This document describes the measurements to perform at mire stations for the characterization of the site investigated. These measurements are performed at the beginning of the ICOS operation of the station and are aimed at assessing the spatial heterogeneity of the mire vegetation. More specifically, they are done (i) to identify the main plant community types that make up the target area and (ii) to evaluate the representativeness of Continuous Measurements Plots (CPs). The methodology for the site characterization is described below. Its implementation has for each station to be discussed and agreed with ETC, adapting it to the complexity and the accessibility of the mire. If existing stations have in the recent past done efforts similar to the ones described in this document, it can be discussed with ETC if and how the available data can be used for ICOS.