First year of SoBEx

Overview

During the past year, the SoBEx team, together with Yannis Alexiou, Gabriela Kelaidi and Chrysa Papadaki, three post-graduate students in UAMECO lab has been conducting field work in several Aegean islands (Figure 1), mainland Greek mountains (Figure 2) and lakes, so as to collect population and environmental data for the Critically Endangered Greek endemic animal and plant species (according to the IUCN).

SoBEx team on Kythira, near the Polygala helenae site

Figure 1: SoBEx team on Kythira, near the Polygala helenae site

At Mt. Kingilos on W Crete, in search of Bupleurum kakiskalae

Figure 2: At Mt. Kingilos on W Crete, in search of Bupleurum kakiskalae

What has been done

So far we have gathered all the relevant data for more than 30 species (13 plants and 18 animals) and we have conducted molecular/genetic analyses for these taxa. We have also run several macroecological analyses so as to estimate the effects of climate change on these Critically Endangered species, as well as to estimate the percent overlap of these species’ distribution range with the NATURA 2000 protected areas network (PAs - gap analysis). We ran correlative Species Distribution Models in an ensemble framework (Araújo et al. 2019), using Breiner’s et al. (2015; 2017; 2018) scheme, since we were dealing with very rare species.

It seems that Isoetes heldreichii, a rare narrow endemic, has gone extinct. It was first described in 1886 from the wider Paleokastro area near Karditsa. It was the only Isoetes species in Greece occurring in exclusively freshwater habitats. This species has not been recorded for nearly 140 years. Its locus classicus has been destroyed so as to construct a dam (Troia and Greuter 2015).

The population of four plant species, namely Aethionema retsina (Figure 3), Anthemis glaberrima, Convolvulus argyrothamnos, and Horstrissea dolinicola (Figure 4), show a decreasing population trend.

Aethionema retsina

Figure 3: Aethionema retsina

Horstrissea dolinicola

Figure 4: Horstrissea dolinicola

On the other hand, three plant species, namely Allium iatrouinum, Bupleurum kakiskalae and Minuartia dirphya (Figure 5) show a weak increasing population trend.

Minuartia dirphya

Figure 5: Minuartia dirphya

We report for the first time, precise population data for Polygala helenaeand Saponaria jagelii (Figure 6). Polygala helenae and Saponaria jagelii comprise 382 and 1815 individuals, respectively. These values now constitute the Favourable Reference Values (FRVs) for the population size of these species. The FRVs for the Extent of Occurrence (EOO) and Area of Occupancy (AOO) for both of these species is 8 km2.

Saponaria jagelii

Figure 6: Saponaria jagelii

According to the SDM analyses, all of the species under study are projected to become extinct in the coming decades, under any Global Circulation Model (GCM), Representative Concentration Pathway (RCP) and climate database combination (for instance: Figure 7). The median percentage loss was 100% across all species. Our models had sufficient predictive power (TSS \(\geq 0.75\) - median TSS: 0.78). All models were found to outperform the null expectation at P \(< 0.05\).

Occurrence probability map of Saponaria jagelii for the present time-period

Figure 7: Occurrence probability map of Saponaria jagelii for the present time-period

According to the gap analysis, the distribution range of the species under study varied from 0.001 km2 to 9756.2 km2. Two gastropods, namely Lindbergia gittenbergeri and Tsoukatosia evauemgei, occur exclusively outside any PA. Thirteen species (nine plants and four gastropods) on the other hand, occur exclusively in PAs. The mean percentage overlap is 48.1%, yet most species (ca. 60%) occur outside the Greek PAs for at least half of their distribution range (Figure 8). The mean percentage overlap was highest in plants (67.6%), followed by molluscs (47.4%), arthropods (39.7%) and vertebrates (17.1%).

Results of the gap analysis for the studied taxa

Figure 8: Results of the gap analysis for the studied taxa

You can find more information here. The SoBEx team has also presented some of the first year’s results in two international and one national scientific congresses.

This project has received funding from the Hellenic Foundation for Research and Innovation (HFRI) and the General Secretariat for Research and Technology (GSRT), under grant agreement No [2418].

References

Araújo, Miguel B, Robert P Anderson, A Márcia Barbosa, Colin M Beale, Carsten F Dormann, Regan Early, Raquel A Garcia, et al. 2019. “Standards for Distribution Models in Biodiversity Assessments.” Science Advances 5 (1). American Association for the Advancement of Science: eaat4858.

Breiner, Frank T, Antoine Guisan, Ariel Bergamini, and Michael P Nobis. 2015. “Overcoming Limitations of Modelling Rare Species by Using Ensembles of Small Models.” Methods in Ecology and Evolution 6 (10). Wiley Online Library: 1210–8.

Breiner, Frank T, Antoine Guisan, Michael P Nobis, and Ariel Bergamini. 2017. “Including Environmental Niche Information to Improve Iucn Red List Assessments.” Diversity and Distributions 23 (5). Wiley Online Library: 484–95.

Breiner, Frank T, Michael P Nobis, Ariel Bergamini, and Antoine Guisan. 2018. “Optimizing Ensembles of Small Models for Predicting the Distribution of Species with Few Occurrences.” Methods in Ecology and Evolution 9 (4). Wiley Online Library: 802–8.

Troia, Angelo, and Werner Greuter. 2015. “A Conspectus of and Key to Greek Isoetes (Isoetaceae), Based on a Reassessment of Haussknecht’s Gatherings of 1885.” Willdenowia 45 (3). BioOne: 391–403.

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Kostas Kougioumoutzis
Post-Doctoral Researcher

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