Are the conditions of the Italian forests worsening due to extreme climatic events? Evidence from the national monitoring networks ICP Forests - CON. ECO.FOR.

Tree defoliation and mortality are triggered in Europe by extreme climatic events that recurring since the beginning of XXI century. Data from ICP Forests monitoring networks reveal a general worsening tree conditions last ten years, as consequence drought heat waves affected Southern (2017) Central (2018-2019). In Italy significant increase mortality, assessed on extensive (Level I) network, was observed after 2017 dry summer, which impacted mainly broadleaved forests (beech oak forests) peninsular regions. Coniferous alpine belt were severely 2021, probably because co-occurrence multiple causes, involving windstorm bark beetle attacks. Chestnut suffer pest (insect pathogen) The intensive II) network provides cases study allows to carry out specific cause-effect studies concerning physiological effects environmental impacts, well observe ecological processes following disturbing events. Defoliation caused or attacks induces loss defenses (namely non-structural carbohydrates), need several years be restored. Then, occurrence more frequent repeated can produce irreversible effects. this view, long-term forest health is key detect extent direction changes structure composition, represents an important tool for conservation management.