Scientific output

 
 
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PAPER - Biogeosciences (2016)

Wetland eco-engineering: measuring and modeling feedbacks of oxidation processes between plants and clay-rich material

Rémon M. Saaltink, Stefan C. Dekker, Jasper Griffioen, and Martin J. Wassen

Abstract. Interest is growing in using soft sediment as a foundation in eco-engineering projects. Wetland construction in the Dutch lake Markermeer is an example: here, dredging some of the clay-rich lake-bed sediment and using it to construct wetland will soon begin. Natural processes will be utilized during and after construction to accelerate ecosystem development. Knowing that plants can eco-engineer their environment via positive or negative biogeochemical plant–soil feedbacks, we conducted a 6-month greenhouse experiment to identify the key biogeochemical processes in the mud when Phragmites australis is used as an eco-engineering species. We applied inverse biogeochemical modeling to link observed changes in pore water composition to biogeochemical processes. Two months after transplantation we observed reduced plant growth and shriveling and yellowing of foliage. The N : P ratios of the plant tissue were low, and these were affected not by hampered uptake of N but by enhanced uptake of P. Subsequent analyses revealed high Fe concentrations in the leaves and roots. Sulfate concentrations rose drastically in our experiment due to pyrite oxidation; as reduction of sulfate will decouple Fe-P in reducing conditions, we argue that plant-induced iron toxicity hampered plant growth, forming a negative feedback loop, while simultaneously there was a positive feedback loop, as iron toxicity promotes P mobilization as a result of reduced conditions through root death, thereby stimulating plant growth and regeneration. Given these two feedback mechanisms, we propose the use of Fe-tolerant species rather than species that thrive in N-limited conditions. The results presented in this study demonstrate the importance of studying the biogeochemical properties of the situated sediment and the feedback mechanisms between plant and soil prior to finalizing the design of the eco-engineering project.

 
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PAPER - in Plant and Soil (2017)

Plant-specific effects of iron-toxicity in wetlands

Rémon M. Saaltink, Stefan C. Dekker, Maarten B. Eppinga, Jasper Griffioen, and Martin J. Wassen

Background and aims Understanding the potential effects of iron toxicity on plant development is important when constructing new wetland from iron-rich sediment. We aim to study plant species-specific effects of iron toxicity when grown in the iron-rich sediments of lake Markermeer (the Netherlands).
Methods Using three sediment sources that varied in total Fe and Fe-P concentrations, we performed a greenhouse
experiment to study the development of three wetland species that differ in their tolerance to iron and
utilization capacity of Fe-P: Rumex maritimus, Phragmites australis and Eupatorium cannabinum.
Results Phragmites australis was the only species that developed an epidermis-damaging iron plaque on its
roots. Plaque formation mainly depended on the Fe(III) and Fe-P concentration of the sediment, which
led to different nutrient imbalances in leaves. All three species showed reduced growth compared to the control
substrate, which could not be linked to indirect Fe toxicity. In contrast, direct Fe toxicity following the
uptake of Fe could not be excluded as a mechanism potentially explaining our results, and this result warrants
further examination in longer-term experiments.
Conclusions Our results highlight the importance of considering the Fe and Fe-P availability in sediments,
as these properties may constrain plant performance anddelay the development of pioneer ecosystems in wetland
construction sites.

 
Article available on request.

Article available on request.

PROFESSIONAL ARTICLE - in Grondboor en Hamer (2016) - DUTCH ONLY

Waarom sediment-mineralogisch onderzoek voor de Building-with-Nature projecten?

Jasper Griffioen, Maria Barciela Rial, Iris R. Pit, Rémon M. Saaltink

De Building-with-Nature technologie (BwN) is enkele jaren geleden opgekomen als alternatief voor de traditionele waterbouw-technieken (http://www.ecoshape.nl/nl_NL). Het doel van BwN is meervoudig: 1. integratie van infrastructuur, natuur en maatschappij in nieuwe of alternatieve vormen van waterbouw, 2. ontwikkelen en implementeren van meer duurzame oplossingen voor de waterbouw, 3. zachtere en natuurlijkere materialen gebruiken in waterbouwconstructies dan beton, etc. In het begin ging de aandacht vooral uit naar de civiel-technische en ecologische aspecten. Inmiddels is de aandacht ook verbreed naar de geochemische en mineralogische aspecten met dus verbreding met een aardwetenschappelijke invalshoek. Dit blijkt o.a. uit het feit dat 1 aio-onderzoek omtrent milieu(geo)chemische aspecten van de Zandmotor  is opgenomen in het STW-programma Nature Coast. Verder worden momenteel 2 aio-onderzoeken uitgevoerd  waarin de Marker Wadden centraal staan en waarbij geochemie en mineralogie een relevante rol spelen. Deze twee onderzoeken worden uitgevoerd in het NWO Urbanising Deltas of the World project Smart ecosystems: Regime shifts from mud systems to dynamic wetlands. De doelstelling van dit verhaal is om de behoefte aan sedimentmineralogisch onderzoek te verklaren middels enerzijds resultaten van deze aio-onderzoeken en anderzijds generieke kennisvragen  op te werpen die zich voordoen bij BwN projecten. We beperken ons hierbij tot BwN projecten waarbij sediment in de vorm van zand of modder wordt verwerkt.

 

POSTER - Building with Nature day, Utrecht (2017)

Smart ecosystems: Integrating biophysics and governance for the Marker Wadden case

Mariëlle C. van Riel, Piet F. M. Verdonschot, Ruurd Noordhuis, Martin J. Wassen

 

PITCH OF KEY-RESULTS - EcoSummit, Montpellier (2016)

 

 

POSTER - EcoSummit, Montpellier (2016)

Smart ecosystems: using the concept of eco-engineering for large-scale wetland construction in the Netherlands

Rémon M. Saaltink, Stefan C. Dekker, Maarten B. Eppinga, Jasper Griffioen, and Martin J. Wassen

 

POSTER - Building with Nature day, Utrecht (2017)

Consolidation and strength development of soft mud deposits

Maria Barciela Rial, Johan C. Winterwerp, Jasper Griffioen, Thijs van Kessel

 

POSTER - Building with Nature day, Utrecht (2017)

Smart ecosystems: Integrating biophysics and governance for the Marker Wadden case - a governance perspective

Mariëlle C. van Riel, Piet F. M. Verdonschot, Ruurd Noordhuis, Martin J. Wassen

 

POSTER - European Geosciences Union, Vienna (2017)

The effect of organic matter oxidation and drying on the geomechanical behavior of anoxic mud

Maria Barciela Rial, Johan C. Winterwerp, Jasper Griffioen, Leon A. van Paassen, Thijs van Kessel

 

POSTER - European Geosciences Union, Vienna (2016)

Constructing wetlands: measuring and modeling feedbacks of oxidation processes between plants and clay-rich material

Rémon M. Saaltink, Stefan C. Dekker, Maarten B. Eppinga, Jasper Griffioen, and Martin J. Wassen

 

POSTER - European Geosciences Union, Vienna (2015)

Biogeochemical processes influencing phosphorus dynamics in freshwater mud deposits

Rémon M. Saaltink, Stefan C. Dekker, Jasper Griffioen, and Martin J. Wassen

 

INVITED TALK - Academy of Ecosystem Services, Utrecht (2015)

Marker wadden: using soft mud to create a dynamic wetland system

Rémon M. Saaltink, Stefan C. Dekker, Jasper Griffioen, and Martin J. Wassen

 

PRESENTATION - Netherlands Anual Ecology Meeting, Lunteren (2016)

Wetland Eco-engineering: measuring and modelling feedbacks of oxidation processes between plants and clay-rich material

Rémon M. Saaltink, Stefan C. Dekker, Jasper Griffioen, and Martin J. Wassen