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Dong Xie - One of the best experts on this subject based on the ideXlab platform.
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Differences in the regeneration traits of Potamogeton Crispus turions from macrophyte- and phytoplankton-dominated lakes.
Scientific reports, 2015Co-Authors: Dong Xie, Hengjie Zhou, Hong ZhuAbstract:Potamogeton Crispus is widely used in submerged macrophyte restoration in China. Turions are an important means of reproduction in this species. To compare the regeneration abilities of P. Crispus turions in macrophyte- and phytoplankton-dominated lakes, we collected P. Crispus turions from a macrophyte-dominated lake (Liangzi Lake) and a phytoplankton-dominated lake (Taihu Lake). Both lakes are important lakes in the middle and lower reaches of the Yangtze River in China. Our field survey revealed that the turions from the phytoplankton-dominated lake had smaller sizes and higher concentrations of total nitrogen (TN) and total phosphorus (TP) than did those from the macrophyte-dominated lake. Rapid sprouting of the turions from the phytoplankton-dominated lake in 32 days was observed under experimental conditions, although the sprout sizes (heights and biomass) were smaller than those from the macrophyte-dominated lake. Compared with sprouted turions from macrophyte-dominated lake, the sprouted turions from the phytoplankton-dominated lake accumulated higher soluble sugar (SS) but lower starch and free amino acid (FAA) concentrations. A 12-day interval sprout removal treatment significantly stimulated the re-sprouting of turions from both lakes, but scale-leaf-removal treatments had no effect. This study provides evidence that the regeneration strategies of P. Crispus turions differ in macrophyte- and phytoplankton-dominated lakes.
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effects of buoyancy and season on turion dispersal of submerged macrophyte Potamogeton Crispus l
Clean-soil Air Water, 2015Co-Authors: Dong Xie, Hengjie Zhou, Yushun ChenAbstract:Propagules dispersal and colonization ability are major issues of macrophyte regeneration. For submerged macrophyte Potamogeton Crispus L., turion dispersal along water flow can favor the long-distance expansion of its population; therefore, it is crucial to investigate factors that affect turion dispersal. For this purpose, we studied effects of buoyancy and season on dispersal P. Crispus turions by collecting field samples from Taihu Lake, over a three-months period (turion-formatting season, from May to July). Germination experiments (30 days in each sampling month) revealed that the floating turions germinated earlier and faster than the sinking ones across the three sampling months. After germination, the floating turions showed higher seedling height; whereas the sinking turions accumulated more sprouts biomass. The soluble sugar, total nitrogen (TN), and total phosphorus (TP) concentrations were found higher in the floating turions. The starch concentrations remained high without buoyancy or season effects. These results indicate that both internal (e.g., buoyancy, soluble sugar, TN, and TP concentrations) and external environmental factors (e.g., light condition and temperature) may contribute to germinability and plant growth of P. Crispus turions. This study offers new insights into the dispersal of asexual propagules of submerged macrophytes.
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Turion morphological responses to water nutrient concentrations and plant density in the submerged macrophyte Potamogeton Crispus.
Scientific reports, 2014Co-Authors: Chang Qian, Wenhua You, Dong XieAbstract:Asexual propagules are the dominant means of propagation in most submerged macrophytes. To improve the understanding of how water nutrient concentrations and population density influence the turion production of Potamogeton Crispus L., the turions were planted in mesocosms with three water nutrient conditions (ambient lake water, high P and high N) and two plant density levels (4 and 15 turions m−2). After a 9-month experiment, the +P in the water column significantly increased the total turion number per plant under both of the plant density treatments. However, the +N in the water column did not affect the turion number per plant under low plant density. The +P in the water and high plant density significantly reduced the turion individual biomass. An examination of 3210 turion individuals from all treatments revealed that the increased water nutrient concentrations and plant density impacted the turion size by producing different stem diameters of individual turions. Most of the scale leaf morphological traits of the turions were significantly increased under higher water nutrients, but these traits were similar between the different plant density treatments. These results demonstrate that the water P concentration interacts with plant density, affecting both the production and traits of turions.
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The Growth and Establishment of Floating Turions of Potamogeton Crispus Are Not Favored by Summer Climate
CLEAN - Soil Air Water, 2014Co-Authors: Dong Xie, Hengjie ZhouAbstract:The dispersion of asexual propagules is an important determinant for the spread and establishment of many aquatic plant species. In order to improve the understanding of the expansion of the Potamogeton Crispus population, an in situ growth experiment with P. Crispus turions was performed in a 30 days period. The sinking turions produced longer seedlings and more leaves than that of floating turions during the experimental period. A lower dark respiration rate and higher activities of superoxide dismutase and peroxidase were detected in the floating turions than those in the sinking turions, indicating that the self-protection process of the floating turions and stress condition (high sunlight exposure and temperature) in summer may influence the primary metabolites of these floating turions. Moreover, we also found that the scale leaf porosities of the floating turions would determine the buoyancy of turions. These results indicated that the sinking and floating of P. Crispus turions are determined by the anatomical structures and in situ summer climatic condition is unfavorable for the establishment of P. Crispus floating turions.
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Stay dormant or escape sprouting? Turion buoyancy and sprouting abilities of the submerged macrophyte Potamogeton Crispus L.
Hydrobiologia, 2013Co-Authors: Dong Xie, Chengxing Xia, Wenhua YouAbstract:The ability of asexual propagules to disperse is an important ecological determinant of the spread and establishment of many aquatic species. However, few previous studies have addressed the relationship between the asexual propagule buoyancy and sprouting abilities in submerged macrophytes. For this reason, turions of Potamogeton Crispus samples were collected from Lake Liangzi, and an incubator sprouting experiment was conducted. Our results revealed that the floating turions showed higher sprouting rates than that of sinking turions, indicating the former ones are possibly with high levels of primary metabolites. The higher N and P concentrations in the floating turions caused lower C:N, C:P, and N:P ratios in these turions compared with sinking turions, which confirmed the activation of floating turions. The free amino acid and soluble carbohydrate concentrations were also higher in floating turions than those in sinking turions. Our results also revealed that turion leaf porosity rather than starch concentration may determine the density of P. Crispus turions. This study makes a contribution to our understanding of how the internal characteristics of turions can (at least partly) determine dispersal outcomes and offers new insights into the dispersal and sprouting of asexual propagules of submerged macrophytes.
Jie Chi - One of the best experts on this subject based on the ideXlab platform.
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Phytoremediation of PAH-contaminated sediments with different organic matter contents by Potamogeton Crispus L.
2019Co-Authors: Si Liu, Fanbo Meng, Zheng Ding, Jie ChiAbstract:In this study, phytoremediation of polycyclic aromatic hydrocarbon (PAH)-contaminated sediments with different contents of sediment organic matter (SOM) by Potamogeton Crispus L. was investigated to find out the key factor controlling PAH dissipation enhancements. After a 36-day experiment, dissipation ratios of phenanthrene and pyrene in sediments were improved by P. Crispus but decreased with increasing SOM content, no matter with or without P. Crispus. Furthermore, the results of polyphenol oxidase activity and PAH bioavailability showed that they were both higher in planted treatments than in unplanted treatments. Finally, the enhancements of rapidly desorbing fraction (i.e., the main portion to be readily biodegradable) in sediments with SOM contents of 1.20%, 3.14%, and 5.08% by plants were 20.0%, 40.7%, and 66.7% for phenanthrene, 22.2%, 36.8%, and 58.8% for pyrene, respectively, which is consistent with the change trends of dissipation enhancements of the contaminants in sediments. However, there was no significant correlation between the enhancement of polyphenol oxidase activity and the dissipation enhancement. These results suggested that the improved bioavailability by P. Crispus should be the key factor leading to the dissipation enhancements of the contaminants in sediments with different SOM contents, which provides essential information for phytoremediation of PAH-contaminated sediments.
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Phytoremediation of PAH-contaminated sediments with different organic matter contents by Potamogeton Crispus L.
International journal of phytoremediation, 2018Co-Authors: Si Liu, Fanbo Meng, Zheng Ding, Jie ChiAbstract:In this study, phytoremediation of polycyclic aromatic hydrocarbon (PAH)-contaminated sediments with different contents of sediment organic matter (SOM) by Potamogeton Crispus L. was investigated t...
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Dissipation gradient of pyrene in the rhizosphere of Potamogeton Crispus L.
Ecological Engineering, 2017Co-Authors: Fanbo Meng, Jie ChiAbstract:Abstract In this study, a self-designed laminar rhizobox divided into six separate compartments was used to investigate the degradation gradient of pyrene in the rhizosphere of submerged aquatic plant Potamogeton Crispus L. ( P. Crispus ). At the end of a 30-day experiment, P. Crispus significantly increased the dissipation of pyrene by 16.7-24.5% within the distance of 4 mm from root surface. Concentrations of 1-OH-pyrene, a hydroxylated metabolite of pyrene, were 1.4-15.5 times higher in unplanted treatment than in planted treatment and were positively correlated to pyrene concentrations. At the same time, aerobic bacterial biomass indicated by phospholipid fatty acid content and polycyclic aromatic hydrocarbon (PAH)-degrading bacterial population were both significantly enhanced by P. Crispus within the distance of 8 mm from root surface. Sediment redox potential within the distance of 5 mm from root surface was also obviously improved. Pearson analysis indicated that dissipation ratios of pyrene were positively correlated to PAH-degrading bacterial populations and aerobic bacterial biomasses. Based on the rhizosphere gradient zones of different parameters influenced by P. Crispus as well as the correlation analysis, it could be concluded that oxygen is the limiting factor in remediating pyrene in sediments.
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Effect of Potamogeton Crispus L. on bioavailability and biodegradation activity of pyrene in aged and unaged sediments.
Journal of hazardous materials, 2016Co-Authors: Fanbo Meng, Jie ChiAbstract:In order to clarify the effect of Potamogeton Crispus L. (P. Crispus) on bioavailability and biodegradation activity of pyrene in aged and unaged sediments, model calculation based on experimental results was carried out. During a 36-day experiment, the dissipation ratio of pyrene was increased by planting but decreased by aging. P. Crispus improved the dissipation more significantly in aged sediments (45.9%) than in unaged sediments (17.6%). Results derived from a two-compartment desorption model showed that the decrease of rapidly desorbing fraction of pyrene was in the order of aged sediments without plant (A)>unaged sediments without plant (U)>unaged sediments with plant (UP)>aged sediments with plant (AP). Moreover, the results of biodegradation kinetic model showed that the first-order biodegradation coefficient was in the order of AP>UP>U and A, which was consistent with that of sediment redox potential. These modeling results indicated that planting could enhance the bioavailability (73.9%) and biodegradation activity (277%) of pyrene more significantly in aged sediments as compared to unaged sediments (13.1% and 150%, respectively), which should be the key reasons leading to more significant dissipation increment of pyrene in aged sediments by P. Crispus.
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phytoremediation of pah contaminated sediments by Potamogeton Crispus l with four plant densities
Transactions of Tianjin University, 2015Co-Authors: Fanbo Meng, Jie ChiAbstract:In order to investigate the effect of plant density of Potamogeton Crispus L. on the remediation of sediments contaminated by polycyclic aromatic hydrocarbons, a 54-day experiment with four plant densities(642, 1,604, 2,567 and 3,530 plants/m2)was conducted. The results showed higher plant density with slower plant growth rate. Surface area per plant was the most sensitive root parameter to plant density. At the end of the 54-day experiment, planting P. Crispus enhanced the dissipation ratios of phenanthrene and pyrene in sediments by 6.5%—26.2% and 0.95%—13.6%, respectively. The dissipation increment increased with increasing plant density. Plant uptake accounted for only a small portion of the dissipation increments. Furthermore, P. Crispus could evidently improve sediment redox potentials, and strong positive correlations between root surface area and the redox potential as well as between the redox potentials and the dissipation ratios of phenanthrene and pyrene were obtained, indicating that the oxygen released by the roots of P. Crispus might be the main mechanism by which P. Crispus enhanced the dissipation of PAHs in sediments.
Fanbo Meng - One of the best experts on this subject based on the ideXlab platform.
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Phytoremediation of PAH-contaminated sediments with different organic matter contents by Potamogeton Crispus L.
2019Co-Authors: Si Liu, Fanbo Meng, Zheng Ding, Jie ChiAbstract:In this study, phytoremediation of polycyclic aromatic hydrocarbon (PAH)-contaminated sediments with different contents of sediment organic matter (SOM) by Potamogeton Crispus L. was investigated to find out the key factor controlling PAH dissipation enhancements. After a 36-day experiment, dissipation ratios of phenanthrene and pyrene in sediments were improved by P. Crispus but decreased with increasing SOM content, no matter with or without P. Crispus. Furthermore, the results of polyphenol oxidase activity and PAH bioavailability showed that they were both higher in planted treatments than in unplanted treatments. Finally, the enhancements of rapidly desorbing fraction (i.e., the main portion to be readily biodegradable) in sediments with SOM contents of 1.20%, 3.14%, and 5.08% by plants were 20.0%, 40.7%, and 66.7% for phenanthrene, 22.2%, 36.8%, and 58.8% for pyrene, respectively, which is consistent with the change trends of dissipation enhancements of the contaminants in sediments. However, there was no significant correlation between the enhancement of polyphenol oxidase activity and the dissipation enhancement. These results suggested that the improved bioavailability by P. Crispus should be the key factor leading to the dissipation enhancements of the contaminants in sediments with different SOM contents, which provides essential information for phytoremediation of PAH-contaminated sediments.
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Phytoremediation of PAH-contaminated sediments with different organic matter contents by Potamogeton Crispus L.
International journal of phytoremediation, 2018Co-Authors: Si Liu, Fanbo Meng, Zheng Ding, Jie ChiAbstract:In this study, phytoremediation of polycyclic aromatic hydrocarbon (PAH)-contaminated sediments with different contents of sediment organic matter (SOM) by Potamogeton Crispus L. was investigated t...
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Dissipation gradient of pyrene in the rhizosphere of Potamogeton Crispus L.
Ecological Engineering, 2017Co-Authors: Fanbo Meng, Jie ChiAbstract:Abstract In this study, a self-designed laminar rhizobox divided into six separate compartments was used to investigate the degradation gradient of pyrene in the rhizosphere of submerged aquatic plant Potamogeton Crispus L. ( P. Crispus ). At the end of a 30-day experiment, P. Crispus significantly increased the dissipation of pyrene by 16.7-24.5% within the distance of 4 mm from root surface. Concentrations of 1-OH-pyrene, a hydroxylated metabolite of pyrene, were 1.4-15.5 times higher in unplanted treatment than in planted treatment and were positively correlated to pyrene concentrations. At the same time, aerobic bacterial biomass indicated by phospholipid fatty acid content and polycyclic aromatic hydrocarbon (PAH)-degrading bacterial population were both significantly enhanced by P. Crispus within the distance of 8 mm from root surface. Sediment redox potential within the distance of 5 mm from root surface was also obviously improved. Pearson analysis indicated that dissipation ratios of pyrene were positively correlated to PAH-degrading bacterial populations and aerobic bacterial biomasses. Based on the rhizosphere gradient zones of different parameters influenced by P. Crispus as well as the correlation analysis, it could be concluded that oxygen is the limiting factor in remediating pyrene in sediments.
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Effect of Potamogeton Crispus L. on bioavailability and biodegradation activity of pyrene in aged and unaged sediments.
Journal of hazardous materials, 2016Co-Authors: Fanbo Meng, Jie ChiAbstract:In order to clarify the effect of Potamogeton Crispus L. (P. Crispus) on bioavailability and biodegradation activity of pyrene in aged and unaged sediments, model calculation based on experimental results was carried out. During a 36-day experiment, the dissipation ratio of pyrene was increased by planting but decreased by aging. P. Crispus improved the dissipation more significantly in aged sediments (45.9%) than in unaged sediments (17.6%). Results derived from a two-compartment desorption model showed that the decrease of rapidly desorbing fraction of pyrene was in the order of aged sediments without plant (A)>unaged sediments without plant (U)>unaged sediments with plant (UP)>aged sediments with plant (AP). Moreover, the results of biodegradation kinetic model showed that the first-order biodegradation coefficient was in the order of AP>UP>U and A, which was consistent with that of sediment redox potential. These modeling results indicated that planting could enhance the bioavailability (73.9%) and biodegradation activity (277%) of pyrene more significantly in aged sediments as compared to unaged sediments (13.1% and 150%, respectively), which should be the key reasons leading to more significant dissipation increment of pyrene in aged sediments by P. Crispus.
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phytoremediation of pah contaminated sediments by Potamogeton Crispus l with four plant densities
Transactions of Tianjin University, 2015Co-Authors: Fanbo Meng, Jie ChiAbstract:In order to investigate the effect of plant density of Potamogeton Crispus L. on the remediation of sediments contaminated by polycyclic aromatic hydrocarbons, a 54-day experiment with four plant densities(642, 1,604, 2,567 and 3,530 plants/m2)was conducted. The results showed higher plant density with slower plant growth rate. Surface area per plant was the most sensitive root parameter to plant density. At the end of the 54-day experiment, planting P. Crispus enhanced the dissipation ratios of phenanthrene and pyrene in sediments by 6.5%—26.2% and 0.95%—13.6%, respectively. The dissipation increment increased with increasing plant density. Plant uptake accounted for only a small portion of the dissipation increments. Furthermore, P. Crispus could evidently improve sediment redox potentials, and strong positive correlations between root surface area and the redox potential as well as between the redox potentials and the dissipation ratios of phenanthrene and pyrene were obtained, indicating that the oxygen released by the roots of P. Crispus might be the main mechanism by which P. Crispus enhanced the dissipation of PAHs in sediments.
Hengjie Zhou - One of the best experts on this subject based on the ideXlab platform.
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Differences in the regeneration traits of Potamogeton Crispus turions from macrophyte- and phytoplankton-dominated lakes.
Scientific reports, 2015Co-Authors: Dong Xie, Hengjie Zhou, Hong ZhuAbstract:Potamogeton Crispus is widely used in submerged macrophyte restoration in China. Turions are an important means of reproduction in this species. To compare the regeneration abilities of P. Crispus turions in macrophyte- and phytoplankton-dominated lakes, we collected P. Crispus turions from a macrophyte-dominated lake (Liangzi Lake) and a phytoplankton-dominated lake (Taihu Lake). Both lakes are important lakes in the middle and lower reaches of the Yangtze River in China. Our field survey revealed that the turions from the phytoplankton-dominated lake had smaller sizes and higher concentrations of total nitrogen (TN) and total phosphorus (TP) than did those from the macrophyte-dominated lake. Rapid sprouting of the turions from the phytoplankton-dominated lake in 32 days was observed under experimental conditions, although the sprout sizes (heights and biomass) were smaller than those from the macrophyte-dominated lake. Compared with sprouted turions from macrophyte-dominated lake, the sprouted turions from the phytoplankton-dominated lake accumulated higher soluble sugar (SS) but lower starch and free amino acid (FAA) concentrations. A 12-day interval sprout removal treatment significantly stimulated the re-sprouting of turions from both lakes, but scale-leaf-removal treatments had no effect. This study provides evidence that the regeneration strategies of P. Crispus turions differ in macrophyte- and phytoplankton-dominated lakes.
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effects of buoyancy and season on turion dispersal of submerged macrophyte Potamogeton Crispus l
Clean-soil Air Water, 2015Co-Authors: Dong Xie, Hengjie Zhou, Yushun ChenAbstract:Propagules dispersal and colonization ability are major issues of macrophyte regeneration. For submerged macrophyte Potamogeton Crispus L., turion dispersal along water flow can favor the long-distance expansion of its population; therefore, it is crucial to investigate factors that affect turion dispersal. For this purpose, we studied effects of buoyancy and season on dispersal P. Crispus turions by collecting field samples from Taihu Lake, over a three-months period (turion-formatting season, from May to July). Germination experiments (30 days in each sampling month) revealed that the floating turions germinated earlier and faster than the sinking ones across the three sampling months. After germination, the floating turions showed higher seedling height; whereas the sinking turions accumulated more sprouts biomass. The soluble sugar, total nitrogen (TN), and total phosphorus (TP) concentrations were found higher in the floating turions. The starch concentrations remained high without buoyancy or season effects. These results indicate that both internal (e.g., buoyancy, soluble sugar, TN, and TP concentrations) and external environmental factors (e.g., light condition and temperature) may contribute to germinability and plant growth of P. Crispus turions. This study offers new insights into the dispersal of asexual propagules of submerged macrophytes.
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The Growth and Establishment of Floating Turions of Potamogeton Crispus Are Not Favored by Summer Climate
CLEAN - Soil Air Water, 2014Co-Authors: Dong Xie, Hengjie ZhouAbstract:The dispersion of asexual propagules is an important determinant for the spread and establishment of many aquatic plant species. In order to improve the understanding of the expansion of the Potamogeton Crispus population, an in situ growth experiment with P. Crispus turions was performed in a 30 days period. The sinking turions produced longer seedlings and more leaves than that of floating turions during the experimental period. A lower dark respiration rate and higher activities of superoxide dismutase and peroxidase were detected in the floating turions than those in the sinking turions, indicating that the self-protection process of the floating turions and stress condition (high sunlight exposure and temperature) in summer may influence the primary metabolites of these floating turions. Moreover, we also found that the scale leaf porosities of the floating turions would determine the buoyancy of turions. These results indicated that the sinking and floating of P. Crispus turions are determined by the anatomical structures and in situ summer climatic condition is unfavorable for the establishment of P. Crispus floating turions.
Wang Guoxiang - One of the best experts on this subject based on the ideXlab platform.
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Effects of sediment deposition on germination and seedling growth of Potamogeton Crispus.
Journal of Ecology and Rural Environment, 2010Co-Authors: Cao Yun, Shi Qiang, Wang GuoxiangAbstract:Effect of sediment deposition on germination and seedling growth of Potamogeton Crispus was studied through an experiment.Results show that sediment deposition deferred its germination,but did not affect much its eventual germination rate;thickness of deposition did not affect the number of leaves of its seedlings but did affect the length,width and area of its leaves,which decreased,while the length/width ratio of its leaves increased with the increase in thickness of the deposition;and the biomass of P.Crispus per plant decreased with the increase of thickness of the deposition.
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spatial variation of Potamogeton Crispus turion and its causes of formation in xuanwu lake of nanjing
Acta Hydrobiologica Sinica, 2010Co-Authors: Yang Wenbin, Wang Guoxiang, Wang GangAbstract:In order to investigate the spatial distribution of the Potamogeton Crispus turion in Xuanwu Lake,a total of 52 samples were collected by the grid method.In each sampling site positioned by GPS,four samples of P.Crispus turion from 15cm depth under surface sediment were collected,summing the data to represent turion density of the site.Spatial variation of P.Crispus turion density in the Lake was studied by using the geostatistical component of ArcGIS.Compared with traditional statistical methods,the geostatistic method took directivity,distance and location of sampling points into account.Semivariogram is the specific theory of the method,it can be used to research the spatial correlation and the spatial pattern by determining differences of regional variable among equidistant sampling sites.The survey data converted by Log function were close to nomal distribution and could be discussed by semivariogram.Theortical model and curve graph of regional variable were derived respectively after calculating semivariogram of all possible distance interval,and spatial variation patten about regional variable could be analyzed quantitatively by model parameters such as nugget,sill,range,fractal dimension etc..Furthmore,the spatial variation map of P.Crispus turion was drawn by the method of Kriging interpolation.The results showed:① The semivariogram of P.Crispus turion density fitted spherical model and exhibited an intense special aggregation.② Spatial heterogeneity of Potamogeton Crispus turion density existed obviously,that is,an average density of P.Crispus turion in the North-east Lake and the North-west was 30.5 and 10 ind./m2 respectively;Omnidirectional,elliptic semi-major axis and elliptic semi-minor axis fractal dimension decreased;③ Mowing and differences of population size,water depth,substrate leaded to spatial variability of the density;④ The scale size of spatial auto correlation of the density was bigger than distance of the tuition fallout itself,which showed flowing water played an important role in the turion diffusion.
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Experimental study over the continuous effects of decaying Potamogeton Crispus on water quality
Applied Mechanics and Materials, 2010Co-Authors: Yang Wenbin, Wang GuoxiangAbstract:The present paper is aimed at introducing its author's experimental study over the accumulating effects of decaying Potamogeton Crispus on the water quality.As is well known, Polamogelon Crispus, being a wild weed, is easy to over-grow in the water bodies, such as in the eutrophic lakes, like Hongze Lake (Jiangsu) , Xuanwu Lake (Nanjing), Gucheng Lake ( Nanjing) , usually prosperous in Spring and early Summer, forming a great primary productivity and decomposing dead slowly.It may lead to endogenous accumulation of nutrient loads and the " yellow water effect in many lakes.Let it alone, the decaying weed may result in the secondary pollution to the water bodies.Looking for its remaining effects on the water quality, we have put 4 kg/m~2, 3 kg/m~2, 2 kg/m~2, 0.8 kg/m~2, 0 kg/m~2 of Polamogelon Crispus in 5 water buckets( numbered A-E) with 10 cm thick sediments, respectively, and then track-monitoring the changes of the water.The results of our experiments show that: (1) The concentration of TN, TP, COD_(Mn) may all reach its peak whereas the concentration of DO may reach the valley when the experiment enters the 10-th to 16-th day.And, subsequently, TN, TP, and COD_(Mn) may decrease rapidly, with main water quality indexes improved significantly in 45 days, showing decaying Potamogeton Crispus had short-time effects on the water quality;(2) The concentration of TN, TP in A proves greater than CK obviously with little difference between B-D and CK at the later stages of the experiment, showing above 3 kg/m~2 of the biomass of the decaying grass would produce serious nitrogen and phosphorous pollution, whereas that below 3 kg/m~2 may have little influence;(3) At later stages of the experiment, the concentration of COD_(Mn) in A-C buckets exceeded class Ⅳ water standard, showing that the organic ingredients of the weed tends to decompose slowly;(4) At the later stages of experiment, the concentration of DO in A-D buckets turned to be less than 5.0 mg/L (class Ⅳ water standard).Thus, it can be concluded that the above described facts are likely to offer some reference to the aquatic plants management.
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Effects of Submersed Plant Potamogeton Crispus on Suspended Mud and Sand.
Journal of Ecology and Rural Environment, 2007Co-Authors: Wang GuoxiangAbstract:Submersed plant Potamogeton Crispus was used to construct a holistic system connecting the shallow layer to the deep layer of water.When sandy water flows through the shallow layer to the deep one,effect of P.Crispus on concentration of suspended mud and sand(MS) in different depth layers and sedimentation of MS.Results show that P.Crispus reduced content of MS,and the longer they stayed with the flow,the greater the effect.The average settlement of MS in P.Crispus system was 65.7 g·m~(-2),39.4% higher than in CK.MS sorption on the surface of P.Crispus is a dynamic process of "adsorption-settlement-adsorption" ranging from 3.26 to 5.69 g·kg~(-1),which was related to biomass per unit area of P.Crispus.Therefore,submerged plant P.Crispus may play an important role in self-purification of water bodies in winter.
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environmental effects of Potamogeton Crispus population in lake xuanwu nanjing
Journal of Lake Sciences, 2007Co-Authors: Yang Wenbin, Wang GuoxiangAbstract:To investigate the environmental effects of Potamogegeton Crispus population in Lake Xuanwu,water quality in and out Potamogeton Crispus population area were monitored from January to June of 2006,and were com- pared from 2003 to 2006 in Lake Xuanwu.The results showed:1)From P.Crispus population area to open water area,concentration of DO gradually decreased;2)From"P.Crispus population area","transition area"to"open water area",concentration of TP and TN increased gradually.Average concentration of TP in those area were 0.062,0.098 and 0.105 mg/L respectively,and average concentration of TN in those area were 1.674,2.202 and 2.412 mg/L respectively;3)TP concentration from March to May in 2006 decreased by 15.4%,45% and 43.3%,compared with the same months from 2003 to 2005;these told us that Potamogegeton Crispus population had vital roles in improving lake environment and purifying water quality.Finally,some suggestions about impro- ving and maintaining stable aquatic ecosystems of Lake Xuanwu were put forward in the article.