In western Iran, mountainous rangelands provide significant resources for livestock productions. Many ecosystems that are of high environmental and economic value are threatened by climate change and social economic pressures. This is especially important for semi-arid rangelands, which have a multifunctional system. Quantifying the direct and indirect effects of grazing disturbance on plant biodiversity in the semi-arid mountainous rangelands can provide sight into the appropriate measures to restore degraded rangelands and conserve biodiversity. Here, the effects of different levels of grazing intensity (Light Grazing (LG), Moderate Grazing (MG), and Heavy Grazing (HG)) on plant biodiversity were examined in Nava-mountain rangeland in Kermanshah Province, Western Iran, in 2016. The results showed that increasing grazing intensity led to a decrease in species richness, Margalef's richness index, and Shannon-Wiener index (p <0.05). Stepwise regression analysis was used to investigate the effect of grazing intensity as (independent variables) on species diversity and richness as (dependent variable). The estimates parameter were significant (p <0.01) for species richness, Margalef's richness and Shannon-Wiener indices in the different levels of grazing intensity. In overall, grazing intensity explained 47%, 47% and 50% of the variation for species richness, Margalef's richness, and Shannon-Wiener indices, respectively. In addition, species richness and diversity were affected in response to grazing disturbance intensity and reducing grazing pressure can contribute to maintaining relatively high species diversity in Nowa-mountain rangeland. پرونده مقاله

Mountain ranges cover around one-half of Iran, and Zagros ecosystem is considered as one of an important biological site in Iran. Physiographic factors such as altitude and aspect have an important role in plant species distribution. This study was conducted in the Nawa mountain ecosystem in the western side of Zagros ranges, located in the western zone of Iran in 2016. The experiment aim was to reveal the influences of altitude and aspect on features of plant biodiversity. Hence in the each main aspect regarding to gradient, transect-lines were established with distance 100 m into another and perpendicular to gradient from the elevation of 1200-2400 m a.s.l. Four plots (1 m²) were randomly located along each transect; generally, 208 plots were drown. The Shannon–Wiener index for α-diversity was calculated, and field data were analyzed using two-way ANOVA. There were 158 identified plant species belonging to 104 genus and 27 families based on the results. Altitude and aspect had a significant effect on the plant diversity and species richness (p<0.01). The highest values of the Shannon–Wiener index and species richness (2.58 and 1033 respectively) were seen in lower elevations (from 1200-1400 m a.s.l.). Results also showed that the highest and lowest values of the plant diversity and species richness for the southern aspect were 2.51 and 8.9 and for eastern aspect 1.20 and 3.63, respectively. Interaction effects of environmental variables were only significant on the species richness. There was a negative correlation between the plant diversity and species richness with altitude in all main aspects, too. Along the altitudinal belts, the highest species diversity and richness belonged to low and mid-elevational zones of the Nawa mountain. پرونده مقاله

Determining the environmental capability of optimally using land and preventing the degradation of natural resources arr important steps towards a sustainable development strategy. The present study was conducted in 2014-2017 aiming to assess the ecological capability for agriculture and rangeland of the Razin watershed in Kermanshah province, west of Iran, in seven classes using the Fuzzy Analytic Hierarchy Process (FAHP) and the application of Geographic Information System (GIS). The information layers were initially selected by the research group and those layers that were important were selected according to the research literature, then the final screening of the information layers was performed by fuzzy Delphi method. These layers were including land form units (slope, elevation, aspect), soil information (texture, depth, hydrological groups, erosion, granulating, gravel percentage, evolution, organic carbon content, exchangeable cations, available phosphorus), climate, water, land use, vegetation density, and lithology. FAHP technique was used to calculate the importance coefficients of the criteria and sub-criteria entered into the evaluation model. Weighted layer modeling was performed by ArcMap 9.3 software using the weighted linear composition method in overlay tool. The results showed that water, climate, slope, and soil texture criteria with 0.23, 0.132, 0.118, and 0.88, respectively, were the most important in modeling Razin ecological capability. 1776 environmental units with unique ecological characteristics were identified. This area has ecological potential for agricultural and rangeland use in seven classes. In terms of effective carrying capacity (ECC), all classes except class 2 and 5 were sustainable. Due to the very high accuracy of the FAHP-GIS integrated model in the use of agricultural land suitability, it is recommended to use this model instead of other conventional methods. پرونده مقاله

به منظور ارزیابی تاثیر سطوح مختلف نیتروژن بر عملکرد و اجزای عملکرد ارقام ذرت آزمایشی به صورت کرت های خرد شده در قالب طرح پایه بلوک های کامل تصادفی با چهار تکرار در سال 1393 اجرا شد. تیمارهای آزمایش شامل چهار سطح کود نیتروژن (40، 70، 100 و 140 درصد نیاز گیاهی ذرت به عنصر نیتروژن که مقدار توصیه شده بر اساس آزمون خاک معادل 138، 238، 350 و 483 کیلوگرم اوره در هکتار در نظر گرفته شد) در قالب کرت های اصلی و سه رقم رایج ذرت 704، سیمون و 678 BC در قالب کرت های فرعی بود. نتایج نشان داد کاربرد کود نیتروژن باعث بهبود تعداد بلال در متر مربع (12 درصد)، تعداد ردیف در بلال (9 درصد)، تعداد دانه در ردیف بلال (32 درصد)، عملکرد دانه (63 درصد) و وزن خشک کل (58 درصد) شد. رقم سیمون نیاز کودی بیشتری برای رسیدن به حداکثر عملکرد داشت و نسبت به ارقام دیگر از عملکرد دانه (19 درصد) بیشتری برخوردار بود. رقم سیمون در سطح کودی 140 درصد از شاخص برداشت بیشتری برخوردار بود در حالی که در دو رقم دیگر با افزایش کود نیتروژن تا 140 درصد، شاخص برداشت کاهش یافت. رقم سیمون (10467 کیلوگرم در هکتار) در سطح کودی 140 درصد و ارقام 704 (8402 کیلوگرم در هکتار) و 678 BC (8030 کیلوگرم در هکتار) در سطح کودی 100 درصد دارای حداکثر عملکرد دانه بودند. به طور کلی نتایج نشان داد که در منطقه مورد بررسی جهت دستیابی به عملکرد بالاتر بهتر است ارقام جدید ذرت مانند رقم سیمون کشت شوند. پرونده مقاله