Thomas Larsen

Thomas Larsen
Max Planck Institute for the Science of Human History · Department of Archaeology

PhD

About

80
Publications
19,073
Reads
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1,973
Citations
Citations since 2016
47 Research Items
1582 Citations
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2016201720182019202020212022050100150200250300
2016201720182019202020212022050100150200250300
Introduction
I focus broadly on how nutritional relationships between consumers and resources affect the natural world. To characterize nutritional relationships between living organisms, I use a system level approach that seeks to integrate small and large earth system processes. To construct meaning in the context of earth systems, my research often crosses the boundaries between conventional disciplines. I am particularly interested in how our world is shaped by what we eat and how we acquire food resources. A large part of my research focuses on finding methodical solutions for characterizing nutritional relationships. I have led the development of the amino acid isotope fingerprinting method, which can track the biosynthetic origins of amino acids to algae, bacteria, fungi and vascular plants.
Additional affiliations
July 2013 - present
Christian-Albrechts-Universität zu Kiel
Position
  • PostDoc Position
October 2012 - July 2013
Aarhus University
Position
  • PostDoc Position

Publications

Publications (80)
Article
Full-text available
Abstract Explaining food web dynamics, stability, and functioning depend substantially on understanding of feeding relations within a community. Bulk stable isotope ratios (SIRs) in natural abundance are well‐established tools to express direct and indirect feeding relations as continuous variables across time and space. Along with bulk SIRs, the S...
Poster
Full-text available
Exposure to the environmentally persistent perfluoroalkyl substances (PFASs) has been linked to harmful health impacts in humans and fauna. PFASs have been used as fire retardants and water & oil repellants since the 1950s, but our understanding of their sourcing, exposure and bioaccumulation is limited, especially for Arctic consumers. The abilit...
Article
Full-text available
Stable isotope analysis of teeth and bones is regularly applied by archeologists and paleoanthropologists seeking to reconstruct diets, ecologies, and environments of past hominin populations. Moving beyond the now prevalent study of stable isotope ratios from bulk materials, researchers are increasingly turning to stable isotope ratios of individu...
Article
Full-text available
Biochemical and biomolecular archaeology is increasingly used to elucidate the consumption, use, origin, and trade of plants in the past. However, it can be challenging to use biomarkers to identify the taxonomic origin of archaeological plants due to limited knowledge of molecular survival and degradation for many key plant compounds in archaeolog...
Article
Full-text available
Olfaction has profoundly shaped human experience and behaviour from the deep past through to the present day. Advanced biomolecular and ‘omics’ sciences enable more direct insights into past scents, offering new options to explore critical aspects of ancient society and lifeways as well as the historical meanings of smell.
Article
Full-text available
Significance Understanding the drivers of South Asian monsoon intensity is pivotal for improving climate forecasting under global warming scenarios. Solar insolation is assumed to be the dominant driver of monsoon variability in warm climate regimes, but this has not been verified by proxy data. We report a South Asian monsoon rainfall record spann...
Article
Full-text available
To meet future seafood demands, ingredients derived from algae and other novel and sustainable sources are increasingly being tested and used as replacers to traditional aquafeed ingredients. Algal ingredients in particular are being promoted for their sustainability and their additional functional attributes in farmed aquatic animals. Test on alga...
Preprint
Explaining food web dynamics, stability, and functioning depend substantially on understanding of feeding relations within a community. Bulk stable isotope ratios (SIRs) in natural abundance are well-established tools to express direct and indirect feeding relations as continuous variables across time and space. Along with bulk SIRs, the SIRs of in...
Article
Full-text available
The rapidly changing climate in the Arctic is expected to have a major impact on the foraging ecology of seabirds, owing to changes in the distribution and abundance of their prey but also that of competitors (e.g. southerly species expanding their range into the Arctic). Species can respond to interspecific competition by segregating along differe...
Article
Full-text available
Climate change alters species distributions by shifting their fundamental niche in space through time. Such effects may be exacerbated by increased inter-specific competition if climate alters species dominance where competitor ranges overlap. This study used census data, telemetry and stable isotopes to examine the population and foraging ecology...
Article
Lakes cover a global area that is about 35 times smaller than the oceans, but carbon burial in lakes and oceans are on the same order of magnitude. Hence, understanding the processes for such high organic carbon burial in lacustrine systems is essential. We applied proxies typically used for marine environments including amino acid (AA) content and...
Article
Full-text available
In the present study, we assessed if different legacy and novel molecular analyses approaches can detect and trace prohibited bovine material in insects reared to produce processed animal protein (PAP). Newly hatched black soldier fly (BSF) larvae were fed one of the four diets for seven days; a control feeding medium (Ctl), control feed spiked wit...
Article
Background: The carbon isotope ratios (CIRs) of individual amino acids (AAs) may provide more sensitive and specific biomarkers of sugar-sweetened beverages (SSBs) than total tissue CIR. Because CIRs turn over slowly, long-term controlled-feeding studies are needed in their evaluation. Objective: We assessed the responses of plasma and RBC CIRAA...
Article
Full-text available
The cycling of especially large size organic nitrogen (N) from plants into stable microbial derived soil organic carbon (C) and N pools is understudied, in spite of organic N composing 90% of soil N and the intimate link between organic N and soil C stabilization. We investigated the fate of peptide-size and protein-size organic N fractions in soil...
Preprint
Extreme events caused by global change are increasingly affecting the ocean’s biogeochemical cycling and ecosystem functioning, but it is challenging to observe how food webs respond to rapid habitat disturbances. Benthic communities are particularly vulnerable because their habitats are easily affected by extreme events. Here, we examined how bent...
Article
Full-text available
Marine food webs are highly compartmentalized, and characterizing the trophic niches among consumers is important for predicting how impact from human activities affects the structuring and functioning of marine food webs. Biomarkers such as bulk stable isotopes have proven to be powerful tools to elucidate trophic niches, but they may lack in reso...
Article
Full-text available
Diet may be a significant determinant of insect gut microbiome composition. However, the extent to which dietary shifts shape both the composition and relevant functions of insect gut microbiomes, and ultimately, impact host energy balance (i.e., metabolic phenotype) is not well understood. We investigated the impacts of diet switching on Diplopter...
Article
Full-text available
The proliferation of invasive marine species is often explained by a lack of predators and opportunistic life history traits. For the invasive comb jelly Mnemiopsis leidyi, it has remained unclear how this now widely distributed species is able to overcome long periods of low food availability, particularly in their northernmost exotic habitats in...
Preprint
To evaluate the influence of temperature on metabolic performance on the invasive ctenophore Mnemiopsis leidyi, we exposed fully acclimatized adults to conditions typical for the annual variability of the Western Baltic Sea region. We derived basal metabolic rates from oxygen consumption rates of adult M. leidyi specimens exposed to temperatures be...
Article
Full-text available
Millennial‐scale reductions in monsoon precipitation, so‐called Weak Monsoon Intervals (WMIs), have been identified in numerous paleoclimate records across the Afro‐Asian monsoon domain throughout the last glacial‐interglacial cycle. These are considered the regional response to cooling during Heinrich events in the North Atlantic realm and several...
Article
Full-text available
Background Stable isotope analysis of single amino acids (AA) is usually applied in food web studies for tracing biosynthetic origins of AA carbon backbones and establishing trophic positions of consumers, but the method is also showing promise for characterizing quantity and quality of dietary lipids and carbohydrates. Methods To investigate whet...
Article
Food webs in soil differ fundamentally from those above ground; they are based on inputs from both living plants via root exudates, and from detritus, which is a complex mixture of fungi, bacteria and dead plant remains. Trophic relationships are difficult to disentangle due to the cryptic lifestyle of soil animals and inevitable microbial contribu...
Article
Full-text available
Quantification of the bacterial, fungal, and plant energy channels to the nutrition of detritivores is methodologically challenging. This is especially true for earthworms that ingest large amounts of litter and soil mixed with microorganisms. Novel methods such as compound-specific stable isotope analysis (CSIA) of C and N of individual amino acid...
Article
Full-text available
Rationale The cycling of peptide and protein‐bound amino acids (AAs) is important for studying the rate limiting steps in soil N turnover. A strong tool is stable C and N isotopes used in combination with compound‐specific isotope analysis (CSIA), where a prerequisite for analysis is appropriate methods for peptide and protein hydrolysis and approp...
Article
Full-text available
With the increasing anthropogenic impacts on fish habitats, it has become more important to understand which primary resources sustain fish populations. This resource utilization can differ between fish life stages, and individuals can migrate between habitats in search of resources. Such lifetime information is difficult to obtain due to the large...
Article
Full-text available
Tools to study seasonal changes in animal diets are needed to address a wide range of ecological questions. This is especially true of migratory animals that experience distinct environments where diets may be substantially different. However, tracking diets of individuals that move vast distances has proven difficult. Compound-specific isotope ana...
Article
The rapid expansion of the aquaculture industry with carnivorous fish such as salmon has been accompanied by an equally rapid development in alternative feed ingredients. This has outpaced the ability of prevailing authentication method to trace the diet and origins of salmon products at the retail end. To close this gap, we developed a new profili...
Article
Full-text available
Stable isotope analysis has been utilized in archaeology since the 1970s, yet standardized protocols for terminology, sampling, pretreatment evaluation, calibration, quality assurance and control, data presentation, and graphical or statistical treatment still remain lacking in archaeological applications. Here, we present recommendations and requi...
Article
Introduction of legumes (i.e. white clover) in agricultural grasslands is a common practice to improve yields, but how this affects soil fauna populations, particularly mesofauna, is still poorly understood. We investigated taxonomical and functional differences of Collembola communities between plots with either perennial ryegrass (Lolium perenne...
Article
Compound-specific isotopic analysis of amino acids (CSIA-AA) has emerged in the last decade as a powerful approach for tracing the origins and fate of nitrogen in ecological and biogeochemical studies. This approach is based on the empirical observation that source amino acids (AAs)s (i.e., phenylalanine), fractionate ¹⁵N very little (< 0.5‰) durin...
Article
Full-text available
Carbon is one of the most abundant elements in the biosphere, and a key element for understanding how consumer and resource relationships affect ecosystem functioning. To trace carbon sources, ecologists predominantly rely on stable carbon ratios but variable 13C baselines and diet-to-consumer offsets can lead to ambiguous results. To improve sourc...
Article
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Objectives: The Rapa Nui "ecocide" narrative questions whether the prehistoric population caused an avoidable ecological disaster through rapid deforestation and over-exploitation of natural resources. The objective of this study was to characterize prehistoric human diets to shed light on human adaptability and land use in an island environment w...
Article
In EU-28, temporary grasslands constitute more than 10% of the total arable land. Grassland tillage will return up to 400 kg N ha⁻¹ in residues that can lead to a pulse of N2O emissions. Here a novel application of the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) was evaluated in a 28-d mesocosm experiment, where DMPP spraying prio...
Chapter
Full-text available
The introduction of invasive species is a fundamental cause of global change that affects ecosystem conservation. At present, conservation management (e.g. National Parks) has to face the consequences of the arrival of new species, especially those that take a strong role in structuring ecosystems. To be able to develop correct management policies...
Article
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Supplementation of nutrients by symbionts enables consumers to thrive on resources that might otherwise be insufficient to meet nutritional demands. Such nutritional subsidies by intracellular symbionts has been well studied; however, supplementation of de novo synthesized nutrients to hosts by extracellular gut symbionts is poorly documented, espe...
Article
Full-text available
Insect gut microbes have been shown to provide nutrients such as essential amino acids (EAAs) to their hosts. How this symbiotic nutrient provisioning tracks with the host’s demand is not well understood. In this study, we investigated microbial essential amino acid (EAA) provisioning in omnivorous American cockroaches (Periplaneta americana), fed...
Article
Full-text available
Climate change is predicted to alter marine phytoplankton communities and affect productivity, biogeochemistry, and the efficacy of the biological pump. We reconstructed high-resolution records of changing plankton community composition in the North Pacific Ocean over the past millennium. Amino acid–specific δ13C records preserved in long-lived dee...
Article
Full-text available
Insects are unable to synthesize essential amino acids (EAAs) de novo, thus rely on dietary or symbiotic sources for them. Wood is a poor resource of nitrogen in general, and EAAs in particular. In this study, we investigated whether gut microbiota of the Asian longhorned beetle, Anoplophora glabri-pennis (Motschulsky), a cerambycid that feeds in t...
Article
Full-text available
Burial of organic carbon in marine sediments has a profound influence in marine biogeochemical cycles and provides a sink for greenhouse gases such as CO2 and CH4. However, tracing organic carbon from primary production sources as well as its transformations in the sediment record remains challenging. Here we examine a novel but growing tool for tr...
Article
Full-text available
The unabated rise in anthropogenic CO₂ emissions is predicted to strongly influence the ocean's environment, increasing the mean sea-surface temperature by 4°C and causing a pH decline of 0.3 units by the year 2100. These changes are likely to affect the nutritional value of marine food sources since temperature and CO₂ can influence the fatty (FA)...
Article
Full-text available
Burial of organic carbon in marine sediments has a profound influence in marine biogeochemical cycles, and provides a sink for greenhouse gases such as CO2 and CH4. However, tracing organic carbon from primary production sources as well as its transformations in the sediment record remains challenging. Here we examine a novel but growing tool for t...
Article
Full-text available
Soil is a complex ecosystem, and also one of the most important natural systems on the planet, given its fundamental role in biogeochemical cycles, the high richness of biodiversity and the many ecosystem services it provides. Soil fauna, with its multiple levels of specialization and its interactions with above-ground biota and with the mineral so...
Article
Plants, bacteria and fungi produce essential amino acids (EAAs) with distinctive patterns of δ13C values that can be used as naturally occurring fingerprints of biosynthetic origin of EAAs in a food web. Because animals cannot synthesize EAAs and must obtain them from food, their tissues reflect δ13CEAA patterns found in diet, but it is not known h...
Article
Full-text available
Compound-specific isotope analysis of amino acids (CSI-AA) is increasingly used to decouple trophic isotopic effects from isotopic composition at the base of food webs. The delta C-13 values of essential amino acids (EAAs) are particularly useful as recorders of primary production, because animals cannot synthesize EAAs de novo, so diagnostic biosy...
Article
Full-text available
Different proxies for sea surface temperature (SST) often exhibit divergent trends for deglacial warming in tropical regions, hampering our understanding of the phase relationship between tropical SSTs and continental ice volume at glacial terminations. To reconcile divergent SST trends, we report reconstructions of two commonly used paleothermomet...
Article
Full-text available
Tracing the origin of nutrients is a fundamental goal of food web research but methodological issues associated with current research techniques such as using stable isotope ratios of bulk tissue can lead to confounding results. We investigated whether naturally occurring δ(13)C patterns among amino acids (δ(13)CAA) could distinguish between multip...