Canopy influence on trace metal atmospheric inputs on forest ecosystems: Speciation in throughfall

doi:10.1016/j.atmosenv.2009.11.028

Atmospheric Environment

Volume 44, Issue 6, February 2010, Pages 824-833

https://doi.org/10.1016/j.atmosenv.2009.11.028 Get rights and content

Abstract

Atmospheric inputs of selected Trace Metals (TM: Cd, Cu, Ni, Pb, Sb, Zn, as well as Al, Fe and Mn) were studied on six forested sites in France. In order to evaluate canopy interaction with atmospheric inputs, TM were measured in both Open Field Bulk Deposition (BD) and Throughfall (TF). Anthropogenic contribution to BD composition is high for Zn, Cd and Sb, reflecting actual TM emissions trends. Canopy greatly influences precipitation composition, through different processes, including assimilation and leaching by canopy, complexation as well as accumulation/dissolution of dry deposition. TM and Dissolved Organic Carbon (DOC) physical fractionation between colloidal and truly dissolved phases was performed with ultrafiltration. Al, Fe, Pb and Cu are found in the colloidal fraction whereas Cd, Ni, Zn and Sb are mostly in the truly dissolved fraction. Chemical speciation predicted with WHAM-VI shows that in throughfall, Al, Fe, Pb and Cu are almost entirely complexed by DOC, whereas Ni, Cd and Zn are present in average 30% in the free metal ion form. TM present in labile forms (Cd, Ni, Zn) interact with the canopy, are cycled in the ecosystem, and their concentration is either slightly increased or even decreased in throughfall. Sb, Pb and Cu concentration are increased through canopy, as a consequence of dry deposition accumulation.

Introduction

Atmosphere plays a key role in global metal cycles as it receives inputs from many sources and leads to metal dispersion at the Earth scale (Rauch and Pacyna, 2009). Trace Metal (TM: Cd, Cu, Ni, Pb, Sb and Zn) spreading in the atmosphere is induced by natural processes (Nriagu, 1989), as well as anthropogenic activity (Pacyna and Pacyna, 2001). They can be conveyed to long distances (Steinnes and Friedland, 2005) and impact remote ecosystems (Shotyk et al., 1996). Forest ecosystems are particularly sensitive to atmospheric inputs since forest canopy has a large interaction surface with the atmosphere (Leaf Area Index, LAI = 3 to 10 m² m⁻², Ulrich et al., 1995). Interactions between canopy and TM atmospheric inputs include accumulation of dry deposition, direct assimilation or release of elements by canopy (Lovett and Lindberg, 1984, Balestrini et al., 2007). Throughfall (TF) chemical composition thus results from all processes occurring in the phyllosphere. In order to study canopy influence on atmospheric inputs, a study of open field Bulk Deposition (BD) and TF is usually performed (Lindberg et al., 1986, Probst et al., 1992, Balestrini et al., 1998, Neal, 2002, Rodrigo et al., 2003, Hou et al., 2005b). TM dynamics in throughfall has also been considered in a few studies (Petty and Lindberg, 1990, Nieminen et al., 1999, Rodrigo et al., 2003, Hou et al., 2005b, Itoh et al., 2006). A high influence of forest canopy is generally observed with element specific dynamics since they are not all enriched through forest cover. Indeed, TM environmental pathways, availability and transport or immobilization in the ecosystem compartments, are directly linked to their speciation (Cheng et al., 1994) and to their potential role for the biosphere. While some of the studied trace elements are micronutrients (Zn, Cu, Ni), others (Cd, Sb, Pb) have no known biological role (Peralta-Videa et al., 2009). Only few studies (Hou et al., 2005a, Casartelli et al., 2006) have dealt with TM speciation in throughfall, although it provides useful information on canopy processes. Complexing capacity of DOC to Cu and some other TM (Bi, Sn, Ag) was proved, highlighting the conveying role of DOC for some metals below canopy. However, no study of throughfall speciation (including modeling and physical partitioning approaches) in temperate climate forest ecosystems has already been performed for the elements we propose to study (Cd, Cu, Ni, Pb, Sb and Zn).

The objectives of the study are to:

(i)
determine TM concentrations in open field Bulk Deposition and Throughfall in six French forest sites,
(ii)
determine TM and DOC physical fractionation between colloidal and truly dissolved phase in throughfall,
(iii)
model TM speciation in all physical fractions,
(iv)
evaluate the main processes controlling metal behavior after interaction with forest canopy.

Section snippets

Studied sites

The study sites (Table 1, Fig. 1) belong to the French RENECOFOR network (Réseau National de suivi à long terme des Ecosystèmes Forestiers, i.e. National Network for the long term Monitoring of Forest Ecosystem), managed by the ONF (Office National des Forêts, i.e. National Forest Board). These sites are part of the European network ICP Forest (level II). They have been chosen because they are representative of a large variety of French forest ecosystems: four main types of soils (podzol,

TM concentrations in bulk open field precipitation and throughfall

Summary information on rainfall amount, as well as pH, DOC, major (Al, Mn and Fe) and trace elements' concentrations is presented in Table 2.

Rainfall amount was modified through the canopy (Viville et al., 1993). Interception represented 20–50% of the rainfall amount for the studied sites, which corresponds to the average value for temperate French forests (Ulrich et al., 1995). BD was slightly acidic (mean pH is 4.3 ± 0.5) and through the canopy, mean precipitation pH slightly increased (mean pH

DOC origin and composition in throughfall

DOC concentration measured in TF is always higher than DOC concentration in BD (Fillion-Guigues et al., 1999, Peichl et al., 2007). Organic carbon in throughfall comes from foliar leaching (Qualls et al., 2000), microbiological as well as herbivore activity in the phyllosphere (Michalzik and Stadler, 2005). In throughfall, DOC concentration is mainly related to rainfall amount and phytophagous insect activity (Kindlmann and Stadler, 2004).

In this study, no influence of tree species on DOC

Conclusion

This study of trace metal deposition in open field bulk deposition and its interaction with forest cover provides new results on present-day trace metal atmospheric pollution in forest ecosystems. French forest ecosystems undergo anthropogenic inputs of TM. Throughfall composition is highly influenced by forest cover. TM concentrations and fluxes are modified in relation to their chemical properties and role for the biosphere. In throughfall, Mn, Sb, Cd, Zn and Ni are mainly found in the truly

Acknowledgements

This project benefited from a financial support by ADEME (French Agency for Environment) and received logistic support from the ONF (French Forest board). The authors warmly thank the ONF staff (Vincent Borthelle, Jean-Pierre Chassagne, Joël Clamart, Gilles Fournel, Jean-Luc Fiol, René Gregoire, Alain Jacquemard, François Mouchot, Florence Pertile, Pierre Trithardt, Jérôme Vany) for great help during field work, Marc Lanier (ONF), Gaël Durbe and Alain Alric (EcoLab, Université de Toulouse,

References (49)

R. Balestrini et al.
Study on throughfall deposition in two north Italian forest sites (Valtellina, Lombardy)
Chemosphere
(1998)
R. Balestrini et al.
Dry deposition of particles and canopy exchange: comparison of wet, bulk and throughfall deposition at five forest sites in Italy
Atmospheric Environment
(2007)
D.A. Burns et al.
Changes in stream chemistry and biology in response to reduced levels of acid deposition during 1987–2003 in the Neversink River Basin, Catskill Mountains
Ecological Indicators
(2008)
J. Cheng et al.
Chemical speciation of Cu, Zn, Pb and Cd in rain water
Analytica Chimica Acta
(1994)
D.M. Cooper et al.
Response of acid lakes in the UK to reductions in atmospheric deposition of sulfur
The Science of the Total Environment
(2003)
M. Filella et al.
Antimony in the environment: a review focused on natural waters: I. Occurrence
Earth-Science Reviews
(2002)
N. Fillion et al.
Natural organic matter contribution to throughfall acidity in French forests
Environment International
(1998)
J. Galloway et al.
Trace metal in atmospheric deposition: a review and assessment
Atmospheric Environment
(1982)
H. Hou et al.
Trace metals in bulk precipitation and throughfall in a suburban area of Japan
Atmospheric Environment
(2005)
P. Kindlmann et al.
Temporal fluctuations in throughfall carbon concentrations in a spruce forest
Ecological Modelling
(2004)

B. Michalzik et al.

Importance of canopy herbivores to dissolved and particulate organic matter fluxes to the forest floor

Geoderma

(2005)

C. Neal

Interception and attenuation of atmospheric pollution in a lowland ash forested site, Old Pond Close, Northamptonshire, UK

The Science of the Total Environment

(2002)

M. Pédrot et al.

Insights into colloid-mediated trace element release at the soil/water interface

Journal of Colloid and Interface Science

(2008)

J.R. Peralta-Videa et al.

The biochemistry of environmental heavy metal uptake by plants: implications for the food chain

The International Journal of Biochemistry & Cell Biology

(2009)

L. Poissant et al.

Trace inorganic elements in rainfall in the Montreal Island

Atmospheric Environment

(1994)

O. Pokrovsky et al.

Trace element fractionation and transport in boreal rivers and soil porewaters of permafrost-dominated basaltic terrain in Central Siberia

Geochimica et Cosmochimica Acta

(2006)

O. Pourret et al.

Competition between humic acid and carbonates for rare earth elements complexation

Journal of Colloid and Interface Science

(2007)

A. Rodrigo et al.

The chemistry of precipitation, throughfall and stemflow in two holm oak (Quercus ilex L.) forests under a contrasted pollution environment in NE Spain

The Science of the Total Environment

(2003)

W. Shotyk et al.

Two thousand years of atmospheric arsenic, antimony, and lead deposition recorded in an ombrotrophic peat bog profile, Jura Mountains, Switzerland

Earth and Planetary Science Letters

(1996)

E. Tipping et al.

The solid-solution partitioning of heavy metals (Cu, Zn, Cd, Pb) in upland soils of England and Wales

Environmental Pollution

(2003)

D. Viville et al.

Interception in a mountainous declining spruce stand in the Strengbach catchment (Vosges, France)

Journal of Hydrology

(1993)

M.R. Casartelli et al.

Study of metal-complexed organic matter in throughfall by gel filtration and atomic absorption spectrometry

Fresenius Environmental Bulletin

(2006)

H.J.W. De Baar et al.

Trace metals in the oceans: evolution, biology and global change

Marine Science Frontiers for Europe

(2003)

R. Duce et al.

Atmospheric trace metal at remote northern and southern hemisphere sites – pollution or natural?

Science

(1975)

Cited by (66)

Evaluating the effect of moss functional traits and sampling on elemental concentrations in Pleurozium schreberi and Ptilium crista-castrensis in Eastern Canada (Québec) black spruce forest
2024, Science of the Total Environment
Characterizing atmospheric depositions allows evaluating the impact of air pollution on ecosystems, human health, and the economy. It also informs decision-makers about the implementation of regulations improving environmental quality. Biomonitoring uses organisms, such as mosses, as proxies to assess the presence of atmospheric contaminants (e.g., metals). This approach is cost-efficient and does not require complicated infrastructure or scientific skills, making it suitable for large-scale monitoring initiatives and citizen-based campaigns. Therefore, precise sampling protocols are needed to limit bias. Biomonitoring data remains scarce in North America, compared to e.g., Europe, and there is a need to develop large-scale and long-term biomonitoring initiatives to record current and future atmospheric depositions. As there is no standardized international sampling protocol, this study assessed the impact of parameters known to affect the elemental concentration of mosses, using samples collected along a 1000-km transect in Eastern Canada (Quebec) from 2016 to 2022. We specifically examined the effects of species, stem color, canopy opening, time of sampling, and stem length on 18 elements. Non-parametric statistical tests indicate that these factors have significant effects on some metals, but differences are generally low (<30 %), except for stem length. These results suggest that sampling protocols can be flexible in terms of species, canopy opening, time of sampling, and stem color. However, normalizing the length of the stems analyzed is required to account for differences in growth rates between sites. Moreover, since no large-scale biomonitoring campaign using mosses has been conducted in Eastern Canada, this paper also provides the first elemental baseline for moss in the region.
Coupling of redundancy analysis with geochemistry and mineralogy to assess the behavior of dust arsenic as a base of risk estimation in Dhaka, Bangladesh
2022, Chemosphere
Citation Excerpt :
Therefore, As would have short residence time and tend to mobilize with increasing pH. The increase of As mobility at pH greater than 8.0 has been reported in a previous study (Xu et al., 2013). Organic matter is also an important factor in regulating the mobility of As in soil and dust environments (Gandois et al., 2010). The complexation of oxyanions with organic ligands may enhance their sorption and coprecipitation with solid inorganic phases (Adriano, 2001; Tang et al., 2014).
Exposure to dust particles enriched with arsenic (As) is a significant health threat for populations living in Southeast Asian megacities. The mineralogical composition of dust particles is the key factor that controls the retention and release of As. This study investigated the degree of metal(oid)s pollution (As, Ca, Fe, K, Ga, Rb, Sr, Ti, V, Y, and Zr) in road dust of Dhaka city, Bangladesh. Enrichment factor and geoaccumulation index suggested that the road dust was heavily enriched with As, which triggers a comprehensive investigation of its controlling mechanisms and potential health risks by combining physicochemical and mineralogical information with multivariate analysis and a simulated probabilistic risk estimation model. Alkaline road dust (pH_1:5 ranges from 8.02 to 10.34) in Dhaka city was found to have significant enrichment of As. Dust alkalinity was possibly controlled by the presence of carbonate minerals, such as calcite. Quartz was identified as the dominant mineral phase followed by magnesium carbon arsenide (MgCAs₂). Carbonate mineral driven alkaline pH conditions in road dust would potentially trigger the release and mobilization of As to the environment. However, organic complexation can stabilize As on particle surfaces. Monte Carlo simulation-based health risk forecast suggested that the probability of As associated cancer risk has greatly exceeded the threshold value of 1E-4 for adults and children, and children are more vulnerable than adults. According to sensitivity analysis, the concentration of As and exposure duration (ED) posed the most significant impact (>58%) on risk estimation.
Terrain-modulated deposition of atmospheric lead in the soils of alpine forest, central China
2021, Science of the Total Environment
Alpine ecosystem has a potential to intercept the transport of atmospheric metals, while the regulation mechanisms with variations in altitude and slope direction remain unclear. In this study, the soil and moss samples on the northern and southern slopes of Shennongjia Mountain were collected with altitude to quantitatively identify the sources of lead (Pb) and to decipher the regulation mechanisms of altitude and slope on the Pb distribution. The results showed that the concentrations of Pb decreased evidently with soil depth, and in the O (organic soils) and A (surface mineral soils) horizons they increased with altitude. The Pb isotopes and moss biomonitoring revealed that Pb was mainly from atmospheric deposition, and the sources included fossil fuel combustion, ore mining and smelting. Based on a binary mixing model of Pb isotopes, the percentage of atmospheric Pb in the O and A horizons and mosses averaged 58.8%, 43.7% and 71.0%, respectively. Atmospheric wet deposition strikingly controlled the distribution of soil Pb along the altitude. Canopy filtering and leaching also impacted the accumulation of Pb in the forest floor. The significant difference in the atmospheric Pb accumulation in the soils between the two slopes was not observed as expected, since atmospheric dry deposition from northwestern China contributed to the Pb accumulation on the northern slope according to the Pb isotopic ratios and air mass trajectories. The results of this study indicate that altitude determines the distribution pattern of atmospheric Pb, while slope direction screens the source region of Pb in alpine ecosystems.
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
2021, Atmospheric Pollution Research
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.
Atmospheric iodine, selenium and caesium depositions in France: II. Influence of forest canopies
2021, Chemosphere
Estimation of the canopy influence on atmospheric inputs of iodine (I), selenium (Se) and caesium (Cs) in terrestrial ecosystems is an essential condition for appropriate biogeochemical models. However, the processes involved in rain composition modifications after its passage through forest canopy have been barely studied for these elements. We monitored I, Se and Cs concentrations in both rainfall and throughfall of fourteen French forested sites throughout one year, and estimated dry deposition and canopy exchange fluxes for these elements, as well as speciation of I and Se. Comparison of rainfall and throughfall elemental composition highlighted an important impact of forest canopy on both (i) concentrations and fluxes of I, Se and Cs, and (ii) I and Se species. For the three elements, most of their throughfall concentrations were higher than corresponding rainfall. The increase of throughfall elemental fluxes was mostly due to dry deposition for I and Se although the canopy exchange model revealed some sorption within the canopy in most cases; for Cs, foliage leaching was most influencing. Regarding speciation, iodine species in rainfall were highly modified by forest canopy with an important increase of unidentified I proportion in throughfall (on average 49 and 82% in rainfall and throughfall, respectively), possibly due to washoff of dry deposition and/or to transformation into organic forms. Similarly, while rainfall was composed of 26–54% of inorganic Se, inorganic species were undetectable in throughfall. This dataset represents key information to improve modelling of I, Se and Cs cycling within forest ecosystems.
Groundwater controls on colloidal transport in forest stream waters
2020, Science of the Total Environment
Citation Excerpt :
They assigned an important role to local atmospheric emissions for the composition of rainwater particles, whereas dry deposition and canopy leaching modified the chemical composition of particles carried by throughfall. Gandois et al. (2010) additionally reported that complexation with organic matter promoted formation and dissolution of colloids in throughfall; specifically Al, Fe and Pb were found associated to org C. Yet, Gandois et al. (2010) restricted their analysis to bulk deposition and throughfall samples collected weekly over one year and, therefore, could not compare their data to soil, stream or groundwater of the same catchment. In contrast to precipitation waters, NNP and colloids dispersed or leached from soil are usually substantially higher concentrated and likely exhibit a more diverse elemental composition.
Biogeochemical changes of whole catchments may, at least in part, be deduced from changes in stream water composition. We hypothesized that there are seasonal variations of natural nanoparticles (NNP; 1–100 nm) and fine colloids (<300 nm) in stream water, which differ in origin depending on catchment inflow parameters. To test this hypothesis, we assessed the annual dynamics of the elemental composition of NNP and fine colloids in multiple water compartments, namely in stream water, above and below canopy precipitation, groundwater and lateral subsurface flow from the Conventwald catchment, Germany. In doing so, we monitored meteorological and hydrological parameters, total element loads, and analyzed element concentrations of org C, Al, Si, P, Ca, Mn and Fe by Asymmetric Flow Field Flow Fractionation (AF⁴). The results showed that colloid element concentrations were < 5 µmol/L. Up to an average of 55% (Fe) of total element concentrations were not truly dissolved but bound to NNP and fine colloids. The colloid patterns showed seasonal variability with highest loads in winter. The presence of groundwater-derived colloidal Ca in stream water showed that groundwater mainly fed the streams throughout the whole year. Overall, the results showed that different water compartments vary in the NNP and fine colloidal composition making them a suitable tool to identify the streams NNP and fine colloid sources. Given the completeness of the dataset with respect to NNP and fine colloids in multiple water compartments of a single forest watershed this study adds to the hitherto underexplored role of NNP and fine colloids in natural forest watersheds.

View all citing articles on Scopus

View full text

Canopy influence on trace metal atmospheric inputs on forest ecosystems: Speciation in throughfall

Abstract

Introduction

Section snippets

Studied sites

TM concentrations in bulk open field precipitation and throughfall

DOC origin and composition in throughfall

Conclusion

Acknowledgements

Chemosphere

Atmospheric Environment

Ecological Indicators

Analytica Chimica Acta

The Science of the Total Environment

Earth-Science Reviews

Environment International

Atmospheric Environment

Atmospheric Environment

Ecological Modelling

Geoderma

The Science of the Total Environment

Journal of Colloid and Interface Science

The International Journal of Biochemistry & Cell Biology

Atmospheric Environment

Geochimica et Cosmochimica Acta

Journal of Colloid and Interface Science

The Science of the Total Environment

Earth and Planetary Science Letters

Environmental Pollution

Journal of Hydrology

Study of metal-complexed organic matter in throughfall by gel filtration and atomic absorption spectrometry

Fresenius Environmental Bulletin

Trace metals in the oceans: evolution, biology and global change

Marine Science Frontiers for Europe

Atmospheric trace metal at remote northern and southern hemisphere sites – pollution or natural?

Science