Coasts are key geographic areas because they lie at the heart of numerous environmental threats, including climatic, human and marine/inundation pressures. Within this context, much attention has been paid to the study of coastal ecosystems and biodiversity which are directly threatened by extreme events (e.g. Diffenbaugh et al. 2007), global sea-level rise (e.g. Nicholls & Cazenave 2010), increased human impacts (e.g. Adger et al. 2005) and recurrent flooding events (e.g. Hallegate et al. 2013; Wahl et al. 2015). The sensitivity of coastal vegetation to different stresses is, however, constructive as it can be reversed and used as an effective means to reconstruct the long-term pressures that have shaped modern ecosystems. Are degraded ecosystems and biodiversity loss markers of their own history?

Here, we probe this question using long-term ecosystem dynamics and evolution of biodiversity to reconstruct 1- the impact of agricultural practices on the dynamics of coastal vegetation between the Azov Sea and the Black Sea during the last 7000 years; 2- the impact of storm activity in the Mediterranean during the last 4500 years and its influences on human economy, 3- the effect of sea-level rise on seabord vegetation in Italy during the last 8000 years, and 4- the pressures linked to the construction of the ancient harbor of Pisa, 2000 years ago. All of these case studies underscore different ecosystem pressures, suggesting that the succession of vegetation patterns through time is a key to understanding their history.

In a more general manner, while the coastal areas represent only 10% of the earth's total land surface, humanity tends to concentrate along or near coasts. It is thus important to understand the respective role of the different pressures that have gradually or abruptly shaped local ecosystems, and to define effective conservation strategies for the future.