The taxonomic status of long-tailed field mouse (Apodemus orestes) is still uncertain up to now.Some scholars regarded it as a subspecies or a synonym of dragon field mouse (A.draco),while other scholars considered it...The taxonomic status of long-tailed field mouse (Apodemus orestes) is still uncertain up to now.Some scholars regarded it as a subspecies or a synonym of dragon field mouse (A.draco),while other scholars considered it a valid species.In the study,five specimens of adult long-tailed field mouse,dragon field mouse and Chevrier's field mouse (A.chevrieri) (as a contrast) were chosen respectively.After treated,with the eyepiece micrometer in the inverted microscope,we made measurements of the widths of hairs and medullas and then calculated the medullary indexes of straight guard hairs from around the mouth,head,back,abdomen and forelimb of each species.The results indicate that,viewing at each of the five parts and the mixture of the five parts,there are no significant differences between A.orestes and A.draco,Significant differences can be found between A.orestes & A.chevrieri and A.draco & A.chevrieri though.The standpoint that A.orestes was listed as a valid species is not supported by this study.展开更多
Based on the daily precipitation data of 83 stations in Guangxi and the NCEP/NCAR monthly reanalysis data from 1979 through 2008, the characteristics of spatial and temporal distribution and variation of the rainstorm...Based on the daily precipitation data of 83 stations in Guangxi and the NCEP/NCAR monthly reanalysis data from 1979 through 2008, the characteristics of spatial and temporal distribution and variation of the rainstorm concentration degree(RCD) and the rainstorm concentration period(RCP) are analyzed by using the methods of Monte Carlo test etc. The results are shown as follows. The rainstorm events are concentrated in April-September, taking up about 90% of the yearly rainfall total, and the percentages of rainstorms in the annual total precipitation have an increasing tendency. RCD in the east of Guangxi is larger than that in the west. The RCP in the northeast and southwest of Guangxi is later than that in the other regions, and has the earliest onset in the northern mountainous regions of Baise and southeast Guangxi. The RCD exhibits an increasing tendency in the northwest and the coastal region while showing a decreasing tendency in the other regions. On a long-term basis, the RCP in the east and coastal region has a postponing trend but tends to be earlier in the other regions. The proposed mechanism is as follows: If the geopotential height in the south of Qinghai-Tibet Plateau and the West Pacific has a highly negative anomaly in winter, the western Pacific subtropical high will be strong in summer, which increases the RCD in Guangxi. If the geopotential height has a highly positive anomaly in winter, the subtropical high will have a significant periodic oscillation in summer, which decreases the RCD in Guangxi. The value of RCD is high(low) in the area of northern mountainous regions of Guangxi and Beihai in strong(weak) South China Sea summer monsoon years, while in the other areas, the value of RCD is low(high).展开更多
The dynamics of high-altitude inland lakes in the Tibetan Plateau are sensitive indicators of climate change. Due to the remoteness and hard access, satellite altimetry becomes an effective approach to obtaining large...The dynamics of high-altitude inland lakes in the Tibetan Plateau are sensitive indicators of climate change. Due to the remoteness and hard access, satellite altimetry becomes an effective approach to obtaining largescale and temporally continuous information of lake-level changes. The CryoSat-2 altimetry is expected to solve the current problem that earlier radar altimeters are only practical for monitoring large water bodies, while ICESat laser altimetry is available only for the period 2003-2009. In this study, the comparison of CryoSat-2 altimetry for Namco with in situ water-level data suggests a high cor- relation coefficient of 0.71 （P 〈 0.01）, with the mean error of -0.12 m and root-mean-square error of 0.18 m. Further, the combination of ICESat and CryoSat-2 altimetry data and in situ lake-level observations reveals a rapid water- level rise of 0.24 4- 0.04 m/year during 2003-2008 and then a slightly decreasing trend of -0.09 4- 0.04 m/year during 2009-2013. This study suggests that the CryoSat-2 altimetry has the potential of sustaining the fine observa- tions on Tibetan lakes, following the ICESat mission. Besides, the examination of four key climatic variables （temperature, precipitation, potential evapotranspiration, and relative humidity） during 1990-2013 indicates that the wetting climate over Namco Basin stagnated or even reversed around 2006, which may be tightly related to the slowing lake growth.展开更多
文摘The taxonomic status of long-tailed field mouse (Apodemus orestes) is still uncertain up to now.Some scholars regarded it as a subspecies or a synonym of dragon field mouse (A.draco),while other scholars considered it a valid species.In the study,five specimens of adult long-tailed field mouse,dragon field mouse and Chevrier's field mouse (A.chevrieri) (as a contrast) were chosen respectively.After treated,with the eyepiece micrometer in the inverted microscope,we made measurements of the widths of hairs and medullas and then calculated the medullary indexes of straight guard hairs from around the mouth,head,back,abdomen and forelimb of each species.The results indicate that,viewing at each of the five parts and the mixture of the five parts,there are no significant differences between A.orestes and A.draco,Significant differences can be found between A.orestes & A.chevrieri and A.draco & A.chevrieri though.The standpoint that A.orestes was listed as a valid species is not supported by this study.
基金National Basic Research Program of China(973 Program)(2013CB430202)Guangxi Natural Science Foundation(0991060)Guangxi Natural Science Foundation(2013GXNSFAA019273)
文摘Based on the daily precipitation data of 83 stations in Guangxi and the NCEP/NCAR monthly reanalysis data from 1979 through 2008, the characteristics of spatial and temporal distribution and variation of the rainstorm concentration degree(RCD) and the rainstorm concentration period(RCP) are analyzed by using the methods of Monte Carlo test etc. The results are shown as follows. The rainstorm events are concentrated in April-September, taking up about 90% of the yearly rainfall total, and the percentages of rainstorms in the annual total precipitation have an increasing tendency. RCD in the east of Guangxi is larger than that in the west. The RCP in the northeast and southwest of Guangxi is later than that in the other regions, and has the earliest onset in the northern mountainous regions of Baise and southeast Guangxi. The RCD exhibits an increasing tendency in the northwest and the coastal region while showing a decreasing tendency in the other regions. On a long-term basis, the RCP in the east and coastal region has a postponing trend but tends to be earlier in the other regions. The proposed mechanism is as follows: If the geopotential height in the south of Qinghai-Tibet Plateau and the West Pacific has a highly negative anomaly in winter, the western Pacific subtropical high will be strong in summer, which increases the RCD in Guangxi. If the geopotential height has a highly positive anomaly in winter, the subtropical high will have a significant periodic oscillation in summer, which decreases the RCD in Guangxi. The value of RCD is high(low) in the area of northern mountainous regions of Guangxi and Beihai in strong(weak) South China Sea summer monsoon years, while in the other areas, the value of RCD is low(high).
基金supported by the National Special Basic Research Project of the Ministry of Science and Technology(2013FY111400-2,2009CB723901)the National Natural Science Foundation of China(41120114001,41125003,41071254,40971048)+3 种基金the European Space Agency(ESA AO 2605)the Knowledge Innovation Foundation Program for outstanding Young Scholar of Chinese Academy of Sciences(CAS)(KZCX2-EWQN104)supported by Open Research Fund of Key Laboratory of Tibetan Environmental Changes and Land Surface Processes in Chinese Academy of SciencesOpen Fund of State Key Laboratory of Remote Sensing Science
文摘The dynamics of high-altitude inland lakes in the Tibetan Plateau are sensitive indicators of climate change. Due to the remoteness and hard access, satellite altimetry becomes an effective approach to obtaining largescale and temporally continuous information of lake-level changes. The CryoSat-2 altimetry is expected to solve the current problem that earlier radar altimeters are only practical for monitoring large water bodies, while ICESat laser altimetry is available only for the period 2003-2009. In this study, the comparison of CryoSat-2 altimetry for Namco with in situ water-level data suggests a high cor- relation coefficient of 0.71 （P 〈 0.01）, with the mean error of -0.12 m and root-mean-square error of 0.18 m. Further, the combination of ICESat and CryoSat-2 altimetry data and in situ lake-level observations reveals a rapid water- level rise of 0.24 4- 0.04 m/year during 2003-2008 and then a slightly decreasing trend of -0.09 4- 0.04 m/year during 2009-2013. This study suggests that the CryoSat-2 altimetry has the potential of sustaining the fine observa- tions on Tibetan lakes, following the ICESat mission. Besides, the examination of four key climatic variables （temperature, precipitation, potential evapotranspiration, and relative humidity） during 1990-2013 indicates that the wetting climate over Namco Basin stagnated or even reversed around 2006, which may be tightly related to the slowing lake growth.
