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Faculty of Health and Life Sciences

Dr Dirk Sanders

Dr Dirk Sanders

BBSRC Discovery Fellow and Lecturer

 01326 259467

 Environment and Sustainability Institute 


Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK


My research aims to link the structure of ecological communities to ecosystem processes and to understand the impact of human stressors on these communities. I study the spread of antimicrobial resistance (AMR) by plasmids that can act as parasites or mutualists in microbial communities. This will reveal how enviromental antibiotic exposure changes the coveolutionary dymanics between plasmids and their bacterial hosts leading to changes in their interaction networks and consequently the risk of AMR spread. I further study the interplay of mutualistic and antagonistic, trophic and non-trophic (i.e. ecosystem engineering) interactions and how these are driving ecosystem stability.  


2008 PhD (University of Goettingen)


2023- BBSRC Discovery Fellow and Lecturer in Ecology and Conservation, University of Exeter

2013–2022 Research Fellow, University of Exeter, Cornwall Campus
2011–2013 Assistant with independent research, University of Bern, Switzerland
2010–2011 Post-doctoral research fellow, University of Exeter, Cornwall Campus
2009–2010 Post-doctoral research fellow, Imperial College London, Silwood Park

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Research interests

My research explores the link between the structure of ecological communities, their stability and important processes. My research aims to understand the ecological consequences of human impact and species losses and how they are transmitted through the network of interacting species. Experiments are a powerful tool to test this impact as they demonstrate the actual community response to species loss. I have manipulated predator presence and abundance, predator functional diversity, and the presence of predators that also act as mutualists or ecosystem engineers in various field experiments. As model systems I use (i) aphids, their parasitoids and hyperparasitoids, and (ii) soil bacteria as hosts for plasmids.

Research projects

1. The spread of antimicrobial resistance in host plasmid networks - BBSRC Dicovery Fellowship                                AMR is rising to dangerously high levels causing a global health crisis. Plasmids, mobile genetic elements, have a crucial role in the spread of AMR. They can carry resistance against antibiotics and pass this on to bacteria. Antibiotics make such AMR carrying plasmids beneficial to their bacterial hosts. Therefore, antibiotic exposure will change coevolutionary dynamics between plasmids and their hosts, resulting in plasmids becoming more prevalent and associated with a higher number of different bacteria. This fundamentally changes the network structure of interacting bacteria and plasmids, and likely increases the spread of novel antibiotic resistance across microbial communities. With a series of experiments using simple and naturally complex microbial communities, I will determine the long-term impact of antibiotic exposure on plasmids and their bacterial hosts. I will also investigate emerging networks between plasmid and bacteria with novel methods. This experimental work in combination with theoretical approaches will help to predict the long-term impact of antibiotic pressure on the spread on antibiotic resistance across microbial communities and to pathogens. 

2. Vulnerability of ecological communities to extinction cascades 
Initial species losses are often followed by secondary extinctions of other species, for not always obvious reasons, with the danger that this leads to a cascade of further extinctions and ecosystem collapse. Predicting these cascades is challenging and requires a detailed understanding of how the interconnectedness of species in ecosystems affects the transmission of human impacts on one species to other species that are not directly linked to it. This is particularly important for species at higher trophic levels (carnivores) which are most vulnerable to extinction. The idea has long existed that species of carnivore that specialise on different prey have positive effects on each other by limiting their prey populations and thereby preventing one prey species from outcompeting the other. A consequence of this is that if a carnivore is lost from the community, its prey is released from control and may subsequently out-compete the other prey species leaving the other carnivore without food and facing extinction. This is potentially an important mechanism by which extinction cascades occur, however, it is difficult to obtain experimental evidence for such effects. We study these mechanisms in field experiments using aphid-parasitoid communities.

3. Integration of food webs and ecosystem engineering
Ecosystem engineering (the modification of the physical environment by organisms) is an important interaction in most ecosystems. When these engineers are trophically coupled to food webs as producers, consumers or decomposers, there is obviously the potential for trophic feedbacks to alter engineer density and engineering activity. This can then lead to a change in the degree to which the environment is modified, subsequent modification of trophic interactions affecting food webs dynamics and stability.

4. Interaction type drives network structure. Ecological communities exist as networks of interacting species, and the structure of these networks determine their stability and function. Observational studies suggest that network structure depends upon whether interactions between species are predominantly mutualistic or antagonistic, however the causality of this relationship remains unclear. I will use communities of bacteria and their symbiotic plasmids to experimentally determine how interaction type (mutualistic versus antagonistic) affects community network structure. The system is ideal to address these questions because bacteria-plasmid interactions can be switched from antagonistic to mutualistic through simple environmental manipulations (the addition of antibiotics to which the plasmids confer resistance), and changes in community network structure can be observed over a matter of weeks. The large-scale of this project is made possible by the application of a novel culture-free method, epicPCR, which allows high-throughput assessment of bacteria-plasmid associations. The predicted role of ecological stability, as well as novel eco-evolutionary mechanisms, underpinning the interaction type-network structure relationships will be assessed by a combination of phenotypic and genetic experiments complemented by theory.

Selected Publications

Risely, A., Newbury, A., Stalder, T., Simmons, B., Top, E., Buckling, A., Sanders, D. (2024) Host- plasmid network structure in wastewater is linked to antimicrobial resistance genes. Nature Communications 15, 555.

Sanders, D., Frago, E., Kehoe, R. , Patterson, C., Gaston, K.J. (2021) A meta-analysis of biological impacts of artificial light at night. Nature Ecology Evolution 5, 74–81.

Sanders D., Kehoe, R., Cruse, D., van Veen F.J.F., Gaston, K.J. (2018) Low levels of artificial light at night strengthen top-down control in insect food web. Current Biology 28, Issue 15, 2474-2478.

Sanders, D.,Thébault,E., Kehoe, R., van Veen, F.J.F. (2018) Trophic redundancy reduces vulnerability to extinction cascades. Proceedings of the National Academy of Sciences 115 (10) 2419-2424;

Sanders, D., Kehoe, R., van Veen, F.J.F., McLean, A., Godfray, H.C.J, Dicke, M., Gols, R., Frago, E. (2016) Protective insect symbiont leads to cascading extinctions and community collapse. Ecology Letters 19.

Sanders D., Kehoe, R., van Veen F.J.F. (2015) Experimental evidence for the population-dynamic mechanisms underlying extinction cascades of carnivores. Current Biology 25, Issue 23, 3106–3109.

Sanders D., Sutter, L., van Veen F.J.F. (2013) The loss of indirect interactions leads to cascading extinctions of carnivores. Ecology Letters, doi: 10.1111/ele.12096

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Journal articles

Sanders D, Frago E, Kehoe R, Patterson C, Gaston K (In Press). A meta-analysis of biological impacts of artificial light at night. Nature Ecology and Evolution
Sanders D, Kehoe R, Cruse D, Van Veen F, Gaston KJ (In Press). Low levels of artificial light at night strengthen top-down control in insect food web. Current Biology
Gaston K, Ackermann S, Bennie J, Cox D, Phillips B, Sanchez De Miguel A, Sanders D (In Press). Pervasiveness of biological impacts of artificial light at night. Integrative and Comparative Biology
Risely A, Newbury A, Stalder T, Simmons BI, Top EM, Buckling A, Sanders D (2024). Host- plasmid network structure in wastewater is linked to antimicrobial resistance genes. Nat Commun, 15(1). Abstract.  Author URL.
Tougeron K, Sanders D (2023). Combined light pollution and night warming as a novel threat to ecosystems. Trends Ecol Evol, 38(8), 701-704. Abstract.  Author URL.
Sanders D, Hirt MR, Brose U, Evans DM, Gaston KJ, Gauzens B, Ryser R (2023). How artificial light at night may rewire ecological networks: concepts and models. Philos Trans R Soc Lond B Biol Sci, 378(1892). Abstract.  Author URL.
Zhong Z, Li G, Sanders D, Wang D, Holt RD, Zhang Z (2022). A rodent herbivore reduces its predation risk through ecosystem engineering. Curr Biol, 32(8), 1869-1874.e4. Abstract.  Author URL.
Newbury A, Dawson B, Klümper U, Hesse E, Castledine M, Fontaine C, Buckling A, Sanders D (2022). Fitness effects of plasmids shape the structure of bacteria-plasmid interaction networks. Proc Natl Acad Sci U S A, 119(22). Abstract.  Author URL.
Sanders D, Baker DJ, Cruse D, Bell F, van Veen FJF, Gaston KJ (2022). Spectrum of artificial light at night drives impact of a diurnal species in insect food web. Sci Total Environ, 831 Abstract.  Author URL.
Kehoe R, Sanders D, van Veen FJ (2022). Towards a mechanistic understanding of the effects of artificial light at night on insect populations and communities. Curr Opin Insect Sci, 53 Abstract.  Author URL.
Li X, Risch AC, Sanders D, Liu G, Prather C, Wang Z, Hassan N, Gao Q, Wang D, Zhong Z, et al (2021). A facilitation between large herbivores and ants accelerates litter decomposition by modifying soil microenvironmental conditions. FUNCTIONAL ECOLOGY, 35(8), 1822-1832.  Author URL.
Kehoe R, Frago E, Sanders D (2021). Cascading extinctions as a hidden driver of insect decline. Ecological Entomology, 46(4), 743-756. Abstract.
Zhong Z, Li X, Sanders D, Liu Y, Wang L, Ortega YK, Pearson DE, Wang D (2021). Soil engineering by ants facilitates plant compensation for large herbivore removal of aboveground biomass. Ecology, 102(5). Abstract.  Author URL.
Hesse E, O'Brien S, Lujan AM, Sanders D, Bayer F, Veen EM, Hodgson DJ, Buckling A (2021). Stress causes interspecific facilitation within a compost community. ECOLOGY LETTERS, 24(10), 2169-2177.  Author URL.
Kehoe R, Sanders D, Cruse D, Silk M, Gaston KJ, Bridle JR, van Veen F (2020). Longer photoperiods through range shifts and artificial light lead to a destabilizing increase in host–parasitoid interaction strength. Journal of Animal Ecology, 89(11), 2508-2516. Abstract.
Sanders D, Gaston KJ (2018). How ecological communities respond to artificial light at night. J Exp Zool a Ecol Integr Physiol, 329(8-9), 394-400. Abstract.  Author URL.
Perkins MJ, Inger R, Bearhop S, Sanders D (2018). Multichannel feeding by spider functional groups is driven by feeding strategies and resource availability. Oikos, 127(1), 23-33. Abstract.
Li X, Zhong Z, Sanders D, Smit C, Wang D, Nummi P, Zhu Y, Wang L, Zhu H, Hassan N, et al (2018). Reciprocal facilitation between large herbivores and ants in a semi-arid grassland. Proc Biol Sci, 285(1888). Abstract.  Author URL.
Kehoe RC, Cruse D, Sanders D, Gaston KJ, van Veen FJF (2018). Shifting daylength regimes associated with range shifts alter aphid-parasitoid community dynamics. Ecology and Evolution, 8(17), 8761-8769. Abstract.
Sanders D, Kehoe R, Thebault E, Van Veen FJF (2018). Trophic redundancy reduces vulnerability to extinction cascades. Proceedings of the National Academy of Sciences
Zhong Z, Li X, Pearson D, Wang D, Sanders D, Zhu Y, Wang L (2017). Ecosystem engineering strengthens bottom-up and weakens top-down effects via trait-mediated indirect interactions. Proc Biol Sci, 284(1863). Abstract.  Author URL.
Sanders D, Kehoe R, van Veen FF, McLean A, Godfray HCJ, Dicke M, Gols R, Frago E (2016). Defensive insect symbiont leads to cascading extinctions and community collapse. Ecol Lett, 19(7), 789-799. Abstract.  Author URL.
Turrini T, Sanders D, Knop E (2016). Effects of urbanization on direct and indirect interactions in a tri-trophic system. Ecological Applications, 26(3), 664-675. Abstract.
Kehoe R, Frago E, Barten C, Jecker F, van Veen F, Sanders D (2016). Nonhost diversity and density reduce the strength of parasitoid–host interactions. Ecology and Evolution, 6(12), 4041-4049. Abstract.
Sanders D, Moser A, Newton J, van Veen FJF (2016). Trophic assimilation efficiency markedly increases at higher trophic levels in four-level host-parasitoid food chain. Proc Biol Sci, 283(1826). Abstract.  Author URL.
Sanders D, Kehoe R, Tiley K, Bennie J, Cruse D, Davies TW, Frank van Veen FJ, Gaston KJ (2015). Artificial nighttime light changes aphid-parasitoid population dynamics. Sci Rep, 5 Abstract.  Author URL.
Sanders D, Kehoe R, van Veen FJF (2015). Experimental Evidence for the Population-Dynamic Mechanisms Underlying Extinction Cascades of Carnivores. Curr Biol, 25(23), 3106-3109. Abstract.  Author URL.
Sanders D, Vogel E, Knop E (2015). Individual and species-specific traits explain niche size and functional role in spiders as generalist predators. Journal of Animal Ecology, 84(1), 134-142. Abstract.
Sanders D, Vogel E, Knop E (2015). Individual and species-specific traits explain niche size and functional role in spiders as generalist predators. J Anim Ecol, 84(1), 134-142. Abstract.  Author URL.
Sanders D, Jones CG, Thébault E, Bouma TJ, van der Heide T, van Belzen J, Barot S (2014). Integrating ecosystem engineering and food webs. Oikos, 123(5), 513-524. Abstract.
Sanders D, Jones CG, Thébault E, Bouma TJ, van der Heide T, van Belzen J, Barot S (2014). Integrating ecosystem engineering and food webs. Oikos
Knop E, Zünd J, Sanders D (2014). Interactive prey and predator diversity effects drive consumption rates. Oikos, 123(10), 1244-1249. Abstract.
Knop E, Zünd J, Sanders D (2014). Interactive prey and predator diversity effects drive consumption rates. Oikos Abstract.
van Veen FJF, Sanders D (2013). Herbivore identity mediates the strength of trophic cascades on individual plants. ECOSPHERE, 4(5).  Author URL.
Eggs B, Sanders D (2013). Herbivory in Spiders: the Importance of Pollen for Orb-Weavers. PLOS ONE, 8(11).  Author URL.
Sanders D, Sutter L, van Veen FJF (2013). The loss of indirect interactions leads to cascading extinctions of carnivores. Ecology Letters, 16(5), 664-669. Abstract.
Sanders D, Sutter L, van Veen FJF (2013). The loss of indirect interactions leads to cascading extinctions of carnivores. Ecol Lett, 16(5), 664-669. Abstract.  Author URL.
Sanders D, Van Veen FJF (2012). Indirect commensalism promotes persistence of secondary consumer species. Biology Letters, 8(6), 960-963. Abstract.
Platner C, Piñol J, Sanders D, Espadaler X (2012). Trophic diversity in a Mediterranean food web—Stable isotope analysis of an ant community of an organic citrus grove. Basic and Applied Ecology, 13(7), 587-596.
Sanders D, van Veen FJF (2011). Ecosystem engineering and predation: the multi-trophic impact of two ant species. Journal of Animal Ecology, 80(3), 569-576.
Sanders D, Schaefer M, Platner C, Griffiths GJK (2011). Intraguild interactions among generalist predator functional groups drive impact on herbivore and decomposer prey. Oikos, 120(3), 418-426. Abstract.
Sanders D, Entling MH (2011). Large variation of suction sampling efficiency depending on arthropod groups, species traits, and habitat properties. Entomologia Experimentalis et Applicata, 138(3), 234-243. Abstract.
Sanders D, van Veen FJF (2010). The impact of an ant–aphid mutualism on the functional composition of the secondary parasitoid community. Ecological Entomology, 35(6), 704-710. Abstract.
Sanders D, Nickel H, Grützner T, Platner C (2008). Habitat structure mediates top–down effects of spiders and ants on herbivores. Basic and Applied Ecology, 9(2), 152-160.
Schuch S, Platner C, Sanders D (2008). Potential positive effect of the ant species Lasius niger on linyphiid spiders. Journal of Applied Entomology, 132(5), 375-381.
Sanders D, Platner C (2006). Intraguild interactions between spiders and ants and top-down control in a grassland food web. Oecologia, 150(4).


Sanders D (2012). Herbivory in Spiders. In  (Ed) Spider Ecophysiology, Springer Nature, 385-391.

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