Lead supervisor: Marie Edmonds, Earth Sciences
Co-supervisor: David Coomes, Plant Sciences, Maximillian Van Wyk de Vries, Geography and Earth Sciences
Brief summary:
Large explosive volcanic eruptions cause substantial perturbation to ecosystems through tephra fall, but the effects and mechanisms are poorly understood, particularly for systems already stressed by anthropogenic factors.
Importance of the area of research concerned:
Large explosive volcanic eruptions cause substantial perturbation to landscapes and ecosystems. Ash may kill or damage vegetation by burial and acid leaching. Persistent degassing from volcanoes may acidify soils and groundwaters and cause dry deposition of heavy metals onto the surfaces of plants. However, over millenia the effects of eruptions have been transient: volcanoes provide new substrate, nutrients and opportunities for life to evolve, diversify and repopulate via succession and rapid speciation, particularly in isolated environments such as islands. Over recent decades however, with the anthropogenic pressures of climate change, invasive species, habitat loss and other stresses, this balance has shifted. Volcanic eruptions, particularly those that occur on small islands or isolated habitats, now have far greater potential to cause more long-lasting damage, with slow or non-existent recovery, which has important consequences for conservation planning. A knowledge gap exists in understanding the rates and mechanisms by which eruptions may cause environmental and ecological impacts on plant dynamics and insect populations, which have severe consequences for macrofauna.
Project summary :
This project aims to quantify and describe the mechanisms by which tephra fall and persistent volcanic gas and aerosol plumes impact vegetation and insect life in complex and diverse forests impacted by volcanic eruptions. The results of the study will be used to inform conservation planning for isolated habitats at risk of volcanic eruptions. The results of the study will also have implications for other multi-hazard scenarios whereby multiple natural hazards impact ecosystems stressed by anthropogenic factors.
What will the student do?:
The student will use a combination of satellite-based data and fieldwork to quantify the impacts of tephra fall and volcanic gas on vegetation and the longevity of these effects, using a case study approach. Case studies will be opportunistic but likely to include work on a volcano known for its persistent activity e.g. Poas or Turrialba, Costa Rica, and any large explosive eruptions that occur in suitable locations (e.g. Patagonia, Indonesia, Lesser Antilles, C. America) in years 1 and 2 of the project. Tephra will be characterised spatially in terms of thickness, grain size, composition and analysed for adsorbed chemical species. Satellite-based studies in the IR and visible wavelengths (e.g. Landsat-7 ETM+, Terra Aster) will be used to quantify the impact on vegetation, accompanied by on-the-ground sampling and measurements. The observations will be used to assess the mechanisms of eruption impacts on vegetation dynamics and the implications for conservation planning in critical areas.
References - references should provide further reading about the project:
Dale VH, Delgado-Acevedo J, MacMahon J, Ernst GG. Effects of modern volcanic eruptions on vegetation. Volcanoes and the Environment. 2005 Oct 6:227-49.
Ayris PM, Delmelle P. The immediate environmental effects of tephra emission. Bulletin of volcanology. 2012 Nov;74:1905-36.
Dalsgaard B, Hilton GM, Gray GA, Aymer L, Boatswain J, Daley J, Fenton C, Martin J, Martin L, Murrain P, Arendt WJ. Impacts of a volcanic eruption on the forest bird community of Montserrat, Lesser Antilles. Ibis. 2007 Apr;149(2):298-312.
Applying
You can find out about applying for this project on the Department of Earth Sciences page.