Distribution patterns of spontaneous vegetation and pollution at a former decantation basin in southern Québec, Canada

tAfter industrial activities shut down, the brownfields remaining on abandoned sites are often left torevegetate naturally, a process that reflects the site’s biotic and abiotic characteristics, including spatialpollutant distribution. The soil of a former decantation basin in Varennes (southern Québec, Canada) wassystematically sampled and described in terms of concentration of PAHs (polycyclic aromatic hydrocar-bons), PHs (petroleum hydrocarbons C10–C50), various trace metals as well as ruderal plant abundanceand diversity. Partial redundancy analysis was used to investigate the effect of heterogeneous pollutionon the plant community’s spatial distribution. Up to 61% of variance in spontaneous plant distributionwas explained by the pollutant dispersion pattern on the study site. These findings provide guidelines forthe design of site-specific and within-site remediation or rehabilitation promoting natural processes thatare already in progress. They also suggest using local vegetation and a greater diversity of plant specieswhen conditions are conducive as this may have many associated benefits. The resulting design, whichpromotes development of the local plant community, can be a more cost effective and environmentallysustainable alternative to traditional plant-based remediation approaches.