Current status of threatened coastal flora in Peninsular Spain and the Balearic Islands

A total of 165 taxa belonging to the protected threatened flora of coastal habitats of mainland Spain and the Balearic Islands, were studied, covering a total coastline length of about 6,350 km. The regulations found in regional and national catalogues have been used, which consider the endangered (EN) and vulnerable (VU) threatened species distributed in three environments: (1) beaches and dunes; (2) cliffs and rocks; (3) marshes and estuaries, also including seagrass meadows.The aim of this study is to conduct a comparative analysis of the protected and endemic coastal flora in different coastal areas of Peninsular Spain and the Balearic Islands. Various aspects are examined, including habitats preferences, coastal surface area in each region, the number and types of endemic species, and their presence in different catalogs documented in regional legislation, both current and repealed. The objective is to determine whether the distribution of these species is influenced by territorial factors or if it is an administrative matter. The results reveal a high number of region-specific endemisms (32.7% of the total coastal flora) and significant differences in the number of protected taxa among autonomous communities. Additionally, it was found that there is no significant correlation between the distribution of these taxa and the considered territorial variables, suggesting that the distribution of these species is more closely related to administrative factors, such as the continuous updating of catalogs. We also suggest the protection of taxa that occupy a small area and have been described in recent years or are included in regional or national red lists and are not included in the regional catalogues.