Manuscript profile

Manuscript profile

کشور ایران دارای اقلیم گرم و خشک بوده و میزان بارندگی سالیانه آن250میلی‌متر است. بنابراین در کشور ایران با بارشی کم و توزیع نامناسب آن، استفاده موثر از فن‌آوری نوین برای بالابردن کارایی مصرف در منابع محدود آبی امری حیاتی است. یکی از این راهکارها برای حفظ و ذخیره رطوبت، استفاده از مواد فراجاذب خاک است. در این تحقیق تاثیر ماده معدنی زئولیت در سه سطح(0،10، 15درصد وزنی) و سوپرجاذب جیوهوموس درچهار سطح (0،100، 150،250 گرم در هرچاله) ودور آبیاری (آبیاری معمولی، کم آبیاری)، بر ویژگی‌های رویشی گیاه قره‌داغ‌در حالت کشت نهال در عرصه وهمچنین اثر آنها بر برخی خصوصیات خاک مورد بررسی قرار گرفت. به منظور ارزیابی اثر هر یک از تیمارها داده‌ها بر اساس جدول تجزیه واریانس و با استفاده از نرم‌افزارSPSS22 مورد تجزیه وتحلیل قرارگرفته وجهت مقایسه میانگین تیمارها از آزمون مقایسه میانگین دانکن استفاده شد. نتایج بدست آمده نشان داد استفاده از سوپرجاذب به کار رفته دراین تحقیق در مجموع تاثیر معنی‌داری بر شاخص‎های رشدی نهالها شامل ارتفاع، قطر بزرگ تاج پوشش، قطر کوچک تاج پوشش و قطر یقه نهال‌های قره‌داغ در مقایسه با شاهد داشته است. بیشترین میزان ‌شاخص‌های رشدی با آبیاری معمولی به دست آمد که به ترتیب عبارتند از (22/60 سانتی‌متر، 33/67 سانتی‌متر، 88/13 سانتی‌مترو6 میلیمتر)وکمترین آن مربوط به تیمار شاهدکم آبیاری بود.علاوه برآن افزودن سوپرجاذب‌های ذکرشده به خاک باعث کاهش هدایت الکتریکی(39/1 دسی‌زیمنس‌برمتر)و وزن مخصوص ظاهری(46/1 گرم برسانتی‌مترمکعب) خاک شد. پس از بررسی بهترین سطح استفاده از سوپرجاذب‌ها 15 درصد وزنی زئولیت و 250 گرم جیوهوموس می‌باشد. Manuscript profile

بیابان‌زایی پدیده‌ای است که براثر فرایندهای اقلیمی و فعالیت‌های بشری در مناطق خشک و نیمه‌خشک رخ‌داده و سبب کاهش توان تولیدی اکوسیستم و زوال پتانسیل اراضی می‌گردد. در این پژوهش، پتانسیل بیابان‌زایی حوزه آبخیز جازموریان با استفاده از مدل حساسیت تخریب اراضی (ESAs) مورد ارزیابی قرار گرفت. به این منظور، ابتدا نقشه واحدهای کاری با استفاده از روش طبقه‌بندی بیشترین شباهت از تصاویر چند طیفی سنجنده OLI ماهواره لندست 8 (سال 2015) استخراج گردید. سپس در هر واحد کاری، شاخص‌های مربوط به هر یک از معیارهای اقلیم، خاک، پوشش گیاهی و مدیریت بر اساس روش‌شناسی مدل و نظر کارشناسی ارزش‌گذاری شد و از میانگین هندسی شاخص‌های مربوط به هر یک از معیارها، وضعیت بیابان‌زایی بر اساس آن معیار و از میانگین‌گیری هندسی معیارها، نقشه وضعیت فعلی بیابان‌زایی ترسیم گردید. نتایج حاصل از ارزیابی، دامنه ارزش ESAs به‌دست‌آمده را در محدوده 46/1 تا 72/1 برآورد نمود که بیانگر پتانسیل بحرانی بیابان‌زایی در منطقه می‌باشد، به‌طوری‌که 3136 و 12299 کیلومتر از وسعت منطقه، به ترتیب در طبقه‌ بحرانی (C2) و (C3) طبقه‌بندی‌شده است. اراضی شور و رسی (83/1=ESAI)، پلایا (78/1=ESAI) و نواحی ارگ و تپه ماسه‎ای (72/1=ESAI) بیشترین امتیاز را کسب نموده‌اند که نشان از حساسیت بالای این نواحی به بیابان‌زایی می‌باشد. همچنین دو معیار کیفیت اقلیم و مدیریت بیشترین امتیاز را به خود اختصاص داده‌اند، لذا در اولویت قرار دادن این معیارها و افزایش سهم آن‌ها در خصوص ارائه مدل‌های منطقه‌ای و روش‌های ارزیابی بیابان‌زایی در منطقه و تدوین برنامه‌های مدیریتی بیابان‌زدایی، از ضرورت بیشتری برخوردار است. Manuscript profile

در سراسر دنیا یکی از مهم‌ترین عوامل غیر زیستی و محدود‌کننده جوانه‌زنی و هم‌چنین رشد اولیه گیاهچه‌ها، تنش خشکی است. پژوهش حاضر با هدف بررسی تأثیر پرایمینگ هورمون‌های شیمیایی بر بذر گیاه دارویی بالنگوی سیاه در مراحل اولیۀ رشد و نقش آن ‌در کاهش اثرات منفی تنش‌ خشکی به ‌صورت فاکتوریل بر پایه طرح کاملاً تصادفی با چهار تکرار جداگانه درآزمایشگاه مرکز آموزش جهاد کشاورزی شهر تبریر طراحی و انجام شد. فاکتور اول پرایمینگ با اسید سالیسیلیک (100، 200 و 300 میلی‌گرم برلیتر)، اسید آسکوربیک ‌(100، 200 و 300 میلی‌گرم بر لیتر) و اکسین (50، 100و 150 ppm) و آب‌مقطر به‌عنوان شاهد و فاکتور دوم 5 سطح خشکی (0، 3/0-، 6/0-، 9/0- و 2/1- مگاپاسکال) با پلی‌اتیلین گلایکول6000 بود. نتایج تجزیۀ واریانس نشان‌داد که پرایمینگ و تیمارهای خشکی و اثرات متقابل آنها بر خصوصیات جوانه‌زنی بذر بالنگوی سیاه اثر معنی‌داری در سطح 1 درصد دارند. تنش‌ خشکی تأثیر بازدارنده‌ای برخصوصیات جوانه‌زنی بذر گیاه داشت و عدم جوانه زنی در سطح خشکی 9/0- و 2/1- مگاپاسکال ثبت شد. لیکن تاثیر منفی این‌ تنش‌ها در بذرهای پرایمینگ شده به‌‌مراتب پایین‌تر از بذور پرایمینگ نشده بود. بیشترین تأثیر به ‌وسیله اسیدسالیسیلیک 200 میلی‌گرم ‌بر‌ لیتر (79 درصد جوانه زنی در سطح خشکی 3/0- مگاپاسکال) و کم‌ترین تأثیر توسط هورمون اکسین با 13 درصد جوانه زنی در سطح خشکی 9/0- مگاپاسکال مشاهده شد. از این رو تیمار سالیسیلیک اسید بهترین تیمار برای کاهش اثرات منفی تنش‌ خشکی بر روی مؤلفه‌های مختلف جوانه‌زنی بالنگوی سیاه بود. Manuscript profile

عمق کاشت بدلیل تأثیر زیادی که بر جوانه زنی، سبز شدن و استقرار گیاهچه دارد، در برنامه های اصلاح و احیای مراتع بسیار حائز اهمیت می باشد. اسپرس (Onobrychis) یکی از مهمترین گونه های مرتعی بوده که از نظر علوفه ایی، حفاظتی و یا به عنوان گیاهان جذب کننده زنبور عسل دارای اهمیت بسیار بالایی می باشند. از این رو، در این تحقیق، اثر 4 سطح عمق کاشت (5/0، 5/1، 3، 5/4 سانتی متر) بر جوانه زنی و سبز شدن اسپرس به صورت طرح بلوک های کامل تصادفی در چهار تکرار تحت شرایط گلخانه ای انجام گردید. بذرها در گلدان های پلاستیکی کشت شده و پس از رشد جوانه ها، تعداد آنها شمارش شده و خصوصیات مختلف جوانه زنی (طول ریشه چه، ساقه چه و گیاهچه، بنیه بذر، درصد و سرعت جوانه زنی، وزن تر و خشک ریشه چه و ساقه چه)، اندازه گیری شده و اطلاعات بدست آمده با استفاده از تجزیه واریانس، آزمون دانکن و دانت مورد تجزیه و تحلیل آماری قرار گرفت. نتایج نشان داد که تیمارها بر خصوصیات جوانه زنی و رشد گیاهچه شامل وزن تر ریشه چه و وزن خشک ساقه چه در سطح 5 درصد تاثیر معنی داری دارند و بر درصد جوانه زنی، سرعت جوانه زنی، طول ریشه چه، بنیه بذر، طول گیاهچه، طول ساقه چه در سطح یک درصد تاثیر معنی دار دارند. نتیجه بدست آمده مبین آن است که میان چهار تیمار کاشت، تفاوت معنی داری وجود دارد و عمق کاشت کمتر نسبت به عمق کاشت بیشتر بهتر می باشد. بنابراین توجه به عمق کشت در برنامه های اصلاح و احیای مراتع امری ضروری بوده و می تواند در موفقیت این برنامه ها نقش مهمی داشته باشد. Manuscript profile

در سراسر دنیا یکی از مهم‌ترین عوامل غیر زیستی و محدود‌کننده جوانه‌زنی و هم‌چنین رشد اولیه گیاهچه‌ها، تنش خشکی است. پژوهش حاضر با هدف بررسی تأثیر پرایمینگ هورمون‌های شیمیایی بر بذر گیاه دارویی بالنگوی سیاه در مراحل اولیۀ رشد و نقش آن ‌در کاهش اثرات منفی تنش‌ خشکی به ‌صورت فاکتوریل بر پایه طرح کاملاً تصادفی با چهار تکرار جداگانه درآزمایشگاه مرکز آموزش جهاد کشاورزی شهر تبریر طراحی و انجام شد. فاکتور اول پرایمینگ با اسید سالیسیلیک (100، 200 و 300 میلی‌گرم برلیتر)، اسید آسکوربیک ‌(100، 200 و 300 میلی‌گرم بر لیتر) و اکسین (50، 100و 150 ppm) و آب‌مقطر به‌عنوان شاهد و فاکتور دوم 5 سطح خشکی (0، 3/0-، 6/0-، 9/0- و 2/1- مگاپاسکال) با پلی‌اتیلین گلایکول6000 بود. نتایج تجزیۀ واریانس نشان‌داد که پرایمینگ و تیمارهای خشکی و اثرات متقابل آنها بر خصوصیات جوانه‌زنی بذر بالنگوی سیاه اثر معنی‌داری در سطح 1 درصد دارند. تنش‌ خشکی تأثیر بازدارنده‌ای برخصوصیات جوانه‌زنی بذر گیاه داشت و عدم جوانه زنی در سطح خشکی 9/0- و 2/1- مگاپاسکال ثبت شد. لیکن تاثیر منفی این‌ تنش‌ها در بذرهای پرایمینگ شده به‌‌مراتب پایین‌تر از بذور پرایمینگ نشده بود. بیشترین تأثیر به ‌وسیله اسیدسالیسیلیک 200 میلی‌گرم ‌بر‌ لیتر (79 درصد جوانه زنی در سطح خشکی 3/0- مگاپاسکال) و کم‌ترین تأثیر توسط هورمون اکسین با 13 درصد جوانه زنی در سطح خشکی 9/0- مگاپاسکال مشاهده شد. از این رو تیمار سالیسیلیک اسید بهترین تیمار برای کاهش اثرات منفی تنش‌ خشکی بر روی مؤلفه‌های مختلف جوانه‌زنی بالنگوی سیاه بود. Manuscript profile

There are many remediating methods for the polluted soils but only phytoremediation is a cost effective, environmental friendly, aesthetically pleasing approach that is most suitable for many countries. The purpose of this study was to investigate the potential of native plants for phytoremediation of contaminated soils with lead, zinc, cadmium and nickel in the rangelands around National Lead & Zinc Factory, Zanjan, Iran. Sampling was done at 11 sites on May, 2014 and plant samples were collected from 14 native plant species. Three soil samples were taken at each site. Soil samples were taken from the rooting zone. Extraction of Pb, Zn, Cd and Ni from plants was done by acid digestion. Plant samples were digested in the di-acid mixture (3:1) of nitric acid (HNO3) and perchloric acid (HClO) and soil samples were digested with 4M HNO3 acid. Metals of Pb, Zn, Cd and Ni were extracted from plant and soil samples were determined using Inductively Coupled plasma Optical Emission Spectroscopy “ICP-OES”. In general, the results showed that no hyperaccumulators of Pb and Zn were identified in the area. All plants were classified as low lead accumulators, excluder and moderate accumulators, low zinc accumulators or excluders; though Pb and Zn concentrations in the plants were higher than standard range. Standard range of lead and zinc in rangeland plants is 0.2-20 and 1-400 mgkg-1, respectively whereas the species of Brassica juncea and Scariola orientalis were classified as Cd hyperaccumulators and Scariola orientalis and Echium amoenum were classified as Ni hyperaccumulators. The normal value of Cd and Ni in these plants were 0.1-2.4 and 0.02-5.0 mgkg-1, respectively. Thus, these native plants had an implication of carrying out phytoremediation in the rangeland soils around National Iranian Lead & Zinc Factory, Zanjan. Manuscript profile

As far as Iran is concerned in arid and semi-arid region and amount of water is limited, improvement of water consuming is very important. One of the ways for storing water is to use superabsorbent polymer. So, this research compared normal and deficit irrigation methods by considering the effects of stockosorb (0.1% and 0.3% by volume) and zeolite (10 weight% and 15 weight%) in two sandy soils (70% and 80%) on soil physicochemical characteristics (EC, pH, field capacity, available water, wilting point, bulk density, practical density, porosity, nitrogen, phosphorus and potassium) and plant morphological traits (plant height, basal area, large and small diameter of canopy) of Atriplex lentiformis (Torr.) S.Wats. The research was carried out in the field of desert research centre in Semnan Province in 2013. A split factorial experiment based on a randomized complete block design with four replications was used. Data were analyzed using SPSS16 software. The result showed that superabsorbent had a significant effect on plant height, large and small diameter of canopy. Also, superabsorbent had a significant effect on EC, pH, field capacity, available water, bulk density, porosity, K. However, they had no significant effect on wilting point, soil particle density, P and N. Also, the result of economical investigation of stockosorb and zeolite showed that using 10 wt% zeolite, 15 wt% zeolite and 0.1% stockosorb with normal irrigation is economical. Manuscript profile

Adaptation of plants under drought and salinity stress depends directly on the type of soil texture. Therefore, in this research, the morpho-physiological variations of Stachys multicaulis,an Iranian wild endemic plant species, were investigated in different soil textures under drought and salinity stress. For this purpose, plants were cultivated in three different light, medium and heavy soil textures under pot condition (outside the greenhouse near the plant original habitat) in 2016. Then, a set of drought stress (3 day intervals of irrigation; 3 to 15 days) and salinity stress (0, 5, 10, 15, 20 and 25 ds/m- NaCl) was used in two separate factorialexperiments based on a completely randomized design with four replications. The results showed that both drought and salinity had significant effects on morpho-physiological properties of S. multicaulis (p<0.01) based on type of soil texture. All of traits had higher performance in heavy soil texture except trichome length. For 15 day interval of irrigation, higher values of plant biomass, plant greenness, leaf length/width ratio, leaf angle, and node distance as 8.25g, 28.1%, 4.17, 55°, 1.5cm respectively were obtained in heavy soil texture. Similarly, for salinity of 25 ds/m, higher values of same traits as 7.7g, 25%, 3.9, 50°, and 1.4cm, respectively were obtained in heavy soil texture. Both drought and salinity stress had no significant effect (p<0.01) on leaves trichome number, trichome length, floret number per plant and branch number per plant in all three soil textures. The morphological variations of the plant occurred with greater intensity in salinity stress and it was concluded that plant tolerance to salinity was lower than drought. Manuscript profile

Semi-arid mountainous areas are of special importance in terms of ecological function i.e. vegetation dynamics and its evaluation under environmental- managerial factors is a necessity for their sustainable use. Due to the highly variable environmental characteristics in these areas, proper land management and utilization can severely affect the Range Condition (RC). Here, the relationship between topography, soil characteristics and management (RC) under grazing] was investigated through multivariate analysis in mountain areas of Golestan’s Chahar Bagh, northeastern Iran in 2019. The RCs were assessed by scoring vegetation and soil characteristics in areas under livestock grazing areas. The preliminary findings of this research showed that environmental factors i.e. clay, P, EC, slope, aspect, Soil Moisture (SM) and K had the most effect on the formation of five different vegetation types (Cum.% of Var.=80.4%). The results showed that RC changes had more significant relationships with managerial factor/grazing than environmental factors. In general, the effect of environmental and management factors and their common effect in changing RC were equal to 1.84%, 74.1 and 21.04%, respectively. The change of soil physical properties was more than soil chemical properties under RC changes. Factors of Organic Matter (OM), Bulk Density (BD), porosity and SM showed significant changes under excellent, good, fair, poor and very poor conditions (P<0.05). In general, excellent and good rangelands were related to more OM and porosity and less slope and K. Moreover, poor/very poor rangelands were related to more SM, BD, P and slope. Overall, managing grazing can significantly decline/improve RC in mountainous area. Manuscript profile

A part of plant species composition in natural ecosystems is live seeds that are hidden in the soil and known as soil seed bank. Detecting this species resource has a key role in protecting and restoring the vegetation. The present study aims to investigate the soil seed bank and its relationship with the aboveground vegetation along an elevation gradient in Kashan, Iran. For sampling from the soil seed bank, three transects with 200 m length were established in June 2017. The soil samples were taken from two depths ranging 0-5 and 5-10 cm out of 1 m2 plots with 20 m intervals. The soil samples were transferred to the greenhouse. Moreover, the cover percent of plant species within each plot was recorded in the vegetation season in spring 2018. The features of soil seed bank in different elevations were compared by F-test. The results of one-way analysis of variance showed that the effect of altitude from sea level on the Shannon's diversity and soil depth on the density, Menhinik and Margalef richness was significant. The higher value of Shannon diversity in upper altitude (2800-3000 m above sea level) and higher value of Dnensity, Margalof and Menhinik in upper soil depth (0-5 cm) was obtained. The results of greenhouse experiments showed that most of the germinated seeds belong to annual grass species. While the surface cover of most species is related to perennial plants. The highest coverage of Artemisia aucheri was from 2600-2800 m and the lowest percentage of cover belonged to Alyssum linifolium in the elevations of 2800-3000 m. It can be concluded that in the study area, seeds of perennial plants do not have a readiness for germination in soil depths or they should remain in soil for a long time and should be described as stable seed banks. Manuscript profile

This research was conducted to investigate the relationships between soil(organic matter, potassium, phosphorous, sodium, fine gravel, soil texture, EC, lime,gypsum, nitrogen) and environmental (elevation, slope) factors with distribution ofvegetation types in rangelands of Sabzdasht, located in Bafgh, Yazd province at 2012. Forthis purpose, four vegetation types were selected as follows: Artemisia sieberi; Artemisiasieberi, Stipa barbata, Eurotia ceratoides; Dorema ammoniacum, Artemisia sieberi,Eurotia ceratoides; and Hammada salicornica. Minimal area was determined using nestedplots. Afterward, vegetation factors were measured and five soil profiles were dugrandomly in minimal area. In each profile, data for depths of 0-10 and 10-80 cm wererecorded. Principal component analysis was applied to analyze the data. Results showedthat soil texture, potassium, phosphorous, EC and lime had the most impact on variationand distribution of vegetation types. Manuscript profile

Environmental pollution with heavy metals is a global disaster that is related tohuman activities. This study was conducted to determine the extent of heavy metalsaccumulation by plant species in Lia industrial city (Qazvin, Iran) and to investigate theremediative capacity of native plant species grown in the contaminated soils. Soil andindustrial wastewater sampling was done radially along transects with 300 m intervalsfrom exit point of wastewater at three sites. In each sampling point, along 100 m transectswithin 5×2 m plots, the plant samples and soil samples were collected in depth of 0-20 cmand 20-40 cm from rhizosphere zone. Concentration of copper, zinc and chromium in rootand shoot of 11 plant species, soil and wastewater were analyzed in three sits formentioned metals. Bio Concentration factors and translocation factor were determined toensure phytoremediation availability. Results showed that the concentrations of metals inthe soil and wastewater greatly exceeded the threshold limit values. The contents of metalsin soils ranged in the order of Cr>Zn>Cu and in wastewater were in the order ofZn>Cr>Cu, respectively. Results showed that Scirpus maritimus L. and Phragmitesaustralis (Cav.) Trin. ex Steudel presented the highest accumulation of Zn, Cu and Cr intheir root tissues which were suitable for phytostabilization (with a high BCF couple withlow TF). The lowest extractable Zn (7.24 and 3.29 mgkg-1 for shoot and root respectively,BCF=0.07) and extractable Cu (2.56 and 2.80 mgkg-1 for shoot and root respectively,BCF=0.14) were related to Hordeum glaucum L. Moreover, the relatively lowest values ofCr were measured for Taraxacum officinale L. Results indicated that the species, whichhad low metal bioaccumulation in their roots and high TF, could play important roles forremoval of heavy metals through phytoextraction. Manuscript profile

Nowadays, in many rangelands, due to over grazing, and problems that some plantshave in germination, the rate of forage production is greatly reduced. So to take advantages ofthe benefits of such plants, it is necessary to identify and remove barriers of germination andestablishment of suitable plants. The present study was designed to investigate differenttreatments of breaking dormancy and stimulating seed germination of Astragalus adscendensand Astragalus podolobus and offer the most effective treatment to enhance germination andgrowth rate. The experiment was conducted using Completely Randomized Design (CRD)with four replications. Treatments included hot water for 5 minute, 30% hydrogen peroxide for5 minute, 98% sulfuric acid for 5 minute and chilling at 4°C for 10 days. Data were collectedfor seed germination percentage, Germination Rate (GR) and Mean Germination Time(MGT). Based on the results, treatment with 98% sulfuric acid for 5 min for A. adscendensand hot water for 5 min for A. podolobus were the best treatments to break dormancy andstimulate seed germination, so that the germination percentage increased from 44% to 82% inA. adscendens and from 28% to 62% in A. podolobus. In A. adscendens 98% sulfuric acidreduced the amount of MGT from 8 days for control treatment to 5 days. In A. podolobus hotwater treatment was more effective on MGT reduction and reduced it from 7 to 5 days.Although sulfuric acid had the highest effect in breaking dormancy, but its application in avast scale is not easy, therefore the hot water was suggested as the substitution treatment. Manuscript profile

At the beginning of twenty-first century, the water crisis in the priority policy andmanagement is inside and outside of the country as principle thoroughly human, social,economic and political rulers of the country is considered abundant. The World Bank hasannounced that during 1960 and 2025, water resources in Middle East, from 3430 m3 for theeach person in year reach to 667 m3 because of population growth, degradation of naturalresources, extent and spread of deserts. Study of ecohydrology in arid and semi aridrangelands of the world is one of the newest methods for available water resourcemanagement. In this science, all of effective ecology elements on water balance equationwere reviewed. In these areas, a strong relation had been seen between ecology and hydrologyprocesses. In these areas, not only lack of precipitation, but also irregular and unpredictabledistribution of precipitation was problematic. Ecohydrology pays particular attention to theseareas of vegetation and its impact on groundwater and surface water. Manuscript profile

Vegetation cover is the first barrier for the raindrops resulting to the interception and infiltration loss. Interception as one of the main components of ecohydrology equation plays a major role in the water balance of rangelands. However, few studies have been done on the interception of rangeland plants in Iran. This study was carried out to find the interception rate in Astragalus parrowianus through the rainfall portable simulator devices. In addition, the relationship between plant structural factors such as height, large and small diameters, volume and surface of cover and rangeland physiographic factors including altitude, slope percentage and slope in the interception rate was evaluated. Data were collected and analyzed based on simple linear regression models and multivariate analysis (stepwise approach and descending). Results showed that in first group with a volume of 0.002 to 0.02 m3 and canopy cover of 642 m2, 4.421% of total amount of rainfall interception was happened while in second group with volume of 0.02 to 0.087 m3 and canopy cover of 1640 cm2, the interception rate was 1.85% out of total precipitation. In the first group, the interception rate showed a significant correlation (P≤1%) with large diameter (r=-0.73) and the canopy cover at 5% level (r=-0.51). Interception rate in the second group at 1% significant correlations with canopy cover (r=-0.93), diverse small diameter (r= -0.874), large diameter (r=-0.76) and plant volume size was calculated (r=-0.83). From the regression equations obtained in each group, the interception rate can be measured in Astragalus parrowianus without clipping and weighing. Manuscript profile

Some of arid regions problems of Iran are saline and sodic soils. In improvement and reclamation of Iranian arid rangelands, some foreign species of Atriplex had been imported and adapted for many years ago. The most adapted species was Atriplex canescens. At the present research, some environmental factors, vegetative characteristics (Na, Ca, Mg and K), soil properties (moisture, EC, pH, solute Na and K, hard pan, CaCO3, CaSO4, etc), topography, climate (rainfall, temperature, frost) and management characteristics (pruning, enclosure, grazing, irrigation) were studied on Atriplex canescens in two sites in Hossein Abad-e-Hapeshloo of Shahriyar, Tehran province, Iran. At first, field survey was done and proper sampling method was selected. Based on distance between and within furrows, one hectare reference area was selected for each of low and high freshness sites, respectively. A random-systematic sampling method was used for vegetation and soil characteristics, along three transects with a length of 100 m vertical to furrows, nine plots were established. Along each transect, three profiles were dug and samples were taken from two depths (0-30 cm and >30 cm). The wet and dried soil samples were weighted and soil moisture was estimated. Then, some physical and chemical soil properties were evaluated. Results of soil analysis showed significant diffrences between two sites for pH in lower depth, Ec in the higher depth , CaCO3 and sand in the both depth, silt in the lower depth and clay in the higher depth. The amount of Ec , ESP, CaCO3 , clay and Na were increased in lower depth of soil, in contrast, for silt, sand and K, the higher values were obtained in the above layer. For others yraits there was no significant difference between two sites. The mean of vegetation characteristics were more in high freshness site. It was concluded that physical (soil texture) and chemical soil parameters (lime, pH and others) had significant effect on shrub freshness. Moreover, it was likely that management parameters including grazing, irrigation and environmental parameters including topography and water logging had important roles in improper growth of Atriplex shrubs. Manuscript profile

The aim of this research was to investigate the effect of index species, Astragalusammodendron on the associated plants of Agropyron tauri and Bromus tomentellus fromdifferent aspects in Shazand rangeland in southwest of Markazi province. The effects ofspecies density and distribution pattern and then index species on the soil properties werestudied. Based on the randomized – systematic method, 4 transects with a length of 50 m wereestablished. To find the relationships between index and associated plants, 30 points wererandomly chosen along the transects and the number of species was counted from these pointsto a 50 cm distance in different aspects. Along the transects, the distribution pattern of indexplants and their presence and absence were determined. To find the effects of index species onsoil properties, soil samples were taken and soil properties were determined in laboratory.Data were analyzed using SPSS software. The results showed that Astragalus ammodendrondensity with Agropyron tauri and Bromus tomentellus were similar to the east and westaspects and near distances. Astragalus ammodendron distribution pattern was randomizedwith a tendency toward the clumped pattern. The effect of Astragalus ammodendron on thesoil characteristics was not significant except for the north aspect. Generally, it is concludedthat the effect of Astragalus ammodendron (index species) on Agropyron tauri and Bromustomentellus densities was not significant. Manuscript profile

چکیده در این پژوهش اثر بازدارندگی اکالیپتوس و عمق کشت بر جوانه زنی و رشد اسپرس در قالب آزمایش فاکتوریل براساس طرح پایه کاملأ تصادفی با چهار تکرار و دو فاکتور مورد بررسی قرار گرفت. فاکتور اول دگرآسیبی در پنج سطح 0، 005/0، 01/0، 02/0 و 03/0% وزنی پودر برگ اکالیپتوس در 1000 گرم خاک و فاکتور دوم عمق کاشت در چهار سطح 5/0 (شاهد)، 5/1، 3 و 5/4 سانتی متر بود. اثر دگرآسیبی، عمق کشت و اثر متقابل آنها بر تمامی صفات به استثنای طول ریشه چه معنی دار بود. اثر دگرآسیب بر وزن خشک اندام هوایی بیشتر از سایر صفات بود. همچنین افزایش عمق کشت منجر به کاهش طول ریشه چه و ساقه چه و سایر صفات رویشی مورد اندازه گیری شد. در مجموع، افزایش میزان دگرآسیبی اکالیپتوس و عمق کشت بر مؤلفه های رشد اسپرس تأثیر منفی داشتند و زمانی که این دو عامل هم زمان لحاظ شدند، تأثیر نامطلوب آنها بیش از زمانی بود که بطور مستقل در نظر گرفته شدند. بنابراین در نظر گرفتن اثرات متقابل آللوپاتی و عمق کشت می تواند نقش تعیین کننده ای در بهینه سازی تولید اسپرس در اراضی دارای اکالیپتوس داشته باشد. Manuscript profile