Nuestros investigadores

David Elustondo Valencia

Publicaciones científicas más recientes (desde 2010)

Autores: Morera Gomez, Yasser (Autor de correspondencia); Alonso-Hernandez, C. M.; Santamaría Ulecia, Jesús Miguel; et al.
ISSN 0944-1344  Vol. 27  Nº 2  2020  págs. 2184 - 2193
Road dust is an indicator widely used when monitoring contamination and evaluating environmental and health risks in urban ecosystems. We conducted an exhaustive characterization of road dust samples coupling their chemical characteristics and stable isotope compositions (C and N) with the aim of evaluating the levels and spatial distribution of local contamination as well as to identify its main source(s) in the coastal city of Cienfuegos (Cuba). Results indicate that the concentrations of several elements(total nitrogen, S, Ca, V, Cu, Zn, Mo, Sn, Hg, and Pb) exceed the background values reported for both Cuban soils and the upper continental crust (UCC) and showed high variability among the sampling sites. We show that road dust contamination in Cienfuegos induces high associated ecological risks. Among the studied elements, Cd and Hg are the major contributors to environmental contamination in the city, mainly along busy roads and downtown.¿13Cand¿15N, coupled to a multivariate statistical analysis, help associate the studied elements to several local sources of contamination: mineral matter derived from local soils, cement plant and related activities, road pavement alteration, power plant, road traffic, and resuspension of particulate organic matter (POM). Our results suggest that incorporating the chemical and isotope monitoring of road dust may help implement more effective environmental management measures in order to reduce their adverse impact on ecosystems.
Autores: Morera Gomez, Yasser (Autor de correspondencia); Alonso-Hernandez, C. M.; Widory, D.; et al.
ISSN 1309-1042  Vol. 11  Nº 7  2020  págs. 1091 - 1098
This study investigates the contents, distribution patterns, and sources of lanthanoid elements (La to Lu) in aerosols with an aerodynamic diameter <= 10 mu m (PM10) in a coastal Caribbean region in order to better constrain the origin of the atmospheric PM contamination. We sampled and analysed PM10 aerosols during 2015 simultaneously at a rural and an urban site in Cienfuegos (Cuba) as well as particles samples from regional contamination sources. Results showed that the sum of the studied lanthanoids concentrations ranged from 0.03 to 13.42 ng m(-3) and from 0.51 to 18.75 ng m(-3) at the rural and the urban site, respectively. Time variations for the lanthanoid concentrations displayed similar trends and showed that the highest concentrations corresponded to the influence of the African dust for both sites, but presented distinct variability and lower concentrations when dust intrusions were less frequent. The lanthanoid distribution patterns in the rural and urban sites were significantly different, due to the impact of different local combustion sources. Our results were comforted by comparing the degree of fractionation of the lighter and heavier lanthanoids and the delta Eu and delta Ce anomalies between our PM10 samples and those of the local sources of contamination. Ultimately, we highlight the added value of lanthanoid elements as reliable indicators for discriminating emission sources and for tracking the origin of atmospheric particulate matter.
Autores: Morera Gomez, Yasser (Autor de correspondencia); Alonso-Hernandez, C. M. ; Cartas-Aguila, H. A.; et al.
ISSN 0169-8095  Vol. 243  2020  págs. 105038
In this study, PM10 aerosol samples were collected at 4 urban and 1 rural sites in the region of Cienfuegos (Cuba) and analyzed for their chemical compositions (total carbon (TC), total nitrogen (TN), NH4+, Cl-, NO3- and SO42-) and their stable carbon (delta C-13) and nitrogen (delta N-15), and radioactive (Pb-210, Be-7, Cs-137 and K-40) isotope systematics, in order to better constrain both their sources of pollution and their atmospheric dynamics. The average PMic, concentrations varied from 21.67 +/- 8.54 mu g.m(-3) at the rural site to 39.01 +/- 8.23 mu g m(-3) at an urban site characterized by high road traffic. Chemical compositions showed low variability and similar abundances of the ionic species, but we observed strong correlations between i) NH4+ and SO42- that indicates the formation of secondary ammonium bisulfate (NH4HSO4), and ii) between PM10, and TC highlighting the significant influence of carbonaceous aerosols. We are reporting here the first Pb-210 aerosol concentrations in this region and demonstrate that, coupled with the corresponding Be-7 concentrations, they allow characterizing the dynamics of the regional continental air masses. delta C-13 values in PM10, appear to be controlled by i) emissions from different types of combustion sources, including fossil fuel and biomass burning and ii) carbonate inputs from the industrial activities located around the limestone quarries, east of the city.
Autores: Morera Gomez, Yasser (Autor de correspondencia); Santamaría Ulecia, Jesús Miguel; Elustondo Valencia, David; et al.
ISSN 1352-2310  Vol. 202  2019  págs. 93 - 104
Atmospheric deposition is considered to be the major pathway by which substances from the atmosphere enter to the terrestrial and aquatic ecosystems. This study constitutes the first exhaustive report on trace metal deposition in Cuba and is aimed to determine the monthly atmospheric flux of 47 major and trace elements in a Caribbean coastal site and investigate the main sources contributing to deposition.
Autores: Vedia Jiménez, Iván; Almeida, D.; Rodeles, A. A.; et al.
Revista: WATER
ISSN 2073-4441  Vol. 11  Nº 3  2019  págs. 1 - 17
The signal crayfish Pacifastacus leniusculus Dana, 1852 is a successful invasive species in the Iberian Peninsula. This is of particular conservation concern, as fish fauna is highly endemic and also threatened within this ecoregion. The aim of this study was to analyze behavioral interactions and trophic overlap between signal crayfish and native fishes in Iberian rivers (northern Spain). Video cameras were used to record fish "dominance/evasion" after spatial encounters with crayfish. Diet composition and isotopic signatures (¿13C and ¿15N) were compared to evaluate the niche overlap. Fish were dominant in 25% of the encounters with juvenile crayfish, whereas this percentage was only 4% with adult crayfish. Observations showed a high fish "evasion" response for Pyrenean stone loach Barbatula quignardi (B¿cescu-Me¿ter, 1967) (>30%). Dietary results showed a high trophic overlap between signal crayfish with the pelagic Pyrenean minnow Phoxinus bigerri Kottelat, 2007 and the benthic loach. However, the isotopic niche overlap was low, with brown trout Salmo trutta L., 1758 showing the highest area (only 0.1 ¿2). Overall, our findings suggest that interferences may occur with native species for food (i.e., benthic invertebrates). Consequently, measures should be applied to control invasive crayfish in Iberian rivers.
Autores: Ciganda, V. S., (Autor de correspondencia); López Aizpún, María; Repullo, M. A.; et al.
ISSN 1436-8730  Vol. 182  Nº 1  2019  págs. 40 - 47
In grassland systems, cattle and sheep urine patches are recognized as nitrous oxide (N2O) emission hot spots due to the high urinary nitrogen (N) concentrations. Hippuric acid (HA) is one of the constituents of ruminant urine that has been reported as a natural inhibitor of soil N2O emissions. The aim of this study was to examine the potential for elevated ruminant urine HA concentrations to reduce N2O emissions, in situ, on an acidic heavy clay soil under poorly drained conditions (WFPS > 85%). A randomized complete block design experiment with three replications and four treatments was conducted using the closed-static-flux chamber methodology. The four treatments were applied inside the chambers: control with no artificial urine application (C), control artificial urine (U), and enriched artificial urine with two rates of HA (55.8 and 90mM, U+HA1, U+HA2). Soil inorganic-N, soil dissolved organic carbon (DOC), soil pH as well as N2O and methane (CH4) fluxes were monitored over a 79-d period. Although N2O emissions were not affected by the HA enriched urine treatments, U+HA2 positively affected the retention of N as NH4+ until day 3, when the soil pH dropped to values < 5. Subsequently, as a consequence of rainfall events and soil acidification, it is likely that leaching or sorption onto clay reduced the efficacy of HA, masking any treatment differential effect on N2O emissions. Moreover, CH4 fluxes as well as DOC results reflected the soil anaerobic conditions which did not favour nitrification processes. Further research is needed to determine the fate of HA into the soil which might clarify the lack of an in situ effect of this compound.
Autores: Santiago, J. L., (Autor de correspondencia); Buccolieri, R.; Rivas, E.; et al.
ISSN 2210-6707  Vol. 48  Nº 101559  2019  págs. 1 - 18
With the objective of reducing population exposure, vegetation barriers composed by hedges and/or trees are usually located near roads to protect pedestrians from traffic-related pollutants. The main objective of this study is to quantify the effectiveness of this type of barriers. Black Carbon (BC) is used an indicator of the effectiveness of vegetation barrier and its concentration reduction behind the barrier is studied. Computational Fluid Dynamics (CFD) modelling, previously validated against BC experimental data across a vegetation barrier located in an avenue of Pamplona (Spain), is applied to simulate different barrier configurations. Additionally, the contribution of each vegetation effect (aerodynamic and deposition) on this reduction, as well as its sensitivity to different deposition velocities, are investigated. Results show barriers with hedge and trees are effective to locally reduce BC concentrations and suggest that the presence of trees is more crucial in reducing concentration rather than the hedge size or density. At 15 m from road in the presence of a row of trees and a 2 m-height and 2 m-width hedge the average concentration reduction percentage ranges between 45% and 66% (depending on deposition velocity) with respect to the case without vegetation barrier.
Autores: Morera Gomez, Yasser (Autor de correspondencia); Santamaría Ulecia, Jesús Miguel; Elustondo Valencia, David; et al.
ISSN 0048-9697  Vol. 642  2018  págs. 723 - 732
The constant increase of anthropogenic emissions of aerosols, usually resulting from a complex mixture from various sources, leads to a deterioration of the ambient air quality. The stable isotope compositions (delta C-13 and delta N-15) of total carbon (TC) and nitrogen (TN) in both PM10 and emissions from potential sources were investigated for first time in a rural and an urban Caribbean costal sites in Cuba to better constrain the origin of the contamination. Emissions from road traffic, power plant and shipping emissions were discriminated by coupling their C and N contents and corresponding isotope signatures. Other sources (soil, road dust and cement plant), in contrast, presented large overlapping ranges for both C and N isotope compositions. delta C-13(PM10) isotope compositions in the rural (average of -25.4 +/- 1.2 parts per thousand) and urban (average of -24.8 +/- 1.2 parts per thousand) sites were interpreted as a mixture of contributions from two main contributors: i) fossil fuel combustion and ii) cement plant and quarries. Results also showed that this last source is impacting more air quality at the urban site. A strong influence from local wood burning was also identified at the rural site. These conclusions were comforted by a statistical analysis using a conditional bivariate probability function. TN and delta N-15 values from the urban site demonstrated that nitrogen in PM10 was generated by secondary processes through the formation of (NH4)(2)SO4.
Autores: García-Gómez, H.; Izquieta Rojano, Sheila; Aguillaume, L.; et al.
ISSN 0269-7491  Vol. 243  Nº Part A  2018  págs. 427 - 436
In Mediterranean areas, dry deposition is a major component of the total atmospheric N input to natural habitats, particularly to forest ecosystems. An innovative approach, combining the empirical inferential method (EIM) for surface deposition of NO3- and NH4+ with stomatal uptake of NH3, HNO3 and NO2 derived from the DO3SE (Deposition of Ozone and Stomatal Exchange) model, was used to estimate total dry deposition of inorganic N air pollutants in four holm oak forests under Mediterranean conditions in Spain. The estimated total deposition varied among the sites and matched the geographical patterns previously found in model estimates: higher deposition was determined at the northern site (28.9 kg N ha-1 year-1) and at the northeastern sites (17.8 and 12.5 kg N ha-1 year-1) than at the central-Spain site (9.4 kg N ha-1 year-1). On average, the estimated dry deposition of atmospheric N represented 77% ± 2% of the total deposition of N, of which surface deposition of gaseous and particulate atmospheric N averaged 10.0 ± 2.9 kg N ha-1 year-1 for the four sites (58% of the total deposition), and stomatal deposition of N gases averaged 3.3 ± 0.8 kg N ha-1 year-1 (19% of the total deposition). Deposition of atmospheric inorganic N was dominated by the surface deposition of oxidized N in all the forests (means of 54% and 42% of the dry and total deposition, respectively).
Autores: Morera Gomez, Yasser; Elustondo Valencia, David; Lasheras Adot, María Esther; et al.
ISSN 1352-2310  Vol. 192  2018  págs. 182 - 192
The deterioration of the air quality is a global concern. Daily PM10 samples were simultaneously collected and chemically characterized at an urban and a rural site in Cienfuegos, Cuba between January 2015 and January 2016. A source apportionment study was conducted in order to identify and quantify the main contributions of both local and long-range sources. Concentrations of PM10 varied similarly at the urban and rural site, with annual averages of 35.4 and 24.8 ug m-3, respectively. The highest concentrations were observed between March and August at both sites, when a strong influence of Saharan dust was identified. The PM10 daily limit (50 ug m-3) established in the Cuban legislation for air quality was exceeded by 3 and 8 times in the rural and urban site, respectively. The chemical characterization of PM10 showed important contributions of mineral matter, total carbon and secondary inorganic compounds in the region, with the highest concentrations observed at the urban site. Marine contribution, by contrast, was higher at the rural site. The highest EFs were obtained for the typical road traffic tracers Mo and Cu. Positive matrix factorization (PMF) analysis coupled with conditional bivariate probability function (CBPF) and concentration weighted trajectory (CWT) identified 5 main sources in the studied sites: Saharan intrusions, marine aerosol, combustion sources and secondary aerosols, road traffic and cement plant.
Autores: López Aizpún, María; Arango-Mora, C.; Santamaría Elola, Carolina; et al.
ISSN 0038-0717  Vol. 116  2018  págs. 378 - 387
The present work was carried out to assess the effect of atmospheric ammonia (NH3) on soil physicochemical properties, soil enzymatic activities (ß-glucosidase -ß-GLU-, nitrate reductase ¿NR-, urease ¿UR-, protease ¿PRO-, acid phosphatase ¿PHO-, dehydrogenase ¿DHA-), soil microbial biomass and soil respiration. The study was conducted along a NH3 gradient in a Q. pubescens Milld. forest in the vicinity of two livestock farms. Because of NHy (NHy: NH3 and NH4+) deposition, N saturation was detected up to 330 m from the farms. This excess of N led to a decrease in soil C:N and an increase in soil nitrification processes, which resulted in an accumulation of the heavy N isotope (15N) in the soil. N saturation was also reflected in the activity of NR enzyme, which was inhibited. On the other hand, while UR enzyme was inhibited close to the farms possibly due to the high amount of N-NH4+ resulting from the hydrolysis of NH3, PRO activity was stimulated by the presence of organic nitrogen compounds and the need of soil organisms to meet the C demand. In addition, the activity of PHO and ß-GLU enzymes was regulated by the relative amount of C and P that organisms need. Regarding biological variables, enhanced NH3 reduced soil microbial biomass and biomass respiratory efficiency. Finally, soil enzyme activities and soil microbial biomass have proved to be good biological indicators of soil quality.
Autores: Izquieta Rojano, Sheila; López Aizpún, María; Irigoyen Iparrea, Juan José; et al.
ISSN 0048-9697  Vol. 619-620  2018  págs. 883 - 895
Ammonia (NH3) emissions are linked to eutrophication, plant toxicity and ecosystem shifts from N to P limitation. Bryophytes are key components of terrestrial ecosystems, yet highly sensitive to N deposition. Hence, physiological responses of mosses may be indicative of NH3-related impacts, and thus useful to foresee future ecosystem damages and establish atmospheric Critical Levels (CLEs). In this work, samples of Hypnum cupressiforme Hedw. were seasonally collected along a well-defined NH3 concentration gradient in an oak woodland during a one-year period. We performed a comprehensive evaluation of tissue chemistry, stoichiometry, metabolic enzymes, antioxidant response, membrane damages, photosynthetic pigments, soluble protein content and N and C isotopic fractionation. Our results showed that all the physiological parameters studied (except P, K, Ca and C) responded to the NH3 gradient in predictable ways, although the magnitude and significance of the response were dependent on the sampling season, especially for enzymatic activities and pigments content. Nutritional imbalances, membrane damages and disturbance of cellular C and N metabolism were found as a consequence to NH3 exposure, being more affected the mosses more exposed to the barn atmosphere. These findings suggested significant implications of intensive farming for the correct functioning of oak woodlands and highlighted the importance of seasonal dynamics in the study of key physiological processes related to photosynthesis, mosses nutrition and responses to oxidative stress. Finally, tissue N showed the greatest potential for the identification of NH3-related ecological end points (estimated CLE = 3.5 mu g m(-3)), whereas highly scattered physiological responses, although highly sensitive, were not suitable to that end.
Autores: Ochoa-Hueso, R. , (Autor de correspondencia); Munzi, S. ; Alonso, R.; et al.
ISSN 0269-7491  Vol. 227  2017  págs. 194 - 206
Mediterranean Basin ecosystems, their unique biodiversity, and the key services they provide are currently at risk due to air pollution and climate change, yet only a limited number of isolated and geographically-restricted studies have addressed this topic, often with contrasting results. Particularities of air pollution in this region include high 03 levels due to high air temperatures and solar radiation, the stability of air masses, and dominance of dry over wet nitrogen deposition. Moreover, the unique abiotic and biotic factors (e.g., climate, vegetation type, relevance of Saharan dust inputs) modulating the response of Mediterranean ecosystems at various spatiotemporal scales make it difficult to understand, and thus predict, the consequences of human activities that cause air pollution in the Mediterranean Basin. Therefore, there is an urgent need to implement coordinated research and experimental platforms along with wider environmental monitoring networks in the region. In particular, a robust deposition monitoring network in conjunction with modelling estimates is crucial, possibly including a set of common biomonitors (ideally cryptogams, an important component of the Mediterranean vegetation), to help refine pollutant deposition maps. Additionally, increased attention must be paid to functional diversity measures in future air pollution and climate change studies to establish the necessary link between biodiversity and the provision of ecosystem services in Mediterranean ecosystems. Through a coordinated effort, the Mediterranean scientific community can fill the above-mentioned gaps and reach a greater understanding of the mechanisms underlying the combined effects of air pollution and climate change in the Mediterranean Basin. (c) 2017 Elsevier Ltd. All rights reserved.
Autores: Avila, A.; Aguillaume, L.; Izquieta Rojano, Sheila; et al.
ISSN 0944-1344  Vol. 24  Nº 34  2017  págs. 26213 - 26226
To assess the impact of nitrogen (N) pollutants on forest ecosystems, the role of the interactions in the canopy needs to be understood. A great number of studies have addressed this issue in heavily N-polluted regions in north and central Europe. Much less information is available for the Iberian Peninsula, and yet this region is home to mountain forests and alpine grasslands that may be at risk due to excessive N deposition. To establish the basis for ecology-based policies, there is a need to better understand the forest response to this atmospheric impact. To fill this gap, in this study, we measured N deposition (as bulk, wet, and throughfall fluxes of dissolved inorganic nitrogen) and air N gas concentrations from 2011 to 2013 at four Spanish holm oak (Quercus ilex) forests located in different pollution environments. One site was in an area of intensive agriculture, two sites were influenced by big cities (Madrid and Barcelona, respectively), and one site was in a rural mountain environment 40 km north of Barcelona. Wet deposition ranged between 0.54 and 3.8 kg N ha-1 year-1 for ammonium (NH4+)-N and between 0.65 and 2.1 kg N ha-1 year-1 for nitrate (NO3-)-N, with the lowest deposition at the Madrid site for both components. Dry deposition was evaluated with three different approaches: (1) a canopy budget model based in throughfall measurements, (2) a branch washing method, and (3) inferential calculations.
Autores: Rodríguez-Oroz, D. ; Lasheras Adot, María Esther; Elustondo Valencia, David; et al.
ISSN 0007-4861  Vol. 98  Nº 1  2017  págs. 91 - 96
The objective of the present work was to verify and compare the performance of different geochemical indices employed to identify the anthropogenic origin of selected heavy metals and other trace elements in soils. To that end, two background values, the upper continental crust and the metal content in the bed rock, were used and obtained from a forested basin of the western Pyrenees. The enrichment factor (EF), geo-accumulation index (I-geo), and contamination factor (C-i (f)) were finally evaluated for their ability to determine anthropogenic contamination: Results indicate that an in-depth knowledge of the bed rock geochemistry and the geological background content is essential to distinguish between the natural variability of soils and any anthropogenic contribution of heavy metals. Although both EF and C-i (f) show a similar ability to detect soil contamination, the latter is proposed as a more appropriate and sensitive marker given its ability for finding episodically elevated contamination levels.
Autores: Aguillaume, L.; Izquieta Rojano, Sheila; Garcia Gomez, H.; et al.
ISSN 1352-2310  Vol. 152  2017  págs. 191 - 200
Bulk/wet and throughfall fluxes of major compounds were measured from June 2011 to June 2013 at four Mediterranean holm-oak (Quercus ilex) forests in the Iberian Peninsula. Regression analysis between net throughfall fluxes and precipitation indicated that the best defined canopy process was leaching for K+ and uptake for NH4+ at all sites. A more variable response between sites was found for Na+, Ca2+, SO42- and Cl-, which suggests that the interplay of dry deposition, leaching and uptake at the canopy was different depending on site climate and air quality characteristics. A canopy budget model (CBM) was used to try to discriminate between the canopy processes and enable to estimate dry deposition and uptake fluxes at three of the sites that complied with the model specifications. To derive N uptake, an efficiency factor of NH4+ vs. NO3- uptake (xNH(4)) corresponding to moles of NH4+ taken up for each NO3- mol, has to be determined. Up to now, a value of 6 has been proposed for temperate forests, but we lack information for Mediterranean forests. Experimental determination of N absorption on Quercus ilex seedlings in Spain suggests efficiency factors from 1 to 6. Based on these values, a sensitivity analysis for xNH4 was performed and the NH4-N and NO3-N modeled dry deposition was compared with dry deposition estimated with independent methods (inferential modeling and washing of branches). At two sites in NE Spain under a milder Mediterranean climate, the best match was obtained for xNH(4) = 6, corroborating results from European temperate forests. Based on this value, total DIN deposition was 12-13 kg N ha(-1) y(-1) at these sites. However, for a site in central Spain under drier conditions, variation of the NH4+ efficiency factor had little effect on DD estimates (which ranged from 2 to 2.6 kg N ha(-1) y(-1) with varying xNH(4)); when added to wet deposition, this produced a total N deposition in the range 2.6-3.4 kg N ha(-1) y(-1). Dry deposition was the predominant pathway for N, accounting for 60-80% of total deposition, while for base cations wet deposition dominated (55-65%). Nitrogen deposition values at the northwestern sites were close to the empirical critical load proposed for evergreen sclerophyllous Mediterranean forests (15 -17 kg N ha(-1) y(-1)). When organic N deposition at these forests is added (3 kg N ha(-1) y(-1)), the total N input to the sites in NE Spain are close to the critical loads for Mediterranean evergreen oak forests. (
Autores: Izquieta Rojano, Sheila; Elustondo Valencia, David
ISSN 1697-2473  Vol. 26  Nº 1  2017  págs. 7 - 15
Atmospheric organic nitrogen (ON) plays a key role in atmospheric chemistry, contributing significantly to N deposition, particle formation and long-distance transport of nitrogenous compounds. This review addresses the most relevant methodological aspects that should be taken into account for the study of the deposit of this fraction. Likewise, it provides information on the important contribution of ON at the global level, both in rainwater and aerosols, and the main sources where it can be formed. Finally, it shows evidence of the influence of ON on the biogeochemical cycles of N and C. The information gathered in this work shows that despite the advances made in recent years, our understanding of the chemical composition and the implications of the organic fraction on health and ecosystems is far from being complete.
Autores: Izquieta Rojano, Sheila; García Gómez, H.; Aguillaume, L.; et al.
ISSN 0269-7491  Vol. 210  2016  págs. 104 - 112
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.
Autores: García-Gómez, H., (Autor de correspondencia); Aguillaume, L.; Izquieta Rojano, Sheila; et al.
ISSN 0944-1344  Vol. 23  Nº 7  2016  págs. 6400 - 6413
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.
Autores: Izquieta Rojano, Sheila; Elustondo Valencia, David; Ederra Indurain, Alicia; et al.
ISSN 1470-160X  Vol. 60  Nº 1  2016  págs. 1221 - 1228
There is a significant lack of data in biomonitoring surveys from southern Europe and other Mediterranean biogeographic areas. This scarcity is mainly due to the impossibility of finding the commonly recommended species in a great portion of these dry environments. The present work was carried out with the aim of assessing the validity of the moss Pleurochaete squarrosa (Brid.) Lindb. (PS) as a feasible alternative in these regions. The study was developed in the Mediterranean area of Navarra, in northern Spain, where the response of PS to multiple atmospheric pollutants (N, Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sb, Ti and Zn) was compared to that of Hypnum cupressiforme Hedw. (HC), an accepted and widely used species in biomonitoring surveys. Moreover, N isotopic signatures from both species were studied to evaluate their effectiveness when identifying nitrogen emission sources. The enrichment factor (EF) approach was used to evaluate the heavy metal uptake, showing a similar behaviour for both species: low EF for Al, As, Cr and Fe; intermediate for Mn, Ni, Pb and Sb; and high for Cd, Cr, Hg and Zn. Equally, both species depicted the same N deposition patterns across the study area. However, regarding ¿15N, PS gave a more congruent picture with the location of the main sources of N emissions in the area. These data suggest that PS may be a suitable biomonitor to fill the aforementioned gaps in Mediterranean biogeographic areas.
Autores: Gazol Burgos, Antonio; Uría Díez, Jaime; Elustondo Valencia, David; et al.
ISSN 1100-9233  Vol. 27  Nº 4  2016  págs. 728 - 738
Autores: Garcia-Gomez, H.; Izquieta Rojano, Sheila; Aguillaume, L.; et al.
ISSN 0269-7491  Vol. 216  2016  págs. 653 - 661
Atmospheric nitrogen deposition is one of the main threats for biodiversity and ecosystem functioning. Measurement techniques like ion-exchange resin collectors (IECs), which are less expensive and time-consuming than conventional methods, are gaining relevance in the study of atmospheric deposition and are recommended to expand monitoring networks. In the present work, bulk and throughfall deposition of inorganic nitrogen were monitored in three different holm oak forests in Spain during two years. The results obtained with IECs were contrasted with a conventional technique using bottle collectors and with a literature review of similar studies. The performance of IECs in comparison with the conventional method was good for measuring bulk deposition of nitrate and acceptable for ammonium and total dissolved inorganic nitrogen. Mean annual bulk deposition of inorganic nitrogen ranged 3.09-5.43 kg N ha(-1) according to IEC methodology, and 2.42-6.83 kg N ha(-1) y(-1) using the conventional method. Intra-annual variability of the net throughfall deposition of nitrogen measured with the conventional method revealed the existence of input pulses of nitrogen into the forest soil after dry periods, presumably originated from the washing of dry deposition accumulated in the canopy. Important methodological recommendations on the IEC method and discussed, compiled and summarized.
Autores: Bermejo Orduna, Raúl; McBride, J.R.; Shiraishi, K.; et al.
ISSN 0048-9697  Vol. 490  2014  págs. 205 - 212
To assess the impact of vehicular emissions on a mixed conifer forest, we measured the contents of the trace elements, N, C, and their respective natural isotopes (delta(15)N and delta(13)C), in the epiphytic lichen, L. vulpina. The samples were collected along transects perpendicular to Interstate 80 (I-80) and along a more remote, secondary forest road (R07). Distance to the road verge, trunk cover, and stand basal area were also recorded. Percent N ranged from 1.10% to 2.00% near I-80 and from 0.78% to 1.13% along R07. Concentrations of N, (15)N, Na, As, Pb, and Zn were enhanced in lichen samples near I-80 and were negatively correlated with distance from the road. Trunk cover values differed between roads (p<0.001) and were negatively correlated with %N (r(2)=0.74; p<0.001). The results indicate that vehicular N emissions are significant enough to alter the surrounding ecosystem, modifying the presence of a sensitive component such as L. vulpina, and suggest that a clean-site threshold of 1.0%N may be too high as an indicator of critical N load exceedance. The study also underscored the potential role of wolf lichen in a large-scale assessment of N deposition and source identification.
Autores: Aldabe Salinas, Janire; Santamaría Elola, Carolina; Elustondo Valencia, David; et al.
ISSN 1759-9660  Vol. 5  Nº 2  2013  págs. 554-559
A microwave digestion method in a closed vessel was developed for the simultaneous determination of trace and major elements, with the highest possible recoveries, in atmospheric aerosols using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). This method was developed to quantify the concentration of Na, Mg, Al, P, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Cd, Sb, Cs, Ba, La, Ce and Pb present in quartz filters containing particulate matter (PM10). The performance of the procedure was evaluated by analysis of the standard reference material NIST 1633b and CTA-FFA-1. Different combinations of nitric acid (HNO3), hydrogen peroxide (H2O2), hydrofluoric acid (HF) and hydrochloric acid (HCl) were tested to improve the recovery factors for the studied elements. The addition of a large amount (3 mL) of HF was required to fully dissolve the quartz filters. This fact made difficult the obtention of high recoveries for alkali (Rb, Cs), alkaline earth (Mg, Ca, Ba), and rare earth (La, Ce) elements, which showed the lowest recoveries. In this study three different digestion methods were assessed using a closed evaporation system, the addition of boric acid and a mixture of both procedures to minimize the effects of residual fluoride.
Autores: Sheppard, L. J.; Leith, I. D.; Leeson, S.; et al.
ISSN 0168-2563  Vol. 116  Nº 1 - 3  2013  págs. 39 - 53
Wet N deposition comprises oxidised (nitrate) and reduced (ammonium) N forms in proportions that vary spatially with source and topography. Field evidence of long-term N form effects on semi-natural ecosystems and how these are modified by phosphorus and potassium availability are lacking. This study describes cover changes for some key peatland species and litter chemistry from Sphagnum capillifolium, Calluna and Eriophorum vaginatum, and peat in response to 9 years of N treatment. Ammonium and nitrate as NH4Cl or NaNO3 were provided to replicate plots in rainwater spray at +8 (low) or +56 (high) kg N ha(-1) year, with and without PK via an automated system coupled to site meteorological conditions. Reduced N caused greater N accumulation in all key species than oxidised N, especially at higher doses, but cover declined more, though not significantly so, with oxidised than reduced N at the high N dose. Overall the detrimental effects of high N on Sphagnum and Calluna cover were significant but small. By comparison PK inclusion with 56 kg N ha(-1) year as oxidised N, not reduced N, had devastating effects on cover, causing both S. capillifolium and Calluna to decrease 3-5-fold, facilitating invasion and expansion of nitrophiles, non-characteristic bog plants e.g. Epilobium angustifolium, Epilobium palustre, Juncus effusus, Digitalis purpurea and Dryopteris dilatata. N form appears to be significant for peatlands because of its effects on pH. The significance of changes in plant cover for peat chemistry and decomposition for biogeochemistry is discussed.
Autores: Aldabe Salinas, Janire; Santamaría Elola, Carolina; Elustondo Valencia, David; et al.
ISSN 1582-9596  Vol. 11  Nº 6  2012  págs. 1049 - 1058
The concentrations of 15 selected polycyclic aromatic hydrocarbons (PAHs) were determined in daily PM10 samples collected at a rural site, an urban site and a traffic site in Navarra during 2009. PAHs were extracted by microwave-assisted extraction (MAE) from the corresponding quartz filters and later analyzed by gas chromatography/mass spectrometry (GC/MS). An intensive annual study was enabled with this analytical procedure as turnover is multiplied by 50 with MAE in comparison with the classical extraction technique (Soxhlet). The annual average total concentrations of the 15 target compounds ranged from 0.6 ng m(-3) to 1.2 ng m(-3) at the rural and traffic sampling stations respectively, showing up to four times higher PAHs concentrations in winter than in summer. When compared to other European cities, Pamplona registered significantly lower PAHs values. Other pollutants like NOx, CO and PM10 were found to be well correlated with PAHs, and O-3 presented a negative correlation. The results of diagnostic ratios and principal component analysis (PCA) revealed the high influence of diesel and gasoline emissions in the three studied areas, although, other main sources were also found.
Autores: Santamaría Ulecia, Jesús Miguel; Moraza Zorrilla, María Lourdes; Elustondo Valencia, David; et al.
ISSN 1582-9596  Vol. 11  Nº 6  2012  págs. 1159 - 1169
Mites and springtails are important members of soil mesofauna and have been proven to be good bioindicators of airborne pollutants. We studied the surrounding area of a steel mill located in a mountain valley of North Spain. Previous studies had documented the existence of a pollution gradient in this area due to the emissions of the factory, thus providing an interesting site to investigate the potential effects of pollutants (heavy metals and nitrogen) on soil biodiversity. The density of Acari and Collembola significantly decreased with the increase in concentration of Cr, Mn, Zn, Cd and Pb. Mites appeared to be more sensitive to heavy metal pollution than springtails. Likewise, the density of these microarthropoda was lower in those soils exhibiting higher nitrogen content. The species composition of the community of Acari and Collembola changed according to heavy metal pollution. Significant differences in abundance, species richness and diversity were observed between the communities of the sampling sites. Some species were exclusive of the less polluted sites, while other appeared in the most contaminated ones. This different response of soil mesofauna to pollutants suggests that some mite or springtail species could be used as bioindicators of heavy metal pollution.
Autores: Rodríguez Oroz, María Delia; Lasheras Adot, María Esther; Aldabe Salinas, Janire; et al.
ISSN 1582-9596  Vol. 11  Nº 6  2012  págs. 1149 - 1158
In this study we explore the processes of sorption and mobility in experimental soil columns in order to assess the response of natural soils to a hypothetical increase of pollution. The soils were sampled in a forest catchment situated in the Bertiz Natural Park at the western end of the Pyrenees. 21 columns, reproducing 21 soil profiles, were treated with a solution of heavy metals four times more concentrated than under actual conditions of deposition. An undisturbed soil column was tested simultaneously. The competition between cations and the content of clay and oxi-hydroxide compounds in the soils were the main factors determining the mobility of metals along with the influence of temperature. Calculated distribution coefficients show retention of Cr3+ Cu2+, and As5+, and in a lesser extent of Pb2+ and leaching of Mn2+, Zn2+, Cd2+ and Ni2+. Consequently, Mn2+ and Zn2+ have a greater tendency to contribute to groundwater pollution, whereas Cr3+ and Cu2+ are more likely to remain on soil surface. In undisturbed soil column, Ni2+ and Zn2+ were preferably sorbed onto dissolved organic matter (DOC), and the sorption of Mn2+ Cu2+ and Zn2+ was controlled by the ambient temperature. The simulation shows the presence of weakly sorbed metals and of others clearly desorbed (Ni2+, Cd2+ and Pb2+), which suggests that in the near future they will reach groundwater becoming a risk for its quality and for the biota. This kind of experiments in disturbed soils did not prove to be successful, hence their analysis in undisturbed soils is suggested.
Autores: Ariño Plana, Arturo; Bermejo Orduna, Raúl; Ibáñez Gastón, Ricardo; et al.
ISSN 1238-7312  Nº 18  2011  págs. 53 - 57
Autores: Aldabe Salinas, Janire; Elustondo Valencia, David; Santamaría Elola, Carolina; et al.
Revista: Atmospheric research
ISSN 0169-8095  Vol. 102  Nº 1  2011  págs. 191 - 205
Autores: González Miqueo, Laura; Elustondo Valencia, David; Lasheras Adot, María Esther; et al.
Revista: Chemosphere
ISSN 0045-6535  Vol. 78  Nº 8  2010  págs. 965 - 971
A biomonitoring survey using the moss species Hypnum cupressiforme Hedw. was conducted in the surroundings of two steel plants located in the North of Spain. Levels of V, Cr, Ni, Cu, Zn, As, Cd, Hg, Pb and N were determined. Very high concentrations in the areas of study were detected when compared to nearby unaffected regions. Similar trends were observed for all the elements in the differently orientated transects, showing an appreciable influence of the NW prevailing winds of the region in the dispersion of pollutants, as well as a clear decreasing gradient in the concentrations of metals in mosses within a distance of 1500 meters from the facilities. A differentiation between the elements emitted by the chimney as result of the industrial activity (V, Cr, Ni, Cu and As) and those with a high presence in steel slag deposits (Zn, Cd, Hg and Pb) was observed. The range of contamination was also established by means of the Contamination Factor, indicating a category 4 out of 6 categories, which shows the high levels reported in the areas of study. A different dynamic was registered for nitrogen regarding the rest of the heavy metals analysed except for Hg, probably due to the elevated volatility and mobility of both elements, as well as their high persistence in the atmosphere.
Autores: González Miqueo, Laura; Elustondo Valencia, David; Lasheras Adot, María Esther; et al.
ISSN 0049-6979  Vol. 210  Nº 1-4  2010  págs. 335 - 346
Autores: González Miqueo, Laura; Bermejo Orduna, Raúl; Parra Villaro, María Asunción; et al.
ISSN 0049-6979  Vol. 206  Nº 1-4  2010  págs. 23 - 34
Autores: Foan, L.; Sablayrolles, C.; Elustondo Valencia, David; et al.
Revista: Atmospheric environment
ISSN 1352-2310  Vol. 44  Nº 26  2010  págs. 3207 - 3214
Autores: Pons Izquierdo, Juan José; Santamaría Ulecia, Jesús Miguel; Ariño Plana, Arturo; et al.
Libro:  Tecnologías de la Información Geográfica: perspectivas multidisciplinares en la sociedad del conocimiento
2018  págs. 414 - 423
La calidad del aire urbano es un aspecto muy relevante para el bienestar de los ciudadanos y está cada vez más presente en el debate social y político. Para contar con una atmósfera saludable en nuestras ciudades, resulta necesario disponer de información detallada sobre cómo se distribuye la contaminación en cada punto de la ciudad y no solo en torno a las cabinas de control de calidad del aire. En este contexto, se inscribe el proyecto LIFE+ RESPIRA (2014-2017), concebido como una iniciativa de ciencia ciudadana, en la que cerca de 150 ciclistas voluntarios han recorrido el área metropolitana de Pamplona a lo largo de dos años, equipados con captadores geolocalizados de diferentes tipos de contaminantes atmosféricos (CO , NOX, O3 y partículas en suspensión). A lo largo de ese tiempo, los voluntarios han recorrido unos 47.000 km en bicicleta, contribuyendo a obtener casi 150 millones de medidas en más de 4 millones de posiciones geolocalizadas a lo largo de las calles de la ciudad y sus alrededores, cubriendo la mayoría de las situaciones estacionales, horarias, climáticas y de tráfico de un año típico. Con toda esa ingente cantidad de información se ha podido realizar gran cantidad de mapas muy detallados de la calidad del aire, que han permitido modelizar el comportamiento de cada contaminante estudiado de acuerdo a las diferentes condiciones que se presentan.
Autores: Santamaría Elola, Carolina; Elustondo Valencia, David; Lasheras Adot, María Esther; et al.
Libro:  Chromatographic analysis of the environment : mass spectrometry based approaches
2017  págs. 427 - 452
Autores: Santamaría Ulecia, Jesús Miguel (Editor); Ariño Plana, Arturo; León Anguiano, Bienvenido; et al.
Recoge los principales resultados generados durante la realización del proyecto LIFE+RESPIRA, llevado a cabo en la ciudad de Pamplona (Navarra, España) por un equipo interdisciplinar constituido por más de 30 investigadores pertenecientes a la Universidad de Navarra, el Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT) y Gestión Ambiental de Navarra (GAN-NIK). El libro, que se ha publicado en castellano y en inglés, se ha dividido en 7 capítulos: 1. ¿Ciudades sostenibles? 2. Exposición de los ciudadanos a la contaminación atmosférica 3. Papel de la vegetación urbana en la calidad del aire 4. Modelos de alta resolución para evaluar la calidad del aire 5. Impactos de la contaminación urbana 6. Movilidad y sostenibilidad urbanas 7. Comunicación y educación ambiental. Este libro pretende ser una guía de utilidad para científicos, gestores y ciudadanos, aportando un conjunto de herramientas que permitan mejorar la calidad de vida de nuestras ciudades. Además, quiere rendir un homenaje a todos los voluntarios ciclistas que han participado en dicho proyecto y que son los verdaderos artífices del mismo, ya que gracias a su dedicación incondicional durante más de dos años, han proporcionado una cantidad ingente de datos sobre la calidad del aire de la ciudad de Pamplona.
Autores: Santamaría Ulecia, Jesús Miguel (Editor); Ariño Plana, Arturo; León Anguiano, Bienvenido; et al.
This book collects the main outcomes that were generated during the implementation of the LIFE+RESPIRA project (LIFE13 ENV/ES/000417), carried out in the city of Pamplona, Navarra, Spain. The research was conducted by a cross-functional team made up of more than 30 researchers belonging to three entities: The University of Navarra, the Centre for Energy, Environmental and Technological Research (CIEMAT) and Environmental Management of Navarra (GAN-NIK).