To detect the response of permafrost to climate change in various terrestrial ecosystems, we established a permafrost monitoring network in 2007, which includes eight boreholes to monitor ground temperatures in forest, meadow, steppe, moderately dry steppe, and wetland ecosystems and three Automatic Weather Stations (AWS) to monitor climatic factors, such as wind speed (Ws), air temperature (Ta), relative humidity (RH), precipitation (P), solar radiation (Rs), net radiation (Rn), soil heat flux (SHF), soil temperature (Ts), and soil water content (SWC), in forest, meadow, and steppe ecosystems in north-central Mongolia. Major indicators, including mean annual ground temperature (MAGT), active layer thickness (ALT), and depth of zero annual amplitude (DZAA), were estimated to detect permafrost degradation. The results show that MAGT has increased by 0.00-0.02 degrees C per year (almost no change) in the ice-poor permafrost areas and by 0.03-0.06 degrees C per year in the ice-rich permafrost on pingos and wetlands. ALT showed an annual increase of -0.78 to 0.36 cm (almost no change) in the forest and meadow ecosystems and 2.3-7.2 cm in wetland ecosystems, whereas it increased by 23.0-28.9 cm per year in the steppe ecosystems over the last decade. This implies that the permafrost has degraded more rapidly in the steppe ecosystems than in other ecosystems. Based on correlation analysis, ALT is correlated to P in the meadow ecosystems and to SWC in the forest ecosystem, and MAGT is correlated to RH. However, both ALT and MAGT show a close correlation with major climatic factors, such as Ta, RH, SHF, and SWC in the steppe ecosystem. DZAA shows a close negative correlation with Ta in all ecosystems. These results provide evidence for permafrost degradation and its different responses to climate change in various terrestrial ecosystems.

Carbon dioxide fluxes between ecosystems of the Earth are presented. It was shown that intensifying its absorption of terrestrial ecosystems by 3.2% would prove sufficient to neutralize carbon dioxide emissions from the combustion of fossil fuels and cement production. It was shown that Polish forests absorb 84.6 million tons of CO2/year, that is 26% of emissions from fossil fuel combustion and cement production, while agricultural crops absorb 103 million tons of CO2/year. Total carbon dioxide sequestration by forests and agricultural crops amounts to 187.5 million tons of CO2/year, which is tantamount to 59% of emissions from fossil fuel combustion and cement production. Forestation of marginal soils would further increase carbon dioxide absorption in Poland by 20.6 million tons of CO2/year. Moreover, if plants were sown in order to produce green manure - instead of leaving soil fallow - sequestration could still be boosted by another 6.2 million tons of CO2/year.