نشریه حفاظت زیست بوم گیاهان
سال سوم شماره 1 (پیاپی 6، بهار و تابستان 1394)

Diversity is an important indicator to assess the condition of ecosystems. Reduction of diversity leads to reduction in the environmental capacity. To this research, some ecological factors such as altitude, slope and aspect in this were determinal. Then, using 480 plots of one meter square (1m2), was done with random – systematic sampling method to measuring the plant species factors. To determine species richness indices of Margalef and Menhinic, for the diversity, indexes of Shanvnvaynr, Simpson, and to calculate evenness, indexes of Simpson and Paylo were used. The results showed that ecological factors have significant influence on the species richness, diversity and evenness, (P

This study was done to investigate the effects of utilization types (private property, collective property, council property) on plant species richness and diversity in summer Plour rangeland in Mazandaran province. The topographical properties of sampling sites in three units of exploitation (Bazam- Mozak, Ghazi Mazraee and Chapak Khas) were the same (same slope, aspect and altitude). Within each unit, 30 plots (1m2) were established in order to studying diversity indices and the type and number of species were recorded. Biodiversity indices (Shannon, Simpson), richness indices (Menhinick, Margalef) and uniformity indices (Equitability) were calculated. Also, three Whittaker plots were established in each sampling site. The data were analyzed using linear and group regression model. The results showed that collective property had an unpleasant effect on biodiversity species. While, private property and council property worked the same and better than the first one. Results of species richness using Whitaker plot showed that Private property (Bazram - Mozak), collective property (Gapak - Khas), council property (Ghazi - Mazraea) had higher richness respectively and their differences were significant (P

Investigating and introducing the flora of each area is very important to reconise biological diversity and management of natural resources. For this perpose, in the present study, in the present study, flora, life form and chorology the medicinal species were investigated and introduced. The results showed that totally, there were 125 medicinal species belonged to 100 genera and 33 families in the study area. Lamiaceae family with 19 species, Astraceae family with 15 species, Papilionaceae family with 11 species, Apiaceae and Rosaceae family with 7 species had the highest number of species. The life forms of plants included: hemicryptophytes (48.8%), therophytes (23.2%), chamaeophytes (10.4%), geophytes (9.6%) and phanerophytes (8%). The highest geographical distribution was Irano- Turanian (65.6%). 20 species were identified as endemic and 41 species were threatened. Overall, the flora of the study area had many medicinal plants they of them affects on the economic ouput and reduring the presure on rangelands.

The aim of this study was to evaluate the condition of the low altitude of the northern rangeland of Sabalan using the soil surface indicators and functional features of rangeland. Using three transects with 50 meters, five structural features 11 soil surface characteristics were measureal. Statistical analysis of data was performed via a landscape functional analysis method. The ANOVA and Tukey test was used to compare the significance of indicators. The results showed that the mean numbers of ecological patches for grass and forb were 57 and 35 respectively. Bare soil patches had the highest average length about 56.23% and then grass with 21.10%. The amount of landscape structure index was 0.31and for the patch area index was 0.01. Comparison of soil surface assessment criteria for different life forms of vegetation and bare soil on the landscape showed that patches with grass life forms had the highest amount of stability and with ecological patches of litter and bare soil had significant differences (P>0.05). Bare soil had the lowest value for stability and from, the statistical point of view showed significant difference (P>0.05) with grass and forb ecological patches. Comparison of soil permeability indices showed that the highest values of permeability index obtained from forb patches and soil patches had the lowest values, and bare soil were statistically significant difference (P>0.05) with other ecological components. Moreover, on the basis of the results of components degradation, which is created under the effect of livestock grazing, it caused the decrease of stability and malfunctioning of the habitat. Therefore, in general the rangelands in low altitude of North Sabalan are degraded, thus it is necessary to act for preventing continues of rangeland degradation and then try to improve and reclaim these rangelands.

Since the roads are considered as one of the indicators of sustainable development and much of the rural dusty roads are passed through the rangelands thus, the effect of roads has a very importance effect on rangeland ecosystems. Near-road rangelands were selected from the edge of the road until 5 meters distance and far-road rangelands were used in 5 to 20 meters from the edge of the road. For measuring canopy cover, production, density, relative importance, richness, evenness and diversity of plants used to 50 m transects and 1 m2 plots were used in each study areas. 4 transects and 40 plots randomly were put along three kilometers of road of Pishkouh Ali-Abad rangelands in the Yazd. Results showed that the road can changes the vegetation composition, production, and cover, therefore,there is reducation in production, canopy cover of near – road. The importance value of shrub species of near road has declined while the importance value of grasses has increased. Richness, evenness and diversity indices were reduced and distribution of plants, moved to the clamps. These factors indicated the site of near- road is less stable and plant community has crossed boundaries of ecological threshold. Therefore, it is suggested that making the rural dusty roads should be implemented with detailed studies and suitable reclamation may be done with paying attention to ecological condition of the study area.

Allelopathy compounds play an important role in the biodiversity and the ability of ecosystem productions . In this study, the allelopathic effect of Artemisia aucheri was tested on the seed germination of two species of Agropyron elongatum and Agropyron repens. For this perpose, , the aerial part powder of Artemisia aucheri (stem, leaf and seed) was collected from habitats at the flowering stage (end of November) and extracted with concentrations of 20, 40, 60, 80 and 100% were prepared with aerial parts. Also a control treatment (distilled water) was used. A completely randomized design was carried out using six treatments and four replications in laboratory. ANOVA results showed that the aqueous extract of Artemisia aucheri significantly influenced the seed germination of both species trait. As a result, we found the significant reduction of the percentage of seed germination, seed germination rate, plumule, radicle, and seed vigor. Overall, the results of this study indicated that Artemisia aucheri containing growth inhibitor that reduced seed germination and the growth of Agropyron elongatum and Agropyron repens.

The present Research used TiO2 NPs for alleviating the negative effects of drought stress in wild pear seedlings. Different concentrations of TiO2 NPs including 20, 40, 80 and 100 ppm were sprayed on the aerial compartments of seedling immediately after the last irrigation. Our experiment design was a completely randomized design with 6 repeats for each treatment. Biomass allocation, growth, physiological-biochemical parameters and microscopic analysis were surveyed as index. Repeated measure ANOVA and surveying of trend showed that photosynthesis performance was less affected by drought. ANOVA results showed that there were significant differences (at 5% level) between the treatments in aspect of stem and root biomass, height growth and root length parameters. On the other hand, sprayed seedlings by nanoparticles had the better biomass allocation compared to non-sprayed seedlings when subjected to drought stress. In contrast with control, xylem water potential has declined more than three times while TiO2 NPs improved the xylem water potential. The spraying of nanoparticles on seedlings improved the relative water content (RWC) till 100% in comparison to the drought stressed plants. A considerable increasing was observed for electrolyte leakage in stressed seedlings. Although proline content is increased in stressed leaf (around 20%) but TiO2 NPs could not increase the parameters. All the treatments increased peroxidase enzyme in leaves but the higher value was for TiO2 NPs 100 ppm. The higher content of catalase enzyme was recorded for drought treatments.