title: Potential effects of large linear pipeline construction on soil and vegetation in ecologically fragile regions.
abstract: Long-distance pipeline construction results in marked human disturbance of the regional ecosystem and brings into question the safety of pipeline construction with respect to the environment. Thus, the direct environmental impact and proper handling of such large projects have received much attention. The potential environmental effects, however, have not been fully addressed, particularly for large linear pipeline projects, and the threshold of such effects is unclear. In this study, two typical eco-fragile areas in western China, where large linear construction projects have been conducted, were chosen as the case study areas. Soil quality indices (SQI) and vegetation indices (VI), representing the most important potential effects, were used to analyze the scope of the effect of large pipeline construction on the surrounding environment. These two indices in different buffer zones along the pipeline were compared against the background values. The analysis resulted in three main findings. First, pipeline construction continues to influence the nearby eco-environment even after a 4-year recovery period. During this period, the effect on vegetation due to pipeline construction reaches 300 m beyond the working area, and is much larger in distance than the effect on soil, which is mainly confined to within 30 m either side of the pipeline, indicating that vegetation is more sensitive than soil to this type of human disturbance. However, the effect may not reach beyond 500 m from the pipeline. Second, the scope of the effect in terms of distance on vegetation may also be determined by the frequency of disturbance and the intensity of the pipeline construction. The greater the number of pipelines in an area, the higher the construction intensity and the more frequent the disturbance. Frequent disturbance may expand the effect on vegetation on both sides of the pipeline, but not on soil quality. Third, the construction may eliminate the stable, resident plant community. During the recovery period, the plant community in the work area of the pipeline is replaced by some species that are rare or uncommon in the resident plant community because of human disturbance, thereby increasing the plant diversity in the work area. In terms of plant succession, the duration of the recovery period has a direct effect on the composition and structure of the plant community. The findings provide a theoretical basis and scientific foundation for improving the environmental impact assessment (EIA) of oil and gas pipeline construction as it pertains to the desert steppe ecosystem, and provide a reference point for recovery and management of the eco-environment during the pipeline construction period.
authors.affiliation: State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Xiao
authors.forename: Ya-Feng
authors.initials: YF
authors.lastname: Wang
authors.forename: Peng
authors.initials: P
authors.lastname: Shi
authors.forename: Lei
authors.initials: L
authors.lastname: Yang
authors.forename: Li-Ding
authors.initials: LD
authors.lastname: Chen
mesh_terms: D002681:China; D002980:Climate; D003247:Conservation of Natural Resources; D004463:Ecology; D017753:Ecosystem; D004777:Environment; D004784:Environmental Monitoring; D006801:Humans; D061329:Oil and Gas Fields; D010944:Plants; D018570:Risk Assessment; D012987:Soil / Q000737:chemistry
chemical_list: D012987:Soil
references.citation: J Environ Manage. 2006 Aug;80(3):266-78
references.pmid: 16490298
references.citation: J Environ Sci (China). 2006;18(5):1020-3
references.pmid: 17278765
references.citation: Conserv Biol. 2008 Aug;22(4):897-911
references.pmid: 18544093
references.citation: Ambio. 2006 Mar;35(2):91-3
references.pmid: 16722256
references.citation: Ambio. 2010 Jul-Sep;39(5-6):447-50
references.pmid: 21053729
references.citation: Eval Program Plann. 2009 May;32(2):138-47
references.pmid: 19054560
references.citation: Environ Monit Assess. 2014 Mar;186(3):1825-35
references.pmid: 24141486
references.citation: Environ Monit Assess. 2013 Oct;185(10):8011-22
references.pmid: 23494193
references.citation: Environ Monit Assess. 2007 Sep;132(1-3):395-409
references.pmid: 17674136