Photosynthesis ( P n ), transpiration ( E ) and water use efficiency ( WUE ) of more than 66 arid sand species from different environmental habitats, shifting sand dune, fixed sand dune, lowland and wetland in ...Photosynthesis ( P n ), transpiration ( E ) and water use efficiency ( WUE ) of more than 66 arid sand species from different environmental habitats, shifting sand dune, fixed sand dune, lowland and wetland in the Maowusu Sand Area were analyzed and the relation among these characteristics and the resource utilization efficiency, taxonomic categories and growth forms of the species were assessed. The results showed that species from Chenopodiaceae, Gramineae, Leguminosae which possessed the C 4 photosynthesis pathway, or C 3 pathway and also with nitrogen_fixation capacities had higher or the highest P n values, i.e., 20～30 μmol CO 2·m -2 ·s -1 , while that of evergreen shrub of Pinaceae had the lowest P n values, i.e., 0～5 μmol CO 2·m -2 ·s -1 . Those species from Compositae, Scrophulariaceae, and Gramineae with C 3 pathway but no N_fixation capacity had the highest E rates, i.e., 20～30 mmol H 2O·m -2 ·s -1 and again the evergreen shrub together with some species from Salicaceae and Compositae had the lowest E rates, i.e., 0～5 mmol H 2O·m -2 ·s -1 . Species from Leguminosae, Gramineae and Chenopodiaceae with C 4 pathway or C 3 pathway with N_fixation capacity, both shrubs and grasses, generally had higher WUE . However, even the physiological traits of the same species were habitat_ and season_specific. The values of both P n and E in late summer were much higher than those in early summer, with average increases of 26%, 40% respectively in the four habitats. WUE in late summer was, however, 12% lower. Generally, when the environments became drier as a result of habitats changed, i.e., in the order of wetland, lowland, fixed sand dune and shifting sand dune, P n and E decreased but WUE increased.展开更多
The mainstreams of lake optics research in recent decades include optical properties of lakewater, observation, transmission and calculation of underwater radiation, determination of absorption coefficient S of yellow...The mainstreams of lake optics research in recent decades include optical properties of lakewater, observation, transmission and calculation of underwater radiation, determination of absorption coefficient S of yellow substance, influence of UV-B radiation of lake primary productivity by bio-optical model. Major lake optics applications, such as calculation of lake primary productivity and chl-a, analysis of factors restricting eu- trophication, and protection against lake eutrophication are summarized.展开更多
Albania has a lot of water re,;ources including： seas, rivers, lakes, lagoons as well as underground waters. Albania has about 485 mm precipitation annual year, with the forms of rain and snow. Most precipitations de...Albania has a lot of water re,;ources including： seas, rivers, lakes, lagoons as well as underground waters. Albania has about 485 mm precipitation annual year, with the forms of rain and snow. Most precipitations descend from the rivers and flow into the Adriatic Sea. About 23% of underground waters are distributed in all country and used by people for different activities. There are also a lot of kinds of natural habitats and ecosystems, such as： Mediterranean shrubs, broadleaves forests, conifer forests, mixed forests, alpine and sub-alpine pasture ecosystems, meadows, rock area, marine ecosystems, coastal, lagoons and other wetland areas, lakes, rivers, but of course and agricultural area. All of them have good correlations between the vegetation and water resources. This correlation is more evident near the rivers, lakes, lagoons etc..展开更多
Water is contaminated mainly by chemical, physical and biological pollutants. At present, domestic reports on biological pollution of water environment are much less. Biological pollution in water environment pollutio...Water is contaminated mainly by chemical, physical and biological pollutants. At present, domestic reports on biological pollution of water environment are much less. Biological pollution in water environment pollution which is stable and infectious is the main part of water pollution. To fastly and accuratly detecte biological contamination of the water environment is extremely important for the control of disease outbreaks and water quality protection and public health security. This paper systematically introduces the research progress in biological water environment pollution detection methods in molecular biology aquatic environment, and explore molecular biology methods in the detection of biological contamination in water environment problems and trends.展开更多
In this paper, we adopted simulation method to discuss influences of litter layer on plants habitat in grassland. Results indicated that ground surface evaporation, soil moisture, surface temperature, soil pH, soil bu...In this paper, we adopted simulation method to discuss influences of litter layer on plants habitat in grassland. Results indicated that ground surface evaporation, soil moisture, surface temperature, soil pH, soil bulk density and soil porosity were all strongly related to the litter quantity. Potassium （K） and organic materials in the soil covered by litter layer were higher than those in the soil uncovered by litter layer. With 100 g.ln-z increase of litter, the percentage of organic materials increased by 17.9%, nitrogen （N） increased by 7.6%, phosphor （P） increased by 26.4%, and K increased by 3.8%. With the litter accumulation amounting up to 600 g-m-2, the percentage of organic materials increased by 1.8 times, N increased by 81.5%, P increased by 1.8 times and K increased by 26.4%. According to the expected coefficient method of optimization, a mathematical model was established about the optimal accumulation quantity of litter.展开更多
Habitat shift is a key innovation that has contributed to the extreme diversification of insects. Most groups are well-adapted to more or less specific environments and shifts usually only happen between similar habit...Habitat shift is a key innovation that has contributed to the extreme diversification of insects. Most groups are well-adapted to more or less specific environments and shifts usually only happen between similar habitats. To colonize a pro- foundly different habitat type does not only present ecological opportunities but also great challenges. We used Hydrophiloidea （water scavenger beetles） as a system to study transitions between terrestrial and aquatic environments. We estimated the diversi- fication rate of different clades using phylogenetic trees based on a representative taxon sampling and six genes. We also investi- gated possible evolutionary changes in candidate genes following habitat shifts. Our results suggest that the diversification rate is relatively slow （0.039-0.050 sp/My） in the aquatic lineage, whereas it is distinctly increased in the secondarily terrestrial clade （0.055-0.075 sp/My）. Our results also show that aquatic species have a G （Glycine） or S （Serine） amino acid at a given site of COI, while terrestrial species share an A （Alanine） amino acid with terrestrial outgroups. This indicates that habitat factors may create selection pressure on the evolution of functional genes and cause homoplasy in molecular evolution [Current Zoology 60 （5）： 561-570, 2014 ]展开更多
文摘Photosynthesis ( P n ), transpiration ( E ) and water use efficiency ( WUE ) of more than 66 arid sand species from different environmental habitats, shifting sand dune, fixed sand dune, lowland and wetland in the Maowusu Sand Area were analyzed and the relation among these characteristics and the resource utilization efficiency, taxonomic categories and growth forms of the species were assessed. The results showed that species from Chenopodiaceae, Gramineae, Leguminosae which possessed the C 4 photosynthesis pathway, or C 3 pathway and also with nitrogen_fixation capacities had higher or the highest P n values, i.e., 20～30 μmol CO 2·m -2 ·s -1 , while that of evergreen shrub of Pinaceae had the lowest P n values, i.e., 0～5 μmol CO 2·m -2 ·s -1 . Those species from Compositae, Scrophulariaceae, and Gramineae with C 3 pathway but no N_fixation capacity had the highest E rates, i.e., 20～30 mmol H 2O·m -2 ·s -1 and again the evergreen shrub together with some species from Salicaceae and Compositae had the lowest E rates, i.e., 0～5 mmol H 2O·m -2 ·s -1 . Species from Leguminosae, Gramineae and Chenopodiaceae with C 4 pathway or C 3 pathway with N_fixation capacity, both shrubs and grasses, generally had higher WUE . However, even the physiological traits of the same species were habitat_ and season_specific. The values of both P n and E in late summer were much higher than those in early summer, with average increases of 26%, 40% respectively in the four habitats. WUE in late summer was, however, 12% lower. Generally, when the environments became drier as a result of habitats changed, i.e., in the order of wetland, lowland, fixed sand dune and shifting sand dune, P n and E decreased but WUE increased.
基金Supported by the Knowledge Innovation Program of CAS (KZCX1-SW-12), and NSFC (No. 30200032, 40203007)
文摘The mainstreams of lake optics research in recent decades include optical properties of lakewater, observation, transmission and calculation of underwater radiation, determination of absorption coefficient S of yellow substance, influence of UV-B radiation of lake primary productivity by bio-optical model. Major lake optics applications, such as calculation of lake primary productivity and chl-a, analysis of factors restricting eu- trophication, and protection against lake eutrophication are summarized.
文摘Albania has a lot of water re,;ources including： seas, rivers, lakes, lagoons as well as underground waters. Albania has about 485 mm precipitation annual year, with the forms of rain and snow. Most precipitations descend from the rivers and flow into the Adriatic Sea. About 23% of underground waters are distributed in all country and used by people for different activities. There are also a lot of kinds of natural habitats and ecosystems, such as： Mediterranean shrubs, broadleaves forests, conifer forests, mixed forests, alpine and sub-alpine pasture ecosystems, meadows, rock area, marine ecosystems, coastal, lagoons and other wetland areas, lakes, rivers, but of course and agricultural area. All of them have good correlations between the vegetation and water resources. This correlation is more evident near the rivers, lakes, lagoons etc..
文摘Water is contaminated mainly by chemical, physical and biological pollutants. At present, domestic reports on biological pollution of water environment are much less. Biological pollution in water environment pollution which is stable and infectious is the main part of water pollution. To fastly and accuratly detecte biological contamination of the water environment is extremely important for the control of disease outbreaks and water quality protection and public health security. This paper systematically introduces the research progress in biological water environment pollution detection methods in molecular biology aquatic environment, and explore molecular biology methods in the detection of biological contamination in water environment problems and trends.
基金Acknowledgements： This research work was supported by the National Natural Science Foundation of China （No. 30590382 and No. 30570273） and Science Foundation for Young Teachers of Northeast Normal University （No. 20070502）.
文摘In this paper, we adopted simulation method to discuss influences of litter layer on plants habitat in grassland. Results indicated that ground surface evaporation, soil moisture, surface temperature, soil pH, soil bulk density and soil porosity were all strongly related to the litter quantity. Potassium （K） and organic materials in the soil covered by litter layer were higher than those in the soil uncovered by litter layer. With 100 g.ln-z increase of litter, the percentage of organic materials increased by 17.9%, nitrogen （N） increased by 7.6%, phosphor （P） increased by 26.4%, and K increased by 3.8%. With the litter accumulation amounting up to 600 g-m-2, the percentage of organic materials increased by 1.8 times, N increased by 81.5%, P increased by 1.8 times and K increased by 26.4%. According to the expected coefficient method of optimization, a mathematical model was established about the optimal accumulation quantity of litter.
文摘Habitat shift is a key innovation that has contributed to the extreme diversification of insects. Most groups are well-adapted to more or less specific environments and shifts usually only happen between similar habitats. To colonize a pro- foundly different habitat type does not only present ecological opportunities but also great challenges. We used Hydrophiloidea （water scavenger beetles） as a system to study transitions between terrestrial and aquatic environments. We estimated the diversi- fication rate of different clades using phylogenetic trees based on a representative taxon sampling and six genes. We also investi- gated possible evolutionary changes in candidate genes following habitat shifts. Our results suggest that the diversification rate is relatively slow （0.039-0.050 sp/My） in the aquatic lineage, whereas it is distinctly increased in the secondarily terrestrial clade （0.055-0.075 sp/My）. Our results also show that aquatic species have a G （Glycine） or S （Serine） amino acid at a given site of COI, while terrestrial species share an A （Alanine） amino acid with terrestrial outgroups. This indicates that habitat factors may create selection pressure on the evolution of functional genes and cause homoplasy in molecular evolution [Current Zoology 60 （5）： 561-570, 2014 ]
