Abstract
One of the keys to halting the global decline in biodiversity lies in understanding of the complexity of the disruptions that affect biodiversity dynamics. My thesis therefore aims to account for the complexity in temporal dynamics of species and anthropogenic pressures, in biotic communities through interactions between species, and in the socio-economic determinants that underpin environmental destruction. Indeed, biodiversity loss is mainly analysed using linear approaches that cannot account for the diversity of potential dynamics and is often still considered from a population point of view, largely ignoring the fate of the interdependence between species. Moreover, the direct effect of human pressures on biodiversity is evaluated without taking into account their dependence on the underlying development model, thus neglecting its effect on the state of biodiversity. In the first part, using breeding bird surveys from France and Europe, I characterise the form shape of population trajectories to report their acceleration, deceleration or reversal, and I analyse the overall impact of anthropogenic pressures on common avifauna and, more specifically, on subgroups of species. In this first part, the decline in biodiversity is therefore assessed on the basis of species dynamics using the example of common European breeding birds. In the second part, I focus on changes in community structure by considering not only species but also the interrelations between species. After estimating species associations in French common bird communities and showing a decrease in their density over the past two decades, I link this decline to human pressures that are already having an impact on species. In this second part, biodiversity loss is depicted through the lens of the links between species on the basis of changes experienced by common breeding bird communities in France. In the third part, I explicitly question the role played by the socio-economic model in biodiversity loss. I first propose a socio-environmental indicator combining social achievements and planetary boundaries to get out of the rut caused by the quest for economic growth at all costs. I then show the gap between theoretical expectations and practical effects on biodiversity of sustainable development in France using an index based on common bird dynamics. In this third part, the decline of biodiversity is shown through its socio-economic determinants. Overall, the results of this thesis highlight the need for a spatial and temporal conservation science, which can only preserve common species and their interdependencies from anthropogenic pressures if it goes beyond the framework imposed by the current development model. More broadly, these results help to raise a pressing question: is it possible to halt and reverse the decline in biodiversity without transformative changes in Western societies?