The projects Impacts of climate change on biodiversity in forests (LWE2103023) and Above and below-ground biodiversity in dehesas (LWE2103024) will study the dehesas of Western Andalusia (Huelva, Seville, Cordoba) dominated by holm oak (Quercus ilex). A network of 30 dehesas has been established covering wide gradients of management intensity, plant diversity and tree health status. Of the 30 selected dehesas, 20 are dehesas affected by symptoms compatible with root rot caused by the exotic pathogen Phytophthora cinnamomi (defoliation, spotting and mortality), while the remaining 10 are considered healthy dehesas as the trees show no symptoms of the disease. A total of 500 holm oaks have been georeferenced and sampled to determine the relationship between biodiversity (plant and microbial) and tree health.
These dehesas constitute unique ecosystems that are partly sustained and have not been degraded thanks to the economy based on extensive livestock farming, and in particular to the production related to the Iberian pig. Within WP8, C, N and S isotopic traceability of diet and products will be studied, so that there is a database to defend the sector against unfair competition based on intensive production and unecological management that is seriously damaging these areas.