reza Hasanpouri; Ali Tavili; seyed akbar javadi
Volume 23, Issue 4 , March 2017, , Pages 800-809
Abstract
Identification of effective environmental factors in distribution and establishment of plant species plays an important role in rangeland ecosystems management. The purpose of this study was investigation of reasons for plant species distribution and relationship between index species in Khorramabad ...
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Identification of effective environmental factors in distribution and establishment of plant species plays an important role in rangeland ecosystems management. The purpose of this study was investigation of reasons for plant species distribution and relationship between index species in Khorramabad rangelands and physical and chemical properties of soil. At preliminary inspection, vegetation types were separated and the key area of each type was recognized. Four vegetation types were identified as follows: Agropyron libanoticum-Acantholimon bromifolium ،Hordeum glaucum-Taeniatherum crinitum، Astragalus adscendens-Agropyron trichophorum andAstragalus adscendens-Daphne mucronata. The size and number of sampling plots were calculated to be 4 square meters with minimal area method, and 160 based on the statistical formula, respectively. Sampling method in each vegetation type was randomize-systematic, so that, in each plot, vegetation factors were measured, then at the beginning and end of each transect a profile was dug and some physical and chemical properties of soil were measured. Vegetation ordination was done by CCA method and results showed that organic matter, nitrogen, phosphorus, potassium and pH were the most important factors affecting Daphne mucronata distribution. The distribution of Agropyron libanoticum and Acantholimon bromifolium were affected by potassium, soil texture, and EC. As well, soil texture and lime had a decisive role in distribution of Taeniatherum crinitum, Hordeum glaucum, Astragalus adscendens and Agropyron trichophorum.
shokoofeh Shokrollahi; Hamidreza Moradi; Ghasem Ali Dianati Tilaki; Zahra Jabeolansar
Volume 21, Issue 3 , December 2014, , Pages 541-548
Abstract
This study is focused on investigation of plant species distribution in relation to edaphic and physiographic factors. For this purpose, after the initial visit and selection of the study area, 23 land units were selected from overlaying the maps of slope, aspect and height using geographic information ...
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This study is focused on investigation of plant species distribution in relation to edaphic and physiographic factors. For this purpose, after the initial visit and selection of the study area, 23 land units were selected from overlaying the maps of slope, aspect and height using geographic information system (GIS). Within each unit, vegetation sampling was performed with randomized-systematic method along three transects of 100 m length. Ten plots (1m2) were established along each transect at 10 meter intervals. Soil samples were taken from 0-30 centimeter in starting, mean and ending points of each transect. Soil factors such as N, P, organic matter, pH, EC and texture were measured. CANOCO software and redundancy analysis (RDA) were used to examine the relationship between species and environmental factors. The first axis of RDA showed a significant correlation with slope, aspect, sand, silt, P, pH and litter, while the second axis had just a significant correlation with EC.
Seyed Ali Hoseini; Mansour Mesdaghi; Serkis Pambukhchyan
Volume 21, Issue 2 , August 2014, , Pages 189-197
Abstract
Determination of forage quality is one of the fundamental factors for suitable management. There are spatial and temporal variations in quality of rangeland species. In this study, forage quality of five important grasses of Bromus tomentellus, Poa angustifolia, Festuca ovina, Agropyron ...
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Determination of forage quality is one of the fundamental factors for suitable management. There are spatial and temporal variations in quality of rangeland species. In this study, forage quality of five important grasses of Bromus tomentellus, Poa angustifolia, Festuca ovina, Agropyron intermedium and Agropyron trichophorum were measured at three phenological stages (vegetative growth, full flowering and seed ripening) in summer rangelands of Golestan province. For this purpose, five replications were randomly selected from each phenological stage. Quality factors of crude protein, ADF, crude fiber, dry matter digestibility and metabolizable energy were measured using in vitro procedures. The results obtained from chemical analysis were analyzed in a factorial experiment at randomized complete block design with SAS software. Results showed that forage quality differed significantly for different species as well as at different phenological stages (p<0.05). Among studied species, the highest forage quality was related to Bromus tomentellus while the lowest was related to Agropyron trichophorum. The highest and the lowest forage quality were recorded for vegetative growth and seed ripening stages, respectively.
Hamidreza Mirdavoodi
Volume 21, Issue 1 , June 2014, , Pages 165-175
Abstract
In this study, the adaptation of six species was investigated in a split plot design for autumn and spring sowings with three replications. The study was conducted in Khoshkrood Aquifer, located in the northwestern of Saveh for three years (2007-2010). The study area has a mean annual rainfall of 234.8 ...
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In this study, the adaptation of six species was investigated in a split plot design for autumn and spring sowings with three replications. The study was conducted in Khoshkrood Aquifer, located in the northwestern of Saveh for three years (2007-2010). The study area has a mean annual rainfall of 234.8 mm, loamy-textured soil, low soil salinity, a soil alkalinity of 8.1 with an appropriate infiltration and high drainage. The study range species were cultivated in pots with a distance of 2.5 m from each other, in late December and early March. According to the results, the highest and lowest viability were recorded for Kochia prostrate and Atriplex canescens (76.9 and 61.6%, respectively) and Halimion verrucifera (14.4%). In addition, the study species showed different responses during the years of experiment with a significant difference in the years of study. Results showed that the highest and lowest vegetation cover and vitality were recorded for K. prostrate and H. verrucifera, respectively with a significant difference at 1% level.The results of mean comparisons of vegetation and vitality were significant in different years at 1% level. However, the effect of sowing date was not significant on viability, vegetation cover and vitality, although the values of these factors were more in autumn sowing as compared to spring sowing. Overall, K. prostrate, a native species to the region, showed superiority in terms of establishment, vitality and vegetation cover as compared to other study species; therefore, the cultivation of this species is recommended for this region.
Farzad Bayat Movahed; Seyed Ahmad Moosavi
Volume 14, Issue 2 , January 2007, , Pages 222-231
Abstract
Whereas more than 90 % of Iran is located in arid and semi-arid area, water is one of the most important factors that can prevent from sustainable development in all of agricultural subjects. Thus, the water can play an important role in ecological condition changes especially for plants. In this research, ...
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Whereas more than 90 % of Iran is located in arid and semi-arid area, water is one of the most important factors that can prevent from sustainable development in all of agricultural subjects. Thus, the water can play an important role in ecological condition changes especially for plants. In this research, it was attempted to survey the water harvesting and its spreading impact on plant composition changes in a flood spreader. The study area is located in the part of the Zanjan plain, in north-west of Zanjan city and between two rivers Sorhain and Qarecharian, which is include rain fed and released lands that, has been occupied by quaternary deposition. For this purpose, the amount of rainfall and diverted floodwater to the station monitored and measured during all flooding time. In order to evaluate the plant composition changes in three sites in spreading area and one in control site, totally 11 permanent transects (9 in spreading area and 2 as control) were stabilized and using Line Intercept Method, the canopy cover percentage of all species were noted and all species were distinguished. This study showed that some species under impact of floodwater spreading omitted, some increased or decreased, and some new species observed for first time. Increasing of the vegetation cover and appearance of palatable plants in last year showed that the floodwater spreading can improve the foliage production. Considering to life form of observed species, although perennial forbs increased, but the floodwater spreading in the case of establishment of perennial grasses did not operate successfully. Therefore, shortage of studying period (8 Years) and changes on amount of harvested floodwater make correctitude of these obtained results rather less valid.