OVERVIEW
WHAT WE DO
The experimental ecology & conservation group focusses on synthesising information from mathematical models, small-scale experimental systems, and long-term wild population data to learn more about the world around us, and in particular help make decisions about how to best preserve biodiversity into the future.
NOVEL TECHNIQUES
A specific focus is on developing new, exciting, and useful techniques to make the experimental systems we work with more realistic reflections of the world around us.
ITS ALL ABOUT THE BIG PICTURE
But our focus is always on how we can learn more about the natural world without having to carry out invasive or damaging experiments in the field.
NEWS
The latest news on papers, grants, and members joining the group!
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For regular news updates follow us on twitter
CURRENT PROJECTS
EARLY WARNING SIGNALS
Predicting the fate of biological systems is critical in the light of continued global change, especially in the field of conservation biology where at risk populations must be prioritised to make the most of limited resources. A long running interest of this group is developing warning signals of approach population, community, and ecosystem collapse based on temporal patterns in abundance, trait, and spatial data.
EXPERIMENTALLY TESTING CONSERVATION THEORY
Designing optimal conservation strategies is key in the face of limited funding and ever increasing anthropogenic stresses. A central theme to the group is using experimental systems to test and develop conservation theory.
TRACKING BIODIVERSITY CHANGE
Understanding whether biodiversity is changing is critical if we are to understand the impacts humanity is having on ecosystems, and whether management interventions are having the desired effects. Our group is working with Bristol City Council to produce a wildlife index to track biodiversity change in Bristol.
THE EFFECTS OF MULTIPLE STRESSORS
The effects of multiple stressors (e.g. including habitat loss, pollution, over harvesting, climatic change, and the introduction of invasive species) on global biodiversity is a continued concern. We are interested in the possible interactive effects of these stressors, and how this may affect populations and communities.
RESILIENCE AND RECOVERY IN FISHERIES
Fisheries are one of the most economic and ecologically important ecosystems on earth. However the vast majority are in a state of significant degradation. We are interested in how such systems might recovery, and the pathways they might take doing so, and how these pathways affect community structure and function.
PEOPLE
Meet the Team
ALUMNI
Publications
In press
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Stewart, K, Venditti, C., Carmona, C., Baker, J., Clements, C., Tobias, J., González-Suárez, M. Threat reduction must be coupled with targeted recovery programmes to conserve global bird diversity, Nature Ecology and Evolution, in press
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Vives-Ingla, M., Capdevila, P., Clements, C., Stefanescu, C., Carnicer, J. Novel Regimes of Extreme Climatic Events Trigger Negative Population Rates in a Common Insect. Global Change Biology, in press
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Pringle, S., ... Clements, C., ... et al. Opportunities and challenges for monitoring terrestrial biodiversity in the robotics age. Nature Ecology and Evolution, in press
2024
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Linke, L., Clements, C. A Sixth Mass Extinction? How linguistic uncertainty shapes our understanding of the biodiversity crisis. Ecology and Evolution 14 (12), e70653
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Li, D., Clements, C., Memmott. J. Isolation limits spring pollination in a UK fragmented landscape. PLos one, 19 (9), e0310679
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Cerini, F., Jackson, J., Childs, D., Clements, C. Multivariate signals of population collapse in a high-throughput ecological experiment. Ecology, 105 (4), e4257
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Johnson, T., Beckerman, A., Childs, D., Griffiths, C., Capdevila, P., Clements, C., Besson, M., Gregory, R., Evans, R., Thomas, G., Delmas, E., Webb, T., Freckleton, R. Overconfidence undermines global wildlife abundance trends. Nature, 628 (8009), 788-794
2023
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O'Brien, D., Deb, S., Gal, G., Thackary, S., Dutta, P., Shin-Ichiro, May, L., Clements, C. Early warning signals require critical transitions in empirical lake data. Nature Communications, 7942.
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Cerini, F., Wolfe, E., Besson, M., Clements, C. Phenotypic response to different predator strategies can be mediated by temperature. Ecology and Evolution, ece3.10474.
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O'Brien, D., Deb, S., Sahil, S., Krishnan, N., Dutta, P., Clements, C. EWSmethods: an R package to forecast tipping points at the community level using early warning signals and machine learning models. Ecography, ecog.06674.
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Stewart, K., Carmona, C., Clements, C., Venditti, C., Tobias, J., González-Suárez, M. Trait diversity metrics can perform well with highly incomplete datasets. Methods in Ecology and Evolution, 14, 2856-2872
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Ledger, S., McRae, L., Loh, J., Almond, R., Boh, M., Clements, C. et al. Past, present, and future of the Living Planet Index. npj Biodiversity, 2, 12.
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Li, D., Memmott, J., Clements, C. Corridor quality buffers extinction under extreme droughts in experimental metapopulations. Ecology & Evolution, in press.
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Cerini, F., Childs, D., Clements, C. Timeline to collapse. Nature Ecology and Evolution, early online.
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O'Brien, D., Gal, G., Thackary, S., Shin-Ichiro, S., Blanchard, J., Clements, C. Planktonic functional diversity changes in synchrony with lake ecosystem state. Global Change Biology, 29, 686-701.
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Wolfe, E., Cerini, F., Besson, M., O'Brien, D., Clements, C. Spatiotemporal thermal variation drives diversity trends in experimental landscapes. Journal of Animal Ecology, 92, 430-441.
2022
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Besson, M., Alison, J., Bjerge, J., Gorochowski, T., Høye, T., Jucker, T., Mann, H., Clements, C. Towards the fully automated monitoring of ecological communities. Ecology Letters, 25, 2753-2775.
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Baruah, G., Ozgul, A., Clements, C. Community structure determines the predictability of population collapse. Journal of Animal Ecology, 91, 1880-1891.
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Capdevila, P., Noviello, N., McRae, L., Freeman, R., Clements, C. Global patterns of resilience decline in vertebrate populations. Ecology Letters, 25 (1), 240-251.
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Capdevila, P., Noviello, N., McRae, L., Freeman, R., Clements, C. Body mass and latitude as global predictors of vertebrate populations exposure to multiple threats. Ecography, 12, e06309.
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Deb, S., Sidheekh, S., Clements, C., Krishnan, N., and Dutta, P. Machine learning methods trained on simple models can predict critical transitions in complex natural systems. Royal Society Open Science, 9: 211475.
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Wolfe, E., Hammill, E., Memmott, J., Clements, C. Landscape configuration affects probability of apex predator presence and community structure in experimental metacommunities. Oecologia, 199, 193–204.
2021
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O'brien, D., Clements, C. Early warning signal reliability varies with COVID-19 waves. Biology Letters, 17: 20210487.
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Williams, N., McRae, L., Freeman, R., Capdevila, P., Clements, C. Scaling the extinction vortex: Body size as a predictor of population dynamics close to extinction events. Ecology and Evolution, 11, 7069-7079.
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Baruah, G., Clements, C., Ozgul, A. Effect of habitat quality and phenotypic variation on abundance- and trait-based early warning signals of population collapses. Oikos, 130, 850-862.
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Li, D., Clements, C., Shan, I., Memmott, J. Corridor quality affects net movement, size of dispersers, and population growth in experimental microcosms. Oecologia 195, 547-556.
2020
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Arkilanian, A., Clements, C., Ozgul, A., Baruah, G. Effect of time-series length and resolution on abundance- and trait-based early warning signals of population declines. Ecology, in press.
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Hammill, E., Clements, C. Imperfect detection alters the outcome of landscape scale management strategies for protected areas. Ecology Letters, 23: 682–691.
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Baruah, G., Clements, C., Ozgul, A. Eco-evolutionary processes underlying early warning signals of population decline. Journal of Animal Ecology, 89:436–448.
2019
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Clements, C., McCarthy, M., Blanchard, J. Early warning signals of recovery in complex systems. Nature Communications, 10:1681.
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Recommended by F1000​
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Baruah, G., Clements, C., Guillaume, F., Ozgul, A. When do shifts in trait dynamics precede population declines? The American Naturalist, 193, pp. 633–644.
2018
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Clements, C., Ozgul, A. Indicators of transitions in biological systems. Ecology Letters, 21, 905-919.
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Recommended by F1000​
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Clements, C., Blanchard, J., Nash, K., Hindell, M., Ozgul, A. Reply to ‘Whaling catch data are not reliable for analyses of body size shifts’, Nature Ecology & Evolution, 2, 757–758.​​
2017
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Clements, C., Blanchard, J., Nash, K., Hindell, M., Ozgul, A. Body size shifts and early warning signals preceded the historic collapse of whale stocks. Nature Ecology & Evolution, 1, 188.
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Carlson, C., Burgio, K., ... Clements, C., ... , Getz, W. (2017). Parasite biodiversity faces extinction and redistribution in a changing climate. Science Advances, 3, e1602422.
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Weissman, T., Davies, K., Clements, C., Melbourne, B. Estimating extinction risk with minimal data. Biological Conservation, 213, 194-202.
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Brooks, M., Clements, C., Pemberton, J., Ozgul, A. Estimation of individual growth trajectories when repeated measures are missing. American Naturalist, 190, 377-388.
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Pimiento, C., Griffen, J., Clements, C., Silvestro, D., Varela, S., Uhen, M., Jaramillo, C. The Pliocene marine megafauna extinction and its impact on functional diversity. Nature Ecology & Evolution, 1, 1100.
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Cizauskas, C., Carlson, C., Burgio, K., Clements, C., Dougherty, E., Harris, N., Phillips, A. (2017). Parasite vulnerability to climate change: an evidence-based functional trait approach.Royal Society Open Science, 4: 160535.​​
2016
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Clements, C., Ozgul, A. Rate of forcing and the forecastability of critical transitions. Ecology & Evolution, 6, 7787-7793.
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Dougherty, E., Carlson, C., Bueno, V., Burgio, K., Cizauskas, C., Clements, C., Seidel, D., Harris, N. Paradigms for parasite conservation: adaptive approaches for a neglected target. Conservation Biology, 30, 724-733.
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Pimiento, C., MacFadden, B., Clements, C., Velez-Juarbe, J., Jaramillo, C., Silliman, B. Geo- graphic distribution patterns of Carcharocles megalodon over time reveal clues about mechanisms of extinction. Journal of Biogeography, 43, 1645-1655.
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Clements, C., Ozgul, A. Including trait-based early warning signals helps predict population collapse. Nature Communications, doi:10.1038/ncomms10984.​
2015
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Clements, C., Drake, J., Griffiths, J., Ozgul, A. Factors influencing the detectability of early warning signals of population collapse. The American Naturalist, 186, 50-58.
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DeLong, J., Gilbert, B., ..., Clements, C., ..., O'Connor, M. The body-size dependence of trophic cascades. The American Naturalist, 185, 354-366.​
2014
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Palamara, G., Childs, D., Clements, C., Petchey, O., Plebani, M., Smith, M. Inferring the temperature dependence of population parameters: the effects of experimental design and inference algorithm. Ecology and Evolution, 4, 4567–4811.
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McCarthy, M., Moore, A., Krauss, J., Morgan, J., Clements, C. Linking indices for biodiversity monitoring to extinction risk theory. Conservation Biology, 28, 1575-1583.
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Pimiento C., Clements C. When did Carcharocles megalodon become extinct? A new analysis of the fossil record. PLoS ONE, DOI: 10.1371/journal.pone.0111086
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Frantz, A., McDevitt, A., ..., Clements, C., ...., Burke, T. Re-visiting the phylogeography and demography of European badgers (Meles meles) based on broad sampling, multiple markers and simulations. Nature Heredity, 113, 443-453.
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Clements, C., Collen, B., Blackburn, T., Petchey, O. Historic environmental change may affect our ability to infer extinction status. Conservation Biology, 28: 971–981.
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Gilbert, B., Tunney, T., McCann, K., ..., Clements, C., ..., O’Connor, M. A bioenergetic framework for the temperature dependence of trophic interactions. Ecology Letters, 17, 902-914
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Clements, C., Collen, B., Blackburn, T., Petchey, O. Effects of directional environmental change on extinction dynamics in experimental microbial communities are predicted by a simple model. Oikos, 123, 141-150​
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Editor's choice​​
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2013
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Clements, C., Warren, P., Collen, B., Blackburn, T., Worsfold, N., Petchey, O. Interactions between assembly order and temperature can alter both short and long-term community composition. Ecology & Evolution, 3(16): 5201–5208
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Carlson, C., Cizauskas, C., Burgio, K., Clements, C., Harris, N. The more parasites, the better? Science, 342, p1041​
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Clements, C. Public interest in the extinction of a species may lead to an increase in donations to a large conservation charity. Biodiversity and Conservation, 22, p.2695-2699.
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Clements, C., Worsfold, N., Warren, P., Collen, B., Blackburn, T., Clark, N., Petchey, O. Experimentally testing an extintion estimator: Solow's Optimal Linear Estmation model.Journal of Animal Ecology, 82, p345-354.
Theses
Clements, C. "Extinction and environmental change: testing the predictability of species loss". http://dx.doi.org/10.6084/m9.figshare.1158947
DATA
In line with the principals of open science and data sharing we are striving to make all the data that our lab group generates available via a github repository. This will take some time, but all data going forward will be uploaded to that site, and data from previous experiments (be that laboratory generated or simulation generated) will be made available as soon as possible.
CURRENT GRANTS
EFFECTS OF MULTIPLE STRESSORS ON THE GLOBAL DECLINE OF VERTEBRATE POPULATIONS
2020 - 2022
Leverhulme Trust
RPG-2019-368
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THE COHERENCE OF ECOLOGICAL STABILITY AMONG ECOSYSTEMS AND ACROSS ECOLOGICAL SCALES
2020 - 2024
NERC
JOIN THE GROUP
We are always looking for enthusiastic members to join the group, from masters students to post docs. Funding for these are available through a number of channels, depending on the career stage.
Please feel free to contact me any time to discuss the possibility of apply for one of these schemes and joining our team.
AVAILABLE POSITIONS
Adverts for funded positions will appear below
FULLY FUNDED MSc BY RESEARCH: 3 PROJECTS AVAILABLE
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Three fully-funded MSc by research studentships are available in the School of Biological Sciences at
the University of Bristol, to start in September 2024. The studentship will cover a stipend of £18,622
plus home studentship fees.
Project details are as given below; any further questions can be directed
to Dr Chris Clements for projects 1 and 2 (c.clements@bristol.ac.uk), Dr Lucy Alford for project 3
(lucy.alford@bristol.ac.uk) or Professor Richard Wall for any of the projects
(richard.wall@bristol.ac.uk). Applications should be submitted via the University of Bristol
postgraduate application portal.
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https://www.bristol.ac.uk/study/postgraduate/apply/start-application/
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Successful applicants will have at least a 2.i honours degree in Biology or related subject by the start
of the MSc and must be UK-based. Please state on your application which of the projects you are
applying for. The closing date for applications is the 1st March 2024, but this will be extended should
the positions not be filled.
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PR1. Modelling non-target impacts on insect decomposer species at a landscape level.
Supervisors : Dr Chris Clements & Prof Richard Wall
A spatial simulation model of the community of invertebrates that colonise and decompose livestock
dung will be built in the R statistical package. The model will be used to explore non-target impacts
of the antiparasitic anthelmintics administered to livestock on important insect decomposer species.
The model will be parameterised using Information on excretion profiles of parasiticides, lethal and
sublethal susceptibility to faecal residues and attractivity of contaminated pats, obtained from the
published literature. Effects on populations will be estimated using data on the frequency and timing
of parasiticides used, proportion of animals treated and excretion profiles of residues, while
accounting for impacts on insect generations over time. The model will provide a more
comprehensive understanding of the landscape-scale risks to invertebrate decomposer communities
associated with current patterns of livestock parasiticide use in the UK.
Ideal candidate: will have strong interests in coding and modelling (preferably in R but other
languages acceptable), and ideally mathematics to A level, as well as an interest in community
and/or population ecology. They will be independent and happy to self-teach aspects of coding and
modelling through online courses and papers/published texts.
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PR2: The environmental benefits of targeted selective treatment of cattle.
Supervisors : Dr Chris Clements & Prof Richard Wall
Strategies which use antiparasitic medicines against the livestock in a population most at need
(Targeted Selective Treatment), are increasingly advocated as a means of reducing the amount of
antiparasitic chemical used, with concomitant environmental benefits, while minimising selection for
resistance. A field study will be undertaken with three groups of farms, one applying a conventional
treatment strategy to beef cattle at spring turnout, one applying no treatments and the other
applying a TST approach where the impacts on dung-colonising invertebrates will be assessed.
Faecal egg counts will be used to assess parasite burdens and help direct treatments in the TSTgroup. Beetle and fly populations will be assessed on each farm using baited pit-fall traps and pat
searching techniques.
Ideal candidate: Will have a strong interest in field ecology and the outdoors, be independent in their
approaches to problems solving, and some experience carrying out ecological experiments. They will
also need good interpersonal skills and some familiarity with farming systems. A full driving licence is
also essential.
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PR3: Impacts of a changing climate on livestock ectoparasites
Supervisors : Dr Lucy Alford & Prof Richard Wall
Arthropod parasites that live on the external bodies of their living hosts are known as ectoparasites
(e.g. mites, lice, ticks and blowfly larvae). Infestation can result in compromised animal health and
welfare, and for livestock, reduced economic value. As ectothermic organisms, these arthropod pests
have limited ability to regulate their body temperature above and below ambient, with
environmental temperature consequently impacting all aspects of their biology. For this reason,
climate change will have profound implications for these economically important parasites,
infestation rates, and ultimately livestock health. A better understanding of the impacts of cold and
heat shock events on a range of ectoparasites will enable a better understanding of the likely impacts
of climate change on populations of these arthropods. This project will consider the resilience of
model ectoparasite species in the laboratory using controlled environment microcosms.
Ideal candidate: will have a strong interest in invertebrate thermal physiology, entomology and/or
parasitology within the wider context of climate change and pest outbreaks.
CONTACT US
School of Biological Sciences
University of Bristol
Bristol Life Sciences Building
24 Tyndall Avenue
Bristol
England
BS8 1TQ