Plot code is unified in the whole CERN. The code is composed of station code (three letters), plot type code (two letters), plot sequence number (two numbers), observing content code (three letters and/or numbers), underline “_”, and plot property code (two numbers). Plot type code: ZH = comprehensive plot, FZ = auxiliary plot, ZQ = survey plot. Observing content code: A = biotic observing, B = soil observing, C = water observing, with number zero “0” representing absent of any observing content. Plot property code: “01” = plot for permanent observing, “02” = plot for destructive sampling. For example, BJFZH01ABC_01 represents the comprehensive plot used for permanent observation of biology, soil and water in Beijing Forest Ecosystem Research Station.