Showing 3 results for ejtehadi
Shana Vosoughrazavi, H Ejtehadi, H Zaree, S Tavakoli,
Volume 10, Issue 4 (2-2011)
Abstract
Aquatic ecosystems are the main biotic ecosystems that contain variety of plant species and their destruction result in the reduction of plant species diversity. In the present investigation, species diversity of aquatic plants in permanent, seasonal, forest wetlands and ricelands of the west and east of Mazandaran province was determined. First, 30 habitats were determined on the map and the total 161 samples, based on systematic-random sampling, were established. 126 species of aquatic plant of the habitats were collected and the cover of each species ,based on the area of quadrate that accupied by plants, was recorded. The results showed that species diversity of aquatic plants in the west and east is governed by the moisture gradient. Based on De Martonne classification system of climate, the west and east of Mazandaran province have wet and mediterranean climate, respectively. Therefore, the condition for the growth of aquatic plants in the west is more appropriate than in the east. Species diversity of wetlands and ricelands in the west was higher than that in the east. In this study, classification system of den Hartog & Veld for aquatic plants that classify them as hygrophytes, real aquatic and wetland species was applied and diversity indices for all three categories were calculated. The results revealed that diversity of hygrophytes is the highest among them and the real aquatic plants have higher species diversity than wetlands. T-test, based on Shannon index, showed significant differences between diversity of the west and east as well as between three group of macrophytes (P<0.05).
Jamil Vaezi, Fatemeh Batyari, Hamid Ejtehadi, Mohammad Farsi, Mohammad Reza Joharchi,
Volume 11, Issue 4 (2-2012)
Abstract
The genus Salvia is morphlogically investigated to provide an identification key based on morphological characters in the Northeast of Iran. In this study, we examined more than 350 herbarium and collected specimens of different populations and measured 79 quantitative and qualitative (vegetative and generative) characters. The results of the multivariate analysis (principal component analysis) and Nonparametric Test (K independent samples) indicate that the morphological characters such as blossom shape, ring of trichome inside of corolla and protrusion style differentiated the Salvia species. For the first time, the species Salvia shariffi is reported in the Jonoubi and Shomali Khorassans.
Javad Mohammadi, Hasan Zaree Maivan, H Ejtehadi, ,
Volume 15, Issue 1 (4-2015)
Abstract
Vegetation of Kasf forest with an area of over 12 ha, located in the east-west direction at a distance of 20 kilometers north of the city of Bardaskan, between 57° and 52' and 30" to 58° and 00' and 00" East longitude and 35° and 22' and 30" to 35° and 30' and 00" North latitude, in a mountainous arid region with a minimum and maximum temperature of -10 and +45° C , respectively and average annual precipitation of 155 mm, at an altitude of about 1600 m above sea level with 15% slope was studied using floristic method 2 years after fire and life forms and geographical distribution of plant species were determined. Sixty nine plant species belonging to 29 families (25 Dicots, 3 monocots and one gymnosperm). The largest families were the mint (Lamiaceae) with 11, Compositeae (Asteraceae) with 9 and carnation family (Caryophyllaceae) with 5 species. The life forms included Therophytes with 36% (25 species), Hemicryptophytes 29% (20 species), Chamaephytes 16% (11 species), Phanerophytes 13% (9 species) and cryptophytes with 6% (4 species). The high percentage of Hemicryptophytes indicated dominance of cold mountainous climate and the presence of Asteraceae species such as harmala (Peganum harmala) showed sever disturbance had taken place in the region and thus, the need for administering greater ecological care and employing more extensive environmental supervision and management was identified.
