How big is the footprint? Quantifying offsite effects of mines on boreal plant communities

• Published in: Global ecology and conservation 2023-01, Vol.41, p.e02372, Article e02372
• Main Authors: Yin, Xiangbo, Martineau, Christine, Fenton, Nicole J.
• Format: Article
• Language: English
• Subjects: Boreal landscapes; Ecosystem types; Enigmatic impacts; Footprint; Human activities; Mine footprint; Mining lifecycle; Mining sites; Offsite effects; Understory diversity; Understory vegetation
• ISSN: 2351-9894; 2351-9894
• DOI: 10.1016/j.gecco.2023.e02372

Threats from mining to the biodiversity and ecological services of boreal forests are increasing as demand for minerals increases globally. However, much less is known about how offsite effects of mines affect understory communities as they occur outside the immediate location of mining and are often overlooked during ecological evaluations. We conducted an extensive field survey along 1-km transects surrounding six mine sites of different mining stages (operating vs non-operating), that crossed four ecosystem types (deciduous, coniferous, mixed forests and open canopy) in Canada’s boreal forest. The offsite effects of mines on the understory were quantified using vascular plants (woody and herbaceous), bryophytes and lichens. Mine offsite effects impacted understory diversity and composition. Understory richness and cover was more reduced near operating than non-operating mines. Mining stage mainly significantly altered understory diversity and community structure in deciduous and mixed forests while understory communities were more resistant to the offsite effects in coniferous forest (P > 0.05). The footprint was quantified using the influenced distance and the strongest effects were generally within 0.2 km from mines. Given the predicted changes in boreal forest ecosystems with encroachment of deciduous species into coniferous forests and the increased sensitivity of mixed and deciduous forests, the area affected by offsite effects of mines could grow in the future. We suggest that offsite effects should be included in ecological evaluations. •Six mine sites selected at different stage of the mining lifecycle.•Offsite effects of mines affected understory in boreal landscapes.•Mining lifecycle and ecosystem type drive offsite effects of mines.•Main effects were detectable within 0.2 km from mine sites.