The Khorassan-Kopet Dagh (KK) floristic province is located in the northeastern parts of Iran and partly in southern Turkmenistan. The area is a transition zone and a corridor connecting different provinces of the Irano-Turanian region and also Hyrcanian montane forests of the Euro-Siberian region. The unique combination of Irano-Turanian species and also presence of a local center of endemism are evidence of a separate biogeographic entity. The complicated topography, high habitat heterogeneity and vegetation history are reasons for the development of diverse vegetation types. In order to achieve up-to-date information on the plant diversity and distribution patterns, a database was prepared using all floristic records from the area defined as KK. A total of 2576 species/infraspecific taxa belonging to 702 genera and 112 families of vascular plants have been reported from the area, 2498 of which occur within Iran. Altogether, 28 different distribution patterns are recognized among five major phytogeographical groups, including widespread, tri-regional, bi-regional, Euro-Siberian and Irano-Turanian patterns. Irano-Turanian elements, which make up the core flora of KK, are subdivided further into 14 distribution patterns. A significant number of species, i.e. 356 species (13.8%), are endemic to the area. The flora of KK is highly influenced by central Irano-Turanian elements. The main vegetation types of the area include Juniperus woodlands, Pistacia vera woodlands, some isolated enclaves of Hyrcanian forests and scrub, cliff vegetation, mountain steppe communities, semi-desert steppes, loess and marl vegetation, halophytic vegetation, aquatic and hygrophilous communities, and ruderal/invasive plant communities. There are several major threats to the ecosystems and biodiversity of the area. The areas presently protected do not cover all of the vegetation types, and therefore many threatened species are not safe.

Khorassan-Kopet Dagh (KK) floristic province located in northeastern Iran and southern Turkmenistan is one of the important centers of plant endemism in Irano-Turanian region. In order to evaluate the plant endemism, distribution and conservation, we generated an updated and annotated checklist of 356 endemic vascular plant taxa belonging to 112 genera and 36 families of angiosperms. The genera Astragalus and Cousinia have the highest number of endemics and the hemicryptophytes are the dominant life form. On the basis of the available distributional data, mainly from herbarium records and reliable references, we analyzed the distribution patterns and diversity of the endemic taxa. The central part of KK has the highest endemic richness, and the least number of endemics occur in the southern part. Mapping the occurrence data of the endemics revealed 16 main distribution patterns. There are only 24 widespread endemics, and more than half of the endemic taxa are restricted to only one of five geographical zones of the area. Analysis of endemic diversity based on 15ʹ grid cell maps showed that the Central part of Kopet Dagh range, Aladagh and Salook ranges and Golestan National Park are located in the areas with the highest endemic richness. Mapping the beta diversity of the grid cells revealed the vast areas of the Central part, following some areas of the Eastern, Western and Northwestern parts, are highly differentiated by composition of endemic plants. All of the KK endemic taxa were evaluated against the IUCN Red List categories and criteria and a total of 200 endemic taxa were globally classified as threatened including 24 Critically Endangered, 72 Endangered and 104 Vulnerable taxa. Areas with the highest threatened endemics richness are located in Central Kopet Dagh range along Iran-Turkmenistan border, Golestan National Park and adjacent Ghorkhod Protected area, Aladagh and Salook ranges, and the eastern part of Binalood range. Implications of the results in conservation prioritization of the endemic taxa and also of the geographical areas are discussed. As far as possible the taxonomic status of known endemics are critically checked, type specimens of some doubtful taxa are consulted, and representative vouchers of reported species are given. The new species Heliotropium khayyamii Akhani sp. nov. is described and seven taxa are placed as new synonyms: Astragalus salehabadensis Ranjbar & Zarin (= A. basineri Trautv.), A. torbathaydariyehensis Ranjbar & Zarin (= A. basineri), Astragalus ghouchanensis Souzani, Zarre & Maassoumi (= A. sumbari Popov), Cousinia golestanica Attar (= C. stahliana Bornm. & Gauba), Centaurea bojnordensis Ranjbar, Negaresh & Joharchi (= C. sintenisiana Gand.), Cyanus persicus Ranjbar & Negaresh (= C. depressus (M. Bieb.) Soják) and Klasea nana Ranjbar & Negaresh (= K. latifolia (Boiss.) L.Martins). Twenty-five taxa with poor taxonomic evidence are listed separately as doubtful. Distribution maps of almost all known endemics are provided.

Endemic and restricted-range species are considered to be particularly vulnerable to the effects of environmental change, which makes assessing likely climate change effects on geographic distributions of such species important to the development of integrated conservation strategies. Here, we determined distributional patterns for an endemic species of Dianthus (Dianthus polylepis) in the Irano-Turanian region using a maximum-entropy algorithm. In total, 70 occurrence points and 19 climatic variables were used to estimate the potential distributional area under current conditions and two future representative concentration pathway (RCP2.6 and RCP8.5) scenarios under seven general circulation models for 2050. Mean diurnal range, iso-thermality, minimum temperature of coldest quarter, and annual precipitation were major factors that appeared to structure the distribution of the species. Most current potential suitable areas were located in montane regions. Model transfers to future-climate scenarios displayed upward shifts in elevation and northward shifts geographically for the species. Our results can be used to define high-priority areas in the Irano-Turanian region for conservation management plans for this species and can offer a template for analyses of other endangered and threatened species in the region.

Aims Understanding fine‐grain diversity patterns across large spatial extents is fundamental for macroecological research and biodiversity conservation. Using the GrassPlot database, we provide benchmarks of fine‐grain richness values of Palaearctic open habitats for vascular plants, bryophytes, lichens and complete vegetation (i.e., the sum of the former three groups). Location Palaearctic biogeographic realm. Methods We used 126,524 plots of eight standard grain sizes from the GrassPlot database: 0.0001, 0.001, 0.01, 0.1, 1, 10, 100 and 1,000 m2 and calculated the mean richness and standard deviations, as well as maximum, minimum, median, and first and third quartiles for each combination of grain size, taxonomic group, biome, region, vegetation type and phytosociological class. Results Patterns of plant diversity in vegetation types and biomes differ across grain sizes and taxonomic groups. Overall, secondary (mostly semi‐natural) grasslands and natural grasslands are the richest vegetation type. The open‐access file ”GrassPlot Diversity Benchmarks” and the web tool “GrassPlot Diversity Explorer” are now available online (https://edgg.org/databases/GrasslandDiversityExplorer) and provide more insights into species richness patterns in the Palaearctic open habitats. Conclusions The GrassPlot Diversity Benchmarks provide high‐quality data on species richness in open habitat types across the Palaearctic. These benchmark data can be used in vegetation ecology, macroecology, biodiversity conservation and data quality checking. While the amount of data in the underlying GrassPlot database and their spatial coverage are smaller than in other extensive vegetation‐plot databases, species recordings in GrassPlot are on average more complete, making it a valuable complementary data source in macroecology.

Endemic species are believed to converge on narrow ranges of traits, with rarity reflecting adaptation to specific environmental regimes. We hypothesized that endemism is characterized by limited trait variability and environmental tolerances in two Dianthus species ( Dianthus pseudocrinitus and Dianthus polylepis ) endemic to the montane steppes of northeastern Iran. We measured leaf functional traits and calculated Grime’s competitor/stress-tolerator/ruderal (CSR) adaptive strategies for these and co-occurring species in seventy-five 25-m 2 quadrats at 15 sites, also measuring a range of edaphic, climatic, and topographic parameters. While plant communities converged on the stress-tolerator strategy, D. pseudocrinitus exhibited functional divergence from S- to R-selected (C:S:R = 12.0:7.2:80.8% to 6.8:82.3:10.9%). Canonical correspondence analysis, in concert with Pearson’s correlation coefficients, suggested the strongest associations with elevation, annual temperature, precipitation seasonality, and soil fertility. Indeed, variance ( s 2 ) in R- and S-values for D. pseudocrinitus at two sites was exceptionally high, refuting the hypothesis of rarity via specialization. Rarity, in this case, is probably related to recent speciation by polyploidy (neoendemism) and dispersal limitation. Dianthus polylepis , in contrast, converged towards stress-tolerance. ‘Endemism’ is not synonymous with ‘incapable’, and polyploid neoendemics promise to be particularly responsive to conservation.