Postgraduate Profiles

Roberta Dayrell

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Thesis: Ecology of natural regeneration in old, climatically-buffered, infertile landscapes

Despite having a scattered global distribution, old, climatically-buffered, infertile landscapes – OCBILs show clear similarities in structural and functional aspects. Soil infertility, especially severe phosphorus (P) deficiency, is a strong environmental filter that leads to a clear predominance of nutrient-conserving, slow-growing strategies among OCBIL plant species. Although associations between P-impoverished habitats and traits of adult individuals are well known, the particularities of regenerative phases have received much less attention. The aim of this project is to investigate the ecophysiological strategies of seedling and juvenile stages in P-impoverished landscapes by assessing 1) ecological strategies of adult and juvenile plants; 2) how plant traits change among different ontogenetic stages; 3) the role of positive interactions in species recruitment. All samples will be collected in the field and the study will be conducted in two OCBILs, the campo rupestre (at Serra do Cipó and Serra da Calçada – MG, Brazil) and the kwongan (at Badgingarra National Park and Alison Baird Reserve – WA, Australia). To assess ontogenetic shifts in ecological strategies, I will measure leaf traits and use the CSR (competitive, stress-tolerant and ruderal) classification to make ecological inferences. I will measure leaf traits (including nutrient concentrations) and physiological functions in seedlings as well as in resprouting and adult plants to understand how ontogeny constrains the viable combinations of plant characteristics. Finally, I will investigate the role of facilitation, especially during the recruitment phase, in structuring a plant community.

Why my research is important

OCBILs occur in at least 12 global biodiversity hotspots, including some of the world’s most species-rich biological floras as the kwongan in south-western Australia and the campo rupestre in south-eastern Brazil. These landscapes are frequently impacted by anthropogenic activities, but effective strategies of landscape-scale restoration are extremely challenging and costly. This research focuses on early stages of plant development, because of their particular susceptibility to stress, which constitutes a major bottleneck for restoration success. This study will further the understanding of natural regeneration processes in OCBILs, and thus provide valuable information for the improvement of restoration strategies and ecosystem conservation of the world’s most biodiverse landscapes.

Funding

A) Typical campo rupestre grassland landscape, south-eastern Brazil. <br> B) Plants resprouting after a recent fire in Badgingarra National Park, south-western Australia.

Mar 2015

Feb 2019

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