Spatial distribution of organic carbon in soils is difficult to estimatebecause of inherent spatial variability and insufficient data. A soil-landscape model for a region,based on 151 samples for parent material and t...Spatial distribution of organic carbon in soils is difficult to estimatebecause of inherent spatial variability and insufficient data. A soil-landscape model for a region,based on 151 samples for parent material and topographic factors, was established using a GISspatial analysis technique and a digital elevation model (DEM) to reveal spatial distributioncharacteristics of soil organic carbon (SOC). Correlations between organic carbon and topographicfactors were analyzed and a regression model was established to predict SOC content. Results forsurface soils (0-20 cm) showed that the average SOC content was 12.8 g kg^(-1), with the SOC contentbetween 6 and 12 g kg^(-1) occupying the largest area and SOC over 24 g kg^(-1) the smallest. Also,soils derived from phyllite were the highest in the SOC content and area, while soils developed onpurple shale the lowest. Although parent material, elevation, and slope exposure were allsignificant topographic variables (P < 0.01), slope exposure had the highest correlation to SOCcontent (r = 0.66). Using a multiple regression model (R^2 = 0.611) and DEM (with a 30 m X 30 mgrid), spatial distribution of SOC could be forecasted.展开更多
Based on the investigation on shellfish resources from the intertidal zone to subtidal zone of Fenjiezhou Island,Hainan during 2012-2014,the quantity,species,ecological distribution and floristic characters of shellfi...Based on the investigation on shellfish resources from the intertidal zone to subtidal zone of Fenjiezhou Island,Hainan during 2012-2014,the quantity,species,ecological distribution and floristic characters of shellfish from the intertidal zone to subtidal zone of Fenjiezhou Island were analyzed.The results showed that a total of 137 shellfish species were found in Fenjiezhou Island,and they belonged to 4 classes [Polyplacophora（1 species）,Gastropoda（94 species）,Bivalvia（40species）,Cephalopoda（2 species）],13 orders and 44 families.Among the families,Cypraeidae included 11 species,Muricacea included 9 species,Veneracea included9 species,Conidae included 8 species,Strombidae included 6 species,Cymatiidae included 6 species,and the other families all included less than 5 species.According to the characteristics of the components,most of the species belonged to the tropical or subtropical region,and they had a close relationship with coral reef.According to the floristic characters,the shellfish in Fenjiezhou Island belonged to the Indonesia-Malayan Subregion of Indo-West Pacific Region.展开更多
Using 12 years of data from the Tropical Rainfall Measuring Mission(TRMM)-based Precipitation Radar(PR),spatial and diurnal variations of deep convective systems(DCSs)over the Asian monsoon region are analyzed.The DCS...Using 12 years of data from the Tropical Rainfall Measuring Mission(TRMM)-based Precipitation Radar(PR),spatial and diurnal variations of deep convective systems(DCSs)over the Asian monsoon region are analyzed.The DCSs are defined by a 20 dBZ echo top extending 14 km.The spatial distribution of DCSs genesis is also discussed,with reference to the National Centers for Environmental Prediction(NCEP)reanalysis data.The results show that DCSs occur mainly over land.They concentrate in south of 20°N during the pre-monsoon season,and then move distinctly to mid-latitude regions,with the most active region on the south slope of the Himalayas during monsoon season.DCSs over the Tibetan Plateau are more frequent than those in central-eastern China,but smaller in horizontal scale and weaker in convective intensity.DCSs in central-eastern China have more robust updrafts and generate more lightning flashes than in other Asian monsoon regions.The horizontal scale of DCSs over the ocean is larger than that over the other regions,and the corresponding minimum infrared(IR)brightness temperature is lower,whereas the convective intensity is weaker.Continental DCSs are more common from noon through midnight,and DCSs over the Tibetan Plateau are more frequently from noon through evening.Oceanic DCSs frequency has a weaker diurnal cycle with dawn maximum,and diurnal variation of DCSs over the tropical maritime continent is consistent with that over the continent.展开更多
基金Project supported by the National Key Basic Research Support Foundation of China (No. G1999011810) the Key Innovation Project of Chinese Academy of Sciences (No. KZCX1-SW01-19) the Frontier Project of the Chinese Academy of Sciences (No. ISSASIP0201
文摘Spatial distribution of organic carbon in soils is difficult to estimatebecause of inherent spatial variability and insufficient data. A soil-landscape model for a region,based on 151 samples for parent material and topographic factors, was established using a GISspatial analysis technique and a digital elevation model (DEM) to reveal spatial distributioncharacteristics of soil organic carbon (SOC). Correlations between organic carbon and topographicfactors were analyzed and a regression model was established to predict SOC content. Results forsurface soils (0-20 cm) showed that the average SOC content was 12.8 g kg^(-1), with the SOC contentbetween 6 and 12 g kg^(-1) occupying the largest area and SOC over 24 g kg^(-1) the smallest. Also,soils derived from phyllite were the highest in the SOC content and area, while soils developed onpurple shale the lowest. Although parent material, elevation, and slope exposure were allsignificant topographic variables (P < 0.01), slope exposure had the highest correlation to SOCcontent (r = 0.66). Using a multiple regression model (R^2 = 0.611) and DEM (with a 30 m X 30 mgrid), spatial distribution of SOC could be forecasted.
文摘Based on the investigation on shellfish resources from the intertidal zone to subtidal zone of Fenjiezhou Island,Hainan during 2012-2014,the quantity,species,ecological distribution and floristic characters of shellfish from the intertidal zone to subtidal zone of Fenjiezhou Island were analyzed.The results showed that a total of 137 shellfish species were found in Fenjiezhou Island,and they belonged to 4 classes [Polyplacophora（1 species）,Gastropoda（94 species）,Bivalvia（40species）,Cephalopoda（2 species）],13 orders and 44 families.Among the families,Cypraeidae included 11 species,Muricacea included 9 species,Veneracea included9 species,Conidae included 8 species,Strombidae included 6 species,Cymatiidae included 6 species,and the other families all included less than 5 species.According to the characteristics of the components,most of the species belonged to the tropical or subtropical region,and they had a close relationship with coral reef.According to the floristic characters,the shellfish in Fenjiezhou Island belonged to the Indonesia-Malayan Subregion of Indo-West Pacific Region.
基金supported jointly by the National Basic Research Program of China(Grant No.2010CB428601)the National Natural Science Foundation of China(Grant Nos. 40930949&40905008)
文摘Using 12 years of data from the Tropical Rainfall Measuring Mission(TRMM)-based Precipitation Radar(PR),spatial and diurnal variations of deep convective systems(DCSs)over the Asian monsoon region are analyzed.The DCSs are defined by a 20 dBZ echo top extending 14 km.The spatial distribution of DCSs genesis is also discussed,with reference to the National Centers for Environmental Prediction(NCEP)reanalysis data.The results show that DCSs occur mainly over land.They concentrate in south of 20°N during the pre-monsoon season,and then move distinctly to mid-latitude regions,with the most active region on the south slope of the Himalayas during monsoon season.DCSs over the Tibetan Plateau are more frequent than those in central-eastern China,but smaller in horizontal scale and weaker in convective intensity.DCSs in central-eastern China have more robust updrafts and generate more lightning flashes than in other Asian monsoon regions.The horizontal scale of DCSs over the ocean is larger than that over the other regions,and the corresponding minimum infrared(IR)brightness temperature is lower,whereas the convective intensity is weaker.Continental DCSs are more common from noon through midnight,and DCSs over the Tibetan Plateau are more frequently from noon through evening.Oceanic DCSs frequency has a weaker diurnal cycle with dawn maximum,and diurnal variation of DCSs over the tropical maritime continent is consistent with that over the continent.
