The investigations on the organic carbon （OC） of core sediments were carried out in Chongming east tidal fiat （CM） during Scirpus mariqueter growing stage （from April to December 2004） in Yangtze Estuary. The Ya...The investigations on the organic carbon （OC） of core sediments were carried out in Chongming east tidal fiat （CM） during Scirpus mariqueter growing stage （from April to December 2004） in Yangtze Estuary. The Yangtze River annually transports a runoff discharge of 30,000 m^3/s, carrying about 480 million tons of sediments to the estuarine and coastal area, which formed a great OC pool. In the sampling spots, seven quadrats of 50 cm × 50 cm and five sediments cores of 20 cm deep （40 cm deep in December） were randomly established in order to collect vegetations and core sediments samples during the low tide each month except November. After pretreatment, the core sediments were sieved and their OC contents were measured according to the potassium dichromate method. The results show that the higher surface sediment OC content in summer comes from allochthonous terrigenous particle settlements on the Chongming east middle tidal fiat S. mariqueter zone. In autumn and winter, the decomposing of the defoliated S. mariqueter increases the surface sediments OC content. Settling velocity, sediment temperature and S. mariqueter growth are the main factors that can control the sediment carbon content. Summer is the “carbon losing” period of the tidal fiat sediments, while from September, it changes into the “carbon accumulating” period of sediment OC pool because of the decomposing of dead S. mariqueter community in the sediments. From this alternation of “carbon losing” period and “carbon accumulating” period, we conclude that carbon in the OC pool of the middle tidal fiat S. mariqueter zone sediments mainly comes from the atmospheric carbon rooted by S. mariqueter photosynthesis.展开更多
The resistance and cross-resistance of Scirpus juncoides Roxb.to ALS-inhibiting herbicides were tested to provide theoretical basis for effectively control Scirpus juncoides Roxb.and rational use of herbicides.To iden...The resistance and cross-resistance of Scirpus juncoides Roxb.to ALS-inhibiting herbicides were tested to provide theoretical basis for effectively control Scirpus juncoides Roxb.and rational use of herbicides.To identify the resistance and crossresistance of 19 populations from nine areas in Heilongjiang Province to four ALS-inhibiting herbicides by agar method and the whole-plant assay.The results are as the followings,the two bioassay methods had good correlation,the resistance indexes in the same area were different by two means,but resistant level was the same,similarity up to 89.5%.The resistant rates to pyrazosulfuronethyl,bensulfuron-methyl,penoxsulam and pyribenzoxim were 26.3%,36.8%,36.1%and 21.1%,respectively.Shangzhi populations evolved the highest level of resistance to pyrazosulfuron-methyl with a resistance index of 15.56.Shangzhi,Tonghe,Fangzheng and Jixi populations showed cross-resistance to four ALS-inhibiting herbicides,accounting for 26.3%.The resistance of Scirpus juncoides Roxb.to four ALS-inhibiting herbicides in Heilongjiang paddy field was low to moderate,five populations showed cross-resistance to four ALS-inhibiting herbicides.展开更多
The research aimed to evaluate the absorption and removal capacity of Cu, Pb, Fe and Zn from Scirpus californicus for potential use in the remediation of polluted aquatic environments. Initially, Scirpus californicus ...The research aimed to evaluate the absorption and removal capacity of Cu, Pb, Fe and Zn from Scirpus californicus for potential use in the remediation of polluted aquatic environments. Initially, Scirpus californicus plants were conditioned in 1.5 liters of 10 ppm Cu solution at a pH of 2.3 as well as Pb, Fe and Zn. Subsequently, the concentration of heavy metals in the root-rhizome, submerged stem and aerial stem was determined;the solution and pH were also analyzed. The greatest capacity of absorption and accumulation occurred in the root-rhizome reaching values for Cu of 491.84, Pb of 739.43, Zn of 830.71 and Fe of 2624.72 mg/kg dry followed by the submerged stem and low values for the aerial stem. The removal efficiency of Cu from the solution was 52.10%, Pb 53.50%, Fe 48.00% and Zn 50.20%. It is concluded that the contact time has a significant effect on the absorption and removal capacity of the metals under study.展开更多
The Hooded Crane(Grus monacha)is listed as a Vulnerable species in the IUCN red list.Tidal wetland(tideland),the major habitat for wintering Hooded Cranes at East China’s Chongming Dongtan,has dramatically changed in...The Hooded Crane(Grus monacha)is listed as a Vulnerable species in the IUCN red list.Tidal wetland(tideland),the major habitat for wintering Hooded Cranes at East China’s Chongming Dongtan,has dramatically changed in the past two decades,but there is limited knowledge about the population and habitat changes of the Hooded Cranes.This study investigated the population size and distribution of wintering Hooded Cranes at Chongming Dongtan from 2000 to 2021.We used remote sensing images combined with a vegetation classification algorithm to analyse the distribution of saltmarsh vegetation.The quadrat method was used to investigate the density and weight of the underground corms of Sea Bulrush(Scirpus mariquter),the main food on tideland for the Hooded Cranes.From 2000 to 2021,the population number of wintering Hooded Cranes at Chongming Dongtan remained stable at approximately 100.In 2000,the area of Scirpus spp.and Common Reed(Phragmites australis)accounted for approximately half of the total saltmarsh area at Chongming Dongtan,respectively.The invasive Smooth Cordgrass(Spartina alterniflora)rapidly expanded on tideland in the 2000s while the Scirpus spp.was competed out and thus significantly reduced in area.After the implementation of an ecological project to control Smooth Cordgrass and to restore Scirpus spp.in the 2010s,the area of the Smooth Cordgrass decreased considerably while the area of Scirpus spp.increased.The corms of Sea Bulrush decreased on the southeastern tideland during the study period,which might be the cause of the northward movement of the foraging Hooded Cranes on tideland.We also found Hooded Cranes foraged crops in the nearby farmland in mid-winter,causing human-bird conflicts in the recent decade.Our results found that changes in habitat and food conditions on tideland impacted wintering Hooded Cranes.Foraging in farmland with human disturbance in the recent decade might be related to insufficient food on tideland.We suggest active intervention to accelerate the restoration of Sea Bulrush on tideland and reduce human disturbance in farmland to improve the habitat quality of the wintering Hooded Crane at Chongming Dongtan.展开更多
基金NationalNaturalScience Foundation ofChina,No.40173030No.40131020+3 种基金ExcellentYoung TeacherProgram ofthe M inistry ofEducationKey Program ofShanghaiScience Foundation,No.02DJ14029Science & TechnologyDepartment of Shanghai, No.04DZ19301 Project
文摘The investigations on the organic carbon （OC） of core sediments were carried out in Chongming east tidal fiat （CM） during Scirpus mariqueter growing stage （from April to December 2004） in Yangtze Estuary. The Yangtze River annually transports a runoff discharge of 30,000 m^3/s, carrying about 480 million tons of sediments to the estuarine and coastal area, which formed a great OC pool. In the sampling spots, seven quadrats of 50 cm × 50 cm and five sediments cores of 20 cm deep （40 cm deep in December） were randomly established in order to collect vegetations and core sediments samples during the low tide each month except November. After pretreatment, the core sediments were sieved and their OC contents were measured according to the potassium dichromate method. The results show that the higher surface sediment OC content in summer comes from allochthonous terrigenous particle settlements on the Chongming east middle tidal fiat S. mariqueter zone. In autumn and winter, the decomposing of the defoliated S. mariqueter increases the surface sediments OC content. Settling velocity, sediment temperature and S. mariqueter growth are the main factors that can control the sediment carbon content. Summer is the “carbon losing” period of the tidal fiat sediments, while from September, it changes into the “carbon accumulating” period of sediment OC pool because of the decomposing of dead S. mariqueter community in the sediments. From this alternation of “carbon losing” period and “carbon accumulating” period, we conclude that carbon in the OC pool of the middle tidal fiat S. mariqueter zone sediments mainly comes from the atmospheric carbon rooted by S. mariqueter photosynthesis.
基金Supported by the National Key Research and Development Program of China(2017YFD0200307)
文摘The resistance and cross-resistance of Scirpus juncoides Roxb.to ALS-inhibiting herbicides were tested to provide theoretical basis for effectively control Scirpus juncoides Roxb.and rational use of herbicides.To identify the resistance and crossresistance of 19 populations from nine areas in Heilongjiang Province to four ALS-inhibiting herbicides by agar method and the whole-plant assay.The results are as the followings,the two bioassay methods had good correlation,the resistance indexes in the same area were different by two means,but resistant level was the same,similarity up to 89.5%.The resistant rates to pyrazosulfuronethyl,bensulfuron-methyl,penoxsulam and pyribenzoxim were 26.3%,36.8%,36.1%and 21.1%,respectively.Shangzhi populations evolved the highest level of resistance to pyrazosulfuron-methyl with a resistance index of 15.56.Shangzhi,Tonghe,Fangzheng and Jixi populations showed cross-resistance to four ALS-inhibiting herbicides,accounting for 26.3%.The resistance of Scirpus juncoides Roxb.to four ALS-inhibiting herbicides in Heilongjiang paddy field was low to moderate,five populations showed cross-resistance to four ALS-inhibiting herbicides.
文摘The research aimed to evaluate the absorption and removal capacity of Cu, Pb, Fe and Zn from Scirpus californicus for potential use in the remediation of polluted aquatic environments. Initially, Scirpus californicus plants were conditioned in 1.5 liters of 10 ppm Cu solution at a pH of 2.3 as well as Pb, Fe and Zn. Subsequently, the concentration of heavy metals in the root-rhizome, submerged stem and aerial stem was determined;the solution and pH were also analyzed. The greatest capacity of absorption and accumulation occurred in the root-rhizome reaching values for Cu of 491.84, Pb of 739.43, Zn of 830.71 and Fe of 2624.72 mg/kg dry followed by the submerged stem and low values for the aerial stem. The removal efficiency of Cu from the solution was 52.10%, Pb 53.50%, Fe 48.00% and Zn 50.20%. It is concluded that the contact time has a significant effect on the absorption and removal capacity of the metals under study.
基金financially supported by the National Key Research and Development Program of China(2022YFF1301004)the Science and Technology Department of Shanghai(21DZ1201902)the Shanghai Landscaping and City Appearance Administrative Bureau(G201610)。
文摘The Hooded Crane(Grus monacha)is listed as a Vulnerable species in the IUCN red list.Tidal wetland(tideland),the major habitat for wintering Hooded Cranes at East China’s Chongming Dongtan,has dramatically changed in the past two decades,but there is limited knowledge about the population and habitat changes of the Hooded Cranes.This study investigated the population size and distribution of wintering Hooded Cranes at Chongming Dongtan from 2000 to 2021.We used remote sensing images combined with a vegetation classification algorithm to analyse the distribution of saltmarsh vegetation.The quadrat method was used to investigate the density and weight of the underground corms of Sea Bulrush(Scirpus mariquter),the main food on tideland for the Hooded Cranes.From 2000 to 2021,the population number of wintering Hooded Cranes at Chongming Dongtan remained stable at approximately 100.In 2000,the area of Scirpus spp.and Common Reed(Phragmites australis)accounted for approximately half of the total saltmarsh area at Chongming Dongtan,respectively.The invasive Smooth Cordgrass(Spartina alterniflora)rapidly expanded on tideland in the 2000s while the Scirpus spp.was competed out and thus significantly reduced in area.After the implementation of an ecological project to control Smooth Cordgrass and to restore Scirpus spp.in the 2010s,the area of the Smooth Cordgrass decreased considerably while the area of Scirpus spp.increased.The corms of Sea Bulrush decreased on the southeastern tideland during the study period,which might be the cause of the northward movement of the foraging Hooded Cranes on tideland.We also found Hooded Cranes foraged crops in the nearby farmland in mid-winter,causing human-bird conflicts in the recent decade.Our results found that changes in habitat and food conditions on tideland impacted wintering Hooded Cranes.Foraging in farmland with human disturbance in the recent decade might be related to insufficient food on tideland.We suggest active intervention to accelerate the restoration of Sea Bulrush on tideland and reduce human disturbance in farmland to improve the habitat quality of the wintering Hooded Crane at Chongming Dongtan.
