Estimating carbon sequestration and nutrient accumulation rates in Northeast China are important to assess wetlands function as carbon sink buffering greenhouse gas increasing in North Asia. The objectives of this stu...Estimating carbon sequestration and nutrient accumulation rates in Northeast China are important to assess wetlands function as carbon sink buffering greenhouse gas increasing in North Asia. The objectives of this study were to estimate accreting rates of carbon and nutrients in typical temperate wetlands. Results indicated that average soil organic carbon(SOC), total nitrogen(TN) and total phosphorus(TP) contents were 37.81%, 1.59% and 0.08% in peatlands, 5.33%, 0.25% and 0.05% in marshes, 2.92%, 0.27% and 0.10% in marshy meadows, respectively. Chronologies reconstructed by 210 Pb in the present work were acceptable and reliable, and the average time to yield 0–40 cm depth sediment cores was 150 years. Average carbon sequestration rate(Carbonsq), nitrogen and phosphorus accumulation rates were 219.4 g C/(m^2·yr), 9.16 g N/(m^2·yr) and 0.46 g P/(m^2·yr) for peatland; 57.13 g C/(m^2·yr), 5.42 g N/(m^2·yr) and 2.16 g P/(m^2·yr) for marshy meadow; 78.35 g C/(m^2·yr), 8.70 g N/(m^2·yr) and 0.71 g P/(m2·yr) for marshy; respectively. Positive relations existed between Carbonsq with nitrogen and precipitations, indicating that Carbonsq might be strengthened in future climate scenarios.展开更多
Accumulation of metals in both sediments and Phragmites australis organs was studied. Samples were collected from seven stations located in Anzali wetland, Iran. The samples were analyzed by inductively coupled plasma...Accumulation of metals in both sediments and Phragmites australis organs was studied. Samples were collected from seven stations located in Anzali wetland, Iran. The samples were analyzed by inductively coupled plasma mass spectrometry(ICP-MS). The results showed that concentration of the studied metals(except As and Cd) were higher in sediments than in P.australis organs. Metal accumulation was found to be signifi cantly(P <0.05) higher in roots than in above-ground organs of P.australis. The bioaccumulation factor(BAF) and the transfer factor(TF) also verifi ed the highest rate of metal accumulation in roots and their reduced mobility from roots to the above-ground organs. Pearson correlation coeffi cient showed signifi cant relationships between metal concentrations in sediments and those in plant organs. It should be pointed out that sediment and plant samples exhibited higher metal concentrations in eastern and central parts than in western and southern parts of the wetland. The mean concentrations of all studied elements(except for Fe, V and Al) were higher in these sediment samples than in the Earth's crust and shale. High accumulation of metals in P. australis organs(roots and shoots) is indicative of their high bioavailability in sediments of the wetland. The correlation between metal concentrations in sediments and in P. australis indicates that plant organs are good bioindicators of metal pollution in sediments of Anzali wetland.展开更多
Carbon budget changes were measured on a farm near Robinson, Texas, where land originally tilled for hay production was abandoned over time periods of 10, 20, and 35 years followed by succession of prairie and forest ...Carbon budget changes were measured on a farm near Robinson, Texas, where land originally tilled for hay production was abandoned over time periods of 10, 20, and 35 years followed by succession of prairie and forest vegetation. Woody biomass accumulation increased following abandonment from 0.14 kg C m2 yr~ during forest initiation to 0.57 kg C m2 yr-1 of the mature forest Soil carbon was highest in the tilled field （ 15.77 kg C m2） with lowest in the grassland （ 11.66 kg C m-2）. Soil nitrogen was highest in the tilled field （0.55 kg N ms） and lowest in the forest transition （0.38 kg N m2）. Soil C：N ratios were highest in the forest transition （C：N=36） and lowest in the grassland （C：N=22）. Soil respiration was constant across the site with an annual average value of 1.46 kg CO2-C m-2 yr-. Results show that land in this region may be a source of carbon for several decades following abandonment due to enhanced soil carbon emissions as a function of nutrient input shifts.展开更多
基金Under the auspices of National Natural Science Foundation of China(No.41471081)Scientific Research Foundation of Graduate School of Northeast Normal University(No.12SSXT149)
文摘Estimating carbon sequestration and nutrient accumulation rates in Northeast China are important to assess wetlands function as carbon sink buffering greenhouse gas increasing in North Asia. The objectives of this study were to estimate accreting rates of carbon and nutrients in typical temperate wetlands. Results indicated that average soil organic carbon(SOC), total nitrogen(TN) and total phosphorus(TP) contents were 37.81%, 1.59% and 0.08% in peatlands, 5.33%, 0.25% and 0.05% in marshes, 2.92%, 0.27% and 0.10% in marshy meadows, respectively. Chronologies reconstructed by 210 Pb in the present work were acceptable and reliable, and the average time to yield 0–40 cm depth sediment cores was 150 years. Average carbon sequestration rate(Carbonsq), nitrogen and phosphorus accumulation rates were 219.4 g C/(m^2·yr), 9.16 g N/(m^2·yr) and 0.46 g P/(m^2·yr) for peatland; 57.13 g C/(m^2·yr), 5.42 g N/(m^2·yr) and 2.16 g P/(m^2·yr) for marshy meadow; 78.35 g C/(m^2·yr), 8.70 g N/(m^2·yr) and 0.71 g P/(m2·yr) for marshy; respectively. Positive relations existed between Carbonsq with nitrogen and precipitations, indicating that Carbonsq might be strengthened in future climate scenarios.
文摘Accumulation of metals in both sediments and Phragmites australis organs was studied. Samples were collected from seven stations located in Anzali wetland, Iran. The samples were analyzed by inductively coupled plasma mass spectrometry(ICP-MS). The results showed that concentration of the studied metals(except As and Cd) were higher in sediments than in P.australis organs. Metal accumulation was found to be signifi cantly(P <0.05) higher in roots than in above-ground organs of P.australis. The bioaccumulation factor(BAF) and the transfer factor(TF) also verifi ed the highest rate of metal accumulation in roots and their reduced mobility from roots to the above-ground organs. Pearson correlation coeffi cient showed signifi cant relationships between metal concentrations in sediments and those in plant organs. It should be pointed out that sediment and plant samples exhibited higher metal concentrations in eastern and central parts than in western and southern parts of the wetland. The mean concentrations of all studied elements(except for Fe, V and Al) were higher in these sediment samples than in the Earth's crust and shale. High accumulation of metals in P. australis organs(roots and shoots) is indicative of their high bioavailability in sediments of the wetland. The correlation between metal concentrations in sediments and in P. australis indicates that plant organs are good bioindicators of metal pollution in sediments of Anzali wetland.
文摘Carbon budget changes were measured on a farm near Robinson, Texas, where land originally tilled for hay production was abandoned over time periods of 10, 20, and 35 years followed by succession of prairie and forest vegetation. Woody biomass accumulation increased following abandonment from 0.14 kg C m2 yr~ during forest initiation to 0.57 kg C m2 yr-1 of the mature forest Soil carbon was highest in the tilled field （ 15.77 kg C m2） with lowest in the grassland （ 11.66 kg C m-2）. Soil nitrogen was highest in the tilled field （0.55 kg N ms） and lowest in the forest transition （0.38 kg N m2）. Soil C：N ratios were highest in the forest transition （C：N=36） and lowest in the grassland （C：N=22）. Soil respiration was constant across the site with an annual average value of 1.46 kg CO2-C m-2 yr-. Results show that land in this region may be a source of carbon for several decades following abandonment due to enhanced soil carbon emissions as a function of nutrient input shifts.
