| A better understanding of lake oxygen biochemical cycle in lake sediments is necessary toassess the impact of natural or anthropogenic perturbations on the sediment-water interfaceEcosystem. Through utilization of the indoor simulation system and micro-interface measuringdevices, we studied physical and biochemical processes of oxygen in the sediment-waterinterface in the West Lake Taihu. The processes included the distribution of oxygen in thesediment-water interface, the spatial heterogeneity of oxygen flux in the material interface andthe impact of temperature on the interfacial oxygen flux. The study sites involved Dapu coastalareas in the west of Taihu Lake, Meiliang Bay, Huzhou coastal areas in the south of Taihu Lakeand the center of Taihu Lake area. The results show that:(1) Compared the interface oxygen flux of the multiple sites with different sedimentproperties, spatial differences of oxygen flux can be found. Besides biological factors, such asbioturbation, irrigation, and biological respiration, oxygen flux is also closely related to the sizedistribution of the sediment, alkaline phosphatase activity in interstitial water and organic mattercontent.(2)TOE values represent the oxygen exchange rate of the lake sediments more accurately.Compared with the DOE and DOEs, TOE not only reflect the total oxygen diffusion flux, butalso the flux of oxygen caused by the respiration of the organisms in the sediment and thedisturbance of the amount of irrigation. The difference of TOE and DOE can be used to expressoxygen exchange rate brought about by the benthic fauna. The variation of SOD of every pointis same to the TOE, DOE and DOEs.And the SOD values in two sites of DP01and M09weresignificantly higher than others.(3) Comparasion of physical and chemical properties and interface oxygen exchange ofsediment in three samples showed that DOE, DOEs, SOD are in the sequence of west of TaihuLake> Meiliang Bay> south of Taihu Lake. The oxygen erosion average depth is in the sequenceof south of Taihu Lake> Meiliang Bay> west of Taihu Lake. TOE value is expressed as: west ofTaihu Lake> south of Taihu Lake> Meiliang Bay. The sediment nature of DP01is significantlydifferent from the other sites. From the outside, compared with other points, the sediment coresamples in Dapu coastal is local black-odor.(4)With increasing temperature, sediment oxygen erosion depth gradually decreased, theoxygen diffusion rate of the sediment-water interface gradually increased, and the DOE valuewere lower at29.9°C. There was a marked increasing trend in the total oxygen flux with increased temperature. The contrast between TOE and DOE significantly proved the effect ofbiological activity in sediments of Taihu Lake on interfacial mass flux. Meanwhile, the influenceof temperature on the erosion depth and sediment-water interface oxygen flux from the shore tothe lake is gradually increasing. |
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