نشریه حفاظت زیست بوم گیاهان
سال دوم شماره 1 (پیاپی 4، بهار و تابستان 1393)

Ecological potential assessment of rangeland plant species on basis existence criteria of rangeland ecosystems could be beneficial for ecosystem management. For this purpose, two rangeland plant species (Artemisia aucheri and Festuca ovina) were assessed in Vavsar region and assessed on basis, nine criteria (soil pH, total nitrogen, Caco3, Sand, Silt, Clay, OC, EC and Water(. In this research, Analytical Hierarchy Process (AHP) was used for assessment. Results showed that the maximum local priority was estimated for Artemisia aucheri from clay. The other criteria have higher value in Festuca ovina. The minimum silt (%), pH, water, sand and EC and total nitrogen was considered in Artemisia aucheri .The calculated overall priority showed which with respect to the criteria the Artemisia aucheri has higher ecological potential compared to the Festuca ovina. Pay attention to obtain results, Artemisia aucheri has more appropriate conditions and efficiency compared to the others at present condition.

Knowing about vegetation and plants floristic composition is essential in rangeland-management-programming.This study was carried out in order to evaluate the vegetation and floristic composition in the Simani watershed of Kermanshah province.There were 113 plant species and 29 plant families in the region. In this regard,the families of Poaceae (25 species), Papilionaceae (17 species), Lamiaceae (11 species) had the highest frequency, while families of the Apiaceae, Asteraceae and Rosaceae had the same frequency (5 species).The obtained results from the study of plant life forms indicated that Hemicryptophytes (36.28%) had the highest frequency, while Therophytes (32.74%) were in the second place, Phanerophytes (12.38%) in the third, Chamephytes (7.96%) in the fourth, Geophytes (7.07%) in fifth and rhizomes and bulbous Geophytes in sixth and sixth place respectively. In terms of chorology,theIrano-Touranian (59.29%) was in the first place, Irano-Touranian and Mediteranian (13.27%) in the second, Irano-Touranian, Mediteranian and Euro-Siberian (8.84 %) in the third, Irano-Touranian and Cosmopolitan (2.65%) in the fourth and Irano – Touranian and Saharo-Sindian (2.65%) in the last place. It can be concluded the area under study despite the destructive factors has fairly high flora by which can be used for assessing the current situation as well as predicting the future conditions of the region.

Studying plant species diversity is vital for knowing and better understanding the relationship between ecological factors and proper management principles. The existence of higher plant species diversity is an indicator of appropriate environmental conditions for deploying diverse species, which in turn lead to the sustainability of plant community in that ecosystem. The goal of current research is investigating the most important factors in the variation of the plant species in Sabzkesh summer rangelands located in Golestan province. In the first step, the data about vegetation and soil respectively in the indicator-regions were collected by random-systematic and Zigzag sampling method. After gathering data, diversity, evenness and richness calculated by using of Shannon Wiener and Pailo indices. In addition, in this stage counting plant species number per area unit was done by means of PAST software. Then, by PC-ORD 5 software major ecological groups and the most effective edaphic and topographical factors in the variation of the ecological groups of species diversity were determined through clustering and ordination analysis (Principal Component Analysis).The result showed that diversity, evenness and richness indices provided valuable information about vegetation response to the environmental variations. In this regard, factors such as elevation, pH, N, P and clay of soil had the most important role in the variation of plant species diversity of ecological groups in the studied region. Moreover, in the region under study plant-distribution-pattern with rank-abundance model indicated that the plant species of the region were compatible with Log-normal pattern therefore, the plant species in the studied region almost were out of stress.

The Purpose of this study is to predict the spatial distribution modeling of habitat potential of Agropyron intermedium and Stipa barbata species in area with the size of 37977.12 hectares in Miany (mideal) Taleghan. For modeling, vegetation data and site condition including topography, climate, geology and soil were prepared by satellite images, digital elevation model (DEM), geology map and climatology data (from related stations) were obtained. Within each plant type, three parallel transects with 150m length, each containing 15 quadrats were established. Sampling method was randomized-systematic method. Quadrats size determined for each vegetation type using the minimal area and their number were determined according to statistical method. Soil samples were taken from 0-30 cm in along of each transects. The soil properties included grovel, texture, pH, EC, organic matter, lime, soluble ions (N, P, K) were measured in the lab. Data analysis and prediction maps were done by geo-statistical and logistic regression methods. The results showed that direction habitat (N) and lime increasing soil (to 27.5 percent) had the greatest effect in the appearance and distribution of S. barbata species. Increasing height (to 2550 m) had the most important role in the appearance of A. intermedium species. Assessment of models using Kappa coefficient indicated that logistic regression models ability to predict habitat for both species was very good With the exception that kappa for A. intermedium (k =0.83) is slightly more than S. barbata (k =0/79).

Study of vegetation changes of grazed and ungrazed rangelands has a significant role in management. The effect of exclosure and grazing was studied on the direction of vegetation changes of rangelands in Semi-Steppe area of Gomishan in Golestan province from 1997 till 2005. The vegetation parameters were measured each year, in several fixed plots, inside and outside of exclosures. The annual forage production was measured by randomized plots by the employing clipping and weighing method. Data were compared with T test analysis by using MiniTab15. Results showed that total canopy and perennial grasses inside the exclosures significantly increased in comparsion with those of outside the exclouser, but shrubs, annual forbs and grasses inside the exclosur were decreased. Increase of the prinnial grasses inside the exclosure was due to Puccinellia distans which belongs to class I species. Reduction of shrubs in outside the exclosure because of the decrease of Halocnemum strobilaceum which belongs to class III. The perennial species such as Artemisia sieberi and Frankenia hirsuta were not inside the exclosure in the first year, but they grew naturally because of the exclosure in the next years. The results of the comparison of forage production and perennial grasses demonstrated that the rate of total forage production and perennial grasses inside exclosure in comparison with outside exclosure was increased. Moreover the range condition inside exclosure, was changed from medium state to good one.

The purpose of this study is not only to classify ecological groups of Artemisia aucheri Boiss. habitats in three rangelands in Isfahan province but also to study their properties and compare these habitats. For this purpose, three habitats of Artemisia aucheri in Yahya Abad (Natanz), Khorus Galu Ghat (Semirom) and Ashan (Najaf Abad) were selected, and sampling carried out in a random-systematic method. The sampling quadrates size was 16 m2 (determined by the minimum area method) and the number of quadrates in each habitat was 21 (determined by statistical methods). Vegetation classification carried out by TWINSPAN and CCA Analysis. Three main groups in each region were determined, and the relationship between environmental factors and quadrates were investigated. Results showed that 36 species were common and Asteraceae, Poaceae and Fabaceae families were the largest families in terms of number of species. Artemisia aucheri- Astragalus verus group was common in three regions. Among studied environmental factors such as height, amount of pebble, pH, electrical conductivity, salinity and percentage of moisture content, height was the most effective factor in the distribution of vegetation. Association among Artemisia aucheri species and two species of Bromus were determined. The study of the soils of rangelands showed that the pH in three regions was more than 8, and soil electrical conductivity was measured between 70 to 100 µS. So, identifying plant communities and environmental factors on these rangelands is essential for proper management.

One of the strategies for restoration and reclamation of arid and semi-arid rangelands is introducing t species which is compatible with the characteristics of these areas. This introduction is possible by the recognition, identification and properties of plants in rangeland ecosystems. Understanding the stages of succession and index species in each stage will help us in the proper management of these areas. This study was done in Karsanak rangelands in the Chaharmahal Bakhtiari province in order to recognizes property- plant index first three regions with different sequence including (1) 3-5 years-it was sown and abandoned; (2) 10-15 years; (3) more than 25 years, as well as a control area were selected then the experiment was followed by transecting and sampling by means of systematic random –method in order to determine vegetation percentage. Indicator Species Analysis (ISA) was used to determine the index species in the each steps of the succession. Non-Metric Multi dimensional Scaling (NMS) was used for separating the species groups of each stage. The results showed, that the highest number of index species was related to the sequence of more than 25 years, and the control group; each of them had 10 index species. And this could be the result of vegetation return after removing destructive agents while the lowest number of index species was related to the sequence of 3-5 years with 7 species. Groups of index species of each step were separated by NMS test results it was observed there was a significant difference among four studied - areas in terms of species composition and index species.