Tellus B (Impact Factor: 2.15). 08/1997; 49(4):393 - 408.
ABSTRACTA better understanding of the long-term global carbon cycle requires improved estimates of the changes in terrestrial carbon storage (vegetation and soil) during the last glacial-interglacial transition. A set of reconstructions of palaeovegetation and palaeoclimate in China for the last glacial maximum (LGM) and the mid-Holocene (MH) allows us to use the Osnabrück biosphere model (OBM), which needs as input only 3 climatic parameters that are easily derivable from palaeodata, to reconstruct the past terrestrial carbon storage since the LGM. The change from the conditions of the LGM (colder and drier than present) to the MH (warmer and wetter than present) resulted in a gain of 116 Pg of terrestrial carbon in China mainly due to the build-up of temperate forest and tropical monsoon rain forest, and to the effects of changes in climate and CO2 levels. However, a loss of 26 Pg of terrestrial carbon (which does not include anthropogenic disturbances) occurred in China between the MH and the present due to shifts in the area covered by the main vegetation types. Results also show that glacial-interglacial changes in climate and vegetation distribution, both associated with variations in the Asian monsoon system, significantly affected terrestrial carbon storage in China which strongly contributed to the global carbon cycle.
"Currently, China retains approximately 137.5 million hectares of cropland (NSSO, 1998) from the southern tropical-humid zone to the northern temperate-arid zone. Its long history of agricultural exploitation and changes in land use suggest that the terrestrial ecosystem of China probably played an important role in the global C cycle (Fang et al., 1996; Peng and Apps, 1997; Zhao et al., 1997; Li and Zhao, 2001; Wu et al., 2003; Pan et al., 2003). An attempt was made to estimate the SIC pool (from 60 to 234.2 Pg C) in China by Pan (1999) and Li et al. (2007) based on approximately 2500 soil profile data. "
[Show abstract][Hide abstract] ABSTRACT: The accurate estimation of soil carbon (C) stocks is a necessary component for understanding the global C budget. Although the importance of soil organic C (SOC) within the C cycle is well established, the quantity of soil inorganic C (SIC, including lithogenic and pedogenic inorganic C) pool, another important soil C pool component, has been poorly studied to date. In this study, soil profile data compiled by China's second national soil survey conducted in the 1980s was used to investigate the spatial distribution of SIC for the entire country under present day conditions as well as changes in SIC under historical land use. Results showed that the total SIC storage in China was approximately 55.3 ± 10.7 Pg C with a current average content of 6.3 ± 1.2 kg C m−2, representing 5.8% of the global SIC pool. Land use has significantly affected SIC levels in cultivated soils. Approximately 51% of total cultivated soil surfaces in China have experienced C loss where the most significant loss has been observed in the eastern part of northern China in dry farmlands as well as irrigated soils and paddy soils. On the contrary, SIC has increased (∼10%) in irrigated soils in northwestern China. No significant change (∼39%) has been observed in soils in southern and the eastern part of northeast China. The total loss of SIC in China was approximately 1.6 Pg C due to extensive human activity. Results of this study indicate that human activity may have had a great impact on SIC as well as SOC pools.
"Table 3 Comparisons of China's SOC storage between this study and previous estimates Data source Soil depth (m) SOC storage (Pg) Reference China's first national soil survey Average depth 185.7 Fang et al. 1996 WOSCN database (Zinke et al. 1984) 1 101.1 Peng & Apps 1997 WOSCN database (Zinke et al. 1984) 1 119.8 Ni 2001 China's second national soil survey 1 92.0 Wang et al. 2003 China's second national soil survey Actual depth 70.3 Wu et al. 2003a China's second national soil survey and field measurement 1 68.1 This study Biogeochemistry "
[Show abstract][Hide abstract] ABSTRACT: Based on the data from China’s second national soil survey and field observations in northwest China, we estimated soil organic
carbon (SOC) storage in China and investigated its spatial and vertical distribution. China’s SOC storage in a depth of 1meter
was estimated as 69.1Pg (1015g), with an average density of 7.8kgm−2. About 48% of the storage was concentrated in the top 30cm. The SOC density decreased from the southeast to the northwest,
and increased from arid to semi-humid zone in northern China and from tropical to cold-temperate zone in the eastern part
of the country. The vertical distribution of SOC differed in various climatic zones and biomes; SOC distributed deeper in
arid climate and water-limited biomes than in humid climate. An analysis of general linear model suggested that climate, vegetation,
and soil texture significantly influenced spatial pattern of SOC, explaining 78.2% of the total variance, and that climate
and vegetation interpreted 78.9% of the total variance in the vertical SOC distribution.
[Show abstract][Hide abstract] ABSTRACT: The effects of climate change and doubling atmospheric CO 2 on carbon dynamics of the boreal forest in the area of the Boreal Forest Transect Case Study in central Canada were investigated using the process-based plant-soil model CENTURY 4.0. The results presented here suggest that: 1) across the transect climate change would result in increased total carbon in vegetation biomass but decreased overall carbon in soil; 2) increased atmospheric CO 2 concentration under current climatic patterns would result in increased total carbon in vegetation and in soil organic matter; and 3) combined climate change and elevated CO 2 would increase both net primary productivity and decomposition rates relative to the current climate condition, but their combined action would be reduction of soil carbon losses relative to those due to climate change along. The interactive effects of climate change and elevated CO 2, however, are not a simple additive combination of the individual responses. The responses to climate change and elevated CO 2 vary across the climate gradient from southern to northern sites on the transect. The present simulations indicate that the northern sites are more sensitive to climate change than the southern sites are, but these simulations do not consider likely changes in the disturbance regime or changes in forest species distribution.
Global Biogeochemical Cycles 06/1998; 12(2-2):393-402. DOI:10.1029/98GB00352 · 3.97 Impact Factor
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