Long-term effects of changing atmospheric pollution on throughfall, bulk deposition and streamwaters in a Mediterranean forest

Aguillaume L., Rodrigo A., Avila A. (2016) Long-term effects of changing atmospheric pollution on throughfall, bulk deposition and streamwaters in a Mediterranean forest. Science of the Total Environment. 544: 919-928.
Link
Doi: 10.1016/j.scitotenv.2015.12.017

Abstract:

The abatement programs implanted in Europe to reduce SO2, NO2 and NH3 emissions are here evaluated by analyzing the relationships between emissions in Spain and neighboring countries and atmospheric deposition in a Mediterranean forest in the Montseny mountains (NE Spain) for the last 3decades. A canopy budget model was applied to throughfall data measured during a period of high emissions (1995-1996) and a period of lower emissions (2011-2013) to estimate the changes in dry deposition over this time span.Emissions of SO2 in Spain strongly decreased (77%) and that was reflected in reductions for nssSO4 2- in precipitation (65% for concentrations and 62% for SO4 2-S deposition). A lower decline was found for dry deposition (29%).Spanish NO2 emissions increased from 1980 to 1991, remained constant until 2005, and decreased thereafter, a pattern that was paralleled by NO3 - concentrations in bulk precipitation at Montseny. This pattern seems to be related to a higher share of renewable energies in electricity generation in Spain in recent years. However, dry deposition increased markedly between 1995 and 2012, from 1.3 to 6.7kgha-1year- 1. Differences in meteorology between periods may have had a role, since the recent period was drier thus probably favoring dry deposition.Spanish NH3 emissions increased by 13% between 1980 and 2012 in Spain but NH4 + concentrations in precipitation and NH4 +-N deposition showed a decreasing trend (15% reduction) at Montseny, probably linked to the reduction ammonium sulfate and nitrate aerosols to be scavenged by rainfall. NH4 +-N dry deposition was similar between the compared periods.The N load at Montseny (15-17kgha-1year-1) was within the critical load range proposed for Mediterranean sclerophyllous forests (15-17.5kgha-1year-1). The onset of N saturation is suggested by the observed increasing N export in streamwaters. © 2015 Elsevier B.V.

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Atmospheric deposition of inorganic nitrogen in Spanish forests of Quercus ilex measured with ion-exchange resins and conventional collectors

García-Gomez, H., Izquieta-Rojano, S., Aguillaume, L., González-Fernández, I., Valiño, F., Elustondo, D., Santamaría, J.M., Àvila, A., Fenn, M.E., Alonso, R. (2016) Atmospheric deposition of inorganic nitrogen in Spanish forests of Quercus ilex measured with ion-exchange resins and conventional collectors. Environmental Pollution. 216: 653-661.
Link
Doi: 10.1016/j.envpol.2016.06.027

Abstract:

Atmospheric pollutants in peri-urban forests of Quercus ilex: evidence of pollution abatement and threats for vegetation

García-Gómez H., Aguillaume L., Izquieta-Rojano S., Valiño F., Àvila A., Elustondo D., Santamaría J.M., Alastuey A., Calvete-Sogo H., González-Fernández I., Alonso R. (2016) Atmospheric pollutants in peri-urban forests of Quercus ilex: evidence of pollution abatement and threats for vegetation. Environmental Science and Pollution Research. 23: 6400-6413.
Link
Doi: 10.1007/s11356-015-5862-z

Abstract:

Peri-urban vegetation is generally accepted as a significant remover of atmospheric pollutants, but it could also be threatened by these compounds, with origin in both urban and non-urban areas. To characterize the seasonal and geographical variation of pollutant concentrations and to improve the empirical understanding of the influence of Mediterranean broadleaf evergreen forests on air quality, four forests of Quercus ilex (three peri-urban and one remote) were monitored in different areas in Spain. Concentrations of nitrogen dioxide (NO2), ammonia (NH3), nitric acid (HNO3) and ozone (O3) were measured during 2 years in open areas and inside the forests and aerosols (PM10) were monitored in open areas during 1 year. Ozone was the only air pollutant expected to have direct phytotoxic effects on vegetation according to current thresholds for the protection of vegetation. The concentrations of N compounds were not high enough to directly affect vegetation but could be contributing through atmospheric N deposition to the eutrophization of these ecosystems. Peri-urban forests of Q. ilex showed a significant below-canopy reduction of gaseous concentrations (particularly NH3, with a mean reduction of 29–38 %), which indicated the feasibility of these forests to provide an ecosystem service of air quality improvement. Well-designed monitoring programs are needed to further investigate air quality improvement by peri-urban ecosystems while assessing the threat that air pollution can pose to vegetation. © 2015, Springer-Verlag Berlin Heidelberg.

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Throughfall and bulk deposition of dissolved organic nitrogen to holm oak forests in the Iberian Peninsula: Flux estimation and identification of potential sources

Izquieta-Rojano S., García-Gomez H., Aguillaume L., Santamaría J.M., Tang Y.S., Santamaría C., Valiño F., Lasheras E., Alonso R., Àvila A., Cape J.N., Elustondo D. (2016) Throughfall and bulk deposition of dissolved organic nitrogen to holm oak forests in the Iberian Peninsula: Flux estimation and identification of potential sources. Environmental Pollution. 210: 104-112.
Link
Doi: 10.1016/j.envpol.2015.12.002

Abstract:

Deposition of dissolved organic nitrogen (DON) in both bulk precipitation (BD) and canopy throughfall (TF) has been measured for the first time in the western Mediterranean. The study was carried out over a year from 2012 to 2013 at four evergreen holm oak forests located in the Iberian Peninsula: Two sites in the Province of Barcelona (Northeastern Spain), one in the Province of Madrid (central Spain) and the fourth in the Province of Navarra (Northern Spain). In BD the annual volume weighted mean (VWM) concentration of DON ranged from 0.25 mg l-1 in Madrid to 1.14 mg l-1 in Navarra, whereas in TF it ranged from 0.93 mg l-1 in Barcelona to 1.98 mg l-1 in Madrid. The contribution of DON to total nitrogen deposition varied from 34% to 56% in BD in Barcelona and Navarra respectively, and from 38% in Barcelona to 72% in Madrid in TF. Agricultural activities and pollutants generated in metropolitan areas were identified as potential anthropogenic sources of DON at the study sites. Moreover, canopy uptake of DON in Navarra was found in spring and autumn, showing that organic nitrogen may be a supplementary nutrient for Mediterranean forests, assuming that a portion of the nitrogen taken up is assimilated during biologically active periods. © 2015 Elsevier Ltd. All rights reserved.

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