Shahram Yousefi Khanghah; Hossein Azarnivand; Mohammad Ali Zare Chahouki; Mohammad Jafari; Hamidreza Naseri
Abstract
The establishment of vegetation is the best way to manage degraded and at risk of degradation lands. Considering that the planting in arid lands is very costly because of ecological restrictions, so experts are looking for methods that increase the percentage of the seedlings establishment and reduce ...
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The establishment of vegetation is the best way to manage degraded and at risk of degradation lands. Considering that the planting in arid lands is very costly because of ecological restrictions, so experts are looking for methods that increase the percentage of the seedlings establishment and reduce the cost of planting, in this regard the correct use of amendments is very important. The study area is located in Nazarabad City in southwest of Alborz province. In this study, the amendments including mineral biochar, arbuscular mycorrhiza fungi and acrylic resin polymer each in four levels were used at the base of Nitraria schoberi seedlings. The soil characteristics of the area was determined at the start of planting. After one year with counting the number of live seedlings, the percentage of establishment for each treatment was calculated. Economical estimates were calculated based on cost-benefit and calculated separately for each treatment. The results showed that there was a significant difference at the 5% level between the amendments and the control. Mycorrhizae had the highest (70%) and the control and biochar 4 treatments had the least (40%) percent of establishment. Economically, mycorrhizal 2, polymer 2 and biochar 1 treatments were the most optimal treatments for each amendment, respectively. The used amendments had different effects on the establishment of seedlings, so that the percentage of establishment increased with increasing level of mycorrhiza use, but with increasing level of polymer and biochar use, negative effects were observed and the percentage of seedling establishment decreased.
Leila Fazel Dehkordi; Hossein Azarnivand; Mohammad Ali Zare Chahouki; Farhad Mahmoudi Kohan; Shahram Khalighi Sigaroudi
Abstract
To identify an appropriate index for monitoring and evaluation of drought, rainfall data obtainedfrom meteorological stations of Ilam Province from 2000 to 2011 and MODIS satellite images with16-day intervals were collected and processed. The Standardized Precipitation Index (SPI) wascalculated based ...
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To identify an appropriate index for monitoring and evaluation of drought, rainfall data obtainedfrom meteorological stations of Ilam Province from 2000 to 2011 and MODIS satellite images with16-day intervals were collected and processed. The Standardized Precipitation Index (SPI) wascalculated based on rainfall data; therefore, the rainfall data were used for measuring SPI andsatellite images were used for calculating NDVI. Also, the percentages of canopy cover in rangetypes were selected from the information of the National Evaluation of rangelands in differentclimatic zones. The correlation between SPI and NDVI and also canopy cover and NDVI wasexamined. The relationship between vegetation index (NDVI) and SPI was determined byregression. The results of SPI showed that in 2000 a severe drought and in 2006 a medium wetoccurred in rangelands of Ilam Province. NDVI value variations have as well confirmed it. Theresults showed that NDVI and life form (annual forb and annual grass) has the highest percentage ofcorrelation. Also examining of result showed that most correlation of SPI and NDVI was in 3 and 6-months intervals. Evaluation of regression models performance in range types described thatmodels in 3 and 6- months intervals was suitable for monitoring drought. The result of regressionconfirmed that NDVI was an appropriate index for monitoring and assessment of drought.
Bahram Gholinejad; Mohammad Jaffari; Mohammad Ali Zarechahuki; Hossein Azarniuand; Hassan Pourbabaei
Abstract
This research has been done with the aim of explaining environmental and managerial factors that affects on rangeland vegetation distribution in Saral rangelands of Kurdistan province. After selecting plant types as working area were done sampling from plant types and determined some of plants parameters ...
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This research has been done with the aim of explaining environmental and managerial factors that affects on rangeland vegetation distribution in Saral rangelands of Kurdistan province. After selecting plant types as working area were done sampling from plant types and determined some of plants parameters such as kind and number of plants and cover percentage. Various environmental factors such as topographic factors (slope, slope direction and elevation), soil physical factors (depths, soil texture, gravel and saturation moisture) and various chemical factors such as acidity, electrical conductivity, lime, gypsum percentage, organic material, nitrogen, phosphor and potassium) were measured and grazing intensity were considered as managerial factors. After collecting data, the Principal Component Analysis (PCA) was used to determine relationship between vegetation cover and environmental factors by PC-ORD software. The results showed that among various environmental and managerial factors affecting in plant distribution, soil depth, grazing intensity, elevation, sand, gravel and silt percentage have the highest correlation with Principal Component Analyses. These factors are the most effective factors on plants type distribution in rangeland ecosystems. Among effective soil factors on distribution of plant communities in this study, soil physical factors have greater impact than soil chemical properties. Physiographic factors including elevation and managerial factors including grazing intensity have considering effect on distribution of plant communities.