Although only halfway through this one week course, I am already blown away! I signed up to open new opportunities for my datasets and this course on Structural Equation Modelling (SEM) is exceeding my expectations. And here again, like on field work, lots of jolly Hydroscape camaraderie with fellow Hydroscape researchers Geoff Phillips, Alan Law and mad tweeter Dr ZP @ZarahPattison
This course, organised by PR Statistics and delivered by experts Jarret Byrnes and Jon Lefcheck, is taking us through all the basic of SEMs and is designed for us to become independent in implementing SEMs using our own data – or even better to collect data that will make the most of this analytical method.
SEMs allow us to account for the complexity of the natural world when analysing data collected in the field and get to grips with direct and indirect cause to effect relationship among variables.
Two more weeks of relentless biological and environmental surveys, in the Glasgow area and in the Lake District! We again had a very ambitious schedule but managed to stick to it. We made a group picture at our last site, marking the official end of our work package’s field work. Great time with a fine team – I will miss it.
Over the two weeks I surveyed aquatic plant at over 40 sites, including a series of stretches of the Forth and Clyde Canal (F&C). F&C is a hotspot for aquatic plant rarities – I recorded species such as Potamogeton trichoides, P. friesii, P. lucens, Lysimachia thyrsiflora in exceptional abundance within some of the stretches – let alone a collection of hybrid mints that made my botanical/herbarium press smell of heaven and specimens of of the charophyte Nitella mucronata, second, third and fourth sightings ever for Scotland.
One week of field work in North Norfolk, surveying aquatic plants and collecting water samples for analysis in the lab. Working as a team with my colleagues from the University of Stirling, we completed all the planned work, which was a mammoth task and only possible thanks to amazing team work. Amongst other things, we completed 34 surveys of aquatic plants (totalling 580 macrophyte observations across North Norfolk) and revisited all of last year’s 28 sites.
“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.
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.
As of January 1st 2014, I will be working as a post-doctoral researcher in University College London, Department of Geography on the NERC-funded project Lake BESS. Please follow updates on our Lake BESS blog: https://lakebess.wordpress.com/
This position will be 60% FTE and the rest of my time will be spent looking after my daughter.
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.