Volume 529, 1 October 2015, Pages 285–296
- Université de Toulouse; INP, UPS; EcoLab (Laboratoire Ecologie Fonctionnelle et Environnement); ENSAT, Avenue de l'Agrobiopole, F-31326 Castanet-Tolosan, France
- CNRS; EcoLab; F-31326 Castanet-Tolosan, France
- Received 20 February 2015, Revised 19 May 2015, Accepted 19 May 2015, Available online 27 May 2015
- Editor J.P. Bennett
Highlights
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- A century of metal deposition was assessed by lichens and mosses in France.
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- A regional forest cover-dependent geochemical background signature was evidenced.
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- The anthropogenic contribution was low but stronger in the North-Eastern region.
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- Changes in the nature of atmospheric deposition were evidenced since the 19th century.
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- Pb isotopes traced a conservative specific contamination in SW France over a century.
Abstract
Lichens
and mosses were used as biomonitors to assess the atmospheric
deposition of metals in forested ecosystems in various regions of
France. The concentrations of 17 metals/metalloids (Al, As, Cd, Co, Cr,
Cs, Cu, Fe, Mn, Ni, Pb, Sb, Sn, Sr, Ti, V, and Zn) indicated overall low
atmospheric contamination in these forested environments, but a
regionalism emerged from local contributions (anthropogenic activities,
as well as local lithology). Taking into account the geochemical
background and comparing to Italian data, the elements from both natural
and anthropogenic activities, such as Cd, Pb, or Zn, did not show any
obvious anomalies. However, elements mainly originating from lithogenic
dust (e.g., Al, Fe, Ti) were more prevalent in sparse forests
and in the Southern regions of France, whereas samples from dense
forests showed an accumulation of elements from biological recycling (Mn
and Zn). The combination of enrichment factors and Pb isotope ratios
between current and herbarium samples indicated the historical evolution
of metal atmospheric contamination: the high contribution of coal
combustion beginning 150 years ago decreased at the end of the 20th
century, and the influence of car traffic during the latter observed
period decreased in the last few decades. In the South of France,
obvious local influences were well preserved during the last century.
Keywords
- Metals;
- Lichen;
- Herbarium;
- Geochemical background;
- Lead isotopes
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