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Kasf forest, with an area of over 12 ha, running in the east-west direction and located at a distance of 20 kilometers in the north of the city of Bardaskan in a mountainous arid region. The minimum and maximum temperature of the area ranges between -10° C and +45° C. The average annual precipitation of the region is 155 mm.  The altitude of the forest is about 1600 m above sea level with a 15% slope. The vegetation of this forest was studied using floristic methods 2 years after a devastative fire and life forms and geographical distributions of plant species were determined. Sixty nine plant species belonged to 29 families (25 Dicots, 3 monocots and one gymnosperm). The largest families were the Lamiaceae with 11, Asteraceae with 9 and Caryophyllaceae with 5 species. The percentages of life forms were determined as follows: Therophytes with 36% (25 species), Hemicryptophytes with 29% (20 species), Chamaephytes with 16% (11 species), Phanerophytes with 13% (9 species) and Cryptophytes with 6% (4 species) of total investigated species. The high percentage of Hemicryptophytes indicated the dominance of cold mountainous climate and the presence of Asteraceae species such as harmala (Peganum harmala) showed that a severe disturbance had taken place in the region, which indicated a poor ecological administration in the studied region.

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The Hezar-Masjed Mountain range is one of the main highlands of the northeasten Iran. The vegetation of its upper elevations has been poorly studied. This study aimed to compare the plant biodiversity of different aspects of the Hezar-Masjed Summit. A total number of 139 random 1m² plots were recorded from different aspects of the study area. In each plot, the abundance and canopy cover percent of vascular plant species were recorded. Hill’s numbers (i.e., N₁, N₂) along with the Camargo evenness index and total species richness with bootstrapping approach were calculated. Rarefaction method was used to compare species richness among the aspects. Also, Hill’s diversity profile for each aspect was drawn. For each aspect, rank-abundance method was used to evaluate the dominant species. Biodiversity calculations and statistical analyses were performed using R software. The east- and south- facingslopes were found to have the highest and lowest indices in richness, evenness, and diversity, respectively. Despite adequate water availability in north-facing slopes, they show lower diversity than that of the east-facing slope, probably due to the of dominance of a poisonous species (Seseli transcaucasicum). Our results shown that in the Hezar-Masjed Summit, aspects have different biodiversity which is a result of their various environmental conditions.
 

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Overgrazing affects plant communities, and is a significant disturbance factor in arid and semi-arid regions. The immediate changes of plant communities after overgrazing in the disturbed arid ecosystems of Iran have been poorly studied. We recorded data from 100 random samples before and after overgrazing in the Golbahar plain located in the northeastern Iran to determine the changes in the plant physiognomic, species composition, and diversity after overgrazing. We compared life-forms spectra, change in the RIVI of the recorded plant species, species composition, and species diversity before and after the grazing. Our results showed that therophytes were the dominant life-form in the area, and decreased after overgrazing. The community composition of the area remained unchanged after overgrazing. Species diversity at the level of rare and frequent species reduced after overgrazing. Our findings implied that overgrazing could not immediately affect the community structure of degraded arid areas. However, it causes changes that might reduce ecosystem services in them. It is not possible to completely exclude grazers in such areas, fencing or reducing the number of the livestock entries should be applied to restore the vegetation in the area.
 
 

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Phelipanche pouyanii is described here as a new species from South Khorassan Province, East of Iran. Its diagnostic morphological features are the calyx teeth being far longer than the calyx tube and staminal filaments being glabrous. These characters clearly differentiated the new species from its closely related taxa, i.e., P. mutelii, P. angustelaciniata and P. nana. Results obtained from the pollen and seed micromorphological characters showed no significant taxonomic value in the delimitation of the new species from its closely related species. The internal transcribed spacer (ITS) sequences, however, showed sufficient differences to delineate the new species from its closely related species.
 

 

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 Piptatherum ferganense is recorded as a new grass species for the flora of Iran collected from Ghorkhod Protected Area and Aladagh Mountains in North Khorassan province. The core distribution range of the species is Eastern Irano-Turanian with a disjunction in northeastern Iran. The morphological characters of P. ferganense are illustrated and compared with the closely related P. latifolium. It can be distinguished from P. latifolium by its evenly arranged spikelets in the panicle, lanceolate fertile lemma, and shorter lemma awns. Notes on taxonomy, ecology, phytogeography, and conservation status of the recorded species are provided.

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Understanding the different patterns of plant diversity and distribution along the environmental gradients is essential for managing ecosystems, especially in fragmented habitats due to intensive human pressure. The Darkash area is located in the western Aladagh Mountains in Khorassan-Kopet Dagh Floristic Province. The easternmost patches of the Hyrcanian montane forests grow in this area. The three main vegetation types in the area are shrublands/scrub forests, oak forests (Quercus castaneifolia), and subalpine vegetation. In this study, we aimed to evaluate the plant diversity in the understory of plant communities along the elevational gradient. We sampled 187 vegetation plots (2m x  2m) along a 1300m elevational gradient (in 100-m classes) using the stratified-random method and estimated the abundance and canopy cover of the species. Floristic characteristics and different diversity indices were measured. In total, 252 plant species belonging to 161 genera and 44 families were identified. Of these, 41 species were found to be endemic or semi-endemic. Hemicryptophytes and therophytes are the dominant life-forms in the study area. The Irano-Turanian elements (46.8%) make the major chorotype in the flora of the area, followed by Bi-regional (17.5%), Tri-regional (17.5%), Pluri-regional (11.5%), and Euro-Siberian (6.7%) elements. The shrubland understory has the highest Hill's and beta diversity indices, followed by the oak forest and the subalpine understory. The biodiversity changes sinusoidally along the elevation. In order to protect plant species, especially young oak seedlings, it is recommended to create a protective corridor along the elevational gradient in this area. This strategy is essential to protect plant diversity in these habitats.


 

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The new species Onosma nuristanica is described and illustrated here on the basis of specimens collected from Parun in Nuristan and Chapa Dareh in Kunar, one of the eastern provinces of Afghanistan. An extensive review of the literature and a comparative study with specimens from several herbaria led to the determine of this new species. Our results represent significant divergence between studied specimens in terms of the most important morphological features, i.e., flower color, pedicel length, bract length filaments length, cauline shape and form.  In this article, a detailed description of the new species and a diagnostic key for Onosma species thriving in Afghanistan are provided and the new species is compared morphologically with its closely related species. In addition, a distribution map is provided for the new species and its close relatives in the area.