To reveal additional effects of aquatic macrophytes on biogeochemical properties of onshore lake phosphorus and to investigate the ecological response of reed communities to this phosphorus,sediments from the Meiliang...To reveal additional effects of aquatic macrophytes on biogeochemical properties of onshore lake phosphorus and to investigate the ecological response of reed communities to this phosphorus,sediments from the Meiliangwan onshore reed area of Lake Taihu were sampled by using a columnar sampler (D=8 cm) on September 18,October 17 and December 3,2003. The samples were compared with those from macrophyte-free areas. The collected samples were dried naturally at room temperature,ground and screened with a 100 mesh sieve. The HClO4-H2SO4 digesting and H2SO4-H2O2 heating digesting methods were used to analyze the total amount of phosphorus (TP) contained in sedi-ments of the reed area and in tissues of reed roots and stems. The result shows: 1) the level of TP,from both the reed area sediment and the reference samples,is highest during the vigorous growing stage and lowest during the slow growing stage. The difference between the two levels is statistically significant (p<0.01); 2) the top layer (0-2 cm) of the sediment from the area without higher aquatic macrophytes and the sediment (4-7 cm) in the central reed area show peak values of phosphorus enrichment; 3) the phosphorus enrichment of different parts of reed tissues is in decreasing order: firous root > rhizome > stem. All are smaller in the level of phosphorous than that in rhizosphere sediments (0-2 cm).展开更多
Aquatic macrophytic growth and its distribution in eutrophic lakes are described in relation to its sediment type and irradiance. Hence, it is necessary to characterize the response of macrophytic growth to lake sedim...Aquatic macrophytic growth and its distribution in eutrophic lakes are described in relation to its sediment type and irradiance. Hence, it is necessary to characterize the response of macrophytic growth to lake sediment and its re-suspension. We conducted two independent experiments to measure the effects of sediment and its re-suspension on the growth of Vallisneria asiatica Miki. Based on our study, we conclude that the amount of total biomass of V. asiatica is related, in important ways, to the type of sediment and its re-suspension. According to our comparison, plants and biomass cultured on lake sediments are 2.1 times and 1.5 times greater than that on brown clay from nearby places beside Lake Taihu. The number of plants and the amount of biomass in a turbid water column are smaller than those in a clear water column. The results indicate that the nutrient-rich lake sediments have promoted the growth of V. asiatica, while the re-suspension of the sediment leads to a high turbid level and low light penetration which has a negative impact on the growth of V. asiatica.展开更多
基金Projects KZCX1-SW-12 supported by the Chinese Academy of Sciences Knowledge Innovation Program2002AA60101 by the National High Technol- ogy Research and Development Program of China
文摘To reveal additional effects of aquatic macrophytes on biogeochemical properties of onshore lake phosphorus and to investigate the ecological response of reed communities to this phosphorus,sediments from the Meiliangwan onshore reed area of Lake Taihu were sampled by using a columnar sampler (D=8 cm) on September 18,October 17 and December 3,2003. The samples were compared with those from macrophyte-free areas. The collected samples were dried naturally at room temperature,ground and screened with a 100 mesh sieve. The HClO4-H2SO4 digesting and H2SO4-H2O2 heating digesting methods were used to analyze the total amount of phosphorus (TP) contained in sedi-ments of the reed area and in tissues of reed roots and stems. The result shows: 1) the level of TP,from both the reed area sediment and the reference samples,is highest during the vigorous growing stage and lowest during the slow growing stage. The difference between the two levels is statistically significant (p<0.01); 2) the top layer (0-2 cm) of the sediment from the area without higher aquatic macrophytes and the sediment (4-7 cm) in the central reed area show peak values of phosphorus enrichment; 3) the phosphorus enrichment of different parts of reed tissues is in decreasing order: firous root > rhizome > stem. All are smaller in the level of phosphorous than that in rhizosphere sediments (0-2 cm).
基金Projects KZCX1-SW-12 supported by the Key Project of CAS 2002AA601011-04 by the Hi-tech Research and Development Program of China
文摘Aquatic macrophytic growth and its distribution in eutrophic lakes are described in relation to its sediment type and irradiance. Hence, it is necessary to characterize the response of macrophytic growth to lake sediment and its re-suspension. We conducted two independent experiments to measure the effects of sediment and its re-suspension on the growth of Vallisneria asiatica Miki. Based on our study, we conclude that the amount of total biomass of V. asiatica is related, in important ways, to the type of sediment and its re-suspension. According to our comparison, plants and biomass cultured on lake sediments are 2.1 times and 1.5 times greater than that on brown clay from nearby places beside Lake Taihu. The number of plants and the amount of biomass in a turbid water column are smaller than those in a clear water column. The results indicate that the nutrient-rich lake sediments have promoted the growth of V. asiatica, while the re-suspension of the sediment leads to a high turbid level and low light penetration which has a negative impact on the growth of V. asiatica.
