Extinction Risk Assessment of the Greek Endemic Flora

The future of plant diversity within a Mediterranean endemism centre: Modelling the synergistic effects of climate and land-use change in Peloponnese, Greece

Climate- and land-use change stand as primary threats to terrestrial biodiversity. Yet, their synergistic impacts on species distributions remain poorly understood. To address this knowledge gap, we conducted the first-ever comprehensive species distribution analysis on an entire regional endemism centre within an eastern Mediterranean country, incorporating dynamic land-use/land-cover change data together with climate change scenarios. Specifically, we apply species distribution modelling and spatial data analysis techniques to compare the individual and synergistic effects of these environmental drivers on the endemic vascular flora of Peloponnese, focusing on potential range contractions, altitudinal shifts, and habitat fragmentation levels. Moreover, we identify fine-scale present and potential future endemism hotspots within our study area, incorporating taxonomic and phylogenetic information. Overall, we aim to enhance our current understanding of endemism patterns and contribute to the development of future-proof conservation strategies for safeguarding Greece's endangered endemic flora. The integration of land-use change projections with climate change yielded less severe impacts compared to the effects anticipated when considering climatic variables alone. Most taxa are expected to undergo significant range declines and nearly half might experience increased habitat fragmentation, due to the synergistic effects of climate- and land-use change. We identified endemism hotspots, which are concentrated in or along the main Peloponnesian mountain massifs. However, our predictions indicate that areas presently recognized as endemism hotspots will undergo a concerning area decline, across all future scenarios considered in this study. Our findings highlight the importance of including dynamic land-use variables alongside climatic predictors when projecting species distributions under global change. Moreover, we showed that endemism hotspots are not static and considering their potential geographic shifts is paramount to delineate effective forward-looking conservation strategies.

Rising Temperatures, Falling Leaves: Predicting the Fate of Cyprus's Endemic Oak under Climate and Land Use Change

Endemic island species face heightened extinction risk from climate-driven shifts, yet standard models often underestimate threat levels for those like Quercus alnifolia, an iconic Cypriot oak with pre-adaptations to aridity. Through species distribution modelling, we investigated the potential shifts in its distribution under future climate and land-use change scenarios. Our approach uniquely combines dispersal constraints, detailed soil characteristics, hydrological factors, and anticipated soil erosion data, offering a comprehensive assessment of environmental suitability. We quantified the species' sensitivity, exposure, and vulnerability to projected changes, conducting a preliminary IUCN extinction risk assessment according to Criteria A and B. Our projections uniformly predict range reductions, with a median decrease of 67.8% by the 2070s under the most extreme scenarios. Additionally, our research indicates Quercus alnifolia's resilience to diverse erosion conditions and preference for relatively dry climates within a specific annual temperature range. The preliminary IUCN risk assessment designates Quercus alnifolia as Critically Endangered in the future, highlighting the need for focused conservation efforts. Climate and land-use changes are critical threats to the species' survival, emphasising the importance of comprehensive modelling techniques and the urgent requirement for dedicated conservation measures to safeguard this iconic species.

DNA Barcoding and Fertilization Strategies in Sideritis syriaca subsp. syriaca, a Local Endemic Plant of Crete with High Medicinal Value

Herein, we applied DNA barcoding for the genetic characterization of Sideritis syriaca subsp. syriaca (Lamiaceae; threatened local Cretan endemic plant) using seven molecular markers of cpDNA. Five fertilization schemes were evaluated comparatively in a pilot cultivation in Crete. Conventional inorganic fertilizers (ChFs), integrated nutrient management (INM) fertilizers, and two biostimulants were utilized (foliar and soil application). Plant growth, leaf chlorophyll fluorescence, and color were assessed and leaf content of chlorophyll, key antioxidants (carotenoids, flavonoids, phenols), and nutrients were evaluated. Fertilization schemes induced distinct differences in leaf shape, altering quality characteristics. INM-foliar and ChF-soil application promoted yield, without affecting tissue water content or biomass partitioning to inflorescences. ChF-foliar application was the most stimulatory treatment when the primary target was enhanced antioxidant contents while INM-biostimulant was the least effective one. However, when the primary target is yield, INM, especially by foliar application, and ChF, by soil application, ought to be employed. New DNA sequence datasets for the plastid regions of petB/petD, rpoC1, psbK-psbI, and atpF/atpH were deposited in the GenBank for S. syriaca subsp. syriaca while the molecular markers rbcL, trnL/trnF, and psbA/trnH were compared to those of another 15 Sideritis species retrieved from the GenBank, constructing a phylogenetic tree to show their genetic relatedness.

Are Mediterranean Island Mountains Hotspots of Taxonomic and Phylogenetic Biodiversity? The Case of the Endemic Flora of the Balearic Islands

The Mediterranean islands are exceptionally rich in endemism, most of which is narrowly distributed. Conservation measures, such as protected areas, have been prioritised, mainly on the basis of species richness and endemism, but phylogenetic information should also be taken into account. In this study, we calculated several taxonomic and phylogenetic metrics at a high resolution for the endemic flora of the Balearic Islands (154 taxa), in order to identify (i) the spatial patterns and environmental factors that explain this endemism, (ii) hotspots of species and phylogenetic endemism, and (iii) gaps in the protected areas. The taxonomic and phylogenetic metrics showed different distribution patterns, but the mountainous areas of Mallorca, and some coastal areas of the Balearic Islands, have the highest values. These values were positively related to elevation, precipitation, temperature, and slope, and negatively related to the distance from the coast, aspect, and the temperature of the wettest quarter. We identified top grid hotspots where all the metrics had the highest values, and we also identified nano-hotspots within these hotspots, in some of the highest peaks of Mallorca, where most of these metrics' maximum values coincided. This approach allowed us to identify some gaps in the conservation priority areas, and to highlight the need to review their boundaries and definition.

Effect of Temperature on Breaking of Morphophysiological Dormancy and Seed Germination Leading to Bulblet Production in Two Endemic Tulip Species from Greece

Due to botanical tulips' economic interest coupled with limited information regarding their seed germination, we investigated the effect of temperature on dormancy release and germination in two endangered local endemic tulip species of Greece (Tulipa hageri Heldr., T. orphanidea Heldr.). Their germination responses at five constant temperatures (5, 10, 15, 20, and 25 °C) were evaluated in growth chambers, while the type of seed dormancy and the temperature effect on its release were determined based on open-sourced, R-derived species-specific ecological profiles illustrating abiotic conditions of their wild habitats. The results indicated a range-specific temperature dependence in seed germination for both studied species with seed germination observed only in very low temperatures (5-10 °C). The seeds of both species after dispersal had an underdeveloped embryo. The existence of a complex morphophysiological seed dormancy was confirmed in both species by the significant embryo development only at 5 and 10 °C (almost doubled after 30 days) coupled with observed delay in germination only at low temperatures. Furthermore, to facilitate their cultivation and ex situ conservation, the germinated seeds were planted in pots to develop bulblets in greenhouse conditions resulting in bigger T. orphanidea bulblets compared to T. hageri.

Adaptability of Wild-Growing Tulips of Greece: Uncovering Relationships between Soil Properties, Rhizosphere Fungal Morphotypes and Nutrient Content Profiles

Wild-growing Greek tulips are protected plants but almost nothing is known about their natural nutrient status and rhizosphere fungal morphotypes in the wild, thus no insight is currently available into their growth and adaptation to their natural environment or artificial settings. To this end, several botanical expeditions were conducted with a special collection permit, and 34 tulip and soil samples were collected, representing 13 species from two phytogeographical regions of Greece (North Aegean Islands, Crete Island) and seven regions of mainland Greece. The tulips' content in essential macro- and micro-nutrients, respective physicochemical soil properties, and rhizosphere fungal morphotypes were assessed across samples, and all parameters were subjected to appropriate statistical analysis to determine their interrelationships. The results showed that soil variables played a significant role in shaping tulips' nutrient content, explaining up to 67% of the detected variability as in the case of phosphorus (P) in the above-ground plant tissue. In addition, significant correlations were observed (with an r value of up to 0.65, p < 0.001) between essential nutrients in the tulips, such as calcium (Ca) and boron (B). The principal component analysis (PCA) revealed that between the three spatial units examined, the total variability of tulips' nutrient content produced a clear distinction among sampled species, while the first two PCA axes managed to explain 44.3% of it. This was further confirmed by the analysis of variance (ANOVA) results which showed corresponding significant differences (at p < 0.05) in both the tulips' nutrient content and the studied soil properties as well (mean values of N, P, and K in the North Aegean Islands tulips' nutrient content, up to 53%, 119%, and 54% higher compared to those of the Crete Island, respectively). Our study sheds light on Greek tulips' adaptability and resilience in their original habitats, facilitating at the same time the undertaken efforts regarding their conservation and potential domestication in artificial settings.

Influence of Temperature on Seed Germination of Five Wild-Growing Tulipa Species of Greece Associated with Their Ecological Profiles: Implications for Conservation and Cultivation

Although tulips are famous worldwide as ornamental plants, the knowledge about the seed germination of wild-growing species remains limited. The aim of the present study was to investigate the effect of temperature on seed germination of the local, wild-growing Greek endemics Tulipa bakeri and T. goulimyi and the sub-Balkan endemic T. undulatifolia, which are threatened with extinction, as well as the Mediterranean T. australis and the Asiatic T. clusiana naturalized on Chios Island (Greece). The germination responses at five constant temperatures (5, 10, 15, 20, and 25 °C) were assessed for all studied species in growth chambers under a 12:12 light-dark photoperiod. The ecological profile for each species was developed in R using open-source bioclimatic data; this was built to illustrate the abiotic environmental conditions of their wild habitats, to facilitate the examination of temperature effects on seed germination, and to facilitate their cultivation in artificial environments. The results indicated that the seed germination requirements of the studied species had a range-specific temperature dependence, reflecting their natural adaptation to local ecological conditions. Seed germination of T. bakeri, T. australis, and T. clusiana was observed only in a narrow range of very low temperatures (5-10 °C), whereas germination of T. undulatifolia and T. goulimyi occurred at temperatures between 5 and 15 °C. A temperature increase to 20 or 25 °C resulted in the absence of seed germination for all five Greek tulip species. The germinated seeds were planted in pots and bulblets were developed under greenhouse conditions. Seeds and bulblets constitute valuable genetic materials for the cultivation and ex situ conservation of these five Greek tulip species, three of which are threatened with extinction.

Phylogenetic data reveal a surprising origin of Euphorbia orphanidis (Euphorbiaceae) and environmental modeling suggests that microtopology limits its distribution to small patches in Mt. Parnassus (Greece)

The Mediterranean Basin is one of the most biodiverse areas in the world, harboring 25,000 plant species, of which 60% are endemic. Some of them have narrow distributions, such as Euphorbia orphanidis, which is only known from alpine screes on Mt. Parnassos in Greece. Its exact distribution in this mountain was, however, poorly known, and its phylogenetic origin was also unclear. We performed extensive field work in Mt. Parnassos and could register E. orphanidis only in five patches of limestone screes in the eastern part of this mountain range, emphasizing its very narrow distribution, which is likely limited by topography influencing water availability as indicated by environmental modeling. We also registered 31 accompanying species and thus characterized its habitat. Using nuclear ribosomal internal transcribed spacer and plastid ndhF-trnL and trnT-trnF sequences, we show that it belongs to E. sect. Patellares, despite not having connate raylet leaves typical for this section, and not to E. sect. Pithyusa as previously suggested. The relationships among the species of E. sect. Patellares are poorly resolved, suggesting their simultaneous divergence that dated to the late Pliocene, which coincided with the establishment of the Mediterranean climate. The relative genome size of E. orphanidis is in the range of that for the other members of E. sect. Patellares, suggesting that it is diploid. Finally, we performed multivariate morphological analyses to generate a comprehensive description of E. orphanidis. Based on its narrow distribution and the anticipated negative impact of global warming, we consider this species endangered. Our study demonstrates how microrelief can limit the distribution of plants in topographically heterogeneous mountain environments and likely plays an important, yet neglected, role in shaping the distribution patterns of plants in the Mediterranean Basin.

Exploring the Ecological Preferences and Essential Oil Variability in Wild-Growing Populations of the Endangered Local Greek Endemic Thymus holosericeus (Lamiaceae)

Thymus holosericeus Čelak. (Lamiaceae) is a taxonomically isolated and endangered local endemic thyme species which is geographically isolated in four Ionian Islands (West Greece). The present study investigated the essential oil (EO) composition, the ecological preferences, and their correlations in three T. holosericeus wild-growing populations from Zakynthos (ΤH-Z), Cephalonia (ΤH-C) and Lefkada (ΤH-L). The variations in essential oil yield and the composition of T. holosericeus populations were evaluated using hydrodistillation, GC/MS, TLC and NMR analysis. The climatic conditions of each sample were organized and analyzed in RStudio with the raster package and in SPSS with Pearson's Canonical Correlation Analysis (CCA), respectively. The aerial parts of the plants varied in EO yields from 1.92 to 2.28% w/v. The analysis of EO constituents revealed noteworthy qualitative and quantitative inter-population variation. The composition of EOs revealed the presence of linalool (82.77%) and borneol (5.95%) as major compounds in ΤH-Z, while carvacrol (35.34%), geraniol (23.98%), linalool (14.37%), borneol (5.66%), thymol (4.27%) and p-cymene (4.08%) were the main compounds in ΤH-C and linalool (40.37%), geraniol (39.42%) and borneol (5.20%) were dominant components in ΤH-L. The results of the gas chromatography procedure have also been confirmed by ¹H and ¹³C-NMR and TLC analysis. The ecological profile showed an average annual precipitation of 942 ± 18.33 mm and the temperature limits in which T. holosericeus seems to adapt to are 6.80± 1.08 °C 27.70 ± 0.70 °C. Regarding the examined samples, TH-C was adapted to the driest summer and coldest winter conditions, TH-Z was adapted to the lowest annual precipitation with the most complex climatic conditions, and TH-L was adapted to the highest summer temperatures with the lowest precipitation in the wettest period of the year. For each sampled population, the CCA identified the association of the samples' EOs composition with the prevailing local environmental conditions.

Climate and Land-Cover Change Impacts and Extinction Risk Assessment of Rare and Threatened Endemic Taxa of Chelmos-Vouraikos National Park (Peloponnese, Greece)

Chelmos-Vouraikos National Park is a floristic diversity and endemism hotspot in Greece and one of the main areas where Greek endemic taxa, preliminary assessed as critically endangered and threatened under the IUCN Criteria A and B, are mainly concentrated. The climate and land-cover change impacts on rare and endemic species distributions is more prominent in regional biodiversity hotspots. The main aims of the current study were: (a) to investigate how climate and land-cover change may alter the distribution of four single mountain endemics and three very rare Peloponnesian endemic taxa of the National Park via a species distribution modelling approach, and (b) to estimate the current and future extinction risk of the aforementioned taxa based on the IUCN Criteria A and B, in order to investigate the need for designing an effective plant micro-reserve network and to support decision making on spatial planning efforts and conservation research for a sustainable, integrated management. Most of the taxa analyzed are expected to continue to be considered as critically endangered based on both Criteria A and B under all land-cover/land-use scenarios, GCM/RCP and time-period combinations, while two, namely Alchemilla aroanica and Silene conglomeratica, are projected to become extinct in most future climate change scenarios. When land-cover/land-use data were included in the analyses, these negative effects were less pronounced. However, Silene conglomeratica, the rarest mountain endemic found in the study area, is still expected to face substantial range decline. Our results highlight the urgent need for the establishment of micro-reserves for these taxa.

Characterization of Sideritis clandestina subsp. peloponnesiaca Polar Glycosides and Phytochemical Comparison to Other Mountain Tea Populations

Sideritis clandestina (Bory & Chaub.) Hayek subsp. peloponnesiaca (Boiss. & Heldr.) Baden (SCP) is endemic to the mountains of the Northern Peloponnese (Greece). This and other Sideritis taxa, collectively known as mountain tea, are widely ingested as beverages for refreshment or medicinal purposes. We describe a methodology for the characterization of SCP. Four iridoid glycosides (monomelittoside, melittoside, ajugoside, and 7-O-acetyl-8-epiloganic acid), two phenolic acid glycosides (vanillic and salicylic acid glycosides), and three caffeoyl ester glycosides (chlorogenic acid, verbascoside, and isoverbascoside) were isolated from SCP for the first time. We used ultrasound-assisted extraction of 3 g of plant material to produce petroleum ether and aqueous extracts, which we then analyzed using GC/MS and LC/MS. This was applied to eight samples from four different taxa. In total, 70 volatile and 27 polar metabolites were determined. The S. clandestina samples had a lower phenolic content and weaker antioxidant properties than S. raeseri and S. scardica. However, S. clandestina ssp. clandestina seemed to be the most aromatic taxon, with almost double the number of volatiles as the others. Τhis study could contribute to authentication and chemotaxonomic studies of Sideritis taxa.

Plant Diversity of Mts. Oligirtos and Farmakas (NE Peloponnisos, Greece) with Emphasis on Their Endemic Flora

Greece is known to be a biodiversity hotspot. Though the plant diversity of Peloponnisos, the southernmost part of the Greek mainland, has been well-studied during the past 200 years, there are still gaps in our knowledge. To this end, the flora of the neighboring mountains Oligirtos and Farmakas was investigated, with a total of 740 and 762 taxa (species and subspecies) recorded, respectively, of which 635 and 756 for the first time. Ten species or subspecies were previously not known from Peloponnisos. Endemics correspond to 10.2% and 8.9% of the total flora and are predominately hemicryptophytes and entomogamous. Almost half of them produce capsules. The number of endemics per 2 × 2 km grid cell reveals that their highest number is found in areas of high elevation, and corresponds to habitats above the tree line, or to the limestone cliffs vegetation. No less than 62 endemic plant taxa of Mt. Oligirtos and 58 of Mt. Farmakas are threatened. A comparison of Mts. Oligirtos and Farmakas with five neighboring mountains shows that elevation correlates positively with the number of regional or bi-regional endemics but not with local or narrow endemics. The importance of mountainous regions for plant conservation is stressed.

Extinction risk of the endemic vascular flora of Kauai, Hawaii, based on IUCN assessments

The International Union for Conservation of Nature's Red List of Threatened Species (IUCN Red List) is the world's most comprehensive information source on the global conservation status of species. Governmental agencies and conservation organizations increasingly rely on IUCN Red List assessments to develop conservation policies and priorities. Funding agencies use the assessments as evaluation criteria, and researchers use meta-analysis of red-list data to address fundamental and applied conservation science questions. However, the circa 143,000 IUCN assessments represent a fraction of the world's biodiversity and are biased in regional and organismal coverage. These biases may affect conservation priorities, funding, and uses of these data to understand global patterns. Isolated oceanic islands are characterized by high endemicity, but the unique biodiversity of many islands is experiencing high extinction rates. The archipelago of Hawaii has one of the highest levels of endemism of any floristic region; 90% of its 1367 native vascular plant taxa are classified as endemic. We used the IUCN's assessment of the complete single-island endemic (SIE) vascular plant flora of Kauai, Hawaii, to assess the proportion and drivers of decline of threatened plants in an oceanic island setting. We compared the IUCN assessments with federal, state, and other local assessments of Kauai species or taxa of conservation concern. Finally, we conducted a preliminary assessment for all 1044 native vascular plants of Hawaii based on IUCN criterion B by estimating area of occupancy, extent of occurrence, and number of locations to determine whether the pattern found for the SIE vascular flora of Kauai is comparable to the native vascular flora of the Hawaiian Islands. We compared our results with patterns observed for assessments of other floras. According to IUCN, 256 SIE vascular plant taxa are threatened with extinction and 5% are already extinct. This is the highest extinction risk reported for any flora to date. The preliminary assessment of the native vascular flora of Hawaii showed that 72% (753 taxa) is threatened. The flora of Hawaii may be one of the world's most threatened; thus, increased and novel conservation measures in the state and on other remote oceanic islands are urgently needed.

Exploring Biodiversity and Disturbances in the of Peri-Urban Forests of Thessaloniki, Greece

Forests host important plant biodiversity. Nevertheless, due to climate change and human disturbances, the floristic quality of forest ecosystems is degraded. Greek peri-urban forests biodiversity is threatened by anthropogenic activities such as forest fragmentation, pollution, garbage, etc. Measurement of biodiversity status and the floristic quality assessment can be used to estimate the degree of forest degradation caused by anthropogenic disturbances. In this study, we compared and evaluated six forest ecosystem types in the peri-urban forests of Thessaloniki, northern Greece, by using Shannon’s biodiversity index as well as and α and β diversity Sørensen indices. Furthermore, we recorded the prevailing anthropogenic disturbances and compared the plant families and the ruderal species appearing in each forest ecosystem. Finally, the average conservatism value (C value) of the plant species found in each ecosystem was determined in order to calculate the ecosystem floristic quality index. Analysis of the results showed that the floristic and ecological parameters tested greatly vary among ecosystems. Broadleaf forests of higher altitude hosted the greatest biodiversity, and the higher floristic quality index and plant conservation value. On the contrary, most disturbances and most ruderal species were recorded in ecosystems of lower altitude, adjacent to the city (Pinus brutia forest and Maqui vegetation), the least disturbed ecosystems were found in the steep slopes (Castanea sativa forest). Most ruderal species found belonged to the Asteraceae and Rosaceae families. Accessibility and attractiveness of stands were positively correlated with disturbances. Insufficient management, lack of protection measures, and littering removal contribute to the increase in the level of disturbance.

Assessing the Ecosystem Services Potential of Endemic Floras: A Systematic Review on the Greek Endemics of Peloponnese

As the interest in new, natural, sustainable products arises in many fields, wild plants are reconsidered as providers of traditional or innovative applications. The notion of ecosystem services (ES) provides a frame to evaluate their benefits, but is still scarcely applied to endemic floras. The present study reviews the available literature on the ES provided by the 494 taxa endemic to Greece that are present in Peloponnese. Six main categories are isolated: medical, aromatic, folk medicine, antimicrobial, environmental and craftsmanship interests. The literature documents such ES for 24.7% of the endemic taxa, with Lamiaceae, Asteraceae and Boraginaceae as the families with the highest numbers of documented taxa. Spatial hotspots with a high density in taxa providing ES are mapped, while gaps of knowledge on the ES of endemic taxa are highlighted. For the first time, to our knowledge, taxonomic and phylogenetic bounds between taxa are exploited as a base to explore potential properties for endemic taxa. The basis for the development of predictive tools utilizing literature review datasets is set. Final outcomes also provide robust scientific evidence to support decision and policy making for the sustainable use and management of rural areas. The development of cultivation areas for threatened taxa of interest is suggested as a potent conservation measure, by selecting fields according to habitat suitability models.

In Vitro Germination and Propagation of Dyckia brevifolia, an Ornamental and Endangered Bromeliad

Dyckia brevifolia is an endangered plant used for ornamental purposes. As no references to the in vitro propagation of the species exist, the present study aims at investigating the possibility of an efficient micropropagation protocol. Seeds collected from mother plants were germinated at high percentages (84–86%) at a range of 15–25 °C, without any pre-treatment, and demonstrated their highest germination speed index (191.51) at 25 °C. In vitro-grown seedlings were used as the starting material for micropropagation on solid, or liquid, MS medium, supplemented with a variety of concentrations of cytokinins (BA, KIN or 2IP). Shoots and leaves were used as starting explants. Liquid media supplemented with BA or 2IP at 1.0 mg L−1 led to high multiplication rate and 2.7, or 2.3, lateral shoots were regenerated while on 2IP a high percentage (77.5%) of rooting occurred at the same time. Rooted microshoots were acclimatised ex vitro at 100% and acclimatised plants were transplanted in pots where they grew with a survival rate of 100% after two months. The in vitro propagation protocol presented in this study could enhance the large-scale propagation use of D. brevifolia as an ornamental plant and, simultaneously, contribute to the ex-situ conservation of the species.

Climate Change Impacts and Extinction Risk Assessment of Nepeta Representatives (Lamiaceae) in Greece

The ongoing climate change has already left its imprint on species distributions, with rare, endemic species being more threatened. These changes are more prominent in regional biodiversity hotspots, such as Greece, which is already facing the short term impacts of human induced climate change. Greek flora hosts numerous endemic medicinal and aromatic plant taxa (MAPs), which are economically important and provide integral ecosystem services. The genus Nepeta is one of the largest Lamiaceae genera, containing several MAPs, yet, despite its taxonomical and economical significance, it remains vastly understudied in Greece. We explore the effects of climate change on the range of the Greek endemic Nepeta MAPs, via a species distribution models (SDMs) approach in an ensemble modeling framework, using soil, topographical and bioclimatic variables as predictors in three different time steps. By doing so, we attempt to estimate the current and future extinction risk of these taxa and to locate their current and future species richness hotspots in Greece. The taxa analyzed are expected to experience severe range retractions, with minor intraspecific variation across all time steps (p > 0.05), driven mainly by soil- and aridity-related variables. The extinction risk status of only one taxon is predicted to worsen in the future, while all other taxa will remain threatened. Current species richness hotspots are mainly located in southern Greece and are projected to shift both altitudinally and latitudinally over time (p < 0.01).

Assessing Climate Change Impacts on Island Bees: The Aegean Archipelago

Pollinators’ climate change impact assessments focus mainly on mainland regions. Thus, we are unaware how island species might fare in a rapidly changing world. This is even more pressing in the Mediterranean Basin, a global biodiversity hotspot. In Greece, a regional pollinator hotspot, climate change research is in its infancy and the insect Wallacean shortfall still remains unaddressed. In a species distribution modelling framework, we used the most comprehensive occurrence database for bees in Greece to locate the bee species richness hotspots in the Aegean, and investigated whether these might shift in the future due to climate change and assessed the Natura 2000 protected areas network effectiveness. Range contractions are anticipated for most taxa, becoming more prominent over time. Species richness hotspots are currently located in the NE Aegean and in highly disturbed sites. They will shift both altitudinally and latitudinally in the future. A small proportion of these hotspots are currently included in the Natura 2000 protected areas network and this proportion is projected to decrease in the coming decades. There is likely an extinction debt present in the Aegean bee communities that could result to pollination network collapse. There is a substantial conservation gap in Greece regarding bees and a critical re-assessment of the established Greek protected areas network is needed, focusing on areas identified as bee diversity hotspots over time.

Pilot Cultivation of the Vulnerable Cretan Endemic Verbascum arcturus L. (Scrophulariaceae): Effect of Fertilization on Growth and Quality Features

The domestication of wild-growing plants, including cultivation and fertilization protocols, is able to alleviate the ecological risks posed by the uncontrolled harvesting of range-restricted local endemic plants. In this field study focused on Verbascum arcturus, a vulnerable local endemic of Crete (Greece), the effect of two kinds of fertilization applied by two methods (foliar/root) was investigated. The foliar application included conventional or integrated nutrient management (INM) fertilization. Root application included the application of conventional fertilizers, biostimulants, or INM with biostimulants. Several properties of plant growth, physiology and nutrition were determined. The results showed that fertilization treatment affected neither leaf color and shape nor plant growth, morphology, dry mass partitioning or nutrient content. However, both kinds of foliar-applied fertilization enhanced Zn and B in leaves and soil-applied biostimulant increased leaf Ca. Considering both chlorophyll and antioxidant compounds’ content, foliar application of the INM fertilizers, as well as soil application of the conventional fertilizers or biostimulants, could be considered as accepted options. This study reports for the first time an assessment of the total phenolic and flavonoids content evidenced in V. arcturus and encourages the use of fertilization in promoting the herbal antioxidant profile without compromising visual quality or yield. The findings of this study could be considered as a documented contribution toward the sustainable exploitation of V. arcturus.

Medicinal-Cosmetic Potential of the Local Endemic Plants of Crete (Greece), Northern Morocco and Tunisia: Priorities for Conservation and Sustainable Exploitation of Neglected and Underutilized Phytogenetic Resources

Medicinal-aromatic plants (MAPs) are important sources for the development of new valuable products of interest to human and animal health, and are also used as ornamentals for the horticulture industry. However, the increased global demand and the uncontrolled exploitation of these plants constitute a threat to their sustainability. To date, few scientific investigations have focused on MAPs valorization and their domestication. The purpose of this study was to evaluate for the first time the medicinal-cosmetic potential of 399 local endemic Mediterranean plants confined to Crete (223 taxa), the Mediterranean coast-Rif of Morocco (94), and Tunisia (82). The new methodological scheme was developed by experts through three multidisciplinary co-creative workshops and was adjusted by end-users to point-scoring of nine attributes evaluating the potential of the targeted neglected and underutilized plants (NUPs) in the medicinal-cosmetic sector. The results were demonstrated as percentage of the maximum possible score. These assessments were further linked and discussed with respect to feasibility and readiness timescale evaluations for sustainable exploitation of the focal NUPs. A great diversity of local endemic NUPs (30 taxa, 11 families) were associated with interesting medicinal-cosmetic properties (>35% up to 94.44%). Among them, 8 taxa showed the highest medicinal-cosmetic potential (>55% of maximum possible score), half of which are threatened with extinction. Although ex-situ conservation efforts and applied research work are needed to safeguard and unlock the full potential of the local endemic NUPs evaluated herein, the proposed multifaceted evaluation scheme revealed that some local endemic NUPs of the studied regions can be sustainably exploited in short- or medium-term, following successful examples of Cretan NUPs e.g., Origanum dictramnus. The sustainable exploitation of high scored taxa of the studied regions can be fastened through targeted species-specific research bridging extant research gaps and facilitating conservation and stakeholder attraction.

Climate-Change Impacts on the Southernmost Mediterranean Arctic-Alpine Plant Populations

Human-induced climate- and land-use change have been affecting biogeographical and biodiversity patterns for the past two centuries all over the globe, resulting in increased extinction and biotic homogenization rates. High mountain ecosystems are more sensitive to these changes, which have led to physiological and phenological shifts, as well as to ecosystem processes’ deformation. Glacial relicts, such as arctic-alpine taxa, are sensitive indicators of the effects of global warming and their rear-edge populations could include warm-adapted genotypes that might prove—conservation-wise—useful in an era of unprecedented climate regimes. Despite the ongoing thermophilization in European and Mediterranean summits, it still remains unknown how past and future climate-change might affect the distributional patterns of the glacial relict, arctic-alpine taxa occurring in Greece, their European southernmost distributional limit. Using species distribution models, we investigated the impacts of past and future climate changes on the arctic-alpine taxa occurring in Greece and identified the areas comprising arctic-alpine biodiversity hotspots in Greece. Most of these species will be faced with severe range reductions in the near future, despite their innate resilience to a multitude of threats, while the species richness hotspots will experience both altitudinal and latitudinal shifts. Being long-lived perennials means that there might be an extinction-debt present in these taxa, and a prolonged stability phase could be masking the deleterious effects of climate change on them. Several ex situ conservation measures (e.g., seed collection, population augmentation) should be taken to preserve the southernmost populations of these rare arctic-alpine taxa and a better understanding of their population genetics is urgently needed.

Linking Taxonomic, Phylogenetic and Functional Plant Diversity with Ecosystem Services of Cliffs and Screes in Greece

Sparsely vegetated habitats of cliffs and screes act as refugia for many regional and local endemic specialized plant taxa most of which have evolved precisely for that type of habitat. The interplay between taxonomic, phylogenetic, and functional plant diversity on rock and scree habitats of extreme environmental conditions, enlightens the relations of plant communities and ecosystems and facilitates management planning for the conservation of biodiversity and ecosystem services. The identification of biodiversity patterns and hotspots (taxonomic, phylogenetic, and functional) contributes to the integration of the ecosystem services (ES) approach for the mapping and assessment of ecosystems and their services (MAES) implementation in Greece and the creation of thematic maps based on the MAES reporting format. The overlap among the protected areas’ network revealed that almost all areas of cliffs and screes of medium, high, and very high taxonomic and phylogenetic plant endemism are included in the Natura 2000 area network. The results of this study provide the baseline information for ES assessments at sparsely vegetated land of cliffs and screes. Our results contribute to the implementation of certain indicators of the national set of MAES indicators in Greece such as (a) floristic diversity and (b) microrefugia of endemic diversity and support of decision-making.

Conservation Genetics of Four Critically Endangered Greek Endemic Plants: A Preliminary Assessment

The Mediterranean basin constitutes one of the largest global biodiversity hotspots, hosting more than 11,000 endemic plants, and it is recognised as an area with a high proportion of threatened taxa. Nevertheless, only a tiny fraction of the threatened Mediterranean endemics have their genetic diversity assessed, and we are unaware if and how climate change might impact their conservation status. This is even more pronounced in Eastern Mediterranean countries with a rich endemic flora, such as Greece, which hosts a large portion of the plant taxa assessed at the European level under the IUCN criteria. Using inter simple sequence repeats (ISSR) markers and species distribution models, we analysed the genetic diversity and investigated the impacts of climate change on four critically endangered and extremely narrow and rare Greek island endemic plants, namely Aethionema retsina, Allium iatrouinum, Convolvulus argyrothamnos, and Saponaria jagelii. All four species are facing intense anthropogenic threats and display moderate genetic diversity (uHe: 0.254–0.322), while climate change is expected to have a profound impact on their range size during the coming decades. A combination of in- and ex-situ measures, such as population reinforcement and seed bank conservation, are urgently needed in order to preserve these highly threatened and rare Greek endemics.

Greek Tulips: Worldwide Electronic Trade over the Internet, Global Ex Situ Conservation and Current Sustainable Exploitation Challenges

From an ornamental viewpoint, tulips are famous clonally propagated crops. This research focuses on 15 wild-growing Greek tulip species including 11 range-restricted species, i.e., six Greek endemics and five Balkan or Aegean endemics and subendemics, among which seven are currently threatened with extinction (two Critically Endangered, three Endangered and two Vulnerable). An overview of the global electronic trade over the internet is presented herein for these valuable phytogenetic resources in an attempt to define the extent of their commercialization (25 nurseries in three countries, mainly bulb trade at various prices) with concomitant conservation implications. In the frame of the repatriation initiatives launched, their global ex situ conservation is overviewed according to the PlantSearch facility of the Botanic Gardens Conservation International (materials from 15 species stored in 41 botanic gardens of 14 countries). The results of this study on the Greek tulips showed that there are both well-established value chains and gaps in the market regarding the “botanical tulips”; revealed the compromised effectiveness of ex situ conservation for the majority of them; raised conservation concerns related to authorized access to these wild phytogenetic resources; and indicated that their future utilization should comply with the provision of national and international legislation. All these are envisaged and discussed within the framework of the newly launched research project TULIPS.GR which aims to be the pilot establishment of a national collection regarding all Greek tulips (currently holding 38 accessions of 13 species, including almost all of the threatened ones). The project’s scope is to enable the creation of a sustainable value chain for the Greek tulips with authorized collections, sustainable conservation schemes, production of DNA barcoded propagation material, species-specific propagation and cultivation protocols, mycorrhizal investigations, field studies, applying innovative precise soil/foliar fertigation, and investigation of the postharvest treatment of fresh cut flowers, promoting networking and synergies with producers and associations in Greece and abroad.