Altitudinal variation of trace elements deposition in forest ecosystems along the NW side of Mt. Amiata (central Italy): Evidence from topsoil, mosses and epiphytic lichens

https://doi.org/10.1016/j.apr.2021.101200Get rights and content

Highlights

  • Metals atmospheric deposition was investigated along the NW side of Mt. Amiata between 120 and 1730 m a.s.l.

  • We compared element composition of the fine fraction of topsoils, epiphytic lichens and epigeic moss.

  • Pb concentrations increased significantly with the altitude in the fine fraction topsoils.

  • Cryptogams showed an enhanced accumulation of Cd, Hg, Zn and Pb in samples from altitudes above 1300 m (beech forest).

  • Mosses and lichens result more suitable matrix than topsoils in assessing the impact of climate change along mountain slopes.

Abstract

Mt. Amiata (1738 m) is a volcanic peak in central Italy, completely covered with native oak, chestnut and beech forests. In this Natura 2000 site of Community Importance overlying a large shallow aquifer, climate change and the long-range transport of nutrients and contaminants might have negative impacts on relict plants populations and spring water chemistry. To evaluate the atmospheric deposition of trace elements in Mt. Amiata forest ecosystems, we analyzed the elemental composition of topsoils, epiphytic lichens (Parmelia species) and epigeic moss (Hypnum cupressiforme) between 120 and 1730 m a.s.l. along the NW side of the mountain, which is scarcely affected by natural and anthropogenic sources of metals. The elemental composition of the topsoil is mainly influenced by the different lithologies of the study area (calcareous up to an elevation of 700 m, volcanic up to the summit) and only Pb concentrations increased significantly with the altitude. The total element concentrations in cryptogams, particularly net of the possible contribution from soil particles, showed an enhanced accumulation of Pb, Cd, Hg and Zn in samples collected at altitudes above 1300 m, where beech forest are frequently shrouded in clouds and fog and receive more snow and rain than the lower chestnut and oak woods. Interestingly, the older and metabolically inactive tissues at the base of moss shoots, which are usually overlooked in biomonitoring surveys, appeared to behave as long-term accumulators of Pb. The possible mechanisms involved in the increased bioaccumulation of Mn in cryptogams inhabiting chestnut woods are discussed.

Section snippets

Credit author statement

Ancora S: Methodology, Resources, Writing – Review & Editing. Dei R.: Resources, Investigation. Rota E: Formal analysis; Writing – Review & Editing. Mariotti G: Investigation, Validation. Bianchi N: Validation, Formal analysis. Bargagli R: Conceptualization, Writing – original draft, Review & Editing, Supervision.

Study area

Mt. Amiata (1738 m a.s.l.; 42°53′N 11°37′E) originated in the late Pleistocene (about 300–230 kyr ago) from volcanic activity (Laurenzi et al., 2015) and isolation is one of its peculiar features. Starting from an altitude of about 700 m a.s.l., volcanic materials (mostly porphyric trachydacites and trachyandesites with sanidine mega-crystals) rest unconformably on structurally complex Neogene tectono-sedimentary deposits. The southern and eastern slopes of the mountain are characterized by

Fine fraction of topsoil

Mean Pb, Hg and Cd concentrations in topsoil samples from beech woods were higher than those in chestnut and oak woods, whereas samples from woods on calcareous substrata (below 700 m a.s.l.) had higher and significantly interrelated Al, Fe, Cu and Zn concentrations (Table 2 and Suppl. Table 1). Although significant relationships (p < 0.05) were found between Hg, Cd and Pb concentrations (Suppl. Table 1), only the distribution pattern of Pb along the mountain slope showed a significant positive

Discussion

Although rather variable, the concentrations of Al, Cd, Cu, Fe, Mn and Zn in the fine fraction of topsoils from the northwestern side of Mt. Amiata (Table 2) were mostly in the same range as, and the Hg and Pb content was slightly higher than, those reported for forest soils (e.g. Kabata-Pendias, 2010). The elemental composition of epiphytic lichens (Table 3) agrees with the results of previous biomonitoring surveys performed in forest ecosystems of central Italy by using the same lichen

Conclusions

Mt. Amiata is a cone-shaped and isolated mountain in central Italy and is characterized by steep altitudinal gradients of temperature and precipitation and succession of oak, chestnut and beech woods. The latter grow above 1200–1300 m of altitude on volcanic substrata and in agreement with the results of previous surveys on topsoils collected along the slopes of mountain ecosystems, our study shows that also in a very isolated mountain, far from significant anthropogenic sources of trace

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

References (63)

  • R. Gerdol et al.

    Effects of altitude on element accumulation in alpine moss

    Chemosphere

    (2006)
  • P. Giráldez et al.

    Testing different methods of estimating edaphic inputs in moss biomonitoring

    Sci. Total Environ.

    (2021)
  • A. Gobiet et al.

    21st century climate change in the European Alps - a review

    Sci. Total Environ.

    (2014)
  • H. Harmens et al.

    Heavy metal and nitrogen concentrations in mosses are declining across Europe whilst some “hotspots” remain in 2010

    Environ. Pollut.

    (2015)
  • A.M. Johansen et al.

    Precipitation chemistry and deposition at a high-elevation site in the Pacific Northwest United States (1989-2015)

    Atmos. Environ.

    (2019)
  • H. Kempter et al.

    Major and trace elements in Sphagnum moss from four southern German bogs, and comparison with available moss monitoring data

    Ecol. Indicat.

    (2017)
  • R. Král et al.

    Background concentrations of lead and cadmium in the lichen Hypogymnia physodes at different altitudes

    Sci. Total Environ.

    (1989)
  • P. Lazo et al.

    Origin and spatial distribution of metals in moss samples in Albania: a hotspot of heavy metal contamination in Europe

    Chemosphere

    (2018)
  • C.S.L. Lee et al.

    Biomonitoring of trace metals in the atmosphere using moss (Hypnum plumaeforme) in the Nanling Mountains and the Pearl River delta, southern China

    Atmos. Environ.

    (2005)
  • E. Lequy et al.

    Spatial analysis of trace elements in a moss bio-monitoring data over France by accounting for source, protocol and environmental parameters

    Sci. Total Environ.

    (2017)
  • A. Magnani et al.

    Soil properties and trace element distribution along an altitudinal gradient on the southern slope of Mt. Everest, Nepal

    Catena

    (2018)
  • Y. Oishi

    Moss as an indicator of transboundary atmospheric nitrogen pollution in an alpine ecosystem

    Atmos. Environ.

    (2019)
  • M. Rogora et al.

    Temporal and spatial patterns in the chemistry of wet deposition in southern Alps

    Atmos. Environ.

    (2016)
  • M. Schmull et al.

    Extraction methods for assessing the availability of cations for epiphytic lichens from bark

    Environ. Exp. Bot.

    (2003)
  • O. Vaselli et al.

    Distribution of gaseous Hg in the Mercury mining district of Mt. Amiata (Central Italy): a geochemical survey prior the reclamation project

    Environ. Res.

    (2013)
  • Z.P. Wallace et al.

    Effects of nitrogen saturation on tree growth and death in a mixed-oak forest

    For. Ecol. Manag.

    (2007)
  • J. Xiao et al.

    Heavy metals in different moss species in alpine ecosystems of Mountain Gongga, China: geochemical characteristics and controlling factors

    Environ. Pollut.

    (2021)
  • H.G. Zechmeister

    Correlation between altitude and heavy metal deposition in the Alps

    Environ. Pollut.

    (1995)
  • R. Bargagli

    Determination of metal deposition patterns by epiphytic lichens

    Toxicol. Environ. Chem.

    (1989)
  • R. Bargagli

    Trace Elements in Terrestrial Plants: an Ecophysiological Approach to Biomonitoring and Biorecovery

    (1998)
  • R. Bargagli et al.

    Lichen biomonitoring of mercury emission and deposition in mining, geothermal and volcanic areas of Italy

    Environ. Monit. Assess.

    (1991)
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    • Lichen biomonitoring of airborne trace elements in the industrial-urbanized area of eastern algiers (Algeria)

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      Citation Excerpt :

      It was not unexpected that heavy metals and rare earths concentrations in Pseudevernia furfuracea lichen transplants are significantly higher in all selected urban-industrial sites of Rouiba−Reghaia region relative to the Reghaia Nature Reserve and the Theniet El-Had control site. In this latter regard, background elements concentrations found at the TH site are plausible control levels (Bergamaschi et al., 2004; Ancora et al., 2021) in agreement with the literature values obtained in unpolluted sites worldwide listed in Table S5 (Freitas et al., 1993; Adamo et al., 2003; Culicov and Yurukova, 2006; Malaspina et al., 2014; Pantelica et al., 2016). Indeed, lichen biomonitoring studies, including the present investigation, have identified Al, Fe, and, in a lesser extent, Mn and Zn, as the major contributors to the contemporary background atmospheric burden.

    Peer review under responsibility of Turkish National Committee for Air Pollution Research and Control.

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