فهرست مطالب parviz gholami

The study of changes in rangeland vegetation at regular intervals and awareness of rangeland conditions is one of the important issues for planning and proper management of rangeland utilization. The present study was designed to study changes in the vegetation features in the grazed and exclosured rangelands in the Razband of Qom province. The vegetation measurement was performed in the form of a pair of transects with a distance of 10 meters from each other. Each pair of transects contained 20 plots. The plots with dimensions of 1 × 1 m were spaced 3 m apart and 10 were placed on each transect. Finally, 240 plots (120 plots inside and 120 plots outside of the enclosure) were evaluated. The data analysis was done by SPSS software and the diversity and species richness were performed using PAST software. Out of a total of 8 plant families, six families were significantly different inside and outside of the exclosure. The exclosure in the study area was significantly increased canopy covered by shrubs and forbs, while the grasses showed no significant difference. Chamephytes, hemicryptophytes, terophytes and class I and III species showed a positive and significant response to exclosure. The T-test for species richness and diversity indices showed that Simpson and Shannon - Wiener diversity indices and Margalef richness index had significant differences. The Menhinick's richness index and evenness index were not significantly different inside and outside of the exclosure. Besides, the RDA analysis to evaluate the impact of exclosure on all of the plant species in plots showed that exclosure had a significant effect on the vegetation (P=0.001, F=29.66). The results of this research showed that a short-term exclosure can cause reconstruction and vitality renewal of plant species such as Bufonia macrocarpa and Artemisia sieberi in the arid rangelands of Qom.

In this research, the effect of different forms of nursing on establishment of natural regeneration in the forests of Vezg region in Boyer-Ahmad basin was investigated. For this purpose, an area of six hectares was selected and the type of nurse species and forms, the type of target species (regeneration) were measured. Overall, 14 woody species of nurse plants with a total of 423 individuals were recorded in the research area, among them, two thorny species include Amygdalus lycioides and Pyrus glabra with 195 and 77, respectively, have the highest number. Also, out of 912 regeneration individuals (target species) under the canopy of nurse plants and rocks, the highest number belonged to Daphne mucronata, Amygdalus lycioides, Prunus sp and Lonicera nummulariifolia. RDA analysis also showed that the regeneration of target species is affected by A.lycioides and P.glabra nursing plants. The results of this study showed that the regeneration of woody species in this area, with the exception of A. lycioides, depends on conservation and nursing. This indicates the role of nurse species in establishing regeneration in semi-arid forests of Zagros, which can be used as a model in forest restoration programs in other parts of the Zagros forests‎.

Fire as an ecological factor has both positive and negative effects on components of the ecosystem. The aim of this study was to investigate the effect of fire on composition, changes in vegetation and some soil properties in areas under fire of Juniperus communis stands in Angas village of Noshahr city. For this purpose, the flexible sample plots were used. Overall 50 sample plots were measured and the name of plant species with their cover percentage was recorded. In order to study of soil properties, a soil sample was taken from depth 0-25 cm from each plot. The richness and diversity species were calculated using PAST software. The results showed that out of 59 species identified, 3 species were exclusively found in the fire region, 12 species exclusively in the control region, and 44 species were shared between the two regions. Fire in the area reduced Shannon diversity index and Margalef and Menhinik richness index. Among soil properties organic carbon, organic matter, potassium, electrical conductivity and pH in the fire area was more than the control. It is recommended due to its not long time of occurrence of these types of fires and invasive species such as Stachys byzantina doesn’t invade whole parts of rangelands, restoration activities such as planting native species in the area is on the agenda.

Floodwater spreading plays an important role in restoring and enhancing the vegetative cover, improving soil fertility, groundwater recharge and desertification control. These have been achieved in some of the arid and semi-arid regions of Iran. Flood water spreading as a corrective measure, in soil seed bank composition and diversity was assessed in the Gareh Bygon Plain, Fasa, the province of Fars. Soil seed bank was evaluated in the water-spreading tracts, water-spreaders planted with Atriplex lentiformis harvesting and the control area (without water-spreading). Sampling of soil seed bank was carried out at a 0-10 cm depth prior to the initiation of seed growth in December 2017, and the composition of the soil seed bank was determined by the germination method in the greenhouse. The results indicated that from 42 species identified in the soil seed bank, 40, 40 and 24 species were present in the three areas. Water- spreaders, water-spreaders planted with Atriplex lentiformis harvesting and the control tracts, respectively. The highest species diversity and richness indices were obtained in the area under water-spreading. The RDA analysis showed that the species composition and functional groups of soil seed bank of the study area were affected by flood water spreading practices and Atriplex lentiformis harvesting planting. Furthermore, the soil seed bank density of plant functional groups was affected by water-spreading. The results indicated that 35 years of floodwater spreading has positively affected the composition, diversity and functional groups indices of the soil seed bank.

The study of soil seed bank provides vital information for rehabilitation and restoration of rangeland ecosystem. In the arid and semi-arid environments, shrub plants may cause accumulation of seed bank under their canopy, thereby protecting them against the livestock herbivory and the other environmental factors. This study was conducted with objective to investigate effect of Astragalus brachycalyx on composition of soil seeds bank, in two area of enclosure and under grazing. For this purpose, sampling of soil seed bank under the canopy of this species and its open space adjacent was measured using a flexible plot along the 100 meters transect. Soils were sampled from 0-5 and 5-10 cm depths. Then seed bank composition was identified after seed germination in glasshouse. The results showed that 16 species under the canopy of Astragalus brachycalyx and 12 plant species in the open space adjacent in enclosure area and 21 species under the canopy of Astragalus brachycalyx and 11 plant species in the open space adjacent in under grazing area. In the soil seed bank of an area under the livestock grazing and understory of Astragalus brachycalyx, the species namely Silene longipetala, Mentha longifolia, Veronica anagallis-aquatica and Anthemis odontostephana had the greatest numbers of seeds respectively. The area under livestock grazing had higher density of seed bank of plants with annual and perennial life, Therophytes and Hemicryptophytes biological forms, annual and perennial vegetative forms of forbs, and palatable classes II and III in understory compared to the open space.

Floodwater spreading (FS) is an efficient and appropriate method for the optimization of runoff utilization, particularly in arid and semiarid region. Beside the reduction of damage caused by the flooding, this technique is also useful in the artificial recharge of groundwater and rangeland restoration. Effects of floodwater spreading on species composition and functional groups were assessed in the Poshtkooh Rangelands of Sari in the Mazandaran Province. Vegetation sampling was evaluated in the FS area, enclosure and a without floodwater spreading (grazing). Sampling was carried out at representative and homogeneous areas of each treatment by the random-systematic method, thus the canopy cover of each plant species was measured in 90 plots of 1 m2/each. Results showed that there were 53 species in floodwater spreading area and 43 species in the enclosure but only 24 species were present in the control area spreading or grazing. Among the studied plant families. The canopy cover of Brassicaceae, Poaceae and Fabaceae was increased by floodwater spreading, shrubs and Chamophytes showed a significant reduction from due to FS as compare with the control area. Comparison of the most functional groups also indicated a reduction in their canopy cover percentage with an increase in floodwater spreading and enclosure. The multivariate analysis showed that the species composition and functional groups of the study area were affected by the FS practices and enclosure; that important and valuable species such as Agropyron elongatum and Onobrychis altissima responded most to such practice. To sum up, our results clearly showed that the FS practices carried out in the area had a positive effect on species composition and functional groups.

Appropriate use of rangelands, creates vegetation stability, prevents degradation and improves their suitability  conditio. Determination of allowable level of vegetation utilization of the species could lead to plan for the proper distribution of livestock on rangeland. To measure the level of use, a 0.5 ha exclosure was established in Karsanak site before the start of the growing season in 2007 and 40 individual Plants of Bromus tomentellus were selected randomly inside of the exclosure in order to determine the effect of different harvesting intensities (simulated grazing) on forage and seed production. Clipped treatments included 0, 25, 50 and 75 percent of annual growth. There were 10 replications in the plan. Clipping continued for 4 years in three months of grazing season. Vigor and freshness, mortality, plant maximum height, forage and seed production were observed and measured during the 4 years. Data were analyzed in a split plot design in time with SAS software. The results of forage production of Bromus tomentellus showed that the effect of years is statistically significant at 1%. And the interaction of the year and different intensities of harvest, is not significant at the 5%. Lowest forage production has happened in 2007 harvesting at 25% and its highest in 2009 in control treatment. The results of seed production showed that the And the interaction of the year and different intensities of harvest is statistically significant at 1% But their interaction was not significant at the 5% error level. Due to environmental changes affecting of this species, it can be concluded that about 50 percent of annual yield removal is safe for persistence and health of Bromus tomentellus in Karsanak and other areas with similar climate and soil conditions in drought years but the harvest of up to 75 percent in normal years apparently does not harm the plant.

Plants are among the most important units of natural ecosystem that are examined for natural resource management. Therefore, identifying the plant assemblage of each region is very important. The purpose of this study was to identify and introduce the floristic composition, biological form, species status and geographical distribution of plants in Robat Kouh area of Bazoft. According to results, 343 species, 238 genera and 63 families, including the largest families named Asteraceae, Lamiaceae, Poaceae, Brassicaceae and Leguminosae having 54, 35, 29, 23 and 22 species, were recognized, respectively. The Astragalus possessing 11 species, Centaurea with 9 species, Silene, Salvia, and Stachys with 6 species, and Allium with 5 species were the largest genera in the region. Hemicryptophytes with 51.31% had the most abundant biological forms followed by therophytes with 23.03%, cryptophytes with 13.41%, phanerophytes with 5.83%, and chasmophyte with 5.54%. In terms of geographical distribution, Iranian-Turonian elements had the highest number of species (66.18%) and other species belonged to two, three or more geographical areas. Conservation of plant elements was classified according to the principles of IUCN (International Union for Conservation of Nature), with 45 species in the low-risk class, 2 species in the vulnerable class, and 3 species in the endangered class. There was insufficient information about 6 species. Moreover, there were 45 endemic Iranian and 158 medicinal species. The results showed the importance of the plant species and the richness of the flora of the region.

Stachys byzantina is one the major increaser species in rangelands of north face of Alborz Mountain in Mazandaran province. The purpose of this study was to assess the effects of its invasion on vegetation under some disturbances in Vaz Chamestan summer rangelands in Mazandaran province. Vegetation sampling was carried out in exclosure, and invaded rangelands including abandoned dryland, moderate grazing and heavy grazing sites. The vegetation and some characteristics of Stachys were sampled in 1 m2 quadrates along transects. The results showed that Stachys byzantina had greater quantities in abandoned dryland and rangelands under moderate grazing. The cover percentage of total perennials, perennial grasses and forbs significantly reduced from exclosure to heavy grazing and abandoned dryland. Total annuals plants, annual grasses and forbs significantly increased in abandoned dryland. A significant negative correlation was found between cover percentage of perennials and the cover and density of Stachys byzantina. Moreover, the forage production of forbs was negatively correlated withthe cover and density of Stachys byzantina. Multivariate analysis showed that species composition significantly changed under invasion, showing a reduction for palatable species.

Grazing of Livestock is one of the factors having influence on the structure and dynamics of the range land vegetation. Grazing management is a vital factor to control the intensity of the rangeland ecosystems degradation. In this study, plant functional traits and diversity and richness properties were used to assess the vegetation response to different grazing intensities. This was done in Nodushan Rangelands in Yazd province. Vegetation cover was recorded under three grazing intensities (heavy, moderate and light rates grazing). Results showed that the cover percentage of Compositeae and Papilionaceae, significantly showed a negative response to grazing intensity while Gramineae was not significantly affected by different grazing pressure. Some functional groups such as annuals, Geophytes, Chamaephytes, Shrubs and Forbs significantly reduced from light to heavy rates. On the other hands, Therophyts and hemicryptophytes were increased. The other findings of this study showed that decreaser plants significantly had less cover under heavy grazing whereas increaser plants had greater cover under heavy grazing. Also diversity and richness had no significant response to grazing intensity. The results of this research showed that plant traits may change under grazing intensity. In conclusion, we recommend using these traits that show the highest response along the grazing as intensity gradient in the arid rangelands.

Livestock grazing can lead to changes in plant composition. In this study, the effect of four grazing intensities including heavy, moderate, light and no grazing (exclosure) were studied on vegetation indices in order to improve management practices and proper planning for sustainable use of rangelands in Karsanak and Bardeh area in Chaharmahal & Bakhtiari province of Iran. Therefore, vegetation sampling was done to record canopy cover percentage and vegetation composition under four grazing intensities. Data were analyzed by one-way ANOVA, t-test,andordination method (CCA) to assess vegetation changes under different grazing intensities. Results showed that plant species such as Agropyron repens, Bromus tomentellus, Astragalus effuses and Poa bulbosa were more found in exclosure and light grazing area.The major species found in heavy grazing area were Boissiera squarrosa, Echinops leiopolyceras, Sisymbrium irio and Euphorbia heteradenia. Due to the vegetation damage and reduction of palatable species, a moderate grazing is recommended in the study rangeland.

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.

Each region''s flora is as a result of communities'' reactions to the current environmental conditions and plant evolution in the past. This aim of this study is to introduce floristic list، life form and endangered species of Helen region. This region covers about 40231 ha and lies in the west part of Chaharmahal and Bakhtiari province. The results showed that 392 plant species existed in the region belonging to 67 families and 267 genera. The families Compositae، Labiatae and Papilionaceae with 60، 37 and 34 species embraced higher species respectively. The genus Astragalus with 15 species was the largest genus in the region. According to Raunkiaer’s life form، species followed as: 43. 88% hemicryptophytes (172 species)، 22. 96% therophytes (90 species)، 14. 03% cryptophytes (55 species)، 7. 44% phanerophytes (37 species) and 8. 93% chamephytes (35 species). The chorology of species showed that 64. 80 percent of species belonged to Irano-Turanian، 6. 12 percent Polyregional، 3. 32 percent Cosmopolitan and the rest to the others. Threatened species included 70 totally belonging to Irano-Turanian. Among which them the endangered class، vulnerable، lower risk and data deficient were 3، 3، 55 and 9 species respectively.

From the perspective of rangeland ecology، awareness of the effects of livestock grazing on the changes of structure، plant vegetation and soil characteristics is essential. The aim of this study was to determine the effect of different grazing intensities including heavy (0-200 m distance from water point)، moderate grazing (200- 800 m) and light grazing (800-1200 m) intensities on vegetation indices and soil characteristics in Nodushan region، Yazd province of Iran. For this purpose، plant vegetation cover and composition were recorded under three grazing intensities. Soil was sampled from depths of 0-30 cm. Data were analyzed by one way ANOVA، t-testandordination method (CCA) to assess the vegetation response in different grazing intensities. Results showed that plant species such as Astragalus achrochlarus، Salsola arbusculata and Tragopogon sp. were found in light grazing area. Allysum minus، Artemisia sieberi، Poa sinacia، Iris songarica، Lactuca glacifolia and Stipa barbata were identified in moderate grazing area. Eryngium sp.، Cousinia desertii، Bromus tectorum and Peganum harmala were the major species in heavy grazing area. Soil properties including N، P، K، OC، EC and pH were measured. According to the results، nitrogen and soil organic matter were decreased by increasing grazing intensities but P، K، EC and pH were increased. Since grazing pressure causes damage to vegetation and some soil properties، a moderate grazing is recommended for sustainable utilization of rangelands.

Assessing the floristic resources of each region is very important because it serves to identify it’s the genetic potential. The purpose of this study was to introduce floristic list, life forms and endangered species of Gheissari region. This region covers about 9816 ha and lies in the west part of Chaharmahal & Bakhtiari province. Field data were collected in the years between 2009 and 2010. During that period, the plant species were collected and then identified based on families, genera and species using appropriate reference. The results showed that there were 487 plant species belonging to 65 families and 301 genera. The families like Composite, Gramineae, Papilionaceae, Labiatae, Cruciferae, Umbeliferae and Caryophyllaceae had 70, 46, 41 39, 38, 30 and 21 species, respectively. These families made up 58.52 percent of the total species. According to Raunkiaer’s life form, species were as below: 50.31% hemicryptophytes (245 species), 23.20% therophytes (113 species), 12.52% cryptophytes (61 species), 7.60% phanerophytes (37 species) and 5.75% chamephytes (28 species). The chorology of species showed that 67.15 percent of species belonged to Iran-Turanian, 5.75 percent Polyregional, 2.67 percent Cosmopolitan and the rest belonged to the others. Threatened species included 86 species of the total species from Iran-Turanian. Among them, the endangered class, vulnerable, lower risk and data deficient were 2, 3, 67 and 14 species respectively.

Nowadays rangeland restoration is important because of severe degradation. It is important to know the ecological processes involved in restoration and its rate of success. This study assesses the effect of exclosure restoration in the area of Dishmook (Delafrooz mountainous) in Kohgiluyeh & Buyer Ahmad Province. For this purpose, plants were sampled in the restoration area and control sites. Random-systematic sampling was done in two range sites (the restoration area and control site) using 440 (2×2 m2) quadrates along 22 transects. Vegetation canopy cover percentage was recorded simultaneously in both range sites. Data were analyzed in the restoration area and control site to evaluate the response of individual species and functional groups. Also, multivariate analyses were applied to assess the response of plant communities. From the data, we found 15 common species, 21 species restricted to the restoration area and only 12 species restricted to the control site. 12 species and some functional groups significantly responded to the restoration project. The Restoration project produced greater species diversity and richness. CCA showed that species composition significantly changed due to the restoration operations and here greater effects were found on important species. This study showed that exclosure induced some positive changes in vegetation indices.

Allelopathy has rarely been challenged in range improvement despite being the main concern in the restoration of rangelands. In this research the potential allelopathic impact of Artemisia aucheri on seed germination and the initial growth of Bromus tomentellus and Bromus inermis was examined. For this aim, the aerial parts powder of Artemisia aucheri (stem, leaf and seed) collected from habitats during the flowering stage (the end of November) was prepared. Also, distilled water was used as control. A completely randomized design was carried out using six treatments and four replications in the laboratory of seed ecology at the faculty of natural recourses in 2011. The research results showed a significant effect of the aqueous extracts of Artemisia aucheri on seed germination percentage, seed germination rate, plumule and radicle length, and seed vigor of the two species. The germination percentage, seed germination rate, plumule and radicle length, and seed vigor of Bromus tomentellus and Bromus inermis were significantly reduced under the aqueous extracts of Artemisia aucheri.

The conversion of natural ecosystems into artificial or man-made ecosystems due to land use change can alter both ecosystem structure and function. The soil seed bank contains a source of viable and germinable seeds which can germinate under suitable environmental conditions. This can produce a new population or renew the present plant community. Information about the soil seed bank for Iranian flora is scarce and this study aimed to study the soil seed bank in rangeland which has been excluded from livestock grazing and the nearby area with a history of rangeland conversion into arable lands. We measured the seed bank in soils taken from two depths (0-5 and 5-10 cm) and how soil seed diversity and richness changes with land use changes. The results of this study showed that land use change significantly influenced soil seed bank diversity, species richness indices and functional group. The exclosure area showed the highest species richness, diversity and functional group while these indices significantly declined as rangeland became converted into arable lands. However, the abandoned area did not show significant differences from other two sites. Moreover, some functional groups such as annuals, therophytes, Gramineae and forb significantly reduced from the exclosure to the dryland area. This may show that abandoned areas have a potential according to their diversity and richness for returning into rangelands.

Diversity indices mainly composed of two components: Species Richness and Evenness. Critical to the analysis of diversity is a clear of the relationships among S (species richness), H' (information), and E (evenness) (i. e. SHE). One historically intractable problem in biodiversity analysis has been: How to Separate species richness and evenness into distinct components within the same system? This is important because H may actually not vary at all, even in the face of increasing species richness. In other cases, H can increase while E remains constant. Due to the importance of these components, a simple solution, SHE analysis, has only recently been derived. In this study SHE analysis was used to define the role of each diversity components in exclosure and grazed of Mahoor, Mamasani Rangelands. Therefore, 50 random- systematic plot of 1 m2 were laid out to determine vegetation cover percentage. SHE analysis was employed to separate species diversity into its richness and evenness component in exclosure and grazing. Results show that the role of species richness is much more than evenness in defining diversity index in both under studied regions.