The aim was to explore dynamic changes of organic matter and nitrogen pol ution in Dongchang Lake. [Method] Monitoring data, including BOD5, CODCr, NH3-N and TN, of Dongchang Lake were chosen for analysis during 2002-...The aim was to explore dynamic changes of organic matter and nitrogen pol ution in Dongchang Lake. [Method] Monitoring data, including BOD5, CODCr, NH3-N and TN, of Dongchang Lake were chosen for analysis during 2002-2011. [Result] Water quality of the six lake districts showed deteriorating in monitor-ing period, and TN was the dominant pol ution factor; BOD5/CODCr ratio was low, suggesting biodegradability of organic pol utant in the lake was lower. NH3/TN ratio was higher, indicating NH3-N was a major factor causing nitrogen exceeding in 2010. In addition, correlations between BOD5 and CODCr and between NH3-N and TN in the lake districts maintained at a significant level. [Conclusion] The research provides references for improving water in Dongchang Lake.展开更多
Invasion of an exotic C4 plant Spartina alterniflora has been shown to increase soil organic carbon （SOC） concentrations in native C3 plant-dominated coastal wetlands of China. However, little is known about the eff...Invasion of an exotic C4 plant Spartina alterniflora has been shown to increase soil organic carbon （SOC） concentrations in native C3 plant-dominated coastal wetlands of China. However, little is known about the effects of S. alterniflora invasion on SOC concentrations and fractions in tidal marshes dominated by native C4 plants. In this study, a field experiment was conducted in a tidal marsh dominated by the native C4 plant Cyperus malaccensis in the Minjiang River estuary, China. Concentrations of SOC and liable SOC fractions, dissolved organic carbon （DOG）, microbial biomass carbon （MBC）, and easily oxidizable carbon （EOC）, were measured in the top 50-cm soils of the C. malaccensis community, as well as those of three S. alterniflova communities with an invasion duration of 0-4 years （SA-4）, 4-8 years （SA-8）, and 8-12 years （SA-12）, respectively. Results showed that both SOC stocks in the 50-cm soils and mean SOC concentrations in the surface soils （0-10 cm） of the C. malaccensis community increased with the duration of S. alterniflora invasion, whereas SOC concentrations in the 10-50-cm soils decreased slightly during the initial period of S. alterniflora invasion, before increasing again. The pattern of changes in labile SOC fractions （DOC, MBC, and EOC） with invasion duration was generally similar to that of SOC, while the ratios of labile SOC fractions to total SOC （DOC：SOC, MBC：SOC, and EOC：SOC） decreased significantly with the duration of S. alterniflora invasion. The findings of this study suggest that invasion of the exotic C4 plant S. alternifora into a marsh dominated by the native C4 plant C. malaecensis would enhance SOC sequestration owing to the greater amount of biomass and lower proportion of labile SOC fractions present in the S. alterniflora communities.展开更多
基金Supported by Major Science and Technology Program for Water Pollution Control and Treatment(2009ZX07106-03)Shandong Provincial Natural Science Foundation(ZR2013DM012,ZR2010DL008,ZR2013DL005)Undergraduate Scientific and Technological Innovation Project(SF2013138,SF2013140,SF2012076,SF2012077,SF2012090)~~
文摘The aim was to explore dynamic changes of organic matter and nitrogen pol ution in Dongchang Lake. [Method] Monitoring data, including BOD5, CODCr, NH3-N and TN, of Dongchang Lake were chosen for analysis during 2002-2011. [Result] Water quality of the six lake districts showed deteriorating in monitor-ing period, and TN was the dominant pol ution factor; BOD5/CODCr ratio was low, suggesting biodegradability of organic pol utant in the lake was lower. NH3/TN ratio was higher, indicating NH3-N was a major factor causing nitrogen exceeding in 2010. In addition, correlations between BOD5 and CODCr and between NH3-N and TN in the lake districts maintained at a significant level. [Conclusion] The research provides references for improving water in Dongchang Lake.
基金supported by the National Natural Science Foundation of China(Nos.31000262 and 41671088)the Program for Innovative Research Team at Fujian Normal University,China(No.IRTL1205)+1 种基金the Research Grants Council of the Hong Kong Special Administrative Region,China(No.CUHK458913)the Chinese University of Hong Kong Direct Grant(No.4052119)
文摘Invasion of an exotic C4 plant Spartina alterniflora has been shown to increase soil organic carbon （SOC） concentrations in native C3 plant-dominated coastal wetlands of China. However, little is known about the effects of S. alterniflora invasion on SOC concentrations and fractions in tidal marshes dominated by native C4 plants. In this study, a field experiment was conducted in a tidal marsh dominated by the native C4 plant Cyperus malaccensis in the Minjiang River estuary, China. Concentrations of SOC and liable SOC fractions, dissolved organic carbon （DOG）, microbial biomass carbon （MBC）, and easily oxidizable carbon （EOC）, were measured in the top 50-cm soils of the C. malaccensis community, as well as those of three S. alterniflova communities with an invasion duration of 0-4 years （SA-4）, 4-8 years （SA-8）, and 8-12 years （SA-12）, respectively. Results showed that both SOC stocks in the 50-cm soils and mean SOC concentrations in the surface soils （0-10 cm） of the C. malaccensis community increased with the duration of S. alterniflora invasion, whereas SOC concentrations in the 10-50-cm soils decreased slightly during the initial period of S. alterniflora invasion, before increasing again. The pattern of changes in labile SOC fractions （DOC, MBC, and EOC） with invasion duration was generally similar to that of SOC, while the ratios of labile SOC fractions to total SOC （DOC：SOC, MBC：SOC, and EOC：SOC） decreased significantly with the duration of S. alterniflora invasion. The findings of this study suggest that invasion of the exotic C4 plant S. alternifora into a marsh dominated by the native C4 plant C. malaecensis would enhance SOC sequestration owing to the greater amount of biomass and lower proportion of labile SOC fractions present in the S. alterniflora communities.
