نتایج جستجو برای: range species
تعداد نتایج: 1168072 فیلتر نتایج به سال:
based on the latest records of typhlops vermicularis merrem, 1820 from iran, this species is distributed in the northern and southern regions of the country. in this study, new records of typhlops vermicularis are presented and it is shown that distribution range of this species is extended towards the eastern and western iran, and according to the new distribution map, it can be assumed that t...
in this study, a simple, rapid and selective method was developed for the determination of dexamethasone. the proposed method is based on inhibitory effect of dexamethasone on the oxidation of orange-g by bromate in sulfuric acid media. the reaction was followed spectrophotometrically at 478.5 nm (?max). under optimum experimental conditions, (72.6 ?mol l-1 of orange-g, 0.76 mol l-1 of h2so4, 0...
this study was conducted to compare the methods of seed bedpreparation in rangelands of khash region in sistan and baluchestan province iniran. a split plot design was conducted based on randomized complete blockdesign with three replications in 1999. five seed bed preparation methods wereused as main plot as: 1) seed sown by passing livestock. 2) seed sown machinery.3) seeds sown as drilled in...
knowledge on habitat characteristics and nature of regional vegetation inrangelands is a prerequisite for any planning and proper range management along withsustainable development of renewable natural resources. rangelands in southern andwestern highlands of kashan, iran are of good vegetation diversity but unfortunately,palatable and desirable species are endangered in recent years. this rese...
plant diversity conservation is a main objective in rangelandmanagement. plant diversity is a suitable index for showing the changes ofvegetation in rangelands and has a high correlation with ecosystem parameters.therefore, using this index it is possible to find the changes and manage theecosystem correctly. the current research was performed to determine the speciesdiversity in fashandak rang...
سازند پابده در برش دره شهر شامل 260متر شیل، شیل آهکی، مارن و آهک می باشد. مطالعات انجام شده بر روی فرامینیفرهای پلانکتون منجر به شناسایی و ارائه تعداد 12 بیوزون شده است. این بیوزون ها عبارتند از: بیوزون شماره یک: parasubbotina pseudobulloides partial-range zone ، بیوزون شماره دو: subbotina triloculinoides partial-range zone، بیوزون شماره سه: morozovella angulata partial-range zone ، بیوزون شمار...
this research was conducted in two protect and destroy region in the middle zagros, in illam province. in order to identification of ecological species group and evaluate density of regeneration, effect of many factors such as protection, vegetation, physiographic factors, physical and chemical properties of soil in study locations were studied. to achieve these purpose number of 54 plots using...
The relationship between niche and distribution, especially the role of biotic interactions in shaping species' geographic distributions, has gained increasing interest last two decades. Most ecological research focused on negative species interactions, competition, predation parasitism. Yet relevance positive – mutualisms commensalisms have been brought to fore recent years by an number empiri...
شبدرکوهسری یا شبدر کوهستان (trifolium radicosum (boiss. & hohen گونه ای است علفی و چند ساله که در اقلیم سرد مدیترانه ای البرز میانی رشد می نماید. استقرار این گونه در عرصه های کوهستانی سردو برف گیر، مرتفع و شیب دار، باعث حفاظت خاک عرصه مستعد فرسایش گردیده و از اهمیت منحصر بفرد مرتعی و اکولوژیک برخوردار است. شیب تند رویشگاه، تولید علوفۀ قابل توجه، شدت چراو باعث گردیده تا این گونه بشدت در معرض...
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