Importance of Plants with Extremely Small Populations (PSESPs) in Endemic-Rich Areas, Elements Often Forgotten in Conservation Strategies

Abstract

The distribution of the threatened fern Ophioglossum vulgatum L., a plant with extremely small populations (PSESPs) in Sardinia, is characterized by small disjunct populations with only a few individuals, and little is known about its status in the wild. To provide information for the conservation of O. vulgatum and with the aim to develop an in situ conservation strategy, we investigated its distribution, population size, and habitat. Field surveys confirmed that the species grows in only five localities. Two representative populations were selected for this study (Funtanamela and Gedili), and in each population, all plants were mapped and monitored monthly from April to August over an 8-year period. During the study, the populations had a very low number of reproductive plants and the populations appeared to be in decline, with the total number of plants per population slightly decreased in Gedili while a sharp reduction was recorded in Funtanamela due to wild boar threat. A fence was built in order to protect the site from further damage, but no noticeable signals of recovery were observed. The most urgent conservation requirement for this species is to preserve the threatened habitat of the remnant populations. Further field surveys and research are also required for an improved understanding of the species’ status.

Knowledge Gaps in Taxonomy, Ecology, Population Distribution Drivers and Genetic Diversity of African Sandalwood (Osyris lanceolata Hochst. & Steud.): A Scoping Review for Conservation

“…The three approaches needed for continued survival of O. lanceolata populations include: conservation, restoration and sustainable commercial use. In particular, conservation of threatened habitats for the species population is necessary [ 123 ]. As different populations exhibit different population dynamics, conservation planning ought to be undertaken at the population level and reinforced by local investigations which are more informative than global studies [ 124 ].…”

First Restoration Experiment for Endemic Fucus virsoides on the Western Istrian Coast—Is It Feasible?

“…The presumed culprit, Sarpa salpa, can often be observed browsing the intertidal zone during high water level and is a predominant Mediterranean and Adriatic herbivorous fish species [ 43 , 44 ]. While grazing pressure is expected and can often drive succession as well as community structure, during longer timeframes, plants (or algae) with extremely small populations (or PSESP-s) are extremely susceptible to overgrazing, as this could further diminish, prevent recovery, or even extirpate the populations [ 45 , 46 , 47 ]. While protecting these small settlements can prevent overgrazing, if such an experiment were to be replicated on a larger scale, some simpler method of grazer exclusion must be developed, or an optimal point in relation to the mean sea level should be identified in order for the macro-grazers to be effectively excluded.…”

Persistence of the Strictly Endemic Plants of Forest Margins: The Case of Cirsium alpis-lunae in the Northern Apennines (Italy)

“…Regardless, to be effective, conservation actions for those species require reliable basic information about the distribution ranges, ecological requirements, population numbers, population sizes, and, if possible, demographic patterns (i.e., vital rates) over a defined period of time [ 3 , 13 , 14 , 15 ]. Although demographic analyses have been successfully applied in plant ecology and evolutionary biology [ 16 , 17 , 18 , 19 ], their use in conservation biology remains lacking [ 15 , 20 , 21 , 22 , 23 , 24 ]; this is especially true in the Mediterranean Basin, where in-depth demographic studies on endemic and threatened plant populations are uncommon [ 7 , 15 , 20 , 25 , 26 , 27 , 28 ]. This lack of knowledge is even more relevant in the case of plants that have been neglected, recently described, or have typical or exclusive dynamic or peculiar habitats, such as ecotones.…”