Seasonal variations in the phytoplankton community and the relationship between environmental factors of the sea area around Xiaoheishan Island are investigated in the present study. Xiaoheishan Island is located at 3...Seasonal variations in the phytoplankton community and the relationship between environmental factors of the sea area around Xiaoheishan Island are investigated in the present study. Xiaoheishan Island is located at 37°58′14″N and 120°38′46″E in Shandong Province, China. A total of 65 species of phytoplankton belonging to three phyla and 27 genera were identified, with Bacillariophyta having the largest number of species. The annual average chlorophyll a concentration for this area was 3.11 μg/L, and there occurs a Skeletonema costatum bloom in winter. The Shannon-Weaver indexes(log_2) of the phytoplankton from all stations were higher than 1, and the Pielou indexes were all higher than 0.3. The results of the canonical correspondence analysis(CCA) indicated that water temperature, PO_4^(3ˉ) and Cu were the environmental factors that had the greatest influence on the distribution of the phytoplankton community throughout the entire year. Although the concentration of heavy metal is well up to the state standards of the first grade of China(GB 3097-1997), these metals still have an impact on the phytoplankton community from this area.展开更多
Community structure of fish in relation to environmental variation was investigated in Nanji Islands National Nature Reserve (NINNR). In order to test this relationship, we delineated 25 survey stations with bottom tr...Community structure of fish in relation to environmental variation was investigated in Nanji Islands National Nature Reserve (NINNR). In order to test this relationship, we delineated 25 survey stations with bottom trawling and measured environmental variables. Samples were taken from November 2013 (autumn), February 2014 (winter), May 2014 (spring) and September 2014 (summer). We found a very strong correlation in space and time between temperature and salinity;abundance and biomass in winter;depth and DO in summer then a strong correlation was found respectively between temperature and biomass;salinity and biomass in winter too and finally a moderate correlation between depth and biomass in spring, (P-value < 0.01) with positive correlation (that the other variable or factor has a tendency to increase). We also found out a negative correlation (P-value < 0.05), respectively between salinity and DO;DO and chlorophyll in summer;temperature and salinity;salinity and DO in spring period (mean that the other variable or factor has a tendency to decrease). A negative correlation observed between temperature, salinity and chlorophyll in winter, spring and autumn period were due by a temperature and salinity window open for species blooms through the movement of the TWC and Jiangzhe coastal current close to shore. By comparing diversity of fish species with environmental factors, the community structure of fish varied significantly as physicochemical parameters changed between different stations for each season. As results and according to the species referencing of environmental factors;species diversity, abundance and evenness vary among different stations, corresponding to significant differences of environmental factors (e.g. physicochemical parameters and chlorophyll-a concentration in different sites). Species richness of microfauna was negatively correlated with salinity levels. Furthermore, they were related to the fish community according to the results. This may be due to the fish community’s adaptability in these different variations of environmental factors, but only tolerant members remaining.展开更多
As an economically crucial species in the southeast Pacific Ocean,understanding the spatiotemporal distribution changes of the habitat of Trachurus murphyi under the influence of climate change is essential for effect...As an economically crucial species in the southeast Pacific Ocean,understanding the spatiotemporal distribution changes of the habitat of Trachurus murphyi under the influence of climate change is essential for effective resource assessment and management.The spatiotemporal changes in suitable habitats of T.murphyi under three climate change scenarios(SSP 126,SSP 370,and SSP 585)of Phase 6 of the Coupled Model Intercomparison Project(CMIP 6)were explored based on key environmental factors affecting the potential distribution of the species in a habitat suitability index(HSI)model.Results show that seawater temperature would increase under different scenarios,while the mixed layer depths would decrease under SSP 370 and SSP 585 scenarios but vary slightly under the SSP 126 scenario,which is similar to the variation in different climate periods.The positive difference in seawater temperature will be distributed in the central,southern,and offshore regions of Chile,and the negative difference in mixed layer depths be accounted for a large region.Under different climate scenarios,the HSI value for fishing ground and the overall proportion of suitable habitat area of T.murphyi will be decreased over the forecasted period.The suitable habitat of T.murphyi is concentrated in the 42°S-47°S area and will move to the southwest in different climate periods.Based on short-term climate change,the proportion of suitable habitat areas in the high seas of Chile is larger than in the exclusive economic zone under medium-and long-term climate change under different scenarios.The results of the gravity center of suitable T.murphyi habitat indicates that the spatial distribution of T.murphyi might be related to variations in oceanic currents.These findings provide insights for the effective fisheries resource management of T.murphyi in the Southeast Pacific Ocean.展开更多
Here we report our recent magnetic fabric investigation of loess deposition in Shagou section, located at the northeastern Qilian Mountains, the northeastern rim of the Tibetan Plateau. On the basis of environmental m...Here we report our recent magnetic fabric investigation of loess deposition in Shagou section, located at the northeastern Qilian Mountains, the northeastern rim of the Tibetan Plateau. On the basis of environmental magnetism data, we indicate that the variation of anisotropy of magnetic susceptibility (AMS) parameters, especially the foliation (F) and degree of anisotropy (P), might be more sensitive to the environmental change in the arid and semiarid regions than the magnetic susceptibility fluctuation. During the investigated interval, from 0.83 to 0.128 Ma, most of the middle to late Pleistocene significant climate change can be unraveled by the AMS parameters, such as the strengthening of cold/dry climate, the step drying event occurred nearly 250 ka, and the severe environmental change in MIS16. Our results also suggest that there is strong correlation between median diameter (Md) of grain size, F, and P. We propose that the AMS parameters can act as an important paleoenvironmental change indicator in the arid and semiarid regions.展开更多
Marine biodiversity is changing in response to altered physical environment, subsequent ecological changes as well as anthropogenic disturbances. In this study, phytoplankton samples in situ collected in the Bering Se...Marine biodiversity is changing in response to altered physical environment, subsequent ecological changes as well as anthropogenic disturbances. In this study, phytoplankton samples in situ collected in the Bering Sea in July of 1999 and 2010 were analyzed to obtain phytoplankton community structure and spatial-temporal variation between the beginning and end of this decade, and the correlation of phytoplankton community dynamics and environmental factors was investigated. A total of 5 divisions, 58 genera and 153 species of phytoplankton belonging to 3 ecological groups were identified. The vast majority of phytoplankton consisted of diatoms accounting for 66.7% of the total species and 95.2% of the total abundance. Considering differentiation in spatial extent and phytoplankton sample types, there were subtle changes in species composition, large altering in abundance and significant variation in spatial distribution between two surveys. The abundance peak area was located at the Bering Strait while sub peak was found at the Bering Sea Basin. The boreal-temperate diatom was the dominant flora, which was subsequently replaced by eurythermal and frigid-water diatom. Phytoplankton community in the Bering Sea was not a simplex uniform community but composed of deep-ocean assemblage and neritic assemblage. The deep-ocean assemblage was located in the northwestern Pacific Ocean and Bering Sea Basin, dominated by boreal-temperate species（Neodenticula seminae, Thalassiothrix longissima, Amphiprora hyperborean, Chaetoceros atlanticus, Thalassiosira trifulta, etc.） and eurychoric species（Thalassionema nitzschioides, Ch. compressus, Rhizosolenia styliformis, etc.）, and characterized by low abundance, even interspecies abundance allocations, diverse dominant species and high species diversity. The neritic assemblage was distributed on the continental shelf and slope of Bering Sea and was mainly composed of frigid-water species（Th.nordenski？ldii, Ch. furcellatus, Ch. socialis, Bacteriosira fragilis, etc.） and eurythermal and euryhaline species（L.danicus, Ch. curvisetus, Coscinodiscus curvatulus, etc.）, and it was characterized by high abundance, uneven interspecies allocations, prominent dominant species and low species diversity. Spatial-temporal variation of species composition and abundance of phytoplankton in the Bering Sea was directly controlled by surface circulation,nutrient supply and ice edge.展开更多
The relationship between gravity variation and the Akto Ms6.7 earthquake on November 11, 2016, was studied by use of mobile gravity observation data from the China continental structural environmental monitoring netwo...The relationship between gravity variation and the Akto Ms6.7 earthquake on November 11, 2016, was studied by use of mobile gravity observation data from the China continental structural environmental monitoring network. The result revealed that before the Akto earthquake, a high positive gravity variation was observed in the Pamir tectonic knots region （within a maximum magnitude of approximately ＋80 microgal）, which was consistent with the existing knowledge of gravity abnormality and the locations of strong earthquakes. In view of the recent strong seismic activities in the Pamir tectonic knots region, as well as the strong upward crust movement and compressive strain, it is believed that gravity change in the Pamir tectonic knots region reflects the recent strong seismic activities and crust movement.展开更多
In the Argentine Puna,a particular type of wetlands called vegas are considered unique,as they are the main biodiversity hotspots in this arid high-elevation environment.Also,they provide essential ecosystem services....In the Argentine Puna,a particular type of wetlands called vegas are considered unique,as they are the main biodiversity hotspots in this arid high-elevation environment.Also,they provide essential ecosystem services.Despite their ecological significance,these ecosystems remain poorly studied.Particularly soil mesofauna,which play critical roles in nutrient cycling and organic matter dynamics,remain to be explored.We investigated the composition,abundance,and richness of taxa and feeding guilds of soil mesofauna communities across 10 vegas.These wetlands were distributed along an environmental gradient,in an elevation range of 3323-4748 m a.s.l.,where we analysed soil properties and plant communities.We collected a total of 5239 invertebrates,from which Acari was the most abundant group,followed by Collembola.Regarding feeding guilds,detritivores and predators dominated soil mesofauna communities.Variability in taxa abundance and richness was strongly influenced by local soil properties,such as organic matter,carbon-to-nitrogen ratio,and phosphorus content,as well as plant community attributes,particularly cushion plant cover.However,no soil or vegetation variables explained the differences in taxa identity across vegas.These findings highlight the critical role of local heterogeneity in shaping soil mesofauna communities and provide the first insights into these understudied ecosystems.展开更多
Fish have a remarkable amount of variation in their swimming performance, from within species dif- ferences to diversity among major taxonomic groups. Fish swimming is a complex, integrative phenotype and has the abil...Fish have a remarkable amount of variation in their swimming performance, from within species dif- ferences to diversity among major taxonomic groups. Fish swimming is a complex, integrative phenotype and has the ability to plastically respond to a myriad of environmental changes. The plasticity of fish swimming has been observed on whole-organismal traits such as burst speed or critical swimming speed, as well as underlying phenotypes such as muscle fiber types, kinematics, cardiovascular system, and neuronal processes. Whether the plastic responses of fish swimming are beneficial seems to depend on the environmental variable that is changing. For example, because of the effects of temperature on biochemical processes, alterations of fish swimming in response to tem- perature do not seem to be beneficial. In contrast, changes in fish swimming in response to variation in flow may benefit the fish to maintain position in the water column. In this paper, we examine how this plasticity in fish swimming might evolve, focusing on environmental variables that have received the most attention： temperature, habitat, dissolved oxygen, and carbon dioxide variation. Using examples from previous research, we highlight many of the ways fish swimming can plastic- ally respond to environmental variation and discuss potential avenues of future research aimed at understanding how plasticity of fish swimming might evolve. We consider the direct and indirect ef- fects of environmental variation on swimming performance, including changes in swimming kine- matics and suborganismal traits thought to predict swimming performance. We also discuss the role of the evolution of plasticity in shaping macroevolutionary patterns of diversity in fish swimming.展开更多
基金Supported by the National Natural Science Foundation of China(NSFC)(No.41206102)the National Marine Public Welfare Research Project(No.201305009)the NSFC-Shandong Joint Fund(No.U1406403)
文摘Seasonal variations in the phytoplankton community and the relationship between environmental factors of the sea area around Xiaoheishan Island are investigated in the present study. Xiaoheishan Island is located at 37°58′14″N and 120°38′46″E in Shandong Province, China. A total of 65 species of phytoplankton belonging to three phyla and 27 genera were identified, with Bacillariophyta having the largest number of species. The annual average chlorophyll a concentration for this area was 3.11 μg/L, and there occurs a Skeletonema costatum bloom in winter. The Shannon-Weaver indexes(log_2) of the phytoplankton from all stations were higher than 1, and the Pielou indexes were all higher than 0.3. The results of the canonical correspondence analysis(CCA) indicated that water temperature, PO_4^(3ˉ) and Cu were the environmental factors that had the greatest influence on the distribution of the phytoplankton community throughout the entire year. Although the concentration of heavy metal is well up to the state standards of the first grade of China(GB 3097-1997), these metals still have an impact on the phytoplankton community from this area.
文摘Community structure of fish in relation to environmental variation was investigated in Nanji Islands National Nature Reserve (NINNR). In order to test this relationship, we delineated 25 survey stations with bottom trawling and measured environmental variables. Samples were taken from November 2013 (autumn), February 2014 (winter), May 2014 (spring) and September 2014 (summer). We found a very strong correlation in space and time between temperature and salinity;abundance and biomass in winter;depth and DO in summer then a strong correlation was found respectively between temperature and biomass;salinity and biomass in winter too and finally a moderate correlation between depth and biomass in spring, (P-value < 0.01) with positive correlation (that the other variable or factor has a tendency to increase). We also found out a negative correlation (P-value < 0.05), respectively between salinity and DO;DO and chlorophyll in summer;temperature and salinity;salinity and DO in spring period (mean that the other variable or factor has a tendency to decrease). A negative correlation observed between temperature, salinity and chlorophyll in winter, spring and autumn period were due by a temperature and salinity window open for species blooms through the movement of the TWC and Jiangzhe coastal current close to shore. By comparing diversity of fish species with environmental factors, the community structure of fish varied significantly as physicochemical parameters changed between different stations for each season. As results and according to the species referencing of environmental factors;species diversity, abundance and evenness vary among different stations, corresponding to significant differences of environmental factors (e.g. physicochemical parameters and chlorophyll-a concentration in different sites). Species richness of microfauna was negatively correlated with salinity levels. Furthermore, they were related to the fish community according to the results. This may be due to the fish community’s adaptability in these different variations of environmental factors, but only tolerant members remaining.
基金Supported by the National Key R&D Program of China(No.2023 YFD 2401303)the Natural Science Foundation of Shanghai(No.23 ZR 1427100)the Shanghai Talent Development Funding(No.2021078)。
文摘As an economically crucial species in the southeast Pacific Ocean,understanding the spatiotemporal distribution changes of the habitat of Trachurus murphyi under the influence of climate change is essential for effective resource assessment and management.The spatiotemporal changes in suitable habitats of T.murphyi under three climate change scenarios(SSP 126,SSP 370,and SSP 585)of Phase 6 of the Coupled Model Intercomparison Project(CMIP 6)were explored based on key environmental factors affecting the potential distribution of the species in a habitat suitability index(HSI)model.Results show that seawater temperature would increase under different scenarios,while the mixed layer depths would decrease under SSP 370 and SSP 585 scenarios but vary slightly under the SSP 126 scenario,which is similar to the variation in different climate periods.The positive difference in seawater temperature will be distributed in the central,southern,and offshore regions of Chile,and the negative difference in mixed layer depths be accounted for a large region.Under different climate scenarios,the HSI value for fishing ground and the overall proportion of suitable habitat area of T.murphyi will be decreased over the forecasted period.The suitable habitat of T.murphyi is concentrated in the 42°S-47°S area and will move to the southwest in different climate periods.Based on short-term climate change,the proportion of suitable habitat areas in the high seas of Chile is larger than in the exclusive economic zone under medium-and long-term climate change under different scenarios.The results of the gravity center of suitable T.murphyi habitat indicates that the spatial distribution of T.murphyi might be related to variations in oceanic currents.These findings provide insights for the effective fisheries resource management of T.murphyi in the Southeast Pacific Ocean.
基金NationalN aturalScience Foundation ofChina,N o.40471016 N o.40401007 The DoctoralFoundation ofM inistry ofEducation ofChina,N o.20030730017
文摘Here we report our recent magnetic fabric investigation of loess deposition in Shagou section, located at the northeastern Qilian Mountains, the northeastern rim of the Tibetan Plateau. On the basis of environmental magnetism data, we indicate that the variation of anisotropy of magnetic susceptibility (AMS) parameters, especially the foliation (F) and degree of anisotropy (P), might be more sensitive to the environmental change in the arid and semiarid regions than the magnetic susceptibility fluctuation. During the investigated interval, from 0.83 to 0.128 Ma, most of the middle to late Pleistocene significant climate change can be unraveled by the AMS parameters, such as the strengthening of cold/dry climate, the step drying event occurred nearly 250 ka, and the severe environmental change in MIS16. Our results also suggest that there is strong correlation between median diameter (Md) of grain size, F, and P. We propose that the AMS parameters can act as an important paleoenvironmental change indicator in the arid and semiarid regions.
基金The National Natural Science Foundation of China under contract Nos 41306116 and 41506217the Basic Research of the National Department of Science and Technology under contract No.GASI-01-02-04the Polar Science Strategic Research Foundation of China under contract No.20140309
文摘Marine biodiversity is changing in response to altered physical environment, subsequent ecological changes as well as anthropogenic disturbances. In this study, phytoplankton samples in situ collected in the Bering Sea in July of 1999 and 2010 were analyzed to obtain phytoplankton community structure and spatial-temporal variation between the beginning and end of this decade, and the correlation of phytoplankton community dynamics and environmental factors was investigated. A total of 5 divisions, 58 genera and 153 species of phytoplankton belonging to 3 ecological groups were identified. The vast majority of phytoplankton consisted of diatoms accounting for 66.7% of the total species and 95.2% of the total abundance. Considering differentiation in spatial extent and phytoplankton sample types, there were subtle changes in species composition, large altering in abundance and significant variation in spatial distribution between two surveys. The abundance peak area was located at the Bering Strait while sub peak was found at the Bering Sea Basin. The boreal-temperate diatom was the dominant flora, which was subsequently replaced by eurythermal and frigid-water diatom. Phytoplankton community in the Bering Sea was not a simplex uniform community but composed of deep-ocean assemblage and neritic assemblage. The deep-ocean assemblage was located in the northwestern Pacific Ocean and Bering Sea Basin, dominated by boreal-temperate species（Neodenticula seminae, Thalassiothrix longissima, Amphiprora hyperborean, Chaetoceros atlanticus, Thalassiosira trifulta, etc.） and eurychoric species（Thalassionema nitzschioides, Ch. compressus, Rhizosolenia styliformis, etc.）, and characterized by low abundance, even interspecies abundance allocations, diverse dominant species and high species diversity. The neritic assemblage was distributed on the continental shelf and slope of Bering Sea and was mainly composed of frigid-water species（Th.nordenski？ldii, Ch. furcellatus, Ch. socialis, Bacteriosira fragilis, etc.） and eurythermal and euryhaline species（L.danicus, Ch. curvisetus, Coscinodiscus curvatulus, etc.）, and it was characterized by high abundance, uneven interspecies allocations, prominent dominant species and low species diversity. Spatial-temporal variation of species composition and abundance of phytoplankton in the Bering Sea was directly controlled by surface circulation,nutrient supply and ice edge.
基金jointly supported by the the special earthquake research grant offered by the China Earthquake Administration(201508009,201308009)the Director Foundation of Institute of Seismology,China Earthquake Administration(IS201326121)
文摘The relationship between gravity variation and the Akto Ms6.7 earthquake on November 11, 2016, was studied by use of mobile gravity observation data from the China continental structural environmental monitoring network. The result revealed that before the Akto earthquake, a high positive gravity variation was observed in the Pamir tectonic knots region （within a maximum magnitude of approximately ＋80 microgal）, which was consistent with the existing knowledge of gravity abnormality and the locations of strong earthquakes. In view of the recent strong seismic activities in the Pamir tectonic knots region, as well as the strong upward crust movement and compressive strain, it is believed that gravity change in the Pamir tectonic knots region reflects the recent strong seismic activities and crust movement.
基金supported by FONCYT grants(PICT 2016-2173,PICT 2018-04228).
文摘In the Argentine Puna,a particular type of wetlands called vegas are considered unique,as they are the main biodiversity hotspots in this arid high-elevation environment.Also,they provide essential ecosystem services.Despite their ecological significance,these ecosystems remain poorly studied.Particularly soil mesofauna,which play critical roles in nutrient cycling and organic matter dynamics,remain to be explored.We investigated the composition,abundance,and richness of taxa and feeding guilds of soil mesofauna communities across 10 vegas.These wetlands were distributed along an environmental gradient,in an elevation range of 3323-4748 m a.s.l.,where we analysed soil properties and plant communities.We collected a total of 5239 invertebrates,from which Acari was the most abundant group,followed by Collembola.Regarding feeding guilds,detritivores and predators dominated soil mesofauna communities.Variability in taxa abundance and richness was strongly influenced by local soil properties,such as organic matter,carbon-to-nitrogen ratio,and phosphorus content,as well as plant community attributes,particularly cushion plant cover.However,no soil or vegetation variables explained the differences in taxa identity across vegas.These findings highlight the critical role of local heterogeneity in shaping soil mesofauna communities and provide the first insights into these understudied ecosystems.
文摘Fish have a remarkable amount of variation in their swimming performance, from within species dif- ferences to diversity among major taxonomic groups. Fish swimming is a complex, integrative phenotype and has the ability to plastically respond to a myriad of environmental changes. The plasticity of fish swimming has been observed on whole-organismal traits such as burst speed or critical swimming speed, as well as underlying phenotypes such as muscle fiber types, kinematics, cardiovascular system, and neuronal processes. Whether the plastic responses of fish swimming are beneficial seems to depend on the environmental variable that is changing. For example, because of the effects of temperature on biochemical processes, alterations of fish swimming in response to tem- perature do not seem to be beneficial. In contrast, changes in fish swimming in response to variation in flow may benefit the fish to maintain position in the water column. In this paper, we examine how this plasticity in fish swimming might evolve, focusing on environmental variables that have received the most attention： temperature, habitat, dissolved oxygen, and carbon dioxide variation. Using examples from previous research, we highlight many of the ways fish swimming can plastic- ally respond to environmental variation and discuss potential avenues of future research aimed at understanding how plasticity of fish swimming might evolve. We consider the direct and indirect ef- fects of environmental variation on swimming performance, including changes in swimming kine- matics and suborganismal traits thought to predict swimming performance. We also discuss the role of the evolution of plasticity in shaping macroevolutionary patterns of diversity in fish swimming.
