In order to explore the differences in the compressive strength parallel to grain （CSPG） between different clones and individual woods of Populus deltoides Marsh., the CSPGs of 5 15-year-old P. deltoides clones were...In order to explore the differences in the compressive strength parallel to grain （CSPG） between different clones and individual woods of Populus deltoides Marsh., the CSPGs of 5 15-year-old P. deltoides clones were determined and analyzed. The results showed that there were significant differences in CSPG of wood between different clones of P. deltoides . The CSPG of the tested clones reached more than 41 MPa, which was higher than the average compressive strength of P. deltoides （32.94 MPa）. Similar to the changes of stem height, the CSPG of the clones gradually increased with the increase of stem height. However, there were significant differences in CSPG of an individual plant at different tree heights. The CSPG of P. deltoides clones was related with their growth traits, but not significantly. Therefore, it is expected to achieve simultaneous and independent improvement on CSPG and the growth of P. deltoides , so as to get excellent individuals with fast growth and high CSPG.展开更多
Botticelli’s The Birth of Venus continues to serve as an iconographic enigma and remains an enduring subject of scholarly analysis concerning the significance of mythological art and its symbolism during the Italian ...Botticelli’s The Birth of Venus continues to serve as an iconographic enigma and remains an enduring subject of scholarly analysis concerning the significance of mythological art and its symbolism during the Italian Renaissance.Therefore,it is particularly noteworthy to examine further the symbolic elements embedded within the imagery.This essay focuses on a specific component in the landscape of The Birth of Venus-the marsh plant on the riverbank,commonly known as cattail in English,tifa or stiancia in Italian,and Typha latifolia in Latin.Botticelli’s The Birth of Venus,executed between 1485 and 1490,is a tempera on canvas with gesso and gold applications.It was commissioned with specific aesthetic,cultural,and intellectual objectives and was intended to be displayed in a private chamber for personal viewing by members of the Medici family.Situated initially within the Medicean Villa at Castello,it has been exhibited at the Galleria degli Uffizi in Florence since 1815.This mythological painting exemplifies the Italian Renaissance principles of both physical and metaphysical humanism,visualized in a fusion of pagan and Christian iconography and iconology,incorporating symbolism that engages with antiquity and classical mythology.It also incorporates Italian Renaissance Neoplatonic philosophy,reflects Renaissance love poetry,demonstrates inventive patronage,and embodies spirituality directed towards a higher purpose.展开更多
Coastal salt marshes provide critical ecological services,including carbon sequestration.However,the landscape patterns,driving factors,and carbon dynamics associated with salt marsh losses and gains remain insufficie...Coastal salt marshes provide critical ecological services,including carbon sequestration.However,the landscape patterns,driving factors,and carbon dynamics associated with salt marsh losses and gains remain insufficiently explored,which is vital for effective restoration.This study conducted a comprehensive analysis of these aspects across China,with a focus on species-specific differences.Based on historical salt marsh data,landscape analysis was applied for identifying the spatiotemporal characteristics of changes.XGBoost algorithm was used for driving factor analysis.Carbon dynamics derived from salt marsh changes were estimated with statistical calculation.Our results indicated that the distribution patterns of salt marshes,as indicated by mean center,ellipse area,and landscape indices,varied significantly from 1985 to 2019,particularly between 2005 and 2010.Native species,such as Phragmites australis and Suaeda salsa,experienced significant losses with a 72% reduction,while exotic species Spartina alterniflora showed substantial gains with a 680-fold.Human disturbances emerged as the primary driver of these changes,with mean temperature and precipitation influencing certain regions and years.Overall,salt marsh changes resulted in a net emission of 68.1 Mt CO_(2),with the highest emission in Shandong and linked to the loss of Phragmites australis.Conversely,carbon sequestration equivalent to 11.1 Mt CO_(2)mainly resulted from the expansion of Spartina alterniflora,with Shanghai contributing the most.This species-specific and site-specific analysis of landscape patterns,drivers,and carbon dynamics in China could enhance our understanding of salt marsh changes and offer valuable insights for targeted restoration efforts at both local and national levels.展开更多
Scirpus mariqueter Tang et Zhang is a typical pioneer plant colonizing the bare beaches of the Yangtse River estuary. To explore the life history strategy of the species with reference to environmental physical stre...Scirpus mariqueter Tang et Zhang is a typical pioneer plant colonizing the bare beaches of the Yangtse River estuary. To explore the life history strategy of the species with reference to environmental physical stress, the biomass allocations to different plant components and some related morphological parameters were examined along an elevational gradient within a salt marsh. Authors found that S. mariqueter performed best at medium elevation within the marsh, with relatively high density of shoot and individual ramet dry mass. Biomass allocation to corm was the highest at low elevations, and the least at high elevations, suggesting that a conservative strategy was adopted by the species to cope with the harsh physical conditions at the low elevation. The investment in rhizome decreased from low to high elevations, while the proportion of inflorescence mass increased, indicating that during the life history, the species shifts from predominant asexual reproduction to predominant sexual reproduction. This may be favourable for the species to colonize larger area, and to spread and persist at a meta_population level. Correlation analyses showed that sexual reproduction was inversely related to growth and asexual reproduction. However, it is difficult to determine the relationship between asexual reproduction and growth possibly because of the varied function of the corms of the species in different life history stages.展开更多
We used sequences of mitochondrial control region （807bp） in 75 samples from three breeding colonies and one wintering population to investigate the genetic diversity and population structure of Marsh Grassbird （Lo...We used sequences of mitochondrial control region （807bp） in 75 samples from three breeding colonies and one wintering population to investigate the genetic diversity and population structure of Marsh Grassbird （Locustella pryeri sinensis） in different regions of China. Marsh Grassbird retained a moderate amount of haplotype （0.759 ± 0.056） and nucleotide diversity （0.002）. The results of FST among 3 phy-logeographic units and ФST between breeding and wintering sites revealed little evidence of genetic distinction between different colonies. Neither UPGMA tree structure analysis nor Network picture analysis showed obvious divergence between populations at different locations. Analysis of molecular variance also showed a lack of regional subdivision within Locustella pryeri sinesis, 98.5% of source of variation within populations and only 1.5% among populations. The neutrality test showed negative Fu’s FS value, which, in combination with detection of the mismatch distribution, suggested that population expansion occurred in the evolu-tionary history of this species. This hypothesis was further supported by Tajima’s D test and Fu’s test （D = -1.80, p = 0.02; Fs = -22.11, p = 0.001）, this expansion was estimated to occur about 28,700 years ago.展开更多
The paper compared the differences between above ground and underground biomass of four types of plants.The heavy metals(Cu,Zn,Cd,Cr,Pb,As,Hg)and nutrients(TN,TP)content in tissues of four maturity plants were detecte...The paper compared the differences between above ground and underground biomass of four types of plants.The heavy metals(Cu,Zn,Cd,Cr,Pb,As,Hg)and nutrients(TN,TP)content in tissues of four maturity plants were detected,and their enrichment coefficient and transfer coefficient were calculated.The results showed that Suaeda salsa had the largest concentrated capacity on Cu,Zn,Pb,As and Phragmites australis was larger on the Cd,Hg than other plants.Considering the purification of four plants,the effect on the restoration of heavy metal pollution was better if we harvested Phragmites australis and Suaeda salsa.Four plants had a larger difference in absorption capacity of nitrogen and smaller absorption of phosphorus.Phosphorus uptake was significantly smaller than nitrogen.Harvesting Phragmites australis and Suaeda salsa can reduce total nitrogen and phosphorus content of the wetland,while harvesting Spartina alterniflora and Typha orientalis can reduce total phosphorus content.展开更多
基金Supported by the Major Science and Technology Program of Hunan Province(2017NK1010)the Research on High Efficient Cultivation of Populus deltoids Industrial Resources in Dongting Lake Area,the Special Found for the Development and Efficient Utilization Technology Innovation of Forestry Resources during the"13th Five-Year Plan"(2016YFD0600402-2)the Research and Demonstration of Populus Engineering Structural Materials Directional Cultivation and Value-Added Key Technologies,the Science and Technology Planning Project for Forestry of Hunan Province(XLK201506)
文摘In order to explore the differences in the compressive strength parallel to grain （CSPG） between different clones and individual woods of Populus deltoides Marsh., the CSPGs of 5 15-year-old P. deltoides clones were determined and analyzed. The results showed that there were significant differences in CSPG of wood between different clones of P. deltoides . The CSPG of the tested clones reached more than 41 MPa, which was higher than the average compressive strength of P. deltoides （32.94 MPa）. Similar to the changes of stem height, the CSPG of the clones gradually increased with the increase of stem height. However, there were significant differences in CSPG of an individual plant at different tree heights. The CSPG of P. deltoides clones was related with their growth traits, but not significantly. Therefore, it is expected to achieve simultaneous and independent improvement on CSPG and the growth of P. deltoides , so as to get excellent individuals with fast growth and high CSPG.
文摘Botticelli’s The Birth of Venus continues to serve as an iconographic enigma and remains an enduring subject of scholarly analysis concerning the significance of mythological art and its symbolism during the Italian Renaissance.Therefore,it is particularly noteworthy to examine further the symbolic elements embedded within the imagery.This essay focuses on a specific component in the landscape of The Birth of Venus-the marsh plant on the riverbank,commonly known as cattail in English,tifa or stiancia in Italian,and Typha latifolia in Latin.Botticelli’s The Birth of Venus,executed between 1485 and 1490,is a tempera on canvas with gesso and gold applications.It was commissioned with specific aesthetic,cultural,and intellectual objectives and was intended to be displayed in a private chamber for personal viewing by members of the Medici family.Situated initially within the Medicean Villa at Castello,it has been exhibited at the Galleria degli Uffizi in Florence since 1815.This mythological painting exemplifies the Italian Renaissance principles of both physical and metaphysical humanism,visualized in a fusion of pagan and Christian iconography and iconology,incorporating symbolism that engages with antiquity and classical mythology.It also incorporates Italian Renaissance Neoplatonic philosophy,reflects Renaissance love poetry,demonstrates inventive patronage,and embodies spirituality directed towards a higher purpose.
基金funded by the key project of Zhejiang Provincial Natural Science Foundation(Grant No.LZJWZ23E090003)the National Natural Science Foundation of China(Grant No.42176170)。
文摘Coastal salt marshes provide critical ecological services,including carbon sequestration.However,the landscape patterns,driving factors,and carbon dynamics associated with salt marsh losses and gains remain insufficiently explored,which is vital for effective restoration.This study conducted a comprehensive analysis of these aspects across China,with a focus on species-specific differences.Based on historical salt marsh data,landscape analysis was applied for identifying the spatiotemporal characteristics of changes.XGBoost algorithm was used for driving factor analysis.Carbon dynamics derived from salt marsh changes were estimated with statistical calculation.Our results indicated that the distribution patterns of salt marshes,as indicated by mean center,ellipse area,and landscape indices,varied significantly from 1985 to 2019,particularly between 2005 and 2010.Native species,such as Phragmites australis and Suaeda salsa,experienced significant losses with a 72% reduction,while exotic species Spartina alterniflora showed substantial gains with a 680-fold.Human disturbances emerged as the primary driver of these changes,with mean temperature and precipitation influencing certain regions and years.Overall,salt marsh changes resulted in a net emission of 68.1 Mt CO_(2),with the highest emission in Shandong and linked to the loss of Phragmites australis.Conversely,carbon sequestration equivalent to 11.1 Mt CO_(2)mainly resulted from the expansion of Spartina alterniflora,with Shanghai contributing the most.This species-specific and site-specific analysis of landscape patterns,drivers,and carbon dynamics in China could enhance our understanding of salt marsh changes and offer valuable insights for targeted restoration efforts at both local and national levels.
文摘Scirpus mariqueter Tang et Zhang is a typical pioneer plant colonizing the bare beaches of the Yangtse River estuary. To explore the life history strategy of the species with reference to environmental physical stress, the biomass allocations to different plant components and some related morphological parameters were examined along an elevational gradient within a salt marsh. Authors found that S. mariqueter performed best at medium elevation within the marsh, with relatively high density of shoot and individual ramet dry mass. Biomass allocation to corm was the highest at low elevations, and the least at high elevations, suggesting that a conservative strategy was adopted by the species to cope with the harsh physical conditions at the low elevation. The investment in rhizome decreased from low to high elevations, while the proportion of inflorescence mass increased, indicating that during the life history, the species shifts from predominant asexual reproduction to predominant sexual reproduction. This may be favourable for the species to colonize larger area, and to spread and persist at a meta_population level. Correlation analyses showed that sexual reproduction was inversely related to growth and asexual reproduction. However, it is difficult to determine the relationship between asexual reproduction and growth possibly because of the varied function of the corms of the species in different life history stages.
基金supported by National Natural Science Foundation of China (No. 130370221 and No. 30770309)
文摘We used sequences of mitochondrial control region （807bp） in 75 samples from three breeding colonies and one wintering population to investigate the genetic diversity and population structure of Marsh Grassbird （Locustella pryeri sinensis） in different regions of China. Marsh Grassbird retained a moderate amount of haplotype （0.759 ± 0.056） and nucleotide diversity （0.002）. The results of FST among 3 phy-logeographic units and ФST between breeding and wintering sites revealed little evidence of genetic distinction between different colonies. Neither UPGMA tree structure analysis nor Network picture analysis showed obvious divergence between populations at different locations. Analysis of molecular variance also showed a lack of regional subdivision within Locustella pryeri sinesis, 98.5% of source of variation within populations and only 1.5% among populations. The neutrality test showed negative Fu’s FS value, which, in combination with detection of the mismatch distribution, suggested that population expansion occurred in the evolu-tionary history of this species. This hypothesis was further supported by Tajima’s D test and Fu’s test （D = -1.80, p = 0.02; Fs = -22.11, p = 0.001）, this expansion was estimated to occur about 28,700 years ago.
基金Supported by Oceanic Scientific Research Special Fund for Public Welfare Industry(200905009-5,200805070)
文摘The paper compared the differences between above ground and underground biomass of four types of plants.The heavy metals(Cu,Zn,Cd,Cr,Pb,As,Hg)and nutrients(TN,TP)content in tissues of four maturity plants were detected,and their enrichment coefficient and transfer coefficient were calculated.The results showed that Suaeda salsa had the largest concentrated capacity on Cu,Zn,Pb,As and Phragmites australis was larger on the Cd,Hg than other plants.Considering the purification of four plants,the effect on the restoration of heavy metal pollution was better if we harvested Phragmites australis and Suaeda salsa.Four plants had a larger difference in absorption capacity of nitrogen and smaller absorption of phosphorus.Phosphorus uptake was significantly smaller than nitrogen.Harvesting Phragmites australis and Suaeda salsa can reduce total nitrogen and phosphorus content of the wetland,while harvesting Spartina alterniflora and Typha orientalis can reduce total phosphorus content.
