Dr. Morgan J. Krüger

Overview

Fields of research Plant population and community ecology Research focus Dr. Krüger is a plant ecologist, with a particular interest in population and community ecology. Her research to date has focused primarily on the relationship between inter- and intra-specific biotic interactions, how the outcome of these interactions changes in relation to changing abiotic conditions, and how the fine-scale impact of these interactions scale-up to influence broader community patterns. During her B.Sc. (Honours) degree, she became interested in the impact of biotic interactions on species’ performance, survival, and distributions. Subsequently, for her M.Sc., she examined the dynamics of insect-host plant interactions and the importance of biotic interactions in mediating species’ current and future projected distributions. For her Ph.D., Dr. Krüger examined the impact of biotic interactions (both within species and bidirectionally between species) on species’ performances and distributions, using sub-Antarctic Marion Island as a model system. She revealed several key ecological findings, with implications for understanding plant-plant interactions in abiotically-severe environments. As Dr. Krüger has moved forward in her career, she has developed an interest in multidisciplinary collaborative research (both nationally and internationally; current collaborators listed below). She is currently involved in a multi-disciplinary study, which uses genomics in conjunction with ecological data and an engineering model of wind flow to understand species’ range expansion rates and the drivers (both biotic and abiotic) of observed ecological and genetic patterns in a keystone species. A second project involves using ecological niche modelling (SDM) and phylogenetics to understand African sea snail ( Afrolittorina ) distributions. Dr. Krüger is also working on a project which aims to advance our understanding of the ecological impacts of climate change using spatial variation in plant functional traits, community composition and ecosystem processes across multiple spatial scales in alpine grasslands. This project more broadly deals with the sustainability of subsistence pastoralism under climate change. Current collaborators: National collaborators: Peter C. le Roux: University of Pretoria Peter R. Teske: University of Johannesburg Bettine Jansen van Vuuren: University of Johannesburg Sally Archibald: WITS University Frances Siebert: North-West University Gerhard du Preez: North-West University International collaborators: Julia Kemppinen: University of Oulu, Finland. Pekka Niittynen: University of Jyväskylä, Finland. Teaching Activities Plant diversity (BOT01B1) Publications Buyens, I.P.R., Raath-Krüger, M.J. , Haddad, W.A., and le Roux, P.C. (2023) Fine-scale variation in the effect of the cushion plant Azorella selago on vascular plants, mosses, hepatics and lichens in the sub-Antarctic. Journal of Vegetation Science , 34, e13200. DOI: https://doi.org/10.1111/jvs.13200 Emami-Khoyi, A., Jooste, C.M., Wasserman, R.J., Dalu, T., Raath-Krüger, M.J. , Jansen van Vuuren, B., and Teske, P.R. (2023) Persistent effects of historical sea levels on the population structure of a temporary wetland copepod. Freshwater Biology , 68, 1442-1452. DOI: https://doi.org/10.1111/fwb.14139 Burger, D.A., van der Merwe, S., Lesaffre, E., le Roux, P.C., and Raath-Krüger , J. (2023) A robust mixed-effects parametric quantile regression model for continuous proportions: quantifying the constraints to vitality in cushion plants. Statistica Neerlandica , 77, 444-470. DOI: https://doi.org/10.1111/stan.12293 Raath-Krüger, M.J. , Schöb C., McGeoch, M.A., Burger, D.A., Strydom, T., and le Roux, P.C. (2023) Long-term spatially-replicated data show no physical cost to a benefactor species in a facilitative plant-plant interaction. Oikos , e09617. DOI: http://doi.org/10.1111/oik.09617 . Raath-Krüger, M.J. , Schöb, C., McGeoch, M.A., and le Roux, P.C. (2021) Inter-specific facilitation mediates the outcome of intra-specific interactions across an elevational gradient. Ecology , 102, e03200. DOI: https://doi.org/10.1002/ecy.3200 Raath-Krüger, M.J. , McGeoch, M.A., Schöb, C., Greve, M. and le Roux, P.C. (2019) Positive plant–plant interactions expand the upper distributional limits of some vascular plant species. Ecosphere , 10, e02820. DOI: https://doi.org/10.1002/ecs2.2820 Raath, M.J. , le Roux, P.C., Veldtman, R., and Greve, M. (2018) Incorporating biotic interactions in the distribution models of African wild silk moths ( Gonometa species, Lasiocampidae) using different representations of modelled host tree distributions. Austral Ecology , 43, 316-327. DOI: https://doi.org/10.1111/aec.12569 Raath, M.J. , le Roux, P.C., Veldtman, R., Campbell, H., Buyens, I.P.R., and Greve, M. (2017) Empty Gonometa postica cocoons function as nest sites and shelters for arboreal ants. Journal of Arid Environments , 14, 42-47. DOI: https://doi.org/10.1016/j.jaridenv.2017.03.013 van der Mescht, L., le Roux, P.C., Matthee, C.A., Raath, M.J. , and Matthee, S. (2016) The influence of life history characteristics on flea ( Siphonaptera ) species distribution models. Parasites & Vectors , 9, 178. DOI: https://doi.org/10.1186/s13071-016-1466-9 Bulletin contributions/popular articles Raath-Krüger, M.J. , Schöb, C., McGeoch, M.A., and le Roux, P.C. (2021) Inter-specific facilitation mediates the outcome of intra-specific interactions across an elevational gradient. Bulletin of the Ecological Society of America , 102, e01806. DOI: https://doi.org/10.1002/bes2.1806