Carsten W. Mueller

Carsten W. Mueller
University of Copenhagen · Department of Geosciences and Natural Resource Management

Associate Professor

About

187
Publications
59,151
Reads
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3,769
Citations
Introduction
My main scientific goal is to provide a better understanding of the fundamental biogeochemical connections between plants, microorganisms and soils in both, managed and natural ecosystems from pore to field scale. In my research I combine physical, biological and chemical analyses to gain a deeper understanding of energy and matter fluxes in the complex 3D soil structures that sustain soil functionality.
Additional affiliations
January 2016 - December 2019
Technische Universität München
Position
  • Professor (Assistant)
November 2011 - present
Technische Universität München
Position
  • Soil micro-scale architecture - soil processes and architecture affected by interactions with plants and microbes
January 2010 - December 2015
Technische Universität München
Position
  • Research Assistant
Education
December 2011 - December 2015
Technische Universität München
Field of study
  • Soil Science
January 2005 - July 2009
Technische Universität München
Field of study
  • Soil Science
October 1998 - November 2004
Technische Universität Dresden
Field of study
  • Forestry

Publications

Publications (187)
Article
For the prediction of permafrost nitrogen (N) climate feedbacks, a better process-based understanding of the N cycle in permafrost ecosystems is urgently needed. Therefore, we characterized and quantified soil organic matter, gross soil microbial ammonification and nitrification and soil-atmosphere exchange of nitrous oxide (N2O) of boreal permafro...
Article
In permafrost soils, substantial amounts of organic carbon (OC) are potentially protected from microbial degradation and transformation into greenhouse gases by association with reactive iron (Fe) minerals. As permafrost environments respond to climate change, increased drainage of thaw lakes in permafrost regions is predicted. Soils will subsequen...
Article
Full-text available
Soil carbon sequestration arises from the interplay of carbon input and stabilization, which vary in space and time. Assessing the resulting microscale carbon distribution in an intact pore space, however, has so far eluded methodological accessibility. Here, we explore the role of soil moisture regimes in shaping microscale carbon gradients by a n...
Article
Full-text available
Reductive dissolution during permafrost thaw releases iron-bound organic carbon to pore-waters, rendering previously stable carbon vulnerable to microbial decomposition and subsequent release to the atmosphere. How mineral iron stability and the microbial processes influencing mineral dissolution vary during transitional permafrost thaw are poorly...
Preprint
Full-text available
Biological soil crusts (biocrusts) composed of cyanobacteria, bacteria, algae, fungi, lichens, and bryophytes stabilize the soil surface. This effect has mainly been studied in arid climates, where biocrusts constitute the main biological agent to stabilize and connect soil aggregates. Besides, biocrusts are an integral part of the soil surface und...
Article
Full-text available
Although the association of minerals and organic matter (OM) in soil plays an important role in the sequestration of C, the factors driving the initial formation of mineral-associated OM (MAOM), and thus the retention of new C input in soils are not yet fully understood. In this study, we investigated how the soil C loading and the differences in t...
Article
Full-text available
Supply of phosphorus (P) as an agricultural input depends on a limited mineral rock phosphate reserve, but inefficient use means this resource is not being used sustainably. Moreover, losses of P from historically accumulated soil reserves can cause substantial environmental harm. Development of sustainable P management will require optimization of...
Article
We still lack crucial knowledge about the contribution of plant vs. microbial residues to specific SOM pools, particularly the relative contribution of arbuscular (AM), ectomycorrhizal (ECM), and saprotrophic (SAP) fungi. We investigated sources of particulate and mineral organic matter (POM and MAOM) around trees with distinct mycorrhizal types, L...
Article
Full-text available
Plain Language Summary The carbon cycle regulates Earth's climate by determining the amount of carbon in our atmosphere. Rivers are important for the carbon cycle because they deliver large amounts of organic carbon from mountains to the oceans. If this carbon is quickly buried in ocean sediment, atmospheric CO2 concentrations decrease. In order to...
Article
Full-text available
Volcanic ash layers are important markers for the chronostratigraphy of paleoclimate and paleoenvironmental archives at the southern tip of South America. However, this requires that tephras are well-dated. We report geochemical data from stalagmite MA1 formed in a non-karst cave near Mt. Burney volcano in southernmost Patagonia (~53°S). High-resol...
Article
The development of effective strategies to maintain/increase soil C is hindered by the poor process-level understanding of the impact of management practices on C preservation, particularly at different soil depths. Based on the distinct biogeochemistry existing across a soil profile, a depth-dependent response of organic matter (OM) to soil amendm...
Article
Full-text available
Purpose Simultaneously interacting rhizosphere processes determine emergent plant behaviour, including growth, transpiration, nutrient uptake, soil carbon storage and transformation by microorganisms. However, these processes occur on multiple scales, challenging modelling of rhizosphere and plant behaviour. Current advances in modelling and experi...
Article
Not only do soils provide 98.7% of the calories consumed by humans, they also provide numerous other functions upon which planetary survivability closely depends. However, our continuously increasing focus on soils for biomass provision (food, fiber, and energy) through intensive agriculture is rapidly degrading soils and diminishing their capacity...
Article
Full-text available
The paradigm that permafrost-affected soils show restricted mineral nitrogen (N) cycling in favor of organic N compounds is based on the observation that net N mineralization rates in these cold climates are negligible. However, we find here that this perception is wrong. By synthesizing published data on N cycling in the plant-soil-microbe system...
Chapter
Nano-scale secondary ion mass spectrometry (NanoSIMS) offers an unprecedented tool to complement classical quantitative measurements (e.g., isotopic ratio, elemental composition) by high resolution imaging of isotope and elemental distributions. It represents a unique technique to follow isotopically labelled compounds at soil microscale hot spots....
Article
Full-text available
Correlations between organic carbon (OC) and fine mineral particles corroborate the important role of the abundance of soil minerals with reactive surfaces to bind and increase the persistence of organic matter (OM). The storage of OM broadly consists of particulate and mineral-associated forms. Correlative studies on the impact of fine mineral soi...
Article
Soil organic carbon management is a nature-based carbon dioxide removal technology at the same time contributing to soil health and agricultural productivity. The soil science communities are refuting the traditional assumptions of the nature of soil organic matter (SOM) as based on ‘humic substances’ that are operationally-defined and have not bee...
Article
As Antarctica is strongly affected by climate change and global warming, the factors that mainly determine soil development might also shift from the dominance of physical to biochemical processes. Vegetation is restricted to the margins of the Antarctic continent with the Antarctic Peninsula being a region of patchily distributed vegetation. While...
Preprint
Reactive iron (Fe) minerals can preserve organic carbon (OC) in soils overlying intact permafrost. With permafrost thaw, reductive dissolution of iron minerals releases Fe and OC into the porewater, potentially increasing the bioavailability of OC for microbial decomposition. However, the stability of this so-called rusty carbon sink, the microbial...
Article
Neutrophilic microbial pyrite (FeS 2) oxidation coupled to denitrification is thought to be an important natural nitrate attenuation pathway in nitrate-contaminated aquifers. However, the poor solubility of pyrite raises questions about its bioavailability and the mechanisms underlying its oxidation. Here, we investigated direct microbial pyrite ox...
Preprint
Purpose Simultaneously interacting small-scale rhizosphere processes determine emergent plant-scale behaviour, including growth, transpiration, nutrient uptake, soil carbon storage and transformation by microorganisms. Current advances in modelling and experimental methods open the path to unravel and link those processes. Methods We present a seri...
Preprint
Full-text available
Reactive iron (Fe) minerals can preserve organic carbon (OC) in soils overlying intact permafrost. With permafrost thaw, reductive dissolution of iron minerals releases Fe and OC into the porewater, potentially increasing the bioavailability of OC for microbial decomposition. However, the stability of this so-called rusty carbon sink, the microbial...
Article
Full-text available
Geogenic organic carbon (GOC) from sedimentary rocks is an overlooked fraction in soils that has not yet been quantified but influences the composition, age, and stability of total organic carbon (OC) in soils. In this context, GOC is the OC in bedrock deposited during sedimentation. The contribution of GOC to total soil OC may vary, depending on t...
Article
Full-text available
The development of high-resolution microscopy and spectroscopy techniques has allowed the analysis of microscopic 3D objects in fields like nanotechnology and life and soil sciences. Soils have the ability to incorporate and store large amounts of organic carbon. To study this organic matter (OM) sequestration, it is essential to analyze its associ...
Article
Incomplete knowledge on the environmental factors linking litter decomposition and the formation of soil organic matter (SOM) hampers the sustainable management of soil as a carbon (C) sink. Here, we explored the effect of soil texture on the fate of C from decomposing litter (Indiangrass; Sorghastrum nutans (L.) Nash) and the concurrent formation...
Preprint
Full-text available
Volcanic ash layers are important markers for the chronostratigraphy of paleoclimate and paleoenvironmental archives at the southern tip of South America. However, this requires that tephras are well-dated. We report geochemical data from the MA1 stalagmite formed in a non-karst cave near Mt. Burney volcano in southernmost Patagonia (~53°S). High-r...
Article
Full-text available
Water-extractable organic carbon (WEOC) is considered as the most important carbon (C) source for denitrifying organisms, but the contribution of individual organic matter (OM) fractions (i.e., particulate (POM) and mineral-associated (MOM)) to its release and, thus, to denitrification remains unresolved. Here we tested short-time effects of POM an...
Article
Full-text available
Clay minerals and pedogenic metal (oxyhydr)oxides are the most reactive soil mineral constituents controlling the long-term persistence of organic carbon (OC) in terrestrial ecosystems. However, their co-occurrence in most soils complicates direct assessment of their individual contribution to OC persistence. Making use of unique mineralogical comb...
Preprint
Full-text available
The largest terrestrial organic carbon pool, carbon in soils, is regulated by the intricate connection between plant carbon inputs, microbial activity, and soil matrix. This is manifested by how microorganisms, the key players in transforming plant-derived carbon into soil organic carbon, are controlled by the physical arrangement of organic and in...
Article
Full-text available
Climate and litter quality drive litter decomposition, but there is currently little consensus on their relative importance, likely because studies differ in the duration, the climatic gradients, and variability in litter‐trait values. Understanding these drivers is important because they determine the direct and indirect (via vegetation compositio...
Article
Full-text available
Letter to the Editor of the European Journal of Soil Science as a reaction to the Russell Review by Phillipe Baveye “Bypass and hyperbole in soil research: worrisome practices critically reviewed through examples” and to his follow‐up Invited Opinion paper “Bypass and hyperbole in soil research: a personal view on plausible causes and possible reme...
Article
Full-text available
It has been shown that reactive soil minerals, specifically iron(III) (oxyhydr)oxides, can trap organic carbon in soils overlying intact permafrost, and may limit carbon mobilization and degradation as it is observed in other environments. However, the use of iron(III)-bearing minerals as terminal electron acceptors in permafrost environments, and...
Article
Full-text available
Tree roots penetrate the soil to several meters depth, but the role of subsoils for the supply of nutrient elements such as phosphorus (P) to the trees is poorly understood. Here, we tested the hypothesis that increased P deficiency in the topsoil results in an increased microbial recycling of P from the forest subsoil. We sampled soils from four G...
Article
Grazed alpine pastures have shaped landscapes of the European Alps for millennia, but have partially been abandoned since the 1950s. Re-grazing of abandoned pastures could preserve this cultural landscape with its high species diversity, but also alter soil carbon and nitrogen cycles, as well as microbial communities, potentially affecting ecosyste...
Article
Full-text available
Permafrost-affected soils of the Arctic account for 70 % or 727 Pg of the soil organic carbon (C) stored in the northern circumpolar permafrost region and therefore play a major role in the global C cycle. Most studies on the budgeting of C storage and the quality of soil organic matter (OM; SOM) in the northern circumpolar region focus on bulk soi...
Article
During the last decade, a paradigmatic shift regarding which processes determine the persistence of soil organic matter (SOM) took place. The interaction between microbial decomposition and association of organic matter with the soil mineral matrix has been identified as a focal point for understanding the formation of stable SOM. Using an improved...
Preprint
Full-text available
Geogenic organic carbon (GOC) from sedimentary rocks is an overlooked fraction in soils that has not been quantified yet, influencing the composition, age and stability of total organic carbon (OC) in soils. In this context GOC is referred to as the OC in bedrocks deposited during sedimentation. However, the contribution of GOC to total soil OC var...
Article
Full-text available
Content and quality of organic matter (OM) may strongly affect the denitrification potential of soils. In particular, the impact of soil OM fractions of differing bioavailability (soluble, particulate, and mineral-associated OM) on denitrification remains unresolved. We determined the potential N2O and N2 as well as CO2 production for samples of a...
Article
Full-text available
Denitrification usually takes place under anoxic conditions and over short periods of time, and depends on readily available nitrate and carbon sources. Variations in CO2 and N2O emissions associated with plant residues have mainly been explained by differences in their decomposability. A factor rarely considered so far is water-extractable organic...
Poster
Full-text available
In this study we demonstrate that spatial relationships between Fe and Al with SOC at the microscale display a shift towards Al-dominated SOC associations at higher precipitation that could not be ascertained from bulk measurements alone. Check out details in the publication: doi.org/10.1016/j.gca.2019.11.030
Preprint
Full-text available
Abstract. Permafrost-affected soils of the Arctic account for 70 % or 727 Pg of the soil organic carbon (C) stored in the permafrost region and therefore play a major role in the global C cycle. Most studies on the budgeting of C storage and the quality of soil organic matter (SOM) in the northern circumpolar region focus on bulk soils. Thus, altho...
Article
Dark, that is, nonphototrophic, microbial CO2 fixation occurs in a large range of soils. However, it is still not known whether dark microbial CO2 fixation substantially contributes to the C balance of soils and what factors control this process. Therefore, the objective of this study was to quantitate dark microbial CO2 fixation in temperate fores...
Article
Climate differences can induce profound changes in organo-mineral associations in soils. However, the magnitude of these modifications, whether as a direct effect of climate conditions or an indirect effect through changes in soil mineralogy, are still not fully understood. In this study, we aimed to improve understanding of how climate and resulta...
Presentation
As major terrestrial carbon reservoirs, permafrost-affected soils of the northern hemisphere play a crucial role in the global carbon cycle. Yet, these soils face tremendous alterations due to enhanced warming. Especially the increased deepening of the active thermal layer is assumed to increase the biovailability of the soil organic matter (SOM) f...
Article
Full-text available
Fossil vertebrates from Antarctica are considerably rare, hampering our understanding of the evolutionary history of the biota from that continent. For several austral summers, the PALEOANTAR project has been carrying out fieldwork in the Antarctic Peninsula in search for fossils, particularly Cretaceous vertebrates. Among the specimens recovered s...
Article
Full-text available
The biogeochemical functioning of soils (e.g., soil carbon stabilization and nutrient cycling) is determined at the interfaces of specific soil structures (e.g., aggregates, particulate organic matter (POM) and organo‐mineral associations). With the growing accessibility of spectromicroscopic techniques, there is an increase in nano‐ to microscale...
Article
Full-text available
Earthworms co-determine whether soil, as the largest terrestrial carbon reservoir, acts as source or sink for photosynthetically fixed CO 2. However, conclusive evidence for their role in stabilising or destabilising soil carbon has not been fully established. Here, we demonstrate that earthworms function like biochemical reactors by converting lab...
Article
Full-text available
Dark, i.e. non‐phototrophic, microbial CO2 fixation occurs in a large range of soils. However, it is still not known whether dark microbial CO2 fixation substantially contributes to the C balance of soils and what factors control this process. Therefore, the objective of this study was to quantify dark microbial CO2 fixation in temperate forest soi...
Article
Iron (Fe) oxides in soils are strong sorbents for environmentally important compounds like soil organic matter (SOM) or phosphate, while sorption under field conditions is still poorly understood. We installed polyvinyl chloride plastic bars which have been coated either with synthetic Fe or manganese (Mn) oxides for 30 days in a redoximorphic soil...