Basic statistics of core variables.

C/R = country/region; BavG = Bavaria_Germany; SLO = Slovenia; SWE = Sweden; Var = Variable; Y = year; n = number of plots; M = mean value; s = sample standard deviation; s% = coefficient of variation; E = standard error; E% = relative standard error; E%all = allowable relative standard error; ngf = n computed by general formula for non-stratified sampling n = (1.96×s%/E%all)2; See also abbreviations in Table 1.