Tea （Camellia sinensis）, an economically important crop grown in mountain regions, has been planted for thousands of years in South China. Tea plantations can potentially act as carbon （C） sink in local agrosystem...Tea （Camellia sinensis）, an economically important crop grown in mountain regions, has been planted for thousands of years in South China. Tea plantations can potentially act as carbon （C） sink in local agrosystems due to their high plant biomass and provide soil conservation service. To assess the contribution of tea plantations to C sequestration, the chronosequence variations of C storage were assessed in the plants and soils （0-20 cm） of tea plantations in China from 1950 to 2010, and then the inter-annual and decadal variabilities of total C storage were estimated. TotM C stocks in tea plants and soils in 2010 were 34.4 and 93.45 Tg, respectively. Carbon sequestration from 1950 to 2010 was 30.6 and 39.0 Tg in the plants and soils, respectively. The highest C sequestration happened during the 1980s and the lowest during the 1950s. The decadal average C sequestration rate ranged from 20.4 to 113.9 g m2 year-1 in the standing tea plants, and from 54.6 to 98.8 g m-2 year-1 in soils during the period of 1950 to 2010. The average ratio of C storage in soils to that in plants was 3.00 ± 0.35 before 1970 and 2.44 ±0.18 after 1970. The results suggested that tea plantation ecosystems made an important contribution to the C sinks in Chinese tea-producing regions.展开更多
On the basis of eight atmospheric reanalyses, we analyzed the spatial-temporal characteristics of global evaporation and also briefly evaluated the eight reanalyses. The results indicate that the long-term mean annual...On the basis of eight atmospheric reanalyses, we analyzed the spatial-temporal characteristics of global evaporation and also briefly evaluated the eight reanalyses. The results indicate that the long-term mean annual evaporation obtained from different reanalyses are consistent over most regions, with significant maritime-continental contrasts, as well as differences in meridional directions, and the land evaporation generally decreases with the increase of altitude. In addition, the temporal evolution of global evaporation varies significantly among the datasets, MERRA, ERA-Interim, NCEP-NCRA, and NCEP-DOE are very similar, whereas CFSR agrees best with ERA-40. Comparison of the inter-annual to inter-decadal variability of land evaporation reveals large differences among the reanalyses, whereas MERRA, CFSR, and NCEP-DOE are exactly similar. The temporal variation of evaporation over the oceans showed a relatively high consistency, which indicates that the quality of the reconstructed evaporation values over the oceans is higher, and even greater uncertainties lie in the estimates of evaporation over the land. In general, MERRA and NCEP-DOE may appropriately reflect the spatial-temporal characteristics of global evaporation, showing strong representativeness. The CFSR and ERA-40 are capable of revealing the characteristics of land evaporation, whereas ERA-Interim, NCEP-NCAR, OAFlux, and HOAPS are relatively applicable for research focused on the evaporation over the oceans. According to ERA-40, NCEP-NCAR, and OAFlux, global evaporation significantly decreased for the period of 1958–1978. In contrast, most of the eight reanalyses show a significant linear increase for the period of 1979–2011, and evaporation over the oceans was even more pronounced. Furthermore, the results are presented for the mean annual cycle of global evaporation, the changes at the low latitudes in the Northern Hemisphere are most distinct, and the monthly variation amplitude of the land evaporation was higher than that of the evaporation over the oceans.展开更多
基金supported by the National Key Research & Development(R&D) Plan of China(No. 2016YFD0200900)the Scientific Research Foundation of Zhejiang University of Science & Technology,China(No.F701104F03)+2 种基金the Zhejiang Provincial Natural Science Foundation of China(No.LY14D010011)the Major Science and Technology Projects of Zhejiang Province,China(No.2015C02037)the China-EU Science and Technology Cooperation Program(No. 2014DFE90040)
文摘Tea （Camellia sinensis）, an economically important crop grown in mountain regions, has been planted for thousands of years in South China. Tea plantations can potentially act as carbon （C） sink in local agrosystems due to their high plant biomass and provide soil conservation service. To assess the contribution of tea plantations to C sequestration, the chronosequence variations of C storage were assessed in the plants and soils （0-20 cm） of tea plantations in China from 1950 to 2010, and then the inter-annual and decadal variabilities of total C storage were estimated. TotM C stocks in tea plants and soils in 2010 were 34.4 and 93.45 Tg, respectively. Carbon sequestration from 1950 to 2010 was 30.6 and 39.0 Tg in the plants and soils, respectively. The highest C sequestration happened during the 1980s and the lowest during the 1950s. The decadal average C sequestration rate ranged from 20.4 to 113.9 g m2 year-1 in the standing tea plants, and from 54.6 to 98.8 g m-2 year-1 in soils during the period of 1950 to 2010. The average ratio of C storage in soils to that in plants was 3.00 ± 0.35 before 1970 and 2.44 ±0.18 after 1970. The results suggested that tea plantation ecosystems made an important contribution to the C sinks in Chinese tea-producing regions.
基金supported by the National Basic Research Program of China(Grant Nos.2013CB430204,2012CB955900)the National Natural Science Foundation of China(Grant Nos.41375078,41175084)the Special Scientific Research Fund of Meteorological Public Welfare Profession of China(Grant No.GYHY201106016)
文摘On the basis of eight atmospheric reanalyses, we analyzed the spatial-temporal characteristics of global evaporation and also briefly evaluated the eight reanalyses. The results indicate that the long-term mean annual evaporation obtained from different reanalyses are consistent over most regions, with significant maritime-continental contrasts, as well as differences in meridional directions, and the land evaporation generally decreases with the increase of altitude. In addition, the temporal evolution of global evaporation varies significantly among the datasets, MERRA, ERA-Interim, NCEP-NCRA, and NCEP-DOE are very similar, whereas CFSR agrees best with ERA-40. Comparison of the inter-annual to inter-decadal variability of land evaporation reveals large differences among the reanalyses, whereas MERRA, CFSR, and NCEP-DOE are exactly similar. The temporal variation of evaporation over the oceans showed a relatively high consistency, which indicates that the quality of the reconstructed evaporation values over the oceans is higher, and even greater uncertainties lie in the estimates of evaporation over the land. In general, MERRA and NCEP-DOE may appropriately reflect the spatial-temporal characteristics of global evaporation, showing strong representativeness. The CFSR and ERA-40 are capable of revealing the characteristics of land evaporation, whereas ERA-Interim, NCEP-NCAR, OAFlux, and HOAPS are relatively applicable for research focused on the evaporation over the oceans. According to ERA-40, NCEP-NCAR, and OAFlux, global evaporation significantly decreased for the period of 1958–1978. In contrast, most of the eight reanalyses show a significant linear increase for the period of 1979–2011, and evaporation over the oceans was even more pronounced. Furthermore, the results are presented for the mean annual cycle of global evaporation, the changes at the low latitudes in the Northern Hemisphere are most distinct, and the monthly variation amplitude of the land evaporation was higher than that of the evaporation over the oceans.
