.Therefore,ecological restoration in subsidence lands of the aeolian sand area,Northwest China,should combat against earlier soil erosion after surface subsidence,and a plant-microorganism integrated remediation approach should be adopted to promote the positive succession of soil and vegetation.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2018年第2期127-134,共8页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金委员会与神华集团有限责任公司联合资助项目(U1261206)
河南省高校创新团队支持计划(18IRTSTHN008)
关键词
土壤
侵蚀
养分
采煤塌陷
生态环境演变
137Cs示踪
风积沙区
soils
erosion
nutrients
mining subsidence
ecological environment evolution
^137Cs tracing method
aeolian sand area
