The contribution of mycorrhizal fungi to multifunctionality in global drylands
Dryland ecosystems are a key terrestrial biome, covering 45% of the Earth´s surface and supporting over 38% of the total global population, but their functioning and the goods and services they provide are vulnerable to global environmental changes such as increasing land use intensity (e.g. grazing pressure) and climate aridification. Mycorrhizal fungi, i.e. obligate plant symbionts colonizing the roots of 90% of all land plants, contribute substantially to dryland biodiversity, to their functioning, and the provision of goods and services by dryland ecosystems. In exchange for plant assimilated carbon, mycorrhizal fungi increase plant nutrient supply, influence soil formation and aggregation, plant defence to herbivory and resistance to drought, among other important processes. Through these mechanisms, they influence plant diversity, multiple ecosystem functions, such as nutrient cycling or biomass production, and likely modulate ecosystem responses to aridity and grazing pressure, which are forecasted to increase in drylands under global environmental change. Mycorrhizal effects depend on environmental conditions and species traits determining the efficiency of the resource exchange between plants and fungi. However, to date little is known about the contribution of mycorrhizal fungi to the diversity and functioning of drylands or to the capacity of drylands to provide multiple functions simultaneously (i.e. multifunctionality). We also do not know how the contribution of mycorrhizal fungi to dryland multifunctionality might change under forecasted global environmental change or depending on the resource economy of the plant community. The MYFUN project aims to fill these gaps in knowledge by assessing the contribution of mycorrhizal fungi to dryland multifunctionality in response to environmental stress (increased aridity, grazing pressure) and plant resource economy.