In this paper, an updated vegetation map of the permafrost zone in the Qinghai-Tibet Plateau （QTP） was delineated. The vegetation map model was extracted from vegetation sampling with remote sensing （RS） datasets ...In this paper, an updated vegetation map of the permafrost zone in the Qinghai-Tibet Plateau （QTP） was delineated. The vegetation map model was extracted from vegetation sampling with remote sensing （RS） datasets by decision tree method. The spatial resolution of the map is 1 km×1 kin, and in it the alpine swamp meadow is firstly distinguished in the high-altitude areas. The results showed that the total vegetated area in the permafrost zone of the QTP is 1,201,751 km2. In the vegetated region, 50,260 km2 is the areas of alpine swamp meadow, 583,909 km2 for alpine meadow, 332,754 km2 for alpine steppe, and 234,828 km2 for alpine desert. This updated vegetation map in permafrost zone of QTP could provide more details about the distribution of alpine vegetation types for studying the vegetation mechanisms in the land surface processes of highaltitude areas.展开更多
The fluxes of CO2 and CH4 emission of the two types of primary swamp were measured in Sanjiang Plain using the opaque chamber and gas chromatogram technique. The mean value of ecosystem respiration flux in continuousl...The fluxes of CO2 and CH4 emission of the two types of primary swamp were measured in Sanjiang Plain using the opaque chamber and gas chromatogram technique. The mean value of ecosystem respiration flux in continuously inundated swamp ecosystem is 548.04 mg·m-2·h-1, lower than that of the seasonal inundated swamp (713.08 mg· m-2·h-1). The peaks concentrated on July and August which are the growing period of the vegetation. CH4 emission was different from the respiration flux of ecosystem. The CH4 flux of continuously inundated swamp was 12.80 mg·m-2· h-1, larger than that of the seasonal inundated swamp (8.56 mg·m-2·h-1), and they were varied at different periods, the continuously inundated swamp emitted CH4 mainly from July to September, whereas from last August to middle Sep-tember in the seasonal inundated swamp. The ecosystem respiration flux of the swamp has the significantly positive correlation with the soil temperature (0—10 cm depth) and the water temperature, but CH4 emission was associated with the soil temperature in a certain degree. The CH4 emission from swamp depends on the integral function of water table and soil temperature.展开更多
Based on plant specimen data,sediment samples,photos,and sketches from 45 coastal cross-sections,and materials from two recent countrywide comprehensive investigations on Chinese coasts and is-lands,this paper deals w...Based on plant specimen data,sediment samples,photos,and sketches from 45 coastal cross-sections,and materials from two recent countrywide comprehensive investigations on Chinese coasts and is-lands,this paper deals with China’s vegetative tidal-flats:salt marshes and mangrove swamps.Thereare now 141700 acres of salt marshes and 51000 acres of mangrove swamps which together cover about30% of the mud-coast area of the country and distribute between 18°N(Southem Hainan Island)and41°N(Liaodong Bay).Over the past 45 years.about 1750000 acres of salt marshes and 49400 acres ofmangrove swamps have been reclaimed.The2.0×10~9 tons of fine sediments input by rivers into the Chinese seas form extensive tidal flats,the soil basis of coastal helophytes.Different climates result inthe diversity of vegetation.The 3～8m tidal range favors intertidal zone development.Of over 20plant species in the salt marshes,native Suaeda salsa,Phragmites australis,Aeluropus littoralis,Zoysiamaerostachys,Imperata cylindrica and展开更多
基金supported by the National Natural Science Foundation of China (Grant No.41101055)the Hundred Talents Program of the Chinese Academy of Sciences granted to Tonghua Wu (Grant No.51Y251571)the “National Basic Research Program of China (973 Program)” (Grant No.2010CB951402)
文摘In this paper, an updated vegetation map of the permafrost zone in the Qinghai-Tibet Plateau （QTP） was delineated. The vegetation map model was extracted from vegetation sampling with remote sensing （RS） datasets by decision tree method. The spatial resolution of the map is 1 km×1 kin, and in it the alpine swamp meadow is firstly distinguished in the high-altitude areas. The results showed that the total vegetated area in the permafrost zone of the QTP is 1,201,751 km2. In the vegetated region, 50,260 km2 is the areas of alpine swamp meadow, 583,909 km2 for alpine meadow, 332,754 km2 for alpine steppe, and 234,828 km2 for alpine desert. This updated vegetation map in permafrost zone of QTP could provide more details about the distribution of alpine vegetation types for studying the vegetation mechanisms in the land surface processes of highaltitude areas.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences(Grant Nos.KZCX1-SW-01 and KZCX3-SW-332)the LAPC National Lab of Institute of Atmosphere Physics,the Chinese Academy of Sciences
文摘The fluxes of CO2 and CH4 emission of the two types of primary swamp were measured in Sanjiang Plain using the opaque chamber and gas chromatogram technique. The mean value of ecosystem respiration flux in continuously inundated swamp ecosystem is 548.04 mg·m-2·h-1, lower than that of the seasonal inundated swamp (713.08 mg· m-2·h-1). The peaks concentrated on July and August which are the growing period of the vegetation. CH4 emission was different from the respiration flux of ecosystem. The CH4 flux of continuously inundated swamp was 12.80 mg·m-2· h-1, larger than that of the seasonal inundated swamp (8.56 mg·m-2·h-1), and they were varied at different periods, the continuously inundated swamp emitted CH4 mainly from July to September, whereas from last August to middle Sep-tember in the seasonal inundated swamp. The ecosystem respiration flux of the swamp has the significantly positive correlation with the soil temperature (0—10 cm depth) and the water temperature, but CH4 emission was associated with the soil temperature in a certain degree. The CH4 emission from swamp depends on the integral function of water table and soil temperature.
基金The project was supported by the NSFC(No.49476281)
文摘Based on plant specimen data,sediment samples,photos,and sketches from 45 coastal cross-sections,and materials from two recent countrywide comprehensive investigations on Chinese coasts and is-lands,this paper deals with China’s vegetative tidal-flats:salt marshes and mangrove swamps.Thereare now 141700 acres of salt marshes and 51000 acres of mangrove swamps which together cover about30% of the mud-coast area of the country and distribute between 18°N(Southem Hainan Island)and41°N(Liaodong Bay).Over the past 45 years.about 1750000 acres of salt marshes and 49400 acres ofmangrove swamps have been reclaimed.The2.0×10~9 tons of fine sediments input by rivers into the Chinese seas form extensive tidal flats,the soil basis of coastal helophytes.Different climates result inthe diversity of vegetation.The 3～8m tidal range favors intertidal zone development.Of over 20plant species in the salt marshes,native Suaeda salsa,Phragmites australis,Aeluropus littoralis,Zoysiamaerostachys,Imperata cylindrica and
