First MANTEL PhDs Awarded

MANTEL is delighted to announce the first three successful PhD defenses for our early stage researchers (ESRs): Nasime Janatian Ghadikolaei, Hares Khan and Jorrit Mesman.  These PhD theses were all double degrees with supervisory teams in two differing universities.  The three PhDs and associated journal publications have all contributed new knowledge to our understanding of the effects of climatic events and climate change on lake ecosystems, and we in MANTEL warmly congratulate our ESRs and all of their supervisors.

 

Left: Nasime with her doctoral hat in EMU; centre: Hares and supervisors Alo Laas and Biel Obrador in UB; right: Jorrit wears his doctoral hat at UNIGE.

Nasime Janatian was a student of the Estonian University of Life Sciences (EMU) (supervisors Prof. Peeter Nõges, Dr Fabien Cremona and Dr Alo Laas) and of University of Barcelona(UB) (supervisor Prof. Biel Obrador) and her thesis title was Hydrometeorological and Climatic Controls over Lake Phytoplankton: the Importance of Time Scales. The work focused on the two extremes of wind speed – storms and atmospheric stilling – and analysed their impacts on lake environments and phytoplankton dynamics over short and long time  periods.  It highlighted that lakes can be strongly affected by climate extremes like storms and by long calm periods, but that the sensitivity to and recovery from climate extremes can be lake type specific and may extend over different temporal scales. The papers from the thesis are available on the MANTEL publications page, and the published PhD can be accessed here: http://hdl.handle.net/10492/6946.

 

Hares Khan was also a student of the University of Barcelona (supervisor Prof. Biel Obrador) and the Estonian University of Life Science (supervisor Dr Alo Laas) and worked on 'Pelagic calcite precipitation in lakes: from a global to a local perspective on its drivers and implications' (PhD thesis: http://hdl.handle.net/10492/6982). Lakes and reservoirs store and emit carbon in large quantities, comparable in magnitude to other major global carbon fluxes. Calcite precipitation is an often overlooked process within the lake carbon cycle, however. This thesis offered a first global estimation of pelagic calcite precipitation in lakes and its associated carbon emissions. Globally, the relevance of this process was found to be of a similar in magnitude to organic carbon burial in the sediments, highlighting the need for researchers to adjust their current understanding of lake carbon cycling by accounting for inorganic processes such as calcite precipitation.

 

Jorrit Mesman was supervised by Prof. Bas Ibelings and Dr Stephane Goyette of University of Geneva (UNIGE) and Dr Don Pierson of Uppsala University (UU). His thesis was on Assessing Future Effects on Lake Ecosystem Resilience using Data Analysis and Dynamic Modelling.  This work used process-based modelling to further explore this topic, and to assess how lake responses to extreme weather events may change under the influence of climate warming. A modelling approach was used to show that internal feedback mechanisms in lakes could potentially result in sudden climate induced transitions in lake mixing regimes. It also used a coupled physical-biogeochemical model to assess the most important drivers of lake phytoplankton responses to storms, and explore how this response might change with climate warming (PhD thesis: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-451835).