Influence of outbreak of macroalgal blooms on phosphorus release from the sediments in Swan Lake Wetland, China

Macroalgal blooms have occurred worldwide frequently in coastal areas in recent decades, which dramatically modify phosphorus (P) cycle in water column and the sediments. Rongcheng Swan Lake Wetland, a coastal wetland in China, is suffering from extensive macroalgal blooms. In order to verify the influence of macroalgal growth on sediment P release, the sediments and filamentous Chaetomorpha spp. were incubated in the laboratory to investigate the changes of water quality parameters, P levels in overlying water, and sediments during the growth period. In addition, algal biomass and tissue P concentration were determined. In general, Chaetomorpha biomasses were much higher in high P treatments than in low P treatments. Compared with algae+low P water treatment, the addition of sediments increased the algal growth rate and P accumulation amount. During the algal growth, water pH increased greatly, which showed significant correlation with algal biomass in treatments with high P (P<0.05). P fractions in the sediments showed that Fe/Al-P and organic P concentrations declined during the algal growth, and great changes were observed in algae+low P water+sediment treatment for both. As a whole, the sediments can supply P for Chaetomorpha growth when water P level was low, and the probable mechanism was the release of Fe/Al-P at high pH condition induced by intensive Chaetomorpha blooms.Macroalgal blooms have occurred worldwide frequently in coastal areas in recent decades, which dramatically modify phosphorus (P) cycle in water column and the sediments. Rongcheng Swan Lake Wetland, a coastal wetland in China, is suffering from extensive macroalgal blooms. In order to verify the influence of macroalgal growth on sediment P release, the sediments and filamentous Chaetomorpha spp. were incubated in the laboratory to investigate the changes of water quality parameters, P levels in overlying water, and sediments during the growth period. In addition, algal biomass and tissue P concentration were determined. In general, Chaetomorpha biomasses were much higher in high P treatments than in low P treatments. Compared with algae+low P water treatment, the addition of sediments increased the algal growth rate and P accumulation amount. During the algal growth, water pH increased greatly, which showed significant correlation with algal biomass in treatments with high P (P<0.05). P fractions in the sediments showed that Fe/Al-P and organic P concentrations declined during the algal growth, and great changes were observed in algae+low P water+sediment treatment for both. As a whole, the sediments can supply P for Chaetomorpha growth when water P level was low, and the probable mechanism was the release of Fe/Al-P at high pH condition induced by intensive Chaetomorpha blooms

Effects of cultivation years on effective constituent content of Fritillaria pallidiflora Schernk

Fritillaria pallidiflora Schrenk has been treasured in traditional classic medicine as an antitussive, antiasthmatic and expectorant for hundreds of years. With gradually decreasing wild F. pallidiflora resources, the herb can no longer satisfy the demand. Artificial cultivation is one of the most effective ways to solve the contradiction between supply and demand in the medicinal material market. During the growth of Rhizomes medicinal plants, root biomass and active ingredient content showed dynamic accumulated variation with increasing cultivation years. Up to now, hardly any attempts have been made to investigate the relationship between quality and cultivation years of F. pallidiflora. Therefore, in this paper, we determined the optimum harvesting time by comparing biomass and biological characteristics of F. pallidiflora at different cultivation times. High-performance liquid chromatography with evaporative light scattering detection and phenol-sulfuric acid visible spectrophotometry was performed to determine imperialine and polysaccharide content of F. pallidiflora bulbs. From year 1 to 6 of cultivation, we observed an upward trend in plant height, diameter and dry weight of F. pallidiflora, while water content decreased. Plant height and dry weight increased remarkably during the fourth year of cultivation. The content of imperialine and polysaccharide of F. pallidiflora bulbs, on the other hand, showed an upward trend from year 1 to 3, after which it decreased from year 3 to 6. By comparing plant growth, biomass development and the accumulation of imperialine and polysaccharide, the best harvesting time of F. pallidiflora was determined to be after 4 years of cultivation. Our results showed that it is possible to establish a safe, effective, stable and controllable production process, which could play an important role in achieving sustainable utilization of F. pallidiflora resources.Fritillaria pallidiflora Schrenk has been treasured in traditional classic medicine as an antitussive, antiasthmatic and expectorant for hundreds of years. With gradually decreasing wild F. pallidiflora resources, the herb can no longer satisfy the demand. Artificial cultivation is one of the most effective ways to solve the contradiction between supply and demand in the medicinal material market. During the growth of Rhizomes medicinal plants, root biomass and active ingredient content showed dynamic accumulated variation with increasing cultivation years. Up to now, hardly any attempts have been made to investigate the relationship between quality and cultivation years of F. pallidiflora. Therefore, in this paper, we determined the optimum harvesting time by comparing biomass and biological characteristics of F. pallidiflora at different cultivation times. High-performance liquid chromatography with evaporative light scattering detection and phenol-sulfuric acid visible spectrophotometry was performed to determine imperialine and polysaccharide content of F. pallidiflora bulbs. From year 1 to 6 of cultivation, we observed an upward trend in plant height, diameter and dry weight of F. pallidiflora, while water content decreased. Plant height and dry weight increased remarkably during the fourth year of cultivation. The content of imperialine and polysaccharide of F. pallidiflora bulbs, on the other hand, showed an upward trend from year 1 to 3, after which it decreased from year 3 to 6. By comparing plant growth, biomass development and the accumulation of imperialine and polysaccharide, the best harvesting time of F. pallidiflora was determined to be after 4 years of cultivation. Our results showed that it is possible to establish a safe, effective, stable and controllable production process, which could play an important role in achieving sustainable utilization of F. pallidiflora resources

Photosynthetic characterization of three dominant plant species in the saline-alkaline soil of the Yellow River Delta, China

The diurnal variations of photosynthesis of three dominant species, including Glycine soja, Phragmites australis, and Cynanchum chinensis, in the Yellow River Delta in China have been studied under the same natural conditions using a Li-6400 portable photosynthesis system. The results showed that the curves of diurnal variations of net photosynthetic rate (P-N) of the three plants were different. The diurnal variation of P-N on C. chinensis was a midday depression pattern and had two peaks. However, P-N of G. soja and P. australis showed single-peak curves. The transpiration rate (E) of G. soja was significantly higher than that of P. australis and C. chinensis, both showed single-peak curves. In general, the diurnal course of stomatal conductance (g(s)) followed the same pattern of P-N. A similar diurnal pattern of intercellular CO2 concentration (C-i), vapor pressure deficit (VPD), and water use efficiency (WUE) was observed among different species. VPD showed single-peak curves, while WUE was characterized by double-peak curves, which was contrary to C-i. Linear correlations among photosynthetic variables and key environmental factors indicate high positive correlations between P-N and E, P-N and photosynthetic active radiation, P-N and leaf temperature (T-leaf), P-N and VPD, and between P-N and g(s) except C. chinensis. Negative correlations among P-N and relative humidity, P-N and C-i were found. The irradiance response curves derived from the leaves were substantially affected by different species. C. chinensis showed highest apparent quantum efficiency, followed by P. australis and G. soja, while apparent dark respiration (R-d), convexity (k), light saturation point, and maximum gross CO2 assimilation rate (P-max) of G. soja were higher than those of P. australis and C. chinensis. The irradiance response curve of P-N and WUE of different plant species followed the same order: G. soja&gt;C. chinensis&gt;P. australis. They were both higher than most of other species. It was concluded that plant species adapting to the saline-alkaline habitat showed higher photosynthesis. In addition, G. soja is also effective to improve saline-alkaline soil quality

Spatial variability of soil salinity in Bohai Sea coastal wetlands, China: Partition into four management zones

Soil salinization constitutes an environmental hazard worldwide. The Bohai Sea coastal wetland area is experiencing dramatic soil salinization, which is affecting its economic development. This study focused on the spatial variation and distribution characteristics of soil salinity in this area using geostatistical analysis combined with the kriging interpolation method, based on a large-scale field investigation and layered soil sampling (0-30, 30-60 and 60-100cm). The results revealed that soil salinity in these layers demonstrated strong variability, obvious spatial structure characteristics and strong spatial autocorrelation. Soil salinity displayed a significant zonal distribution, gradually decreasing with increasing distance from the coastline. Apart from the northern part of the study area, which appeared to be not affected by soil salinization, there were varying degrees of soil salinization in nearly 70% of the total area. With increasing soil depth, the areas of non-salinized and mild salinized soil gradually decreased, while those of moderate salinized and strong salinized soils increased. The area of saline soil first decreased and then increased. The study area could be divided into four management zones according to soil salinities in the top 1-m soil body, and utilization measures, adapted to local conditions, were proposed for each zone. The results of our study present an important theoretical basis for the improvement of saline soils, for wetland re-vegetation and for the sustainable utilization of soil resources in the Bohai Sea coastal wetland.Soil salinization constitutes an environmental hazard worldwide. The Bohai Sea coastal wetland area is experiencing dramatic soil salinization, which is affecting its economic development. This study focused on the spatial variation and distribution characteristics of soil salinity in this area using geostatistical analysis combined with the kriging interpolation method, based on a large-scale field investigation and layered soil sampling (0-30, 30-60 and 60-100cm). The results revealed that soil salinity in these layers demonstrated strong variability, obvious spatial structure characteristics and strong spatial autocorrelation. Soil salinity displayed a significant zonal distribution, gradually decreasing with increasing distance from the coastline. Apart from the northern part of the study area, which appeared to be not affected by soil salinization, there were varying degrees of soil salinization in nearly 70% of the total area. With increasing soil depth, the areas of non-salinized and mild salinized soil gradually decreased, while those of moderate salinized and strong salinized soils increased. The area of saline soil first decreased and then increased. The study area could be divided into four management zones according to soil salinities in the top 1-m soil body, and utilization measures, adapted to local conditions, were proposed for each zone. The results of our study present an important theoretical basis for the improvement of saline soils, for wetland re-vegetation and for the sustainable utilization of soil resources in the Bohai Sea coastal wetland

Optimizing medium for producing ethanol from industrial crop Jerusalem artichoke by one- step fermentation and recombinant Saccharomyces cerevisiae

In order to obtain a high ethanol yield from the Jerusalem artichoke raw extract and reduce the fermentation cost, we have engineered a new recombinant Saccharomyces cerevisiae strain that could produce ex-inulinase. The response surface methodology based on Plackett-Burman and Box-Behnken design was used to optimize the medium for the ethanol production from the Jerusalem artichoke raw extracts by the recombinant strain. In the first optimization step, Plackett-Burman design was employed to select significant factors, including concentrations of yeast extract, inoculum, and MgSO(4)7H(2)O. In the second step, the steepest ascent experiment was carried out to determine the center point with the three significant factors; the selected combinations were further optimized using the Box-Behnken design. The maximum ethanol production rate was predicted at 91.1g/l, which was based on a medium consisting of yeast extract 9.24g/l, inoculum 39.8ml/l, and MgSO(4)7H(2)O 0.45g/l. In the validating experiment, the ethanol fermentation rate reached 102.1g/l, closely matching the predicted rate.In order to obtain a high ethanol yield from the Jerusalem artichoke raw extract and reduce the fermentation cost, we have engineered a new recombinant Saccharomyces cerevisiae strain that could produce ex-inulinase. The response surface methodology based on Plackett-Burman and Box-Behnken design was used to optimize the medium for the ethanol production from the Jerusalem artichoke raw extracts by the recombinant strain. In the first optimization step, Plackett-Burman design was employed to select significant factors, including concentrations of yeast extract, inoculum, and MgSO(4)7H(2)O. In the second step, the steepest ascent experiment was carried out to determine the center point with the three significant factors; the selected combinations were further optimized using the Box-Behnken design. The maximum ethanol production rate was predicted at 91.1g/l, which was based on a medium consisting of yeast extract 9.24g/l, inoculum 39.8ml/l, and MgSO(4)7H(2)O 0.45g/l. In the validating experiment, the ethanol fermentation rate reached 102.1g/l, closely matching the predicted rate

Charge-dependent flow and the search for the chiral magnetic wave in Pb-Pb collisions at root s(NN)=2.76 TeV

Peer reviewe

Ranunculus

Hy. 155, 20 mi. W. of Lake IsabellaS. slope, grass-oakOa

hastata

Populus trichocarpa Torrey & A. Grayblack cottonwood;western balsam poplarpeuplier de l'Ouest;peuplier baumier de l'OuestE. side Oldman River. Country Club golf coursetreed terrace along riverP. acuminata , angustifolia, deltoides & trichocarp