Planktonic and microbial contributions to phosphorus release from fresh and air-dried sediments

1995 ◽  
Vol 46 (7) ◽  
pp. 1039 ◽  
Author(s):  
S Qiu ◽  
AJ McComb
Keyword(s):  
Microbial Biomass ◽  
Sediment Cores ◽  
Phosphorus Release ◽  
Bacterial Respiration ◽  
Air Drying ◽  
Drying And Rewetting ◽  
Dissolved Reactive Phosphorus ◽  
Bacterial Uptake ◽  
Reactive Phosphorus ◽  
North Lake

There was a fivefold increase in the concentration of P (dissolved reactive phosphorus) after intact sediment cores from North Lake, Western Australia, were air-dried and reflooded. Effects of plankton and microbial biomass on phosphorus release were investigated. Freshly killed plankton released P before drying, but less P was released when plankton biomass was air-dried. Bacteria were important contributors of P during drying and rewetting, and their contributions occurred through two processes: (I) when sufficient moisture and oxygen were available, bacteria rapidly removed soluble P from the water and incorporated it into the particulate phase, the amount of P taken up being positively correlated with bacterial respiration; and (2) upon drying, bacterially stored P was partly returned to the water, the release increasing with increasing bacterial uptake. The bacterial contribution of P upon drying was further investigated by sterilizing air-dried and wet sediments with a low dose of gamma irradiation (10 kGy). It was thus possible to discriminate among P contributed from the native (initial) microbial biomass (Pi) before drying, P released from the increased (developed) microbial biomass (Pii) during drying, and P stored in bacteria that had survived air-drying (Ps). It was estimated that air-drying killed about 76% of the microbial biomass. At relatively low external P concentrations (<1000 μg L-1), the increased P brought about by air-drying was mainly derived from killed microbial biomass.

Effects of oxygen concentration on phosphorus release from reflooded air-dried wetland sediments

1994 ◽  
Vol 45 (7) ◽  
pp. 1319 ◽  
Author(s):  
S Qiu ◽  
AJ McComb
Keyword(s):  
Early Stage ◽  
Sediment Cores ◽  
Lake Management ◽  
Inorganic Phosphorus ◽  
Phosphorus Release ◽  
Phosphorus Loading ◽  
Management Technique ◽  
Anaerobic Conditions ◽  
Air Drying ◽  
North Lake

Intact sediment cores from North Lake (Perth, Western Australia) were air-dried for 40 days, reflooded with lake water and incubated at 20°C. Under aerated conditions, air-drying increased phosphorus release. When aeration was stopped, air-dried sediments continued to release P into the water, but the rate was much slower than that in the early stage of the aeration. The results suggest a gradual depletion of labile phosphorus from the dried sediments. Under anaerobic conditions, the phosphate release was also markedly higher for air-dried sediments than for the 'wet' controls. The accumulation of soluble inorganic phosphorus during air-drying, owing to breakdown of organic material and a drying-induced decrease in phosphate sorption, may be the cause of release on rewetting. The results suggest that drought-induced sediment dehydration in natural wetlands may be followed by a significant increase of internal phosphorus loading under both aerobic and anaerobic conditions. Care must therefore be taken in using drawdown as a lake management technique to improve water quality.

Response of microbial biomass to air-drying and rewetting in soils and compost

Geoderma ◽  
2002 ◽  
Vol 105 (1-2) ◽  
pp. 111-124 ◽  
Author(s):  
C Mondini ◽  
M Contin ◽  
L Leita ◽  
M De Nobili
Keyword(s):  
Microbial Biomass ◽  
Air Drying ◽  
Drying And Rewetting

Assessing Bioavailability of Typical Lakes and Reservoirs in Northeast China Based on Phosphorus Fractions

2021 ◽  
pp. 1-11
Author(s):  
Junqiu Wu ◽  
Yue Zhao ◽  
Ran Zhao ◽  
Liming Jia ◽  
Zimin Wei
Keyword(s):  
Microbial Biomass ◽  
Organic Phosphorus ◽  
Mineralization Rate ◽  
Dissolved Phosphorus ◽  
Positive Effects ◽  
Algae Blooms ◽  
Dissolved Reactive Phosphorus ◽  
Lakes And Reservoirs ◽  
Concentration Changes ◽  
Reactive Phosphorus

To explore the eutrophication degree in the typical lakes and reservoirs of the northeast region of China, the bioavailability of dissolved organic phosphorus (DOP) of the lakes has been examined in this study. The laboratory incubation was carried out at 20 °C for 55 days and the concentrations of total dissolved phosphorus (TDP), dissolved reactive phosphorus (DRP), DOP and the microbial biomass have been detected. Results showed that, during the process of incubation, the concentrations of TDP and DRP were increased, whereas the DOP was decreased, which leads to the decreased mineralization rate. In addition, the changes of microbial biomass were fluctuant, but they had significantly positive effects on the concentration changes and mineralization rate of DOP (p < 0.05). The correlation analysis among the phosphate fractions showed that the TDP significantly promoted the DRP concentration, mineralization rate of DOP and the cumulative mineralization of DOP. The kinetics model was conducted to predict the further mineralization of DOP and to analyze the pollution degree of the eight lakes and reservoirs. Accordingly, the lakes with high DRP and TDP had worse water quality and are prone to algae blooms.

MICROBIAL BIOMASS AND EXTRACTABLE SULFATE SULFUR LEVELS IN NATIVE AND CULTIVATED SOILS AS INFLUENCED BY AIR-DRYING AND REWETTING

1989 ◽  
Vol 69 (4) ◽  
pp. 889-894 ◽  
Author(s):  
V. V. S. R. GUPTA ◽  
J. J. GERMIDA
Keyword(s):  
Microbial Biomass ◽  
Key Words ◽  
Microbial Activity ◽  
Microbial Biomass Carbon ◽  
Biomass Carbon ◽  
Air Drying ◽  
Sulfate Sulfur ◽  
Drying And Rewetting ◽  
Source And Sink ◽  
Cultivated Soils

Air-drying decreased (> 80%) microbial activity, microbial biomass carbon (MB-C) and sulfur (MB-S) levels of both native and cultivated soils. This resulted in a flush (~ 4 μg g−1) in the 0.01 M CaCl2 extractable SO4-S. Rewetting soils restored microbial activity and biomass contents to their original levels, but this led to immobilization of the SO4-S. Restoration of the MB-S levels was slower than MB-C levels. Thus, during drying and rewetting cycles, the MB-S pool acts as both a source and sink for the SO4-S pool in soil. Key words: Microbial activity, microbial biomass sulfur, extractable sulfate sulfur

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