Aim Species–area relationships (SARs) are fundamental scaling laws in ecology although their shape is still disputed. At larger areas, power laws best represent SARs. Yet, it remains unclear whether SARs follow other shapes at finer spatial grains in continuous vegetation. We asked which function describes SARs best at small grains and explored how sampling methodology or the environment influence SAR shape. Location Palaearctic grasslands and other non‐forested habitats. Taxa Vascular plants, bryophytes and lichens. Methods We used the GrassPlot database, containing standardized vegetation‐plot data from vascular plants, bryophytes and lichens spanning a wide range of grassland types throughout the Palaearctic and including 2,057 nested‐plot series with at least seven grain sizes ranging from 1 cm2 to 1,024 m2. Using nonlinear regression, we assessed the appropriateness of different SAR functions (power, power quadratic, power breakpoint, logarithmic, Michaelis–Menten). Based on AICc, we tested whether the ranking of functions differed among taxonomic groups, methodological settings, biomes or vegetation types. Results The power function was the most suitable function across the studied taxonomic groups. The superiority of this function increased from lichens to bryophytes to vascular plants to all three taxonomic groups together. The sampling method was highly influential as rooted presence sampling decreased the performance of the power function. By contrast, biome and vegetation type had practically no influence on the superiority of the power law. Main conclusions We conclude that SARs of sessile organisms at smaller spatial grains are best approximated by a power function. This coincides with several other comprehensive studies of SARs at different grain sizes and for different taxa, thus supporting the general appropriateness of the power function for modelling species diversity over a wide range of grain sizes. The poor performance of the Michaelis–Menten function demonstrates that richness within plant communities generally does not approach any saturation, thus calling into question the concept of minimal area.

Present study was designed to verify which or if any of plastome loci is a hotspot region for mutations and hence might be useful for molecular species identification in feather grasses. 21 newly sequenced complete plastid genomes representing 19 taxa from the genus of Stipa were analyzed in search of the most variable and the most discriminative loci within Stipa. The results showed that the problem with selecting a good barcode locus for feather grasses lies in the very low level of genetic diversity within its plastome. None of the single chloroplast loci is polymorphic enough to play a role of a barcode or a phylogenetic marker for Stipa. The biggest number of taxa was successfully identified by the analysis of 600 bp long DNA fragment comprising a part of rbcL gene, the complete rbcL-rpl23 spacer and a part of rpl23 gene. The effectiveness of multi-locus barcode composed of six best-performing loci for Stipa (ndhH, rpl23, ndhF-rpl32, rpl32-ccsA, psbK-psbI and petA-psbJ) didn’t reach 70% of analyzed taxa. The analysis of complete plastome sequences as a super-barcode for Stipa although much more effective, still didn’t allow for discrimination of all the analyzed taxa of feather grasses.

Central Pamir-Alai, which is located almost entirely within the area of Tajikistan, is one of the world hotspots of biodiversity, harbouring ca. 4,300 species and 1,400 endemic plants. The first application of the IUCN Red List criteria reveals that among all native species occurring in Tajikistan 1,627 taxa (38.11%) are threatened, including 23 extinct (0.54%), 271 (6.34%) critically endangered (CR), 717 (16.79%) endangered (EN) and 639 (14.96%) vulnerable (VU). Globally, 20 taxa are extinct, 711 (16.65%) threatened, including 144 (3.37%) critically endangered, 322 (7.54%) endangered and 245 (5.73%) vulnerable. As we found positive correlation between human density and the number of threatened species, we suspect this indirect factor responsible for the species diversity decline. Extinct or threatened taxa have short blooming periods in spring or early summer, have limited geographical range and inhabit mainly valley bottoms at lower altitudes. Threatened taxa occupy extremely dry or wet habitats, such as deserts, semi-deserts, water reservoirs and fens. The group of threatened plants consists mostly of Central Asian, Indo-Indochinese and Arctic species. Ornamental plants have a higher extinction risk than other plants, but species collected for medicinal reasons and used for forage or food reveal lower retreatment rate. Our assessment fills a gap for important plant area and provides the data for raising the effectiveness of plant diversity conservation. Species diversity loss still remains one of the main imperatives of our time and therefore one of the main topics of scientific studies. Currently, hundreds of plant species and many habitat types are globally threatened 1,2. A range of factors are responsible for these declines, with human population growth, habitat fragmentation and climate change regarded as the most crucial 3. The continuing decline of plant diversity demands continuous research on evaluation of the conservation status of flora with the use of comprehensive International Union for Conservation of Nature (IUCN) criteria (www.iucnredlist.org). These criteria are widely recognised as the most comprehensive tool for assessing the global conservation status of species and categorising plants according to their estimated risk of extinction (e.g. Orsenigo et al. 4 , Maes et al. 5). As the most effective conservation actions, policies and law implementation take place at the national scale, numerous countries have established national lists of threatened species with the use of IUCN criteria and guidelines at regional levels (Rossi et al. 6). Despite some biases and shortcomings of scientific foundations 7 , red lists are widely accepted as an appropriate measure for setting conservation priorities. In some countries, including Tajikistan, they also have a legal status and directly influence the state governance of the plant diversity 8. However, based on the information available in the National Red List Database 9 , almost 20% of Eurasian countries still have no available red lists for vascular p...