Temperature sensitivity of respiration of forest soils is important for its responses to climate warming and for the accurate assessment of soil carbon budget. The sensitivity of temperature (T_(i)) to soil respiratio...Temperature sensitivity of respiration of forest soils is important for its responses to climate warming and for the accurate assessment of soil carbon budget. The sensitivity of temperature (T_(i)) to soil respiration rate (R_(s)), and Q_(10) defined by e^(10(lnRs−lna)/Ti) has been used extensively for indicating the sensitivity of soil respiration. The soil respiration under a larch (Larix gmelinii) forest in the northern Daxing’an Mountains, Northeast China was observed in situ from April to September, 2019 using the dynamic chamber method. Air temperatures (T_(air)), soil surface temperatures (T_(0cm)), soil temperatures at depths of 5 and 10 cm (T_(5cm) and T_(10cm), respectively), and soil-surface water vapor concentrations were monitored at the same time. The results show a significant monthly variability in soil respiration rate in the growing season (April–September). The Q_(10) at the surface and at depths of 5 and 10 cm was estimated at 5.6, 6.3, and 7.2, respectively. The Q_(10@10 cm) over the period of surface soil thawing (Q_(10@10 cm, thaw) = 36.89) were significantly higher than that of the growing season (Q_(10@10 cm, growth )= 3.82). Furthermore, the Rs in the early stage of near-surface soil thawing and in the middle of the growing season is more sensitive to changes in soil temperatures. Soil temperature is thus the dominant factor for season variations in soil respiration, but rainfall is the main controller for short-term fluctuations in respiration. Thus, the higher sensitivity of soil respiration to temperature (Q_(10)) is found in the middle part of the growing season. The monthly and seasonal Q_(10) values better reflect the responsiveness of soil respiration to changes in hydrometeorology and ground freeze-thaw processes. This study may help assess the stability of the soil carbon pool and strength of carbon fluxes in the larch forested permafrost regions in the northern Daxing’an Mountains.展开更多
The Engineering Geological Map of the Sakha（Yakutia） Republic covers about 3 million kilometers which is one-fifth of the territory of Russia.The map displays ground and geocryological conditions and active faults.S...The Engineering Geological Map of the Sakha（Yakutia） Republic covers about 3 million kilometers which is one-fifth of the territory of Russia.The map displays ground and geocryological conditions and active faults.Seismic intensity,schemes of zoning by factors of engineering geological conditions,and the general scheme of engineering geological zoning of the Sakha（Yakutia） Republic or the SR（Y）,are shown on the inset maps.The map is required to provide information for planning,construction and exploitation of engineering structures in the SR（Y）.A distinguishing feature of the map is the indication of almost blanket distribution of the frozen ground class.Types of the frozen ground class are separated by lithology,while ground varieties are separated by temperature.Fresh and ultra-fresh suprapermafrost water is predominant within the territory.The compiled map indicates parts of the Arctic-Asian and Baikalo-Stanovoi planetary seismic belts that make engineering geological conditions more complicated.展开更多
基金financially supported by the CFERNthe Funds of the Beijing Techno Solutions Award on Excellence in Academic Achievementsthe National Key Research and Development Program of China (2017YFC0504003)
文摘Temperature sensitivity of respiration of forest soils is important for its responses to climate warming and for the accurate assessment of soil carbon budget. The sensitivity of temperature (T_(i)) to soil respiration rate (R_(s)), and Q_(10) defined by e^(10(lnRs−lna)/Ti) has been used extensively for indicating the sensitivity of soil respiration. The soil respiration under a larch (Larix gmelinii) forest in the northern Daxing’an Mountains, Northeast China was observed in situ from April to September, 2019 using the dynamic chamber method. Air temperatures (T_(air)), soil surface temperatures (T_(0cm)), soil temperatures at depths of 5 and 10 cm (T_(5cm) and T_(10cm), respectively), and soil-surface water vapor concentrations were monitored at the same time. The results show a significant monthly variability in soil respiration rate in the growing season (April–September). The Q_(10) at the surface and at depths of 5 and 10 cm was estimated at 5.6, 6.3, and 7.2, respectively. The Q_(10@10 cm) over the period of surface soil thawing (Q_(10@10 cm, thaw) = 36.89) were significantly higher than that of the growing season (Q_(10@10 cm, growth )= 3.82). Furthermore, the Rs in the early stage of near-surface soil thawing and in the middle of the growing season is more sensitive to changes in soil temperatures. Soil temperature is thus the dominant factor for season variations in soil respiration, but rainfall is the main controller for short-term fluctuations in respiration. Thus, the higher sensitivity of soil respiration to temperature (Q_(10)) is found in the middle part of the growing season. The monthly and seasonal Q_(10) values better reflect the responsiveness of soil respiration to changes in hydrometeorology and ground freeze-thaw processes. This study may help assess the stability of the soil carbon pool and strength of carbon fluxes in the larch forested permafrost regions in the northern Daxing’an Mountains.
文摘The Engineering Geological Map of the Sakha（Yakutia） Republic covers about 3 million kilometers which is one-fifth of the territory of Russia.The map displays ground and geocryological conditions and active faults.Seismic intensity,schemes of zoning by factors of engineering geological conditions,and the general scheme of engineering geological zoning of the Sakha（Yakutia） Republic or the SR（Y）,are shown on the inset maps.The map is required to provide information for planning,construction and exploitation of engineering structures in the SR（Y）.A distinguishing feature of the map is the indication of almost blanket distribution of the frozen ground class.Types of the frozen ground class are separated by lithology,while ground varieties are separated by temperature.Fresh and ultra-fresh suprapermafrost water is predominant within the territory.The compiled map indicates parts of the Arctic-Asian and Baikalo-Stanovoi planetary seismic belts that make engineering geological conditions more complicated.
