Conservation of Mediterranean wetlands: interest of historical approach.

The wetlands of North Africa are an endangered and invaluable ecological heritage. Some of these wetlands are now protected by various conservation statutes; which actual impact has not yet been reliably evaluated. This article aims to assess the conservation management (Nature Reserve and Ramsar site) of a protected Tunisian lake, Majen Chitane, by using palaeoecological, historical and modern data, and by comparing it with the unprotected lake Majen Choucha. While located in similar environments, these lakes are today home to very different flora. Baseline conditions reconstructed from literature indicate that both lakes were very similar until the 1950s, and comparable to the current state of Majen Choucha, housing rich oligotrophic plant communities. In the 1960s, at the time that cultivation of the adjacent peatland began, Majen Chitane underwent strong ecological changes as the initial oligotrophic plant, diatom and zooplankton communities were replaced by eutrophication-tolerant ones. Eutrophication led to the local extinction of 40-55% of the hydrophytic and temporary-pool plant species, including those characteristic of the Isoetion. Given the damages and despite the recent conservation status of the site, it's unlikely that Majen Chitane will undergo any natural regeneration. Restoring it would start with completely protecting the complex lake-peatland and re-introducing the locally extinct species from Majen Choucha. This work exemplifies the usefulness of connecting palaeoecological, historical and modern data for the conservation of Mediterranean wetlands.

Recent discovery of the small pillwort (Pilularia minuta Durieu, Marsileaceae) in Tunisia: hope for an endangered emblematic species of Mediterranean temporary pools?

This article presents a synthesis of all localities where Pilularia minuta, an endangered Pteridophyte endemic of acidic Mediterranean temporary pools, was observed since its discovery in 1835. It aims at analysing the implications of its recent discovery in Tunisia, based on the comparison between new and previously published floristic surveys. The obtained data confirm the heliophilous pioneer character of P. minuta and reveal a disturbance-favoured behaviour in Tunisia. The small pillwort, which occurs in 16 locations around the Mediterranean basin, could be characterised by a good dispersion. However, it experienced the extinction of a quarter of its known populations over the last century. This decline seems to have affected only small populations (Maritime-Alps, France; Lazio, Italy) and highly disturbed areas (Algeria), while large ones (Sardinia, Italy; Corsica and Hérault, France; Andalusia, Spain; western Morocco), presumably more stable, survived. In a context of metapopulation, these large populations could be considered as 'source populations', and should be taken more especially in account in conservation strategies. Further investigations are needed for improving the conservation of the rare plants of Mediterranean temporary pools as well as contributing to a better knowledge of the mechanisms controlling their distribution and their present-day status.