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دسترسی آزاد مقاله
1 - تغییرات گروههای عملکردی گیاهان در اثر آتشسوزی در مراتع نیمه استپی استان چهارمحال و بختیاری
الهام بنی هاشمی علی اصغر نقی پوربرجزمینه و هدف: درک چگونگی پاسخ گیاهان به آتشسوزی برای پیشبینی ویژگیها و پراکنش بسیاری از زیست بومها ضروری است. هدف این تحقیق شناسایی، طبقهبندی و تجزیه و تحلیل صفات عملکردی گیاهان است که بتوانند به عنوان وسیلهای برای شناسایی تغییرات جوامع گیاهی در اثر آتشسوزی در فوا چکیده کاملزمینه و هدف: درک چگونگی پاسخ گیاهان به آتشسوزی برای پیشبینی ویژگیها و پراکنش بسیاری از زیست بومها ضروری است. هدف این تحقیق شناسایی، طبقهبندی و تجزیه و تحلیل صفات عملکردی گیاهان است که بتوانند به عنوان وسیلهای برای شناسایی تغییرات جوامع گیاهی در اثر آتشسوزی در فواصل زمانی مختلف مورد استفاده قرار گیرند. روش بررسی: مطالعه حاضر در منطقه کرسنک در شهرستان بن و در استان چهارمحال و بختیاری انجام یافته است. تعداد 6 سایت با سابقه آتشسوزی یکساله و پنج ساله انتخاب و نمونهبرداری به روش تصادفی طبقه بندی شده انجام یافت. در هر پلات پس از شناسایی گونههای موجود، درصد پوشش هریک از گونهها تخمین زده شد و صفات گیاهی اندازهگیری شدند. یافته ها: نتایج نشان داد که صفات گیاهی همچون ارتفاع گیاه، تولید، شاخص سطح برگ SLA، مساحت و وزن خشک برگ، درصد ترکیب گونههای گندمی، علفی و بوتهای، درصد ترکیب گیاهان با خوشخوراکی کلاس II و III، درصد ترکیب گونههای با اشکال زیستی همیکریپتوفیت و کامفیت در دو منطقه آتشسوزی و شاهد اختلاف معنیداری داشتند (05/0Sig ≤). طبق نتایج تحلیل مولفه های اصلی، تأثیرپذیرترین صفات به ترتیب عبارت از شاخص سطح برگ SLA، خوشخوراکی کلاس II، طول برگ، درصد ترکیب همیکریپتوفیت، درصد ترکیب پهنبرگان علفی و مساحت برگ بودند که ارتباط مستقیمی با آتشسوزی پنجساله و آتشسوزی یکساله داشتند. بحث و نتیجه گیری: بنابراین میتوان نتیجهگیری نمود که صفات گیاهی نقش مهمی در تعیین پاسخ گونههای گیاهی به آشفتگیهای محیطی دارند و از این رو میتوانند بر سیر توالی ثانویه مرتع نیمه استپی پس از آتشسوزی تأثیرگذار باشند. پرونده مقاله -
دسترسی آزاد مقاله
2 - فنولوژی گونههای Ferula ovinia و Poa bulbosa و بهترین زمان ورود و خروج دام در مرتع گوراب اصفهان
مریم غلامی مصطفی سعیدفرزمینه و هدف: مطالعه فنولوژی یکی از عوامل مهم و اساسی در اعمال مدیریت جهت بهره برداری بهینه از پوشش گیاهی است. گونه های مرتعی Ferulaovinia وPoabulbosaاز نظر علوفه ای و مرتعی و همچنین جلوگیری از فرسایش خاک از اهمیت خاصی برخوردار هستند. این تحقیق به منظور تعیین زمان مناسب چکیده کاملزمینه و هدف: مطالعه فنولوژی یکی از عوامل مهم و اساسی در اعمال مدیریت جهت بهره برداری بهینه از پوشش گیاهی است. گونه های مرتعی Ferulaovinia وPoabulbosaاز نظر علوفه ای و مرتعی و همچنین جلوگیری از فرسایش خاک از اهمیت خاصی برخوردار هستند. این تحقیق به منظور تعیین زمان مناسب ورود و خروج دام از مرتع، درسایت گوراب اصفهان در 35 کیلومتری غرب شهرستان فریدونشهر به مدت 4 سال (1395-1392) شده است. روش بررسی: در این تحقیق ده پایه انتخاب و اطلاعات مربوط به مراحل فنولوژی برای هر پایه در مقاطع زمانی 7 روزه در مرحله رویشی و 15 روزه در مرحله زایشی اندازه گیری و در فرم ویژه ای ثبت گردید. هم زمان آمار هواشناسی روزانه از ایستگاه هواشناسی مستقر در محل اجرای طرح برداشت شد. یافته ها: رشد رویشی گونه ovinia Ferulaاز اواخر اسفند آغاز و تا اواسط خرداد ادامه یافت. دوره گلدهی اوایل خرداد آغاز و تا اواخر خرداد به طول انجامید. مرحله رسیدن بذر از اواسط خرداد آغاز و تا اواخر تیر کامل شد. در گونه Poabulbosaرشد رویشی از اواخر اسفند شروع و تا اواسط خرداد ادامه داشت. دوره گل دهی از اوایل خرداد شروع و تا اواسط خرداد ادامه یافت. مرحله رسیدن بذر از اواسط خرداد شروع و تا اوایل تیر به پایان رسید. بحث و نتیجه گیری: نتایج نشان داد که با توجه به رفتار گونه های مورد مطالعه در بروز پدیده های زیستی در سال های مختلف مطالعه این امکان فراهم شده است که رفتار گیاهان را با تغییرات رطوبتی و دما در شرایط مختلف بررسی کنیم. بهترین زمان و ورود و خروج باید براساس نحوه بروز پدیده های زیستی در گونه ی Poa bulbosa تنظیم شود که در این صورت براساس مطالعات انجام یافته بهترین زمان می تواند در آخر اردیبهشت و اوایل خرداد باشد و زمان خروج دام به علت وجود پایه های خشک شده به ویژه در گونه ی Ferula ovina که در زمان خشک شدن (شروع تابستان) مورد استفاده دام قرار می گیرد، می تواند تا اواسط شهریور (مشروط بر رعایت تعداد دام مبتنی بر ظرفیت مرتع)، ادامه یابد. پرونده مقاله -
دسترسی آزاد مقاله
3 - Determining Timely Entry and Exit of Livestock in Rangelands Using Bromus tomentellus Phenological Stages (Case Study: Goorab Rangeland of Isfahan)
Maryam Gholami Mostafa SaeedfarIn the rangelands of Iran, the lack of appropriate grazing management is one of the major problems ultimately leading to untimely and excessive grazing intensity of forage. Accordingly, most of the rangelands show a retrogression trend and poor conditions. In forage spe چکیده کاملIn the rangelands of Iran, the lack of appropriate grazing management is one of the major problems ultimately leading to untimely and excessive grazing intensity of forage. Accordingly, most of the rangelands show a retrogression trend and poor conditions. In forage species, phenological stage is one of the most important criteria for range management. Bromus tomentellus species is an important range species for forage production controlling soil erosion. In order todeterminethetimely entry and exit of livestock in rangelands based on phenological stages of B. tomentellus, this study was conducted in Goorab rangeland, Fereydoun Shahr, Iran during four years (2007-2010). In this research, ten plant bases of B. tomentellus were selected and their phonological stages were recorded in a 7-day interval period. At the same time, meteorological data were collected from meteorological station adjacent to the study site. According to the occurrence of biological phenomena in the different years of study (wet conditions in 2007, severe droughts in 2008 and normal years in 2009 and 2010) and also based on plant growth stage in the 4 year study, it was concluded that 30th April and 31th May were suggested as the best time for livestock to enter and exit from the rangeland, respectively. پرونده مقاله -
دسترسی آزاد مقاله
4 - Role of Plant Species and Ecological Patches in Conserving and Fixing Natural Landsʹ Soil Using Landscape Functional Analysis (LFA) (Case Study: Dehbar Rangeland, Torghabeh, Mashhad, Iran)
Reyhaneh Azimi Gholam Ali Heshmati mohamad kia kianian samira hossein jafari Dawood ZakeriDegradation of plant patches is considered as one of the indices for rangeland degrading health condition. Investigating the accuracy of triple indices (infiltration, stability and soil nutrient cycle) presented by LFA method seems necessary to determine its efficiency چکیده کاملDegradation of plant patches is considered as one of the indices for rangeland degrading health condition. Investigating the accuracy of triple indices (infiltration, stability and soil nutrient cycle) presented by LFA method seems necessary to determine its efficiency in semi-arid areas with the least cost. This study aims to investigate the role of vegetative species and growing forms on soil surface characteristics in Dehbar semi-steppe rangelands, Iran in 2014. So, eleven soil surface characteristics in different vegetative types each of 3 replicates were measured using landscape functional analysis (LFA). Then, the measured parameters were classified based on their sustainability, permeability and food chain continuum for each plant species. According to the results obtained from various analytical investigations, the ecological patches consisting of Artemisia aucheri (46.83%) and complex of Artemisia aucheri and Agropyron intermedium (with the amount of 41.7%) were higher than other forms of vegetative growth for soil sustainability. The complex of Acantholimon sp., Artemisia aucheri and Astragalus commixtus had the lowest amount in terms of soil sustainability (38%). The comparison of soil permeability indices for different types of plant covers showed that the percentage of Artemisia aucheri (32.06%) and complex of Artemisia aucheri and Agropyron intermedium (33.5%) had the highest amount while all other patches were equal and had the lowest amount. In terms of food chain, the ecological patches such as Artemisia aucheri (25.63%) and complex of Artemisia aucheri and Agropyron intermedium (27.66%) had the highest amount. The complex of Artemisia aucheri and Astragalus commixtus (16.36%), the complex of Acantholimon sp., Artemisia aucheri and Astragalus commixtus (13.63%) and the complex of Acantholimon sp. and Agropyron intermedium (15.36%) had the lowest values (p≤0.01). Therefore, Artemisia aucheri (shrub) and a complex of Artemisia aucheri and Agropyron intermedium (grass) patches, introduced as ecological indicators for the study area, are suggested for rangelands restoration. پرونده مقاله -
دسترسی آزاد مقاله
5 - Changes in Vegetation and Soil Characteristics of Steppe and Semi-Steppe Rangelands under Impact of Solar Power Plant in Absard and Shahrerey, Iran
Mahshid Souri Nadia kamaliIn recent years, Iran has begun to move towards the development of the use of renewable energy sources in line with global developments. In this study, Side effects of two solar power plants on rangeland condition were studied. These solar power plants have been constru چکیده کاملIn recent years, Iran has begun to move towards the development of the use of renewable energy sources in line with global developments. In this study, Side effects of two solar power plants on rangeland condition were studied. These solar power plants have been constructed using mosaic panels for installation obliquely on 16 ha in Absard rangeland (semi-steppe) and 23 ha in Shahrerey rangeland (steppe), Iran in 2016. In this study, sampling was performed in both rangelands for solar power plant and adjacent control. Sampling was done in 2019, based on the use of 100 m transects with one and two square-meter plots for semi-steppe and steppe, respectively, with a distance of 10 m on transects, systematically. Soil samples were taken from a depth of 0-30 cm from the beginning, middle and end of each transect as a composite sample. The obtained data were compared using independent T-test by SPSS software. Results showed that in comparing of soil factors between solar power plant and adjacent control site in both rangelands, there were no significant differences between treatments. However, vegetation cover and total biomass between solar power plant and control in Absard were significantly different (P<0.01). In Absard site, the vegetation cover (39% vs. 51%) and total biomass with values of (254 vs. 312 kg/h) were obtained in solar power plant and control, respectively, so the panel significantly reduced the performance of the vegetation cover and biomass in semi-steppe rangeland. In contrast, In Shahrerey , the vegetation factors between the solar power plant and the control were not significantly different from each other. So, from the point of view of natural resources and according to the results of the present study, for electricity generation, the establishment of solar power plant in the steppe rangelands is recommended as compared to semi-steppe rangeland. پرونده مقاله -
دسترسی آزاد مقاله
6 - Evaluation of Meteorological Factors in Estimating Forage Production in Steppe and Semi-steppe Rangelands of Iran
Hossein Arzani Zahra Mansouri Aliraza Moghaddamnia Javad Motamedi Shahram Khalighi SigaroudiRangeland production is especially important in meeting food requirement of rangeland societies. Sometimes, historical data are required for long-term grazing capacity estimation. Regression equations that are reasonably reliable for predicting forage production from pr چکیده کاملRangeland production is especially important in meeting food requirement of rangeland societies. Sometimes, historical data are required for long-term grazing capacity estimation. Regression equations that are reasonably reliable for predicting forage production from precipitation characteristics have been developed for rangeland yield estimation. In this research, the relationship between forage production and meteorological factors was evaluated with six-year data for Pashaylogh and Incheboron rangelands (2003 to 2007 and 2017- Golestan province, Iran) and eleven-year data for Nemati rangeland (1998 to 2007 and 2017- Markazi province, Iran). For sampling, four parallel transects with a length of 300 m and at a distance of 100 m from each other were established in the steppe area (Nemati) and six 200-m transects were created in the semi-steppe area (Pashaylogh and Incheboron) and they were located parallel and at a distance of 100 m from each other. Due to the need for uniformity in the data of the rangelands of different provinces and their comparison, plot size of 1×2 m was selected in steppe site, and 1×1 m for semi-steppe sites. Data analysis was done through regression models. The results showed that forage production was related to temperature and precipitation rather than other meteorological factors (temperature, precipitation, sunlight hours, relative humidity, evapotranspiration and average wind speed). The best equation that can predict the relationship between meteorological data and forage production was August precipitation and temperature (R2=0.88) in Pashaylogh, the precipitation of June (R2=0.88) in Incheboron rangelands. There was a relationship between forage production (R2=0.79) with precipitation and temperature in July and in Nemati rangeland. The forage production index was determined based on effective meteorological factors and The Standardized Precipitation-Evapotranspiration (SPEI) drought index. According to meteorological data, a coefficient could be obtained to estimate long-term rangeland production and prevent from forage loss. پرونده مقاله