Data from: Patterns and drivers of atmospheric nitrogen deposition retention in global forests

unspecified# Patterns and drivers of atmospheric nitrogen deposition retention in global forests We searched the Web of Science Database for peer-reviewed papers prior to February 22, 2023, using “retention” and “N-15” as the keywords. The following criteria were applied to filter the peer-reviewed papers: (1) Selection of 15N tracer experiments in forest ecosystems conducted in the field, excluding laboratory incubation or greenhouse experiments; (2) Selection of the absolute value of 15N retention obtained from the 15N tracer experiment, excluding the relative value; (3) Selection of 15N tracer experiments including N addition treatments, excluding other treatments such as fire, phosphorus (P) addition, potassium addition, etc. Due to limited data on litter layers and understory vegetation components (i.e., shrubs, herbs, and grasses), the 15N retention of litter layers was combined into organic soil 15N retention. Within the entire forest ecosystem, the 15N retention of understory vegetation was not consider, focusing instead on the 15N allocation among different plant organs (i.e., leaves, branches, stems, roots). Ultimately, 408 observations were obtained from 56 peer-reviewed papers, totaling 62 sites and 92 site-years. The study sites were distributed across North America (25 sites), Europe (14 sites), Asia (14 sites), South America (3 sites), Oceania (4 sites), and Africa (2 sites), covering tropical forests (5 sites), subtropical forests (10 sites), temperate forests (42 sites), and boreal forests (5 sites). Raw data for 15N retention of different ecosystem compartments were obtained from tables, figures, results, or supplementary information in the peer-reviewed papers. When data were presented in figures, specific values were extracted using Getdata software 2.22 (GetData, Kogarah, NSW, AUS). Note: N_retention_data_v2 is based on N_retention_data_v1, with the addition of raw data. 'XX' in the 'forest_type' and '15N_tracer_type' sheets represents the 15N retention in different ecosystem compartments (i.e., plant, leaf, branch, stem, root, soil, organic soil, mineral soil, and total ecosystem). 'XX_n' in the 'forest_type' and '15N_tracer_type' sheets represents the sample size of 'XX'. 'XX_mean' in the 'forest_type' and '15N_tracer_type' sheets represents the mean value of 'XX'. 'XX_se' in the 'forest_type' and '15N_tracer_type' sheet represents the standard error of the mean value of 'XX'. 'NA' in the 'raw_data' sheet represents unavailable observed data. 'MAT_CRU' and 'MAP_CRU' columns of the 'raw_data' sheet indicate that the missing values in the references are extracted from the CRU.