Mohammad Ali Zare Chahouki; Lyla Khalsi Ahvazi; Hossein Azarnivand; Asghar Zare Chahouki
Abstract
The aim of this study preparation of the predicted soil maps by using kriging and Inverse Distance Weighting methods in east rangeland of Semnan. Sampling was done within each unit of sampling parallel transects and 1 vertical transect with 750m length. Soil samples were taken from 0-20 cm in starting ...
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The aim of this study preparation of the predicted soil maps by using kriging and Inverse Distance Weighting methods in east rangeland of Semnan. Sampling was done within each unit of sampling parallel transects and 1 vertical transect with 750m length. Soil samples were taken from 0-20 cm in starting and ending points of each transect. There were used kriging and Inverse Distance Weighting methods by Gs+ and GIS software to predict clay, sand, lime, EC and available moisture factors. For comparing these methods, cross validation were used by statistical parameters of MAE and MBE. Results showed that kriging method is better than Inverse Distance Weighting method in all factors except clay factor.
Mojtaba Akhavan Armaki; Hossein Azarnavand; Mohammad Hasan Asareh; Ali Ashraf Jafari; Ali Tavili
Abstract
Environmental stress especially drought is one of the most important factors to reduce and disturbance in different stages of floral growth especially sprouting in dry and semi-dry lands of Iran. For this purpose a factorial essay executed in accidentally manner with four iterations in vitro condition. ...
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Environmental stress especially drought is one of the most important factors to reduce and disturbance in different stages of floral growth especially sprouting in dry and semi-dry lands of Iran. For this purpose a factorial essay executed in accidentally manner with four iterations in vitro condition. Four genotypes of Bromus tomentellus pasture types were used (92 Tehran, 630 Kordestan, 3414 Shahrekord and 9507 Lorestan) and four drought care (-3, -6 and -9 times distilled water). In this essay the sprouting percentage, Root length, Shoot length, Seedling length, Root length to Shoot length rate, Seedling dry weight, Seedling fresh weight, dry to fresh weight rate sprouting rate and seed health index were determined. The result showed that the with stress drought increase, all attributes except the dry weight to fresh weight proportion reduced significantly. The reduction in all under assessment properties were from -3 to -6 in potential. In general, in tested genotypes, Lorestan (9507) genotype showed a better sprouting in under study potentials and had a meaningful preference to other genotypes. From assessed parameters, Seedling length and seed index standard showed the most possible reaction to changing potential of water. The best levels to assess the stability to drought were the -6 and -9 load potentials in all drought levels.
M. Ghorbani; H. Azarnivand; A.A Mehrabi; S. Bastani; M Jafari; H. Nayebi
Abstract
Since last decades, there has been a growing interest in the human/social dimensions of natural resources governance especially the structure of social networks in achieving to successful co-management of natural resources. Network analysis as a suitable tool in optimum planning of the “network ...
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Since last decades, there has been a growing interest in the human/social dimensions of natural resources governance especially the structure of social networks in achieving to successful co-management of natural resources. Network analysis as a suitable tool in optimum planning of the “network management” of rangeland in regional scale, can improve inter-organizational decision-making and coordination among key actors. Trust development and mutual relations among various actors is a key factor in policy of rangeland co-management issue. In this study, trust and collaboration networks between informal and formal institutions and rangeland users in co-management process have been investigated. Social network analysis as a quantitative method has been implicated in this research. The results of this study indicate that “Veterinary Office of Taleghan” and “Village Council” can play a key role in policy and planning of rangeland co-management which is related to higher density of trust and collaboration ties. Moreover, trust and collaboration networks among the Veterinary Office and rangeland users have more sustainability than these in related to other institutions. However, the sustainability of networks among all of institutions and rangeland users has low level. Statistical results show there is a high correlation (70%) between trust and collaboration networks and also 50% of collaboration changes are related to trust factor. Also, it can be state that lack of trust and collaboration between the Natural Resources Office and rangeland users is a key challenge for initiating of rangeland co-management. Finally, social network analysis helps manager and planner in detecting of the challenges of rangeland co-management and policy in tune with solving these challenges.
Mohammad Ali Zare Chahouki; Masoud Yousefi; Mohammad Jafari; Hossein Azarnivand; Marjan Shafizadeh Nasrabadi
Abstract
The current research was carried out to find out the most effective environmental factors in plant species occurrence by classification and ordination methods. For this purpose, the study was conducted in Nir rangelands of Yazd province and topography, climate, soil and grazing intensity data of the ...
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The current research was carried out to find out the most effective environmental factors in plant species occurrence by classification and ordination methods. For this purpose, the study was conducted in Nir rangelands of Yazd province and topography, climate, soil and grazing intensity data of the region were determined. Sampling method was randomized–systematic and within each sampling unit 3-5 parallel transects with 300-500 m length, each containing 30-50 quadrates (according to vegetation variations) were established. Quadrate size was determined for each vegetation type using the minimal area; hence suitable quadrate size for different species was determined 1*2m–10*10m (2-100 m2). Soil samples were taken from 0-30 and 30-80 cm in starting and ending points of each transect. Measured soil properties included gravel, texture, available moisture, saturation moisture, organic matter, lime, gypsum, pH and electrical conductivity. To analyze environmental data, classification (using TWINSPAN) and ordination (using PCA, CCA) were used. The results indicated that soil salinity, texture and available water play the main role in distribution of plant species.
M Jafari; H Azarnivand; A Hajibaglo; E Alizadeh
Volume 63, Issue 3 , December 2010, , Pages 307-318
Abstract
This study investigates the relationship between litter quality and aerial parts of plant on C, N, K, P and C/N ratio of soil in four rangeland species including Agropyron intermedium, Bromus tomentellus, Eurotia ceratoides and kochia prostrata. After recognizing the sites of these species in Hamand ...
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This study investigates the relationship between litter quality and aerial parts of plant on C, N, K, P and C/N ratio of soil in four rangeland species including Agropyron intermedium, Bromus tomentellus, Eurotia ceratoides and kochia prostrata. After recognizing the sites of these species in Hamand Absard located in 65 km of northern Tehran, at the end of growing season, samples of litter, aerial part of plants and soil were taken using systematic- random method. For this purpose, five transects, each of l00 m length and 50 m spacing were taken. Two plots in each transect with an area of 1 m2 were established. In each plot, soil samples under plants and without plant area (control samples) at depth of 0-30 cm were taken. The C, N, P, K, EC, pH and texture of samples were analyzed in laboratory. Analysis of variance, Dunnett's test and t-student test were applied to the data. Results show that in the aerial part of plant, C and C/N ratio of Agropyron intermedium and P, K and N of Kochia prostrata are higher than other species. In case of litter, C, K and C/N of Eurotia ceratoides and N and P of Kochia prostrata showed higher values. However the results of soil samples show that C of Agropyron intermedium, N and C/N of Kochia prostrata and K of Bromus tomentellus are higher than other species. Totally, Kochia prostrata showed the best litter quality, decomposition rate and effects on soil.
A Azarnivand; M Rabiee; H Arzani; Yones Asri
Volume 62, Issue 1 , June 2009
Abstract
With respect to wide distribution of A. sieberi Besser in Iran, various studies have been done on its habitats and different ecological properties have been referred as effective factors in establishment of this species. In this research, we tried to study the ecological range of A. sieberi and its ...
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With respect to wide distribution of A. sieberi Besser in Iran, various studies have been done on its habitats and different ecological properties have been referred as effective factors in establishment of this species. In this research, we tried to study the ecological range of A. sieberi and its relationship with vegetative characteristics. Therefore, climate properties including annual precipitation, number of days with precipitation, annual, minimum and maximum temperature, absolute minimum and maximum temperature; topographic property including altitude; edaphic properties including pH, EC, SP, texture, lime, gypsum, C, Na, K, Ca, Mg, N and P; and vegetative characteristics including large and small diameter of canopy, height of plant and diameter of most thickness branch were measured in 34 populations. For determination of ecological range, normal curve with histogram of frequency have been drawed for total properties. All populations divided in 3 groups by cluster analysis. Measured properties compared by analysis of variance between 3 groups. The significant properties were: average of annual, minimum and maximum temperature, absolute minimum and maximum temperature, large and small diameter of canopy and height of plant in 0.1 % probability level, altitude and C in 1 % probability level, while annual precipitation, number of days with precipitation, N, P and Na in 5 % probability level.