The 5.12 Earthquake in 2008 and 8.14 Debris Flow in 2010 resulted in large-scale landslides that disturbed vast areas of vegetation in the Hongchun Gully, Wenchuan County, China. To define the specific characteristics...The 5.12 Earthquake in 2008 and 8.14 Debris Flow in 2010 resulted in large-scale landslides that disturbed vast areas of vegetation in the Hongchun Gully, Wenchuan County, China. To define the specific characteristics of vegetation restoration during natural recovery after catastrophic events,vegetation species composition and interspecific associations were investigated on this typical landslide. Field survey data selected from a total of 51 sample plots belonged to seven belt transects and were analysed by Schluter's variance ratio, pearson's chi-squared test, Spearman's correlation coefficients and ecological species groups. Plant communities on the landslide consisted of 78 species, 65 genera and52 families. Of the total of 78 species, 25 are identified as dominant species, among which Camptotheca acuminate, Toxicodendron vernicifluum, Coriaria nepalensis, Robinia pseudoacacia, Buddleja alternifolia, Anemone vitifolia and Nephrolepis auriculata play a constructive role during the natural afforestation. Moreover, according to environmental and ecological factors, these 25 dominant species could be divided into four ecological species groups.This study found that even though the landslide had frequently suffered from interference due to heavy rain, the vegetation succession processes are ongoing,and it is now at a shrub–herb community succession stage, which indicates that vegetation can naturally recover in the denuded sites. This study provides a useful insight into the ecological interactions and interdependence between plant species during the natural recovery of vegetation and provides valuable information on vegetation recovery modelling in the landslide area.展开更多
The salt-resistant nitrogen-fixing cyanobacteria 888 was experimentally applied to the reclamation of saline and alkali soil in Songnen Plain in China. The pH, electrical conductivity (EC) and sodium adsorption ratio ...The salt-resistant nitrogen-fixing cyanobacteria 888 was experimentally applied to the reclamation of saline and alkali soil in Songnen Plain in China. The pH, electrical conductivity (EC) and sodium adsorption ratio (SAR) of different saline soils were studied and compared. Results show that different saline soils exhibit various physico-chemical properties. Saline-sodic soils in Songnen Plain are ameliorated by using nitrogen-fixing blue-green algae 888 in the experiment. It is indicated that cyanobacteria 888 can grow in saline and alkaline soils, and the conditions favorable for its growth are soil moisture of 50% and dry algae inoculation at 0.03 mg/cm2. The main actions of nitrogen-fixing cyanobacteria are keeping the adsorbability of rubber sheath for sodium, increasing the organic matter content of the soils and decreasing the pH and the degree of salinity in the soils. But the arid climate and soil depth are the main factors that limit the restoration of saline and alkaline soils.展开更多
Many aspects of the Late Ordovician Mass Extinction(LOME)aftermath and recovery have been puzzling due to heterogeneities in tempo and triggering mechanisms.Benthic fossil groups,which are the most severely affected b...Many aspects of the Late Ordovician Mass Extinction(LOME)aftermath and recovery have been puzzling due to heterogeneities in tempo and triggering mechanisms.Benthic fossil groups,which are the most severely affected by oxidative stress,offer the best opportunities for understanding both biological and ecological recovery after the LOME.In recent studies,deep-water sponge assemblages(which may have had high physiological tolerance to oxygen deviations)have been reported widely across South China in the immediate aftermath of the extinction interval.In order to further explore the lateral and temporal distributions of sponges,and ecological effects of benthic recovery during this critical interval,this study presents new Llandovery sponge assemblages recovered from two sections in Hunan Province,South China,accompanied by geochemical analyses.The sponge communities are preserved by pyritic spicule replacements and shows a relatively deep-water affinity(estimated around 60-150 m in depth)comparable to several previously reported assemblages in South China,and consistent with the observed graptolite ecology.Geochemical analysis of total organic carbon(TOC)and major and trace element composition in both sections show similar trends,indicating a shift in redox state of the bottom-water from persistent anoxia or intermittent euxinia in the earliest Rhuddanian,becoming oxygenated in the early Aeronian.Based on the present study and previous biological and geochemical data from South China,the distribution of early Silurian sponge assemblages in South China demonstrates a gradual expansion towards deeper regions when ocean redox conditions ameliorated.This study confirms the continuity of the end-Ordovician sponge faunas and taxa,both laterally across South China,and temporally through the early Silurian.The pioneering colonization of sponges in low-oxygen environments after the LOME may have set the stage for the subsequent recovery of other benthic organisms.展开更多
基金Funds of China West Normal University (17YC332 17YC114)+2 种基金the National Natural Science Foundation of China (31572293)the Natural Science project of the Sichuan Department of Education (16ZB0177)the Fundamental Research Funds of China West Normal University (14D010)
文摘The 5.12 Earthquake in 2008 and 8.14 Debris Flow in 2010 resulted in large-scale landslides that disturbed vast areas of vegetation in the Hongchun Gully, Wenchuan County, China. To define the specific characteristics of vegetation restoration during natural recovery after catastrophic events,vegetation species composition and interspecific associations were investigated on this typical landslide. Field survey data selected from a total of 51 sample plots belonged to seven belt transects and were analysed by Schluter's variance ratio, pearson's chi-squared test, Spearman's correlation coefficients and ecological species groups. Plant communities on the landslide consisted of 78 species, 65 genera and52 families. Of the total of 78 species, 25 are identified as dominant species, among which Camptotheca acuminate, Toxicodendron vernicifluum, Coriaria nepalensis, Robinia pseudoacacia, Buddleja alternifolia, Anemone vitifolia and Nephrolepis auriculata play a constructive role during the natural afforestation. Moreover, according to environmental and ecological factors, these 25 dominant species could be divided into four ecological species groups.This study found that even though the landslide had frequently suffered from interference due to heavy rain, the vegetation succession processes are ongoing,and it is now at a shrub–herb community succession stage, which indicates that vegetation can naturally recover in the denuded sites. This study provides a useful insight into the ecological interactions and interdependence between plant species during the natural recovery of vegetation and provides valuable information on vegetation recovery modelling in the landslide area.
基金Sponsored by the Major State Scientific and Technological Projects of Water Pollution Control and Treatment(Grant No.2008ZX07208-005)
文摘The salt-resistant nitrogen-fixing cyanobacteria 888 was experimentally applied to the reclamation of saline and alkali soil in Songnen Plain in China. The pH, electrical conductivity (EC) and sodium adsorption ratio (SAR) of different saline soils were studied and compared. Results show that different saline soils exhibit various physico-chemical properties. Saline-sodic soils in Songnen Plain are ameliorated by using nitrogen-fixing blue-green algae 888 in the experiment. It is indicated that cyanobacteria 888 can grow in saline and alkaline soils, and the conditions favorable for its growth are soil moisture of 50% and dry algae inoculation at 0.03 mg/cm2. The main actions of nitrogen-fixing cyanobacteria are keeping the adsorbability of rubber sheath for sodium, increasing the organic matter content of the soils and decreasing the pH and the degree of salinity in the soils. But the arid climate and soil depth are the main factors that limit the restoration of saline and alkaline soils.
基金funded by the National Natural Science Foundation of China(Grant Nos.41772001 and41872151)supported by the State Key Laboratory of Palaeobiology and Stratigraphy(Nanjing Institute of Geology and Palaeontology,CAS)(No.213120)the Natural Science Foundation of Hunan Province(No.2023JJ20063 and No.2021JJ30816)。
文摘Many aspects of the Late Ordovician Mass Extinction(LOME)aftermath and recovery have been puzzling due to heterogeneities in tempo and triggering mechanisms.Benthic fossil groups,which are the most severely affected by oxidative stress,offer the best opportunities for understanding both biological and ecological recovery after the LOME.In recent studies,deep-water sponge assemblages(which may have had high physiological tolerance to oxygen deviations)have been reported widely across South China in the immediate aftermath of the extinction interval.In order to further explore the lateral and temporal distributions of sponges,and ecological effects of benthic recovery during this critical interval,this study presents new Llandovery sponge assemblages recovered from two sections in Hunan Province,South China,accompanied by geochemical analyses.The sponge communities are preserved by pyritic spicule replacements and shows a relatively deep-water affinity(estimated around 60-150 m in depth)comparable to several previously reported assemblages in South China,and consistent with the observed graptolite ecology.Geochemical analysis of total organic carbon(TOC)and major and trace element composition in both sections show similar trends,indicating a shift in redox state of the bottom-water from persistent anoxia or intermittent euxinia in the earliest Rhuddanian,becoming oxygenated in the early Aeronian.Based on the present study and previous biological and geochemical data from South China,the distribution of early Silurian sponge assemblages in South China demonstrates a gradual expansion towards deeper regions when ocean redox conditions ameliorated.This study confirms the continuity of the end-Ordovician sponge faunas and taxa,both laterally across South China,and temporally through the early Silurian.The pioneering colonization of sponges in low-oxygen environments after the LOME may have set the stage for the subsequent recovery of other benthic organisms.
