Prioritizing conservation areas for coastal plant diversity under increasing urbanization

Spatial heterogeneity and temporal stability characterize future climatic refugia in Mediterranean Europe

Climate plays a major role in shaping biodiversity patterns over time and space, with ongoing changes leading to the reorganization of ecosystems, which challenges conservation initiatives. Identifying areas that could serve as possible climate change refugia for future biodiversity is, thus, critical for both conservation and management. Here, we identify potential future climatic refugia within the Euro-Mediterranean biome, which is a global biodiversity hotspot, while accounting for multiple emission climate change projections over the next 50 years. We developed two metrics of climatic variability: temporal stability and spatial heterogeneity. We then used a systematic conservation planning approach to identify climate-based priority areas. While we used a climate-based, species-neutral methodology, we deliberately implemented low climatic velocity thresholds, so that the identified climatic refugia would even be compatible with the needs of species with low dispersal capacity, such as plants. Our projections showed that future climatic refugia would be more frequently observed in mid-altitudes, for gradients with steep elevations, and mainly in the eastern part of the Euro-Mediterranean biome, with possible conflicts with existing land uses and future conservation implications. Climatic, land use, and topography results indicated that only a limited number of refugia would be hosted by high elevation habitats (>1500 m), raising possible concerns about the biodiversity of Mediterranean mountain regions. Our analyses show that the current network of protected areas captures future climatic refugia disproportionally, despite their importance for safeguarding present and future biodiversity in the Mediterranean. Key climatic refugia could limit the impacts of future climate change on biodiversity in mid-altitude and mountainous regions, and should be included in management guidelines for a climate-ready conservation design in the Mediterranean biome.

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.

Extinction Risk Assessment of the Greek Endemic Flora

Simple Summary

This study assesses for the first time all the vascular endemic plant taxa of Greece, according to their decline and rarity. Phylogenetic analysis and its spatial overview highlight areas for conservation prioritization. Several of the Greek endemics are threatened with extinction and fourteen of them need to be prioritized, due to their evolutionary distinctiveness. This assessment could act as the baseline and supporting tool for conservation actions, decision- and policy-making for biodiversity, while highlighting the need for a new Red Data Book for the Greek flora.

Abstract

Human-induced biodiversity decline has been on the rise for the past 250 years, due to various causes. What is equally troubling, is that we are unaware which plants are threatened and where they occur. Thus, we are far from reaching Aichi Biodiversity Target 2, i.e., assessing the extinction risk of most species. To that end, based on an extensive occurrence dataset, we performed an extinction risk assessment according to the IUCN Criteria A and B for all the endemic plant taxa occurring in Greece, one of the most biodiverse countries in Europe, in a phylogenetically-informed framework and identified the areas needing conservation prioritization. Several of the Greek endemics are threatened with extinction and fourteen endemics need to be prioritized, as they are evolutionary distinct and globally endangered. Mt. Gramos is identified as the most important conservation hotspot in Greece. However, a significant portion of the identified conservation hotspots is not included in any designated Greek protected area, meaning that the Greek protected areas network might need to be at least partially redesigned. In the Anthropocene era, where climate and land-use change are projected to alter biodiversity patterns and may force many species to extinction, our assessment provides the baseline for future conservation research, ecosystem services maintenance, and might prove crucial for the timely, systematic and effective aversion of plant extinctions in Greece.

New insights on the conservation status of the Endangered coastal endemic plant Astragalus berytheus (Fabaceae) in Lebanon

Coastal vegetation includes unique species with adaptations to the specific conditions of this environment, and in the Mediterranean region urban development of coastal areas has severely affected coastal ecosystems. Astragalus berytheus Boiss. & Blanche is a narrow endemic plant of the eastern Mediterranean coast, occurring in Lebanon and Palestine/Israel; its Red List status has not been previously assessed. As a result of the effects of urban sprawl in coastal areas A. berytheus is one of the most threatened plant taxa in Lebanon. We assess the conservation status of this taxon and propose conservation measures. Only one population of A. berytheus is extant in Lebanon, in the Tyre Coast Nature Reserve. We recommend that A. berytheus should be categorized as Endangered globally and as Critically Endangered at the national level in Lebanon. Unless adequate conservation measures are implemented A. berytheus is likely to go extinct in Lebanon in the near future.

De novo transcriptome assembly and population genetic analyses of an important coastal shrub, Apocynum venetum L

BACKGROUND

Apocynum venetum L. is an important medicinal plant that is mainly distributed in the coastal areas and northwest of China. In addition to its high medical and economic value, its adaptation to saline-alkali and coastal saline lands makes A. venetum an ideal candidate for use in vegetation restoration. To date, the study of A. venetum has been limited in the northwest region of China, little attention has been paid to the genetic diversity and population structure of A. venetum populations in the coastal region. Here, we performed transcriptome sequencing of total RNA from A. venetum leaves and developed efficient expressed sequence tag-simple sequence repeat (EST-SSR) markers for analyzing the genetic diversity and population structure of A. venetum in the coastal region.

RESULTS

A total of 86,890 unigenes were generated after de novo assembly, and 68,751 of which were successfully annotated by searching against seven protein databases. Furthermore, 14,072 EST-SSR loci were detected and 10,243 primer pairs were successfully designed from these loci. One hundred primer pairs were randomly selected and synthesized, twelve primer pairs were identified as highly polymorphic and further used for population genetic analysis. Population genetic analyses showed that A. venetum exhibited low level of genetic diversity (mean alleles per locus, N_A = 3.3; mean expected heterozygosity, H_E = 0.342) and moderate level of genetic differentiation among the populations (genetic differentiation index, F_ST = 0.032-0.220) in the coastal region. Although the contemporary (mean m_c = 0.056) and historical (mean m_h = 0.106) migration rates among the six A. venetum populations were moderate, a decreasing trend over the last few generations was detected. Bayesian structure analysis clustered six populations into two major groups, and genetic bottlenecks were found to have occurred in two populations (QG, BH).

CONCLUSIONS

Using novel EST-SSR markers, we evaluated the genetic variation of A. venetum in the coastal region and determined conservation priorities based on these findings. The large dataset of unigenes and SSRs identified in our study, combining samples from a broader range, will support further research on the conservation and evolution of this important coastal plant and its related species.

Multiple drivers of plant diversity in coastal dunes: A Mediterranean experience

In light of the global biodiversity loss, syntheses of the available knowledge about drivers of biodiversity are becoming increasingly important. However, despite the high number of studies analyzing patterns of plant species diversity, few attempts have been made to synthesize findings within different ecosystems. In this work, the relative role of a wide set of predictors imputable to three conceptual-methodological domains (abiotic, human-mediated disturbance and landscape domain, hereafter AD, DD and LD) was simultaneously analyzed in 644 random plots distributed along the coastal dunes of Central Italy. Native species richness and focal species cover, both field-recorded, were used as response variables. Predictors pertaining to the three domains were derived from both field surveys and high-resolution remotely sensed imagery (LiDAR and orthophotos). To test how AD, DD and LD affect native species richness and focal species cover, a GLM and a linear model were fitted respectively. The three domains were then ranked according to their relative importance. Although the role of the three domains was always significant, they turned out to unequally contribute to the explanation of native species richness and focal species cover patterns. For Mediterranean coastal dune ecosystems, AD appears to be the key biodiversity driver, followed by DD and LD. Our results suggest that as long as human disturbance is limited, plant diversity will distribute according to species abiotic tolerances, regardless of habitat loss and fragmentation per se. Representing a first effort towards a synthesis of plant diversity drivers in coastal dunes, this work points to the importance, in Mediterranean coastal dune ecosystems, of zonation dynamics, whose occurrence should be addressed as a priority issue by efficient conservations strategies.

Conservation gaps and priorities in the Tropical Andes biodiversity hotspot: Implications for the expansion of protected areas

The Tropical Andes (TA) contain some of the most important and threatened areas for biodiversity conservation on earth. Despite the proportion of protected areas (PAs) that currently cover the TA, it is unknown if these areas are adequately protecting the biodiversity throughout the region and where the expansion of PAs is most needed to preserve biodiversity in the future. Here, we examine the conservation status of 1743 vertebrate species endemic to the TA (including mammals, birds, amphibians and reptiles), for which conservation actions should be prioritized within the region itself. Using species' geographical range maps, refined by their known elevational and habitat requirements, we carry out a gap analysis to examine to what degree endemic vertebrate species in the TA are represented by PAs. Then, using the irreplaceability-vulnerability framework, we localize first and second priority areas for conservation action, where important ecological features are subjected to severe anthropogenic disturbance. Our results show that 72% of all species and 90% of all threatened species are insufficiently covered by PAs. Furthermore, 73% of the first priority sites and 84% of the second priority sites are not covered by current PAs. These areas are predominantly located in the surroundings of major population centers in Ecuador and Colombia. To prevent species from extinction in the near future, actions to conserve their remaining habitat in prioritized areas are urgently required.