排序方式: 共有6条查询结果,搜索用时 15 毫秒
1
1.
2.
Anthropogenic pollutants affect ecosystem services of freshwater sediments: the need for a “triad plus x” approach 总被引:1,自引:0,他引:1
Gerbersdorf Sabine Ulrike Hollert Henner Brinkmann Markus Wieprecht Silke Schüttrumpf Holger Manz Werner 《Journal of Soils and Sediments》2011,11(6):1099-1114
Purpose
Freshwater sediments and their attached microbial communities (biofilms) are essential features of rivers and lakes, providing valuable ecosystem services such as nutrient recycling or self-purification which extend beyond the aquatic environment. Anthropogenic pollutants, whether from the industrial era or as a result of our contemporary lifestyles, can negatively affect these functions with hitherto unknown consequences on ecology, the economy and human health. Thus far, the singular view of the involved disciplines such as ecotoxicology, environmental microbiology, hydrology and geomorphology has prevented a deeper understanding of this emerging issue. 相似文献3.
Sabine U. Gerbersdorf Rui M. L. Ferreira Gudrun Hillebrand 《Journal of Soils and Sediments》2018,18(10):3041-3043
4.
Sabine U. Gerbersdorf Thomas Jancke Bernhard Westrich 《Journal of Soils and Sediments》2007,7(1):25-35
Background, Aim and Scope
Riverine sediments store large quantities of hazardous contaminants, remaining a 'legacy of the past' world-wide. Natural
events such as floods may cause the resuspension of polluted sediments and accordingly, the former immobilized contaminants
might become bioavailable and toxic again. Hence, a comprehensive erosion risk assessment of contaminated sites is of crucial
importance. The present study aimed to implement 'master-variables' for a reliable, easy-to-manage and economically more viable
determination of stability in cohesive sediments.
Materials and Methods:
A wide range of physico-chemical (bulk density, water content, particle size, mineral composition, cation exchange capacity
/ CEC, total organic matter / TOC, liquid and plastic limits of a soil) and biological (macrofauna abundances, microalgal
biomass and species composition, bacterial cell numbers, EPS fractions such as carbohydrates and proteins) properties were
determined simultaneously over depth spanning the zone between 0-35 cm. The data were related to sediment stability, determined
as the 'critical shear stress for mass erosion' in the SETEG (Stroemungskanal zur Ermittlung der tiefenabhaengigen Erosionsstabilitaet
von Gewaessersedimenten) - flume. The investigations were done on natural sediments, thereby covering vertical (over depth),
spatial (different study sites) and temporal (different seasons) aspects to ensure the transferability of the data. Here,
first data originating from three contaminated reservoirs in the lock-regulated River Neckar / Germany are presented.
Results:
Comparison of the rather low critical shear stress values (resisting force of sediment, determined in SETEG) with the possibly
occurring natural bottom shear stresses (attacking force, calculated for different hydraulic scenarios) at the three reservoirs
indicated a severe risk of sediment erosion even under moderate hydraulic conditions and was not restricted to the surface.
Critical shear stress was characterised by the following sediment properties of depth, grain size, CEC (Cation Exchange Capacity)
and concentrations of TOC (Total Organic Carbon), proteins as well as carbohydrates (water- and resin-extractable). Firstly,
biological stabilisation by extracellular polymeric substances (EPS) could be shown for riverine sediments, even over depth.
Secondly, erosion resistance was determined by the inter-particles forces, an interplay of the biologically produced compounds
constituting active surfaces and the binding capacity as well as charge densities of the sediments. The combined influence
of sedimentological and biological properties on sediment stability over depth was assessed by PCA (Principal Component Analysis).
Discussion:
Hence, a better correlation coefficient between sediment stability and the master variables could be achieved (Main component
II: Polymeric substances, R = 0.7, Main component III: Grain size, TOC, CEC, R = 0.9) compared to single correlations.
Conclusions:
The present paper revealed the combined influence of physico-chemical and biological properties on sediment stability over
depth by simultaneous investigation and statistical evaluation. It can be shown, that inter-particle forces, determined by
particles size classes, CEC, TOC and polymeric substances such as proteins and carbohydrates, affected sediment stability
most. Thereby, the impact of biogenic sediment mediation on riverine sediment stabilisation became evident, even over depth,
where mostly sedimentological parameters were considered as important before.
Recommendations and Perspectives:
The importance of a comprehensive risk assessment of contaminated riverine sites was again highlighted in the present study
by the comparison of natural occurring bottom shear stresses with the determined sediment erosion resistance. If a realistic
risk assessment is to be derived, the stabilizing potential of micro-organisms needs to be taken into account and the covariance
patterns of biological and physico-chemical sediment properties have to be addressed. 相似文献
5.
Sabine Ulrike Gerbersdorf Robert Bittner Helen Lubarsky Werner Manz David M. Paterson 《Journal of Soils and Sediments》2009,9(6):640-652
Purpose
Sediment erosion and transport is a governing factor in the ecological and commercial health of aquatic ecosystems from the watershed to the sea. There is now a general consensus that biogenic mediation of submersed sediments contributes significantly to the resistance of the bed to physical forcing. This important ecosystem function has mainly been linked to microalgae (“ecosystem engineers”) and their associated extracellular polymeric substances (EPS), yet little is known about the impact of bacterial assemblages and how their varying interactions with microalgae affect the overall biostabilization potential of the combined community. 相似文献6.
David M. Paterson Julie A. Hope Joseph Kenworthy Catherine L. Biles Sabine U. Gerbersdorf 《Journal of Soils and Sediments》2018,18(10):3044-3054
Purpose
The objective of this work is to better understand the role that biological mediation plays in the behaviour of fine sediments. This research is supported by developments in ecological theory recognising organisms as “ecosystem engineers” and associated discussion of “niche construction”, suggesting an evolutionary role for habitat modification by biological action. In addition, there is acknowledgement from engineering disciplines that something is missing from fine sediment transport predictions.Materials and methods
Advances in technology continue to improve our ability to examine the small-scale 2D processes with large-scale effects in natural environments. Advanced molecular tools can be combined with state-of-the-art field and laboratory techniques to allow the discrimination of microbial biodiversity and the examination of their metabolic contribution to ecosystem function. This in turn can be related to highly resolved measurements and visualisation of flow dynamics.Results and discussion
Recent laboratory and field work have led to a paradigm shift whereby hydraulic research has to embrace biology and biogeochemistry to unravel the highly complex issues around on fine sediment dynamics. Examples are provided illustrating traditional and more recent approaches including using multiple stressors in fully factorial designs in both the laboratory and the field to highlight the complexity of the interaction between biology and sediment dynamics in time and space. The next phase is likely to rely on advances in molecular analysis, metagenomics and metabolomics, to assess the functional role of microbial assemblages in sediment behaviour, including the nature and rate of polymer production by bacteria, the mechanism of their influence on sediment behaviour.Conclusions
To fully understand how aquatic habitats will adjust to environmental change and to support the provision of various ecosystem services, we require a holistic approach. We must consider all aspects that control the distribution of sediment and the erosion-transport-deposition-consolidation cycle including biological and chemical processes, not just the physical. In particular, the role of microbial assemblages is now recognised as a significant factor deserving greater attention across disciplines.
1