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.
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.
Heydari Wildlife Refuge (HWR) is located in Binalood mountain range of the Razavi Khorassan Province in Northeastern Iran. The area belongs to the central part of Khorassan-Kopet Dagh floristic province, which is a transitional zone between different phytogeographical units in the Irano-Turanian region. We investigated the floristic composition, life-form spectrum and the phytogeography of the area during 2014-2017 by collecting vascular plants and establishing 443 random-quadrats in representative stands of different vegetation types. A total of 588 vascular plant taxa (species and subspecies) belonging to 304 genera and 65 families are recorded as native and naturalized in the study area. The richest plant families are Asteraceae (40 genera/87 species), Fabaceae (15/72), Poaceae (33/60), Brassicaceae (33/49), Lamiaceae (19/32), and Apiaceae (18/27). The genera Astragalus (44 species), Cousinia (17), and Allium (10) are the richest ones. However, the dominant canopy cover belongs to Acantholimon, Astragalus, Artemisia, and Acanthophyllum species. Raunkiaer's plant life-form spectrum in the area is dominated by hemicryptophytes (41.50%) and therophytes (28.06%). The core flora of HWR has the Irano-Turanian origin; the widespread elements are also well represented in the study area. Based on the Sørensen dissimilarity index, the HWR has about 50% dissimilarity to the adjacent areas. The study area is inhabited by several Iranian and/or Khorassan-Kopet Dagh endemic (19%), threatened (16%), and narrow-range plant species. The results indicate the importance of the HWR in the plant diversity of NE Iran.
In grazing conditions, unpalatable species may induce either associational defense or neighbor contrast susceptibility in neighboring communities. Using surveys from eight grasslands, we tested whether various unpalatable species have the same impacts on neighboring communities in response to grazing. The studied unpalatable species were: Phlomis cancellata (an unpalatable nonpoisonous plant), Euphorbia boissieriana, E.microsciadia (poisonous plants), and Seseli transcaucasicum (a highly poisonous plant). Our results showed that, in the ungrazed grasslands, communities containing P. cancellata had lower biodiversity than communities without it. In the moderately- and heavily grazed grasslands, P. cancellata induced associational defense in the neighboring communities. In heavily grazed grasslands, both Euphorbia species promoted neighbor contrast susceptibility in the neighboring communities. Similarly, S. transcaucasicum in a heavily grazed grassland, induced neighbor contrast susceptibility. Different responses of plant community vulnerability among the studied unpalatable plants might be due to herbivore different foraging decisions. Accordingly, grazers selectively choose from other patches when facing P. cancellata and other plant individuals when there is a poisonous plant in a patch. Our results suggested that grazing intensity may not substantially affect the foraging decisions of sheep and goats in response to unpalatable species. We recommend monitoring the abundance of poisonous species to maintain the sustainable use of grasslands.
On the Ground • Information on seasonal trends in quantity and quality of available forage for the goitered gazelle may be useful to wildlife managers in developing management practices to maintain healthy populations and reduce the consumption of toxic plants by protected wildlife. • Goitered gazelles in Golestan National Park in Iran relied on a variety of grasses, shrubs, and forbs, to meet their nutrituional needs across seasons. • Increased knowledge of the goitered gazelles diet is expected to assist wildlife managers in determining carrying capacity and assessing viable habitats for future reintroduction programmes, including overall successful management within the protected areas of Iran.
The study aimed to analyze vegetation data using a phytosociological method and to identify species composition and relationships between vegetation and environmental data in communities that include two threatened species (Dianthus pseudocrinitus Behrooz. & Joharchi and D. polylepis Bien. ex Boiss.) endemic to the montane steppes of Khorassan-Kopet Dagh floristic province in northeastern Iran. We sampled 75 vegetation plots in 15 sites where the endemic Dianthus species occur. In order to evaluate community characterization of the species, we investigated floristic composition, life-form spectrum and the phytogeography of the study sites. In all, 370 plant species were recorded, belonging to 184 genera in 45 families. Floristic analysis revealed that Hemicryptophytes are the dominant life-form in these habitats, and Iran-Turanian floristic elements contributed 74.5% of the total number of species. Classification analysis based on TWINSPAN showed a clear separation of the study sites based on Dianthus taxa, which was confirmed by detrended correspondence analysis (DCA). The results reflected the highly diverse flora at all Dianthus sites. Species composition and the distribution of vegetation groups were influenced by some environmental factors. Habitats for both species could be managed by a community ecological approach; our study provided a better knowledge of these communities' ecological and floristic composition to enhance effective management and conservation of the threatened species.
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