The symbiosis between plants and mycorrhizal fungi is a fundamental factor for the phytoremediation of contaminated soils in the Guadiamar Valley.
From the 15th to the 18th of May 2017, Professor Mark Tibbett (University of Reading, UK) visited the IRNAS-CSIC to participate in a collaborative work on the effects of contamination by trace elements on soil biodiversity.
Professor Tibbett gave a conference in the IRNAS´ Seminar Cycle, entitled “The mysterious world of mycorrhizas: Unrecognized attributes of the commonest plant-fungal symbiosis”. The role of mycorrhizas and the plant-fungi-soil interface was remarked, as well as their importance in plant nutrition and stress tolerance. “Bare roots does not exist in nature” he stated, remarking the universality of plant-fungal associations.
The field visit included a general overview of the Aznalcóllar mine complex and the old tailings dams which collapsed, provoking the spill.
In the experimental plot for the long-term study of the effects of amendment addition on soil remediation, the interactions between soil properties (mainly pH), mycorrhizas and colonizing plants were discussed in contaminated and remediated soils.
Lastly, in La Herrería (Sanlúcar la Mayor) field, the relations of different tree species such as stone pine (Pinus pinea), white poplar (Populus alba) and wild olive (Olea europaea) with the soil organic matter underneath, the phytostabilization of trace elements, and the communities of mycorrhizal fungi were discussed.
The RESTECO researcher María T. Domínguez has given the conference “Soil contamination and provision of ecosystem services in the Guadiamar River Basin”, within the Open Classroom program of the University of Córdoba, Spain, on May 9th 2017.
In the conference, the main concepts relative to the role of soil provisioning ecosystem services were introduced. The Guadiamar River Valley was presented as a case study, where many works focused on the impact of soil contamination on the provision of ecosystem services have been carried out.
On March 24th, the students of the subject “Ecology of Global Change: Current Transition of the Biosphere” visited the Guadiamar River basin. The subject belongs to the Biology degree of the University of Seville (US).
The objective of the excursion was to carry out an ecological and environmental analysis of the landscape and ecosystem transformations produced by the anthropic action during centuries in the outskirts of the city of Seville. The Guadiamar River, because of its ancestral importance as a source of water and resources, is a good example of these transformations that can be observed from its birth in the Sierra Norte until its mouth in the Guadalquivir River, in the marshes of the Doñana Park.
The professors María Cruz Díaz Antúnez-Barradas (US) and María José Leiva Morales (US) described the different ecosystems where the Guadiamar River flows. In its high part, in the mountain range, the Guadiamar River crosses forests and plantations of eucalyptus trees. In the middle section, the amplitude of the fluvial valley appears increasing riverside vegetation in the borders and meadows in the high zones. Further down, the river enters the Protected Landscape of the Guadiamar Green Corridor where the forest of the alluvial plains was reforested with Mediterranean shrubs and trees (oaks, olive trees, brooms, etc.), while the forest gallery shows poplars, ash trees and willows. Finally, in the low section, it ends in the marshes of Doñana, where crops of rice and brackish pastures appear.
At the Doblas stop (Sanlúcar la Mayor), Marta Gil Martínez (IRNAS-CSIC) was invited to talk about the consequences and restoration measures after the Aznalcóllar mine spill to the Guadiamar River, as well as the results of the investigations which is carried out by IRNAS-CSIC researchers in the Green Corridor (RECARE and RESTECO projects). Soil contamination by heavy metals, such as lead, zinc, cadmium and copper, affects the growth and health of plants, soil organisms and, in general, the ecosystem food web. Soil-plant-microorganism interaction is being investigated in soils with different levels of contamination. The ability of plants and their associated microbes to stabilize heavy metals in the soil (a technique known as phytostabilization) and thus reduce the risk of toxicity in the ecosystem is studied.
On Friday February 10th 2017 a group of students from the Master in Advanced Biology: Research and Application (University of Seville) visited the Guadiamar Green Corridor. That was a field practice of the subject Environmental Contamination, Ecotoxicology and Phytoremediation.
The visit was guided by the RESTECO researcher María T. Domínguez (IRNAS, CSIC). She showed the experimental plots where the measures for remediation of contaminated soils are evaluated. In particular, the demonstration was focused on the amendment addition and the phytostabilization of trace elements by the planted trees.
In particular, three oral communications were presented within the Symposium “Filling current knowledge gaps: understanding the role of plant-soil interactions on the functioning and resilience of Mediterranean ecosystems in a changing world”: