Global analyses underrate part of the story: finding applicable results for the conservation planning of small Sardinian islets’ flora

Although many studies have addressed island biogeography, the biodiversity of very small islets has mostly been ignored due to the lack of high-resolution data. We analysed the vascular plant taxa distribution pattern of 81 satellite islets scattered around Sardinia, the second largest island in the Mediterranean Basin. Power models were used to determine the influence of environmental and anthropogenic factors on both endemic and non-endemic species richness. Analyses of the distribution pattern highlighted the high endemism rate in these islets. In addition, reliable results for conservation, such as correlations with land use diversity, climate and human presence, were found only when categorising the islets by their environmental characteristics instead of their geographical position. This study of a representative set of Mediterranean islets contributes to the knowledge base about the controversial role of very small islets in biological conservation. Large-scale analyses have often underrated their importance and we therefore suggest that local studies about their conservation planning are needed worldwide.