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Observations of atmospheric gas concentrations are very useful in the study of globally important ecosystems. Past observational efforts, however, have been focused on atmospheric measurements of ‘background air’, leaving the continental interiors under-represented. I present results from pilot, multi-species, atmospheric measurement campaigns in the Hainich Forest, Germany in 2005, and I describe the development, deployment, and results from high-precision continuous atmospheric measurements of CO2, O2, CH4, CO and N2O at the Zotino Tall Tower Observatory (ZOTTO) in the boreal forest of central Siberia from November 2005 to June 2007. Atmospheric variations were studied on seasonal, synoptic and diurnal time scales. Among the interesting features of the ZOTTO record are: 1) CO2 and O2 seasonal amplitudes of 26.6 ppm and 190 per meg (equivalent to 39.8 ppm in CO2); 2) a west-east gradient of –7 ppm of CO2 (in July 2006) between Shetland Islands (Scotland) and ZOTTO that reflects summertime continental CO2 uptake; 3) attenuation of the oceanic component of the O2 seasonal amplitude (Atmospheric Potential Oxygen; APO) at ZOTTO resulting in an amplitude of 45 per meg compared to 56 per meg observed at Shetlands; 4) high fire emissions of CH4 and CO in summertime with the minima of their monthly averages similar to seasonal cycles of these gases in the marine boundary layer; 5) large vertical gradients in CO2, CH4 and CO during ‘cold events’ (air temperatures below -30°C), suggesting separated layers of air and local sources possibly combined with other effects; 6) lower CO/CO2 ratios (1-4 ppb/ppm) from fossil fuel burning compared to those measured in Europe, with large CH4 contributions; 7) diurnal vertical CO2 gradients in spring 2007 giving estimates of night-time respiration fluxes of 0.04±0.02 mol C m-2 d-1. A comparison with REgional MOdel (REMO) simulations showed discrepancies in daily averages of CO2 attributed to errors in the model’s vertical mixing and prescribed terrestrial fluxes. Nevertheless, REMO exhibited good agreement in meteorological variables (compared to weather stations close to ZOTTO) and seasonal cycles of CO2, APO and CO. Studies of fire events showed high emission ratios of CO/CO2 and CH4/CO2, comparable with those reported for similar ecosystems, and in relatively good agreement with the model estimates.