Glass Domes with Adjustable Windows: A Novel Technique for Exposing Juvenile Forest Stands to Elevated CO2 Concentration

摘要: We present a new technological approach for in situ investigation of long-term impacts elevated CO2 concentration (EC) on juvenile forests characterised by an intensive community level and canopy closure phase. Construction the glass domes is based properties earlier tested open-top chambers (OTCs). An air climatisation device together with adjustable window system, that forms shell cover domes, able to keep required [CO2] both time spatial scales relatively small consumption supplied CO2. This achieved half-closing windows windward side. evidenced good coupling treated trees atmosphere, including mutual interactions among trees. The semi-open design moderates problems strong wind, humidity, temperature gradients associated OTCs. frequency distributions environmental variations within indicate that: maintained ambient range ±1.0 °C ca. 80 % time, changes relative humidity vary from −15 0 82 time. most important chamber effect penetration solar irradiance, which reduced 26 compared open condition outside domes. dimensions are 10×10 m length 7 high central part. experiment was done three identical stands twelve-year-old Norway spruce 56 planted at two different spacings estimate stand structure relation EC.