Ministerio de Economía y Competitividad: 139.150 €
From January 1st, 2012 to December 31st, 2015
Universidad Politécnica de Cartagena
The revegetation or phytostabilization of these areas has been proposed as an effective technique to decrease soil erosion and thus the spread of pollutants via wind or run-off water. The initial hypothesis, based on previous studies, is that pioneer vegetation, which grows in situ in mine tailings, may promote the colonization of non-metal tolerant plant species through interactions of facilitation.
These interactions could be improved by employing mycorrhiza inoculation and/or addition of organic amendments. Based on that previous hypothesis the main goals of the project are:
1) Characterization of the edaphic gradients which determine the colonization of pioneer vegetation in abandoned mine tailings from the Cartagena-La Unión Mining District;
2) Ecophysiologic characterization of pioneer vegetation in abandonded mine tailings from the Cartagena-La Unión Mining District;
3) Description of the facilitation/competition interactions among the pioneer vegetation in mine tailings and its response to myccorhiza inoculation and/or amendments.
The specific goals are:
1) Create a climate and edaphic adapted plant species list to be used in further revegetation/stabilization works
2) Determine the different combinations of plant species/treatments to facilitate the long term stability (sustainability) of the plant cover in mine tailings.
To achieve these objectives, a field work stage and a pot experiment were performed. The first field survey was focused on the description of the edaphic and ecological gradients along a transect from a control non-polluted site to the mine tailings. The edaphic patch distribution was found to be determining for the selective establishment of spontaneous vegetation. The salinity gradient was the main factor involved in the shifts of the plant species inventory and the decrease of ecological diversity and richness along the steps from the non-polluted area to the tailings plateau, while metal(loid)s soil concentrations played a minor role. The colonisation of the mine tailings by other native late successional plant species was related with the fertility gradient generated by the enhancement of soil conditions as a result of the early development of pioneer vegetation. This natural process has provided the occurrence of high dense vegetated patches in the tailings called “fertility islands” which contain climax vegetation of the local area. The identification of plant favourable niches for plant growth should be taken into account when phytostabilisation works are carried out on mine tailings. Ploughing or the addition of certain amendments that could raise soil salinity should be carefully evaluated in order to not destroy those favourable niches.
The usefulness of spontaneous vegetation for the phytomanagement of mine tailings was firstly assessed through a field study focused on the characterisation of the rhizospheres and the ecophysiology of some spontaneous plant species (grasses, shrubs and trees). The similarity between the rhizosphere of individual trees (Tetraclinis articulata, but especially Pinus halepensis) and that one of the “fertility islands” may lead to the suggestion that trees are the key for the development of these dense vegetation areas. The rhizosphere of pioneer grass and shrub species (Piptatherum miliaceum, Helichrysum decumbens) showed a significant enhancement of soil microbiology. Regarding to plant selection, the use of combinations of plant species with different life forms and complementary water and nutrient acquisition strategies may result in a more efficient employment of edaphic resources. This may favour the achievement of a long-term stable plant community and may provide a higher resilience to environmental disturbances.
Regarding to grasses and shrubs, a field survey was conducted in order to evaluate the different performance of spontaneous halophyte and non-halophyte species and to asses if the former could be more suitable for specific sites on the tailings. Some halophyte plant species (Limonium cossonianum, Zygophyllum fabago, Atriplex halimus, Inula chrithmoides, Tamarix canariensis) has been found to be very appropriate for the phytostabilisation of mine tailings due to a relatively lower metal(loid) uptake and a higher enhancement of soil rhizosphere properties than non-halophyte ones.
In the case of trees, three specific studies focused on Pinus halepensis were done in order to gain insight into the ability of pine trees to cope with the soil conditions at the tailings. The first study was focused on the accumulation of metal(loid)s in P. halepensis along a polluted gradient, while the second and the third ones dealt with the ecophysiological status, elemental and isotopic foliar composition and internal nutrients and metal(loid)s retranslocation in spontaneous populations of P. halepensis growing on mine tailings. Pinus halepensis showed a good tolerance to the poor soil conditions of the tailings. In spite of a severe foliar phosphorus deficiency, pine trees showed substantial macronutrient retranslocation and resorption from senescent leaves, which may help them to cope with some nutritional deﬁciencies, especially in relation to K, Mg and P. The analysis of the foliar isotope composition showed that pines growing at mine tailings are less water stressed that those ones at natural forest in the area (Control), and that mycorrhizal association might be critical for the development of these trees on the mine tailings. Moreover, pine trees showed a relatively low metal(loid) uptake and some mechanisms to cope with them such as the immobilisation in less biologically active tissues (Cd, Cu, Pb and Sb in woody stems) or the accumulation in edible parts (As, Cd, Sb, Pb and Zn in litter). Therefore, the tree species Pinus halepensis seems to be suitable for phytostabilisation of mine tailings by its adaptation to climate and the potential role for facilitating the occurrence of fertility islands.
Finally, a pot experiment was performed using the grass species Piptatherum miliaceum (commonly found on local tailings) and a mine tailings soil amended with a municipal solid waste from the recycling of metallic containers. P. miliaceum showed tolerance to tailings soil conditions with and without amendment. The addition of the municipal solid waste improved some soil fertility indicators, although the main effect was on plant growth and development. Metal(loid) accumulation in leaves was below the toxic thresholds for fodder. Plant growth was also influenced by intra-specific competition. Therefore, the grass species Piptatherum miliaceum could be also considered in phytostabilisation of mine tailings, but to obtain a faster growth and development, organic amendments should be added.
- JCR articles:
Parraga-Aguado, I., Álvarez-Rogel, J., González-Alcaraz, M.N., Conesa, H.M. 2017. Metal mobility assessment for the application of an urban organic waste amendment in two degraded semiarid soils. Journal of Geochemical Exploration. 173:92-98
Parraga-Aguado, I., López-Orenes, A., Ferrer-Ayala, M.A, González-Alcaraz, M.N., Conesa, H.M. 2016. Evaluation of the environmental plasticity in the xerohalophyte Zygophyllum fabago L. for the phytomanagement of mine tailings in semiarid areas. Chemosphere. 161: 259-265.
Párraga-Aguado, I., González-Alcaraz, M.N., Schulin, R., Conesa, H.M. 2015. The potential use of Piptatherum miliaceum for the phytomanagement of mine tailings in semiarid areas: role of soil fertility and plant competition. Journal of Environmental Management.158:74-84.
Párraga-Aguado, I., González-Alcaraz, M.N., Álvarez-Rogel, J., Conesa, H.M. 2014. Assessment of the employment of halophyte plant species for the phytomanagement of mine tailings in semiarid areas. Ecological Engineering. 71:598-604
Párraga-Aguado, I., Querejeta, J.I., González-Alcaraz, M.N., Jiménez-Cárceles, F.J., Conesa, H.M. 2014. Usefulness of pioneer vegetation for the phytomanagement of metal(loid)s enriched tailings: grasses vs. shrubs vs. trees. Journal of Environmental Management. 133:51-58
Párraga-Aguado, I., Querejeta, J.I., González-Alcaraz, M.N., Jiménez-Cárceles, F.J., Conesa, H.M. 2014. Elemental and stable isotope composition of Pinus halepensis foliage along a metal(loid) polluted gradient: implications for phytomanagement of mine tailings in semiarid areas. Plant and Soil. 379: 93-107.
Párraga-Aguado, I., Querejeta, J.I., González-Alcaraz, M.N., Conesa, H.M. 2014. Metal(loid) allocation and nutrient retranslocation in Pinus halepensis trees growing on semiarid mine tailings. Science of the Total Environment. 485-486:406-414
Párraga-Aguado, I., González-Alcaraz, M.N., Álvarez-Rogel, J., Jiménez-Cárceles, F.J., Conesa, H.M. 2013 Assessment of metal(loid)s availability and their uptake by Pinus halepensis in a Mediterranean forest impacted by abandoned tailings. Ecological Engineering. 58:84-90
Párraga-Aguado, I., González-Alcaraz, M.N., Álvarez-Rogel, J., Jiménez-Cárceles, F.J., Conesa, H.M. 2013. The importance of edaphic niches and pioneer plant species succession for the phytomanagement of mine tailings. Environmental Pollution. 176:134-143.
- PhD Thesis
Isabel María Párraga Aguado "The importance of edaphic niches and spontaneous vegetation for the phytomanagement of mine tailings under semiarid climate" Junio de 2015. Directores: Dr. Héctor Miguel Conesa Alcaraz y Dr. María Nazaret González Alcaraz.
- Communications in Congresses
Héctor M. Conesa, María Nazaret González Alcaraz, Francisco J. Jiménez-Cárceles, María del Carmen Tercero Gómez, Isabel Párraga Aguado.2015. How does metal(loid) pollution affect soil enzymatic activities at metal(loid) enriched mine tailings? The role of pioneer plant rhizospheres. CICTA 2015-10ºCongreso Ibérico y 7ªIberoamericano de Contaminación y Toxicología Ambiental. Vila Real, Portugal. 14 al 17 de Julio de 2015
Isabel Párraga-Aguado; María Nazaret González-Alcaraz; María del Carmen Tercero-Gómez; José Álvarez-Rogel; Héctor M. Conesa. 2015. Metal(loid) allocation in the soil-plant system of a Pinus halepensis population growing on semiarid mine tailings. CICTA 2015-10ºCongreso Ibérico y 7ªIberoamericano de Contaminación y Toxicología Ambiental. Vila Real, Portugal. 14 al 17 de Julio de 2015
Párraga-Aguado, I., Alcoba Gómez, P., Tercero-Gómez, M.C., González-Alcaraz, M.N., Moya, J., Conesa, H.M. 2014. The use of organic municipal waste refuse (MWR) for the improvement of soil fertility in mine tailings: implications for metal(oid) plant allocation. In: Arenas-Lago, D., Alonso-Vega, F., Rodríguez-Seijo, A., PPS International Congress of Phytoremediation of Polluted Soils. Book of Abstracts. Vigo, Spain, July 29-30, ISBN: 978-84-697-0747-0, pag. 48
Párraga-Aguado, I., Jiménez-Cárceles, F.J., Álvarez-Rogel, J., Tercero-Gómez, M.C., González-Alcaraz, M.N., Moya, J., Conesa, H.M. 2014. The potential of Piptatherum miliaceum for the phytomanagement of mine tailings in semiarid areas: Role of soil fertility and plant competitionIn: Arenas-Lago, D., Alonso-Vega, F., Rodríguez-Seijo, A., PPS International Congress of Phytoremediation of Polluted Soils. Book of Abstracts. Vigo, Spain, July 29-30, ISBN: 978-84-697-0747-0, pag. 47
Isabel M. Párraga-Aguado, María del Carmen Tercero-Gómez, José Álvarez-Rogel, María Nazaret González-Alcaraz, Francisco J. Jiménez-Cárceles, Rainer Schulin, Héctor M. Conesa. 2014.The importance of pioneer plant species succession and edaphic niches for the phytomanagement of mining impacted ecosystems. In: Stefan Holzheu & Birgit Thies (eds.) BIOGEOMON 2014, 8th International Symposium on Ecosystem Behavior, University of Bayreuth, Germany, July 13th – 17th, 2014, Book of Abstracts, ISSN 0944 - 4122, Pag. 321.
Héctor M. Conesa, Jose-Ignacio Querejeta-Mercader, Antonio López-Orenes, María-Nazaret, González-Alcaraz, Mari-Ángeles Ferrer-Ayala, Antonio A. Calderón-García, Isabel Párraga-Aguado. 2014. The role of plant assemblage in the phytomanagement of mining impacted ecosystems. In: Stefan Holzheu & Birgit Thies (eds.) BIOGEOMON 2014, 8th International Symposium on Ecosystem Behavior, University of Bayreuth, Germany, July 13th – 17th, 2014, Book of Abstracts, ISSN 0944 - 4122, Pag. 327-328
Isabel M. Párraga-Aguado, José Álvarez-Rogel, María del Carmen Tercero-Gómez, María Nazaret González-Alcaraz, Francisco J. Jiménez-Cárceles, Héctor M. Conesa. 2012. Primeros datos sobre gradientes edáficos y pautas de colonización de la vegetación pionera en balsas mineras de la sierra de Cartagena- La Unión (SE Península Ibérica). V Congreso Ibérico de la Ciencia del Suelo. Angra do Heroismo (Portugal), 6-10 septiembre de 2012