Exclosure

دسترسی آزاد مقاله

1 - بررسی تاثیر قرق بر ویژگی های پوشش گیاهی مراتع رزبند استان قم
سید مهدی ادنانی علیرضا افتخاری پرویز غلامی حسین توکلی نکو عباس پورمیدانی

10.30495/jrnr.2022.67076.10245

بررسی تغییرات پوشش گیاهی مراتع در فواصل زمانی معین و‌ آگاهی از روند وضعیت آن، یکی از موارد مهم برای برنامه‌ریزی و اعمال مدیریت ‌صحیح بهره‌برداری از مراتع است. تحقیق حاضر به منظور بررسی روند تغییرات برخی ویژگی های پوشش گیاهی در مراتع چرا شده و قرق در منطقه رزبند استان چکیده کامل

بررسی تغییرات پوشش گیاهی مراتع در فواصل زمانی معین و‌ آگاهی از روند وضعیت آن، یکی از موارد مهم برای برنامه‌ریزی و اعمال مدیریت ‌صحیح بهره‌برداری از مراتع است. تحقیق حاضر به منظور بررسی روند تغییرات برخی ویژگی های پوشش گیاهی در مراتع چرا شده و قرق در منطقه رزبند استان قم صورت پذیرفت. اندازه‌گیری پوشش گیاهی در قالب ترانسکت‌های جفتی با فاصله 10 متر از هم انجام شد. هر جفت ترانسکت شامل ۲۰ پلات بود. پلات ها به ابعاد 1×1 متر به فاصله 3 متر از هم و به تعداد 10 عدد بر روی هر ترانسکت قرار گرفت. در نهایت تعداد 240 پلات (120 پلات در داخل و 120 پلات در خارج قرق) مورد ارزیابی قرار گرفت. آنالیز داده ها به وسیله نرم افزار SPSS و بررسی تنوع و غنای گونه ای با استفاده از نرم افزار PAST صورت پذیرفت. از مجموع 8 تیره گیاهی، تعداد 6 تیره دارای اختلاف معنی داری در داخل و خارج قرق بود. انجام قرق در منطقه مورد مطالعه باعث افزایش معنی دار پوشش تاجی فرم های رویشی بوته ای و پهن برگان علفی گردید، درحالی که فرم رویشی گندمیان اختلاف معنی داری نداشت. فرم های زیستی کاموفیت ، همی کریپتوفیت و تروفیت و نیز گونه های گیاهی با کلاس خوشخوراکی I و III پاسخ معنی دار و مثبت به انجام قرق نشان دادند. آزمون t برای شاخص های تنوع و غنای گونه ای نشان داد، شاخص تنوع سیمپسون و شانون وینر و نیز شاخص غنای مارگالف دارای تفاوت معنی دار می باشد. این امر در حالی است که شاخص غنای منهینیک و شاخص یکنواختی تفاوت معنی داری در داخل و خارج قرق نداشت. همچنین آنالیز RDA به منظور بررسی تاثیر قرق بر کل گونه های گیاهی موجود در پلات ها نشان داد قرق بر پوشش گیاهی اثر معنی دار داشته است (29/66 = F، 0/001 = P). نتایج این تحقیق بیانگر این مطلب بود که قرق کوتاه مدت می تواند شرایط را برای بازسازی و تجدید شادابی گونه هایی نظیر Bufonia macrocarpa و Artemisia sieberi در مراتع مناطق خشک مانند رزبند قم فراهم سازد. پرونده مقاله

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2 - تاثیر قرق بر برخی خصوصیات شیمیایی و آلی خاک (مطالعه موردی: حوضه گنبد شهر همدان)
عباس قبادی داوود اخضری

10.22034/jest.2021.32769.4059

زمینه و هدف: چرای دام به‌عنوان یکی از آشفتگی‌های اکولوژیک باعث تغییر در خصوصیات خاک و پوشش گیاهی مراتع می‌شود. هدف از این تحقیق مطالعه اثر قرق بر ذخایر میکروبی زی‌توده و برخی خصوصیات خاک مراتع حوضه گنبد شهر همدان است. یکی از این مناطق تحت قرق 20 ساله است و منطقه دیگر در چکیده کامل

زمینه و هدف: چرای دام به‌عنوان یکی از آشفتگی‌های اکولوژیک باعث تغییر در خصوصیات خاک و پوشش گیاهی مراتع می‌شود. هدف از این تحقیق مطالعه اثر قرق بر ذخایر میکروبی زی‌توده و برخی خصوصیات خاک مراتع حوضه گنبد شهر همدان است. یکی از این مناطق تحت قرق 20 ساله است و منطقه دیگر در خارج از منطقه حفاظت‌شده تحت چرای دام‌ است. روش بررسی: نمونه‌گیری خاک بر اساس روش سیستماتیک- تصادفی انجام شد. پنج ترانسکت 1000 متری با جهت شمالی-جنوبی به‌طور تصادفی در هر منطقه (قرق و چرا شده) به‌صورت جداگانه در نظر گرفته شد. نمونه‌برداری خاک در هر 100 متر ببا روش سیستماتیک- تصادفی و در اردیبهشت ماه سال 95 انجام گرفت. عناصر مس، آهن، پتاسیم، منیزیم، منگنز و روی به‌وسیله طیف‌سنجی جذب اتمی، اسیدیته با دستگاه pH متر، وزن مخصوص ظاهری از روش کلوخه‌ای، نیتروژن کل از روش کجلدال، کربن آلی و ماده آلی خاک از روش اکسیداسیون تر والکی بلک و زیتوده میکروبی کربن به روش تدخین- استخراج محاسبه شد. یافته ها: پس از انجام تجزیه و تحلیل‌های آماری مشخص شد که غلظت عناصر پتاسیم و روی در خاک منطقه قرق و غلظت عنصر منیزیم در خاک منطقه چرا شده افزایش معنی‌داری در سطح 5 درصد داشته است. اسیدیته خاک در منطقه چرا شده از 01/7 در منطقه قرق به مقدار 23/7 افزایش یافت. رطوبت خاک در منطقه چراشده کاهش معنی‌داری ‌یافته و از 11/27 درصد در منطقه قرق به مقدار 12/18 درصد رسیده بود. جرم مخصوص ظاهری خاک نیز در منطقه چراشده 16/1 گرم بر سانتی‌متر مکعب بود که در منطقه قرق کاهش معنی‌داری داشته و به 98/0 گرم بر سانتی‌متر مکعب رسید. زی‌توده میکروبی کربن در خاک مناطق قرق و چرا شده تفاوت معنی‌داری داشت. مقایسه میانگین زی‌توده میکروبی کربن در خاک مراتع گنبد نشان داد که این پارامتر از 83/0 گرم بر کیلوگرم در منطقه چرا شده به مقدار 95/0 گرم بر کیلوگرم رسیده و افزایش معنی‌داری داشته است. بحث و نتیجه گیری: نتایج به‌دست‌آمده نشانگر این نکته است که در منطقه قرق با اعمال قرق، خصوصیات خاک در مسیر توالی و رسیدن به شرایط ایده آل قرارگرفته‌ است اما همچنان این منطقه نیاز به توجه و ادامه حفاظت دارد. پرونده مقاله

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3 - بررسی اکولوژیکی تغییرات وضعیت مرتع و ارتباط آن با گونه های سمی
کوروش خلعتبری محمدحسن جوری حمیدرضا محرابی

تغییرات شدید ساختار بهره برداری از مراتع باعث دگرگونی پوشش گیاهی مراتع شده است که هجوم گونه های سمی در مناطق عاری از پوشش گیاهان بومی بعنوان نمادی از این تغییرات مطرح است. آگاهی از درجات وضعیت مراتع باعث اتخاذ تصمیم درست مدیریت بهره برداری از مراتع می گردد. به منظور برر چکیده کامل

تغییرات شدید ساختار بهره برداری از مراتع باعث دگرگونی پوشش گیاهی مراتع شده است که هجوم گونه های سمی در مناطق عاری از پوشش گیاهان بومی بعنوان نمادی از این تغییرات مطرح است. آگاهی از درجات وضعیت مراتع باعث اتخاذ تصمیم درست مدیریت بهره برداری از مراتع می گردد. به منظور بررسی روند این تغییرات و ارتباط آن با حضور گونه های سمی، مراتع جواهرده رامسر تحت سه تیمار قرق بلندمدت (30 سال)، کوتاه مدت (7 سال) و منطقه چرایی انتخاب شد. به کمک پیمایش صحرایی اقدام به جمع آوری گونه ها و شناسایی آنها توسط منابع معتبر شد. تعدادی پلات به روش تصادفی در هر سایت به منظور تعیین وضعیت و گرایش انداخته شد. وضعیت مرتع به روش شش فاکتوره و گرایش نیز با استفاده از روش ترازوی گرایش تعیین شد. همچنین به منظور تعیین میزان مصرف گونه های سمی توسط دام، از روش شمارش لقمه استفاده شد. نتایج نشان داده است که در این منطقه 133 گونه متعلق 19 تیره و 56 جنس حضور دارند. همچنین با توجه به وضعیت خوب (قرق بلندمدت)، متوسط (قرق 7 ساله) و ضعیف (تحت چرا)، 39 گونه بصورت سمی بوده است. 46 گونه مورد مصرف دام قرار گرفت که از بین آنها 15 گونه دارای خاصیت سمی بوده اند. بنابراین مطالعه روند وضعیت مرتع در منطقه نشان داده است که در مواقعی که فشار چرایی شدید می گردد و یا اینکه مراتع تحت چرای مداوم قرار دارند، گونه های بومی عرصه را به نفع گونه های مهاجم (که اکثرا غیرخوشخوراک و سمی هستند) خالی می کنند. اما بعضی از گونه های سمی بومی نیز وجود دارند که با توجه به خاستگاه اکولوژیک خود، عرصه عاری از گونه های خوشخوراک را تحت اشغال خود درمی آورند. پرونده مقاله

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4 - Rangeland Restoration Analysis on the South Slope of Al-Jabal Al-Akhdar, Northeast Libya
Adel Mahmoud Mohd Bin Ismail Mohamad Alias Alias Sood

This study was conducted on the south slope of Al-Jabal Al-Akhdar (the Green Mountain) rangelands, northeast Libya to investigate changes in perennial plant species richness, landscape function and soil surface condition in order to determine whether exclosures are effe چکیده کامل

This study was conducted on the south slope of Al-Jabal Al-Akhdar (the Green Mountain) rangelands, northeast Libya to investigate changes in perennial plant species richness, landscape function and soil surface condition in order to determine whether exclosures are effected strategy for the improvement and rehabilitation of rangeland ecosystem at the regional level. Four study sites are positioned along a strong north-south rainfall gradient. A total of 28 monitoring sites were reinstalled and assessed between May and December 2014, the sites were then initially installed and assessed between the period of May and December 2006. The monitoring site layout is based on the Western Australia Rangeland Monitoring System (WARMS). The response variables measured were those included in the protocols of Landscape Function Analysis technique (LFA). Based on the results, LFA indices were in the low and medium scales in all of the monitoring sites within the exclosures. Notably, it is considered a good comparison tool for what it is currently occurring at the target grazing areas. No changes in perennial plant species richness amid the study areas, with the exception of the Thahar Altair area (TT). Overall, in estimation, at least 10 years of protection from grazing is required in the highest rainfall area (Maduar Zetun), and a considerably longer period in the lower rainfall areas to the south before vegetation cover and soil surface conditions recover sufficiently to be re-exposed to grazing. Consequently, grazing should be controlled to conserve national forage resources. پرونده مقاله

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5 - Effects of Exclosure on Soil Properties in Winter Rangelands in Golestan Province, Iran
Hamid Niknahad Gharmakher Esmaeil Sheidai-Karkaj Isa Jafari

Rangeland degradation is one of the global concerns affecting the pastoralists and those who suffer from its negative environmental consequences. Grazing exclosure has been extensively used among the techniques implemented by the government to protect the fertility of t چکیده کامل

Rangeland degradation is one of the global concerns affecting the pastoralists and those who suffer from its negative environmental consequences. Grazing exclosure has been extensively used among the techniques implemented by the government to protect the fertility of threatened rangelands. The impact of exclosure has been a controversial issue; therefore, it is important to understand its effectiveness in restoring the degraded rangeland ecosystems. The goal of the present study was to evaluate the changes in some physico-chemical properties of soils following the grazing exclusion as compared to the adjacent grazed areas in three winter rangelands in Golestan province, Iran in 2011-2012. In each rangeland, ten soil samples were taken at the depth of 0–20 cm. Then in the laboratory, some soil properties such as soil texture, bulk density, porosity, saturated humidity, pH, EC, OM, total N, lime content, the amount of exchangeable Na+, K+, Mg++ and Ca++ were measured. Data of exclusion and grazed areas were analyzed using the independent T test in SPSS18 software. The results demonstrated that the establishment of exclosure had positive significant effects on the soil physico-chemical properties in Gomishan and Inchehbroun rangelands. So, a significant increase in the mean value of porosity, saturated humidity, OM and total nitrogen (p<0.05) as well as the significant decrease in bulk density and lime content (p<0.05) was observed in these rangelands. According to the results, the application of exclosure is recommended in Gomishan and Inchehbroun rangelands. پرونده مقاله

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6 - Forage Loss Valuation under Traditional Pastoralism in Arid to Semiarid Rangelands of Iran
Azam Khosravi Mashizi Mohsen Sharafatmandrad

10.30495/rs.2023.689643

Economic valuation of rangelands is one of the best methods for conservation goals. A study was conducted to assess the economic value of forage loss under the two main forms of traditional pastoralism i.e. sedentary pastoralism and nomadism in historic grazing semiarid چکیده کامل

Economic valuation of rangelands is one of the best methods for conservation goals. A study was conducted to assess the economic value of forage loss under the two main forms of traditional pastoralism i.e. sedentary pastoralism and nomadism in historic grazing semiarid rangelands in Khabr National Park, Kerman province, Iran in 2019. Forage production was measured by clip-and-weigh method and forage quality was assessed using Crude Protein (CP) and Acid Detergent Fibre (ADF) indices. The replacement cost method was used for forage valuation and Total Digestible Nutrients (TDN) was used as the principal character of forage value. Forage production was decreased by 65% and 78% under nomadism and sedentary pastoralism respectively as compared to exclosure. Assessing species distribution along grazing gradient, using Detrended Correspondence Analysis (DCA), showed that forage quality decreased as grazing intensity increased due to plant composition change. Lathyrus annuus and annual grasses were the highest and lowest value forage, respectively. The forage values for exclosure area, near exclosure area and near village and pastoral tent were 75 $, 20-25 $ and 6-10 $.ha-1.year-1, respectively, indicating 65 to 92% reduction in the forage value in traditional pastoralism forms than to exclosure area. Therefore, there was priority to perform appropriate grazing systems such as rest rotational grazing to improve the condition of historic grazing lands and pastoral’s income. پرونده مقاله

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7 - The Impact of Exclosure on the Rehabilitation of Steppe Vegetation at Naâma Rangelands in Algeria
Anteur Djamel Benaradj Abdelkrim Boucherit Hafidha

10.30495/rs.2022.682375

The Naâma steppe rangelands in Algeria are undergoing continuous degradation due to overgrazing, land clearing, silting up and desertification. Given the seriousness of this situation and the ecological deterioration of these steppe rangelands, the need for an act چکیده کامل

The Naâma steppe rangelands in Algeria are undergoing continuous degradation due to overgrazing, land clearing, silting up and desertification. Given the seriousness of this situation and the ecological deterioration of these steppe rangelands, the need for an action plan to preserve and rehabilitate the degraded rangelands is becoming more and more urgent. Among the solutions proposed for the degraded rangeland rehabilitation, the exclosure has proven to be an effective and inexpensive fight against the degradation factors. This study aimed to quantifying the effectiveness and impact of the exclosure rehabilitation technique after a protection period (2009-2015) in the esparto grasslands (Stipa tenacissima L.) ranges located at Djedida in the Naâma region (Western Algeria). The adopted methodological approach is that of the comparative analysis of vegetation descriptors based on a quantitative (recoveries, floristic richness) and qualitative assessment, evaluation of the plant cover (biological, systematic, biogeographic phytodiversity) between the exclosure rangeland and the nearby located grazing rangeland having about the same climato-edaphic station conditions. Thirty phytoecological surveys were carried out for the exclosure rangeland as well as on an unprotected control range (outside the exclosure area). The comparative analysis of the obtained results shows that, in general, the exclosure rangeland is relatively much richer in terms of quantity and quality than the grazing range. In the exclosure areas, the vegetation was more productive and more diversified, the average vegetation cover was 25% vs 5%, Number of species was 41 vs. 14 and density was 19.3 vs, 4.6 plants/100m² for exclosure and open grazing range, respectively. On the other hand, in the grazing range, the vegetation was much diversified in terms of biological, systematics and biogeographic aspects in terms of floristic diversity. The impact of exclosure of pastoral improvement was interesting after a period of more than 6 years. پرونده مقاله

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8 - Study on Vegetation Changes of Natural Ranges in KhoyBilehvar Semi-Steppic Area of West Azarbaijan Province
M.T. Gaemi M. Akbarzade Sh. Abedi

The study of the exclosure effects on the vegetation changes undergrazing and non-grazing conditions in the rangeland areas has particularimportance in the rangeland improvement and revivification projects. Theresearch was accomplished in semi-steppe KhoyBilehvar area, چکیده کامل

The study of the exclosure effects on the vegetation changes undergrazing and non-grazing conditions in the rangeland areas has particularimportance in the rangeland improvement and revivification projects. Theresearch was accomplished in semi-steppe KhoyBilehvar area, from 1999 to2005. Vegetation cover was annually measured within fixed plots during transact.The results showed that during nine years of research, on KhoyBilehvarexclosure, the total canopy cover has increased inside the exclosure, and thehighest increase was observed in the perennial grasses (more than 3.5) andperennial Forbs (more than 2.5). Outside the exclosure, the total vegetation coverwas almost constant and changes were less in vegetation cover types. Within theexclosure, some desirable species appeared consisting almost 19% of vegetationcomposition. Medium species proportion in the plant composition increased tomore than two times and undesirable species decreased by half. Whereas, outsidethe exclosure, scarce desirable species and medium species of vegetation ratiohas increased a little. The vegetation average of annual species during the studywithin exclosure is more than outside and the vegetation average of forbs insideand outside the exclosure is more than annual grasses. Nine year research inBilehvar exclosure showed that the correlation between precipitation changes andvegetation cover was significant in the most species. پرونده مقاله

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9 - Selection of Appropriate Estimation Methods of Range Conditions (Case Study: Kabirkooh Rangelands of Zagros, Iran)
Freidoon Soleimani Parviz Karami Nosrat Safaian

The range conditions explain its health as a management tool. Obviously, theimplementation of this important assessment requires the most appropriate study methodfor each region. In order to select the most appropriate methods of range conditions inKabirkooh grasslands چکیده کامل

The range conditions explain its health as a management tool. Obviously, theimplementation of this important assessment requires the most appropriate study methodfor each region. In order to select the most appropriate methods of range conditions inKabirkooh grasslands of Zagros in Iran, five estimation methods (i.e. six-factor, fourfactor,vegetation and soil combination, value of pasture and climax) were studied in threekey and critical areas. In each area, five stations were selected using the randomizedsystematicmethod. The differences between methods were analyzed using the factorialexperiment by the help of the randomized complete blocks design with five replications.The results showed that there were significant differences (p<0.01) between both rangeconditions’ determination methods and different areas. Regarding Kabirkooh rangelands incurrent circumstances, four-factor method for semi-arid region is more applicable for therange condition determination. Biomass production and range conditions had a closerelationship using Pearson correlation test (p<0.01, r=0.86). پرونده مقاله

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10 - Effects of Grazing Exclusion on Plant Productivity and Carbon Sequestration (Case Study: Gomishan Rangelands, Golestan Province, Iran)
Hamid Niknahad Gharmakher Isa Jafari Foutami Arezou Sharifi

In recent years, rangelands have been regarded as potential carbon sinks. One of the most widely suggested options to sequester more C in rangelands is the restoration of the degraded rangelands through grazing the exclusion. In present study, the effects of exclusion o چکیده کامل

In recent years, rangelands have been regarded as potential carbon sinks. One of the most widely suggested options to sequester more C in rangelands is the restoration of the degraded rangelands through grazing the exclusion. In present study, the effects of exclusion on the carbon sequestration of Gomishan rangelands were investigated. Three transects were established in a key area inside and outside the exclosure. In each transect, ten plots were established systematically and in each plot, the number of plant individuals for each plant species was recorded and used to estimate the density of each species per unit area. In order to estimate the plant biomass, a few individuals of each species were sampled by the clipping and weighing method. The carbon content of aerial and root biomass were obtained by the combustion of 10 g of oven-dried samples. Five soil samples at the depths of 0–10 and 10–20 cm were taken along each transect and then, transported to the laboratory. The soil organic carbon percent was determined by the Walkley–Black method. Plant data analysis was performed by one way analysis of variance (ANOVA) and Tukey test. The rate of soil carbon sequestration inside and outside the exclosure was compared using the independent T test at significance level of 1%. Finally, the economic benefit of sequestrated carbon was estimated. The results revealed that the response of plant and soil carbon storage to the exclosure in Gomishan rangelands was positive and there was a significant difference between exclosure and grazing areas for the stored carbon of plant biomass and soil. After a 20 year exclosure, the value of carbon sequestration per hectare in Gomishan rangelands was estimated as 14743 $/h. It can be argued that the education and extension of carbon sequestration in Iran will offer new incentives to restore the degraded rangelands. پرونده مقاله

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11 - Estimation of Soil Carbon Sequestration Rate in Steppes (Case Study: Saveh Rudshur Steppes)
M. Mahdavi H. Arzani M. Mesdaghi KH. Mahdavi J. Mahmodi M. Alizadeh

Since Renaissance, the natural ecosystems have fallen into a complete state ofdisarray due to the rise in the amount of carbon dioxide. Soil, the unsparing stuff, is one of themajor sources of carbon storage, and plays a paramount role in the global equilibrium ofcarbon چکیده کامل

Since Renaissance, the natural ecosystems have fallen into a complete state ofdisarray due to the rise in the amount of carbon dioxide. Soil, the unsparing stuff, is one of themajor sources of carbon storage, and plays a paramount role in the global equilibrium ofcarbon as well as carbon sequestration. Given that Iran is benefiting from vast steppes, therate of carbon sequestration in them deserves attention. In order to estimate the soil carbonsequestration, the Saveh Rudshur steppes were selected and placed into three treatments:long-term exclosure, medium-term exclosure and grazing rangelands. The soil sampling wasconducted at the depth of 0-30 cm under the plants and between the plants. As many as 60 soilsamples on each area and 180 soil samples in total were taken. The sampled soils were driedout in the open air and sifted through a sieve of 2mm meshes in the laboratory. The soilorganic carbon was measured using the Walkley-Black method. The findings indicated thatthere was a significant difference between the amount of the soil organic carbon under theplants and the carbon between the plants on each area separately (P<0.05). The results alsoshowed that the amount of organic carbon under the plants is greater than that between themin the treated exclosures while the grazing areas proved a different result. It can be seen fromthe mean of the total carbon sequestration that there is also a statistically significant differencebetween the medium-term exclosure with a mean of 22.45 ton/ha and the long-term exclosurewith a mean of 17.76 ton/ha and the grazing rangelands with a mean of 18.50 ton/ha. پرونده مقاله

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12 - Comparison between Some Vegetation Traits and Bioindicators in Two Grazing and Exclosure Areas (Case Study: Sorkhe-Graz and Valikbon Rangelands)
Soode Miarrostami Mohammad Hasan Jouri

Overgrazing, via harvesting of forage species and decrease the other herbs, is of progressive factors in biodiversity destroying. In order to investigate the animal grazing impacts on changing of plant structure and diversity, we selected the comparison between this eff چکیده کامل

Overgrazing, via harvesting of forage species and decrease the other herbs, is of progressive factors in biodiversity destroying. In order to investigate the animal grazing impacts on changing of plant structure and diversity, we selected the comparison between this effect with exclosure area, and proving of the excluded area effects on plant diversity; two sites of Kojour rangeland, Mazandran province, Iran. Four transects, 50 m were systematic-accidentally established on two different aspects including along of slope (two transects) and staple on steep slope side. Cover percentage was recorded by 10 plots 1m2 in each transect. Rangeland condition and trend was determined by 6-factor and Trending Balance methods, respectively. Diversity indices in each area, by analysing of vegetation parameters, were calculated using PAST software. Vegetation traits and bioindicators were analysed by independent T-test using SPSS software. The result showed that percentages of all life-forms in rangeland were different between the exclosure and grazing areas, especially, grasses and forbs were meaningfully remarked. Regarding to bioindicators, diversity-Shannon index and richness-Menhinick index values were higher in the exclosure area than open area (P<0.01). Dominance index in grazing area was significantly higher than exclosure area (P<0.05). Evenness index, however, has not punctual difference in both areas. پرونده مقاله

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13 - Studying the Vegetation Changes of Natural Rangelands in Inche Shorezar of Agh Ghala, North Golestan Province, Iran
Seyyed Ali Hosseini Jamshid Khatir Namany Morteza Akbarzadeh

Studies on vegetation changes of rangelands under grazed and non-grazedconditions are of great importance in the range management planning programs. To determinethe change process of vegetation, this study was performed in Inche Shorezar site of Golestanprovince for nin چکیده کامل

Studies on vegetation changes of rangelands under grazed and non-grazedconditions are of great importance in the range management planning programs. To determinethe change process of vegetation, this study was performed in Inche Shorezar site of Golestanprovince for nine years (1997-2005). The vegetation parameters were measured every year inseveral fixed plots inside and adjacent of exclosures. The canopy cover of each species wasestimated in each plot. Forage production was randomly measured on one meter square plotsin each year using the clipping and weighing method. Correlations between canopy cover ofspecies and growth forms with the rainfall of different months and periods were calculatedusing SPSS software. Results showed that total canopy cover in 2005 was significantly higherthan 1997 both inside and adjacent of exclosures which has been mainly related to increasedannual plant cover but the perennial canopy cover was decreased in these years. Perennialspecies of (class I) did not grow inside the fixed plots. Cover of increasers (class II) specieswas reduced from the first year to the final one for both inside and adjacent of exclosures.However, the cover of (class III) species in the final year was not significantly increased thanthat for the first year. Forage production generally was higher inside than adjacent ofexclosures. Litter increased during the study period for both inside and adjacent. Litter wassignificantly higher inside of exclosures than adjacent in 2005. Although the plant canopycover was affected by rainfall but correlation coefficient was statistically significant only fortotal, annual and some perennial canopy cover species. Although total and annual cover washigh inside and adjacent of exclosures in 2005, the cover of perennials was decreased. By thereduction of palatable species, unpalatable species were increased inside and adjacent.Although by increasing the plant cover, the range condition was relatively improved, thisimprovement was achieved by the increase in the annuals instead of perennials. It wasconcluded that the exclosure cannot be used as a range improvement method to improve theserangelands’ conditions. For the rehabilitation of these areas, human interference is necessary. پرونده مقاله

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