International Conference on Mycorrhiza

Last August, the 9th International Conference on Mycorrhiza was held in Prague (Czech Republic). This conference, organised by the International Mycorrhiza Society, provided a global platform for exchanging the latest mycorrhizal symbiosis knowledge (anatomy, molecular mechanisms, mycorrhizal ecology and functioning) as well as its implications for the ecosystems and for the human society.

Researchers from RESTECO Project, together with collaborators, presented their last results in the session “Advances in biological conservation through a better understanding of mycorrhizal ecology”.  A poster was presented with the study of the functional traits of ectomycorrhizal fungi (ECM) in holm oak (Quercus ilex) tree species in trace elements contaminated soils of the Guadiamar Green Corridor (Seville, Spain). In this study, two hypotheses were validated: soil contamination affects ECM species composition and their functionality, and ECM functional traits mediate in the effect of soil contamination on plant status.

Link to the poster: Marta Gil-Martínez et al. “Ectomycorrhizal functional traits mediate plant-soil feedback processes in trace elements contaminated soils”.

Collaboration with Professor Mark Tibbett on mycorrhizal studies

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.

International Congress of mediterranean Ecosystems

Researchers of the RESTECO project have presented their results in the International Congress of Mediterranean-type Ecosystems – XIV MEDECOS – which was held at Sevilla, Spain, on February 2017.

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”:

Marta Gil-Martínez et al. “Understanding feedback processes between holm oak (Quercus ilex) and their ectomycorrhizal fungal symbionts in trace-element polluted soils in Mediterranean ecosystems”.

Álvaro López García et al. “Assessment of the recovery of functional diversity of ectomycorrhizal fungal communities in metal polluted soils”.

Teodoro Marañón et al. “Soil functioning and ecosystem services: using trees to remediate contaminated soils”.

Three poster communications, also related to the project, were presented in other sessions:

María Teresa Domínguez Núñez et al. “Soil contamination and the provision of ecosystem services in Mediterranean lands: implications for livestock and bionergy uses”.

Sara Muñoz Valdés et al. “Modelling resilience and ecosystem services of soils contaminated by heavy metals under remediation measures and Climate Change scenarios: The Case Study of Guadiamar”.

Carmen M. Navarro-Fernández et al. “A functional approach to explore the drivers of mycorrhizal trait variability in Mediterranean plant communities”

Diversity of ectomycorrhizal fungi associated with holm oaks in the Guadiamar

portada

Ectomycorrhizal (ECM) fungi associate with plants to conform one of the most important symbioses in terrestrial ecosystems, with important incidence in the provision of some ecosystem services.

Álvaro López García presented on December 6, 2016, the seminar “Taxonomic and functional diversity of ectomycorrhizal fungal communities in metal polluted soils” within the Cycle of seminars of Section for Terrestrial Ecology, Deptartment of Biology, University of Copenhagen, Denmark.

To deepen in how anthropogenic disturbance affect the taxonomic and functional diversity of ECM, we characterized the ECM fungal communities associated with holm oak trees used in the restoration of the Aznalcóllar toxic mine spill (SW Spain). The comparison between contaminated and control (non-contaminated) sites showed no differences in terms of taxonomic diversity. However a certain clustering in key traits of ECM fungi was found in communities exposed to higher levels of heavy metal pollution. This finding is in agreement with what expected from an environmental filtering process, i.e. species in a community tend to be more similar between them than expected by chance, and indicates that the functional diversity of ECM in contaminated sites is lower than in control sites.

Mycorrhization patterns along an environmental gradient

figura_micorrizasMycorrhizal symbiosis is a mutualist association between plants and fungi which may be critical under stressful environmental conditions, like in Mediterranean forests constrained by water stress and resource scarcity.

Researchers of the IRNAS-CSIC and the University of Córdoba have studied how the degrees of colonization by ectomycorrhizal (ECM) and arbuscular mycorrhizal (AM) fungi were related to other root and leaf traits, in woody plant communities of Sierra Morena (Córdoba) distributed along a gradient of soil resources.

The level of ECM colonization was positively related to the abundance of evergreen species and to tissue dry matter content (in leaves and roots), but negatively to specific root length and specific leaf area. The best abiotic predictor of ECM colonization was soil moisture, with higher ECM colonization in drier sites.

However, AM colonization was not related to any of the plant traits studied and was positively related to soil Cu and other physico-chemical soil properties.

Changes in community ECM mycorrhization were primarily due to plant species turnover, while in the case of AM colonization was more important the intraspecific variability.

The proposed mycorrhizal trait-based approach is novel and useful to understand the functioning of Mediterranean forests and shrublands.

The study has been published (on line since August 29 2016) in the Journal of Vegetation Science.

Navarro-Fernández CM, Pérez-Ramos IM, de la Riva EG, Vera JR, Roumet C, Villar R, Marañón T (2016). Functional responses of Mediterranean plant communities to soil resource heterogeneity: a mycorrhizal trait-based approach. Journal of Vegetation Science, DOI: 10.1111/jvs.12446.