ICP Forests Defoliation and Symptoms Data Set

This data set has been obtained after processing original data from the ICP Forests data infrastructure. It includes "clean" defoliation and symptoms data from 19 countries over the period 1990-2022 after removing dubious cases of e.g. species attribution, dubious coding, long-standing dead trees. It is based on ICP Forests Level I plots. Defoliation is the relative loss (shed or not formed) of tree needles / leaves in relation to a hypothetical fully foliated optimum and is visually assessed using a sliding scale recorded in 5% steps (from 0%= no defoliation to 100%=standing dead tree). Occurrence of s^Symptoms attributable to damaging agents (e.g., insects, fungi, drought, hail, fire, direct action of men…) on each tree and associated to defoliation are also included in this data set. This data set includes a total of 2’688’512 observations from 219’854 trees in 12’104 plots. In addition there are two associated datasets included here relating to Forest Carbon data at the national level and Plot level Climate and Air Pollution variables which were used in publications based on the primary dataset. The Forest Cabon data was extracted from the common reporting format (CRF) tables provided by all countries signatory to the Conference of Parties (https://unfccc.int/ghg-inventories-annex-i-parties/2024). Climate data were obtained from two primary sources: SPEIbase v2.9, provided by the Spanish National Research Council (CSIC) ( https://spei.csic.es/) and the ERA5-Land dataset, produced by the European Centre for Medium-Range Weather Forecasts (ECMWF) (https://cds.climate.copernicus.eu/dataset). Air pollution data were sourced from the European Monitoring and Evaluation Programme (EMEP)(https://emep.int/).