6 research outputs found
Climate change influences on the potential distribution of Dianthus polylepis Bien. ex Boiss. (Caryophyllaceae), an endemic species in the Irano-Turanian region
This work is licensed under a Creative Commons Attribution 4.0 International License.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.Office of the Vice-President for Research and Technology of Ferdowsi University of Mashhad (3/42756
ASSOCIATION BETWEEN HELICOBACTER PYLORI SEROPOSITIVITY AND HEPATIC ENCEPHALOPATHY
ABSTRACT Objective: The knowledge on Helicobacter pylori (H. pylori) contribution in the pathology of the liver and biliary tract diseases in human is very limited. The aim of this study was to assess the probable association between H. pylori seropositivity and hepatic encephalopathy. Methodology: This is a case control study conducted through three groups, cirrhotics with hepatic encephalopathy (HE), cirrhotics without HE and healthy controls. All subjects were examined serologically for determination of IgG class antibodies to H. pylori based on ELISA technique. Results: H. pylori seropositivity was present in 88% cirrhotic patients with hepatic encephalopathy, 86% cirrhotics without hepatic encephalopathy and 66% healthy controls. Conclusion: According to our results, H. pylori seropositivity rate in cirrhotic patients with or without hepatic encephalopathy was higher than healthy controls. But H. pylori seropositivity rate was not significantly different among cirrhotics with hepatic encephalopathy and those without it
Habitat characteristics, ecology and biodiversity drivers of plant communities associated with Cousinia edmondsonii, an endemic and critically endangered species in NE Iran
Mountains hold high species diversity and endemism because of topographic diversity and isolation. Many mountainous
regions are being affected by climate changes. Furthermore, mountain soils can affect plant communities by altering species
components and community structure. The sub-alpine areas of western Khorassan-Kopet Dagh Mountains in the Irano-
Turanian region have received little attention. We aim to provide new information on vegetation, ecological characteristics,
and biodiversity drivers of plant communities associated with Cousinia edmondsonii, a very narrow endemic and critically
endangered plant in NE Iran. We sampled 35 vegetation plots by stratified-random sampling in this area. Modified TWIN-
SPAN and DCA analyses were used to classify plant communities. We used CCA analyses to assess vegetation-environment
relationships and Hill numbers to evaluate diversity in plant communities. In all, 127 species were recorded, belonging to
83 genera and 29 families. The hemicryptophytes and Irano-Turanian elements were the dominant life-form and chorotype,
respectively. Endemic and sub-endemic species comprised 41 species in the study area. Five plant communities types are
identified in the study area based on the diagnostic and dominant species. Stipa lessingiana-Acantholimon erinaceum and
Muscari neglectum-Juniperus sabina communities are dominated by thorny cushion and dwarf shrubby species, respectively.
The communities dominated by C. edmondsonii, i.e., Gypsophila aretioides-Cousinia edmondsonii, Alyssum lanigerum-
Cousinia edmondsonii, and Thymus kotschyanus-Cousinia edmondsonii, exhibited higher species diversity than the other
communities. Based on CCA, the composition of plant communities was significantly correlated with seven topographic and
environmental factors. The results showed that C. edmondsonii, its habitats, and vegetation types in the higher mountains
of western Khorassan-Kopet Dagh deserve special conservation attention
Relative contributions of taxonomic and functional diversity to the assembly of plant communities hosting endemic Dianthus species in a mountain steppe
Abstract Plant community assembly is the outcome of long-term evolutionary events (evident as taxonomic diversity; TD) and immediate adaptive fitness (functional diversity; FD); a balance expected to shift in favour of FD in ‘harsh’ habitats under intense selection pressures. We compared TD and FD responses along climatic and edaphic gradients for communities of two species (Dianthus pseudocrinitus and D. polylepis) endemic to the montane steppes of the Khorassan-Kopet Dagh floristic province, NE Iran. 75 plots at 15 sites were used to relate TD and FD to environmental gradients. In general, greater TD was associated with variation in soil factors (potassium, lime, organic matter contents), whereas FD was constrained by aridity (drought adaptation). Crucially, even plant communities hosting different subspecies of D. polylepis responded differently to aridity: D. polylepis subsp. binaludensis communities included a variety of broadly stress-tolerant taxa with no clear environmental response, but TD of D. polylepis subsp. polylepis communities was directly related to precipitation, with consistently low FD reflecting a few highly specialized stress-tolerators. Integrating taxonomic and functional diversity metrics is essential to understand the communities hosting even extremely closely related taxa, which respond idiosyncratically to climate and soil gradients
Floristic diversity and vegetation of communities associated with two endemic Dianthus species in the montane steppes of northeastern Iran
75 sampling plots were established in the study area in Spring 2016-2017. In each 25 m2 quadrat, canopy cover was estimated as a percentage of ground area and the Braun-Blanquet cover-abundance scale was obtained. All species were identified using relevant Floras. The vegetation data were stored in the TURBOVEG database and exported into JUICE 7.0 program for classification using TWINSPAN. The diagnostic species were determined on the basis of the fidelity concept using the phi coefficient. The complete scientific names of the plant species are listed in the supporting information in Behroozian et. al. (2022).
Behroozian et al. 2022. Floristic diversity and vegetation of communities associated with two endemic Dianthus species in the montane steppes of northeastern Iran. Nordic Journal of Botany e03581. https://doi.org/101111.njb.03581</p