Second post-doc on freshwater biodiversity

From January 1st 2016, I will start working as a post-doctoral researcher on the newly funded project Hydroscape, one of NERC’s highlight topics.

Hydroscape is led by Dr Nigel Willby at the University of Stirling and is interested in the importance of interactions between connectivity and stressors for freshwater biodiversity.

From   :

“Hydroscape is a four-year project that started in December 2015 and is funded by the UK Natural Environment Research Council (NERC). It aims to determine how stressors and connectivity interact to influence biodiversity and ecosystem function in freshwaters across Britain. While stressors such as nutrient pollution and climate change drive ecological degradation, connectivity between freshwater habitats is a major force behind both dispersal of stressors and biodiversity. Currently, the implication for freshwaters of future changes in stressor intensity and in connectivity levels across Britain are poorly understood. Hydroscape will significantly improve this understanding and therefore inform the work of organisations engaged in waterbody restoration, biological conservation, the control of invasive species and diseases of wildlife and humans, at the international, national and local level.”

My main focus within Hydroscape will be on the “Distribution of biodiveristy within the landscape” and how connectivity affects biodiversity distibution, connectivity being a measure of potential for dispersal.

PhD Thesis abstract, final version after revisions, February 2014

Tree cover in the early Holocene in temperate Europe and implications for the practice of re-wilding in nature conservation

This thesis addresses the methodological challenges of determining the variability of large herbivore populations through time and their impact on European vegetation.

Large herbivores are at the heart of conservation policy however, opinions widely diverge on whether we should aim for fewer herbivores and managed populations or, on the contrary (as advocated by the rewilding movement) more herbivores and self-regulating populations acting as ecosystem engineers. This controversy has roots in a debate regarding the nature of ecosystems before the prevalence of human activities. Baseline ecosystems are either described as continuous forest cover with passive large herbivores, or, in contrast, as mosaics with patchy forest cover driven inter alia by bison, aurochs and horses, now rare or extinct in Europe. The main obstacle in moving this debate forward is a poor understanding of large-herbivore densities in the past.

I analysed modern pollen and spore assemblages from known environmental settings to improve palaeoecological interpretation of fossil assemblages dating from the pre-human (baseline) period. The sites investigated are the rewilded grasslands of the Oostvaardersplassen (The Netherlands), the mosaic habitats of The New Forest (UK) and the old-growth closed-canopy forest of Białowieża (Poland).

I demonstrate that the common practice of interpreting pollen percentages fails to estimate past forest cover in situations with natural grazing. As an explanation, I suggest that pollen productivity fluctuates with biotic factors such as herbivory and canopy shading. As a result, new insights into the baseline debate require additional lines of evidence. In this thesis, I develop an existing methodology to reconstruct past herbivore presence using fossil dung fungal spores. I synthesise current knowledge of this method with an emphasis on spore identification and, finally, I demonstrate that dung fungal spore abundance in lake sediments can be translated into large herbivore numbers.

The evidence presented in this thesis contributes to the debate on re-wilding and addresses a fundamental challenge of nature conservation in the human-dominated landscapes of Europe.

December 2013: PhD Viva

December 2013: PhD Viva

Following a challenging, intense and very constructive discussion with the examiners, I passed my PhD Viva with minor corrections, University of Oxford. My examiners were Prof Richard Bradshaw, University of Liverpool and Prof Amy Bogaard, University of Oxford. Many thanks to them and to my supervisors, Prof Kathy Willis and Dr Shonil Bhagwat.