Hosein Tavakoli; Abbas ali Sanadgol; Uosef Garivani
Volume 13, Issue 2 , February 2006, Pages 69-73
Abstract
Russian brome (Bromus tomentellus) is a prennial grass with good adaptability to climatic condition of north Khorasan. So, it has promise for using in range improvement projects. Because threre is no enough local information about mangement of this plant, the present experiment has been conducted in ...
Read More
Russian brome (Bromus tomentellus) is a prennial grass with good adaptability to climatic condition of north Khorasan. So, it has promise for using in range improvement projects. Because threre is no enough local information about mangement of this plant, the present experiment has been conducted in Sisab Reaserch Station (SRS) to evaluate the response of this species to grazing intensities and rest grazing. Four grazing intensities of light (20 to 45% of forage removal), moderate (45- 65% of forage removal), heavy (65- 80% of forage removal) and without grazing as control applied by herd of lamb and sheep for three consequent years from 1999 to 2001. The year of 2002 considered as rest period from grazing. Herbage mass and number of plant per unit area measured as an index response. Herbage mass production decreased by reduction in precipitation. Heavy grazing resulted in significant reduction in herbage production and number of plants per unit area, but one year rest from grazing componsated the negative effect of intensive grazing on herbage mass reduction. Management implication based on this results show that plant can tolerate grazing intensity by 45-65% of herbage removal and indicate on the importance of rest grazing on survivance of this plant.
Jalal Abdollahi; Hosein Arzani; Naser Baghestani; Fakhr.... MirAskarshahi
Volume 13, Issue 2 , February 2006, Pages 74-81
Abstract
An optimal planning system for managing the range and maintaining it’s vegetation is highly influenced by the humidity and rainfall of the range. In this research, the reactions of the seidlitzia rosmarinous species to the fluctuation of precipitation and under ground water were studied at Chah-Afzal ...
Read More
An optimal planning system for managing the range and maintaining it’s vegetation is highly influenced by the humidity and rainfall of the range. In this research, the reactions of the seidlitzia rosmarinous species to the fluctuation of precipitation and under ground water were studied at Chah-Afzal in Ardakan-Yazd. Regarding the amount of collecting data after five years, by applying Minitab software, using linear regression, an equation between the amount of the production and precipitation was obtained with a high correlation coefficient (r=0.93). The results showed that the variation of the plant production was due to the fluctuation of the annual precipitation. Moreover, result of another analysis was demonstrated a lack of agreement between the cover and density of the se.rosmarinous species with the amount of precipitation. In addition, the results state that the downward trend in the percentage of canopy cover and the density of the se.rosmarinous species in the region are highly influenced (r=0.94 and r=0.99 respectively) by the discharge of ground water table. Thus, the gradual decrease of this source in the coming years might bring out negative effects on the cover, density and finally on the condition of the range in Chah-Afzal. Also, Interaction between the effect of ground water table changes on the amount of forage production was not significant.
Mir mansur Khalighi; Nemat Khalighi; Mahdi Farahpoor
Volume 13, Issue 2 , February 2006, Pages 82-93
Abstract
According to influences of different exploitation methods of Rangelands on welfare or demolition of rangelands and existing of different methods in Iran, identification, assessment and comparison of different exploitation methods was taken action from condition, trend, production, extra animal unit on ...
Read More
According to influences of different exploitation methods of Rangelands on welfare or demolition of rangelands and existing of different methods in Iran, identification, assessment and comparison of different exploitation methods was taken action from condition, trend, production, extra animal unit on the area unit and minimum area for each user on each units of exploitation of Amirkabir dam watershed. For reaching to these results, Individual ranching, group ranching and Shoraee method with range plans and group ranching and Shoraee method without Range plans had been chosen and assessed. At the end with the comparison of these methods and comparison of rangelands with range plans and without range plans was proved that Range managements projects in this zone have not been succeeded and Individual ranching method with range plans , with emphasis on individual part was chosen as the best exploitation method of this zone for welfare and keeping safe of Range lands.
Mahmood khosravi fard; Abbas ali sandgol; Ahmad Akbarinia
Volume 13, Issue 2 , February 2006, Pages 94-101
Abstract
About 15% of Iranian lands are affected by salinity. Species of chenopodiacea family, such as Atriplex canescens is special for planting in these area. This study was conducted from 1993 to 2003 in Nowdehak rangeland station of Qazvin province. objectives of this research were planting density of Atriplex ...
Read More
About 15% of Iranian lands are affected by salinity. Species of chenopodiacea family, such as Atriplex canescens is special for planting in these area. This study was conducted from 1993 to 2003 in Nowdehak rangeland station of Qazvin province. objectives of this research were planting density of Atriplex canescens. The statistic design was split split plot (using on CRBC) with three replication. Main plot were density (2´2, 4´4, 6´6 meter), sub plots were pruning period (annual, binnial, triennial) and sub sub-plot were hight pruning (control, complete pruning, 20, 40, 60 heights). Result showed that planting density and pruning had significant effect on forage yield (P<0.01). Planting density 2´2 m had higher yield than others treatments. Complete pruning and pruning 20 cm height had no differet yield but produced forage were higher than other treatments. Triennial pruning preiod was better than anuual and binnial praning priod in respect of forage yield. Generally result showed that in this area and similar zone planting, distance (2´2m) with triennial pruning and complete pruning had maximum forage yield.
Majid Hoseini; Mohammad Khosroshahi; Abbas Atapour; Aziz Karami
Volume 13, Issue 2 , February 2006, Pages 102-108
Abstract
Characteristics of desert areas are different from viewpoint of various sciences. Surveying the desert descriptions from viewpoint of geology, geomorphology, climatology, land cover and pedology sciences shows diversity of desert characteristics. Each one of the mentioned sciences has introduced special ...
Read More
Characteristics of desert areas are different from viewpoint of various sciences. Surveying the desert descriptions from viewpoint of geology, geomorphology, climatology, land cover and pedology sciences shows diversity of desert characteristics. Each one of the mentioned sciences has introduced special indices to identify desert. Therefore to achieve a common description of desert and to classify them in order to use in natural resources fields is a very necessary matter. In this research, the desert indices have been surveyed and assessed from viewpoint of geology, geomorphology, climatology, pedology and land cover sciences then according to it, the desert characteristics which commonly accepted by scientists and experts of the related science have been determined and the desert plan has been drawn from viewpoint of that science and then, by overlying , geomorphology, climatology, pedology and land cover maps determined Climatic deserts. Therefore consider to effective factors, the province deserts were divided in 3 groups include of geologic deserts resulted from the desert indices of geology and hydrology, climatic deserts resulted from desert characteristics of climate, land cover,pedology and geomorphology. By overlying all of 6 maps, they contribute only one zone that it was named real or hard desert .the desert characteristics of all factors and appropriate to that, the general characteristics of the related desert limits was obtained. According to the obtained results, the geologic, climatic and hard deserts have 2170.21, 6768 and 342.42 km2 area in Tehran province respectively and have allocated to themselves 11.2%, 35% and 1.4% of the total province surface respectively.
Esmayil filehkesh; Gholam ali Gazanchian; Abbas Aliabadi; Hosein Farzaneh; Ebrahim Sadegh zadeh
Volume 13, Issue 2 , February 2006, Pages 109-115
Abstract
The degradation trend and descending capacity of Iran’s renge lands due to lack of regular policy and programming in it’s usage, increasing of population, food and protein requirements, are some of problems that turned the ammenment and improvement of rangelands as an essential problem for ...
Read More
The degradation trend and descending capacity of Iran’s renge lands due to lack of regular policy and programming in it’s usage, increasing of population, food and protein requirements, are some of problems that turned the ammenment and improvement of rangelands as an essential problem for the users. Eurotia ceratoides plant, due to bushy from, resistance to drought, proper protein percent, simple propagation and… is one of the native plants of desert rangelands that has special importance in arid and semiarid rangelands these charachteristics caused to wide use of this plant in rangelands ammendment programs. The aim of this research was to determine the optimum time for sowing and the best method for sowing of this species in desert rangelands, to use in rangeland management designs. This research was conducted in split plots experimental design frame, in the main plots the sowing date was in 4 treatments (5th of December, 5th of Junury, 5th of Februry and 5th of March) and the secondary plots were included 4 treatments (Heap cropping, Hole cropping, Sowing with disct moldboard, Sowing with plow) with 4 replications in 2 successive years of 1996 and 1997 in plots with 6 * 4 dimensions. The number of established plant per plot was determined and the data analysis was done by SAS program . Results showed that, the best method of sowing in establishment percent of Eurotia were sowing by plow and disc, heap cropping and hole cropping respectirely. The dates of 5th of December and 5th of Junury had more establishment percent. The plow and disc methods in 5th of December had the most establishment percentage.
Mostafa saeedfar; Mohammad taghi Feyzi; Amr ali Shahmoradi
Volume 13, Issue 2 , February 2006, Pages 116-126
Abstract
To manage renewable natural resources is impossible, without attention to its ecological characteristic. Therefore study of rangeland species autecology is very importance. In this research, the autecology of Salsola orientalis S.G.Gamelin was studied from 1997 to 1999 in Isfahan province (Mouthe). Thus ...
Read More
To manage renewable natural resources is impossible, without attention to its ecological characteristic. Therefore study of rangeland species autecology is very importance. In this research, the autecology of Salsola orientalis S.G.Gamelin was studied from 1997 to 1999 in Isfahan province (Mouthe). Thus several factors as, geographical distribution, botanical characteristics, phenology, reproduction, seed rate, root system, chemical composition, nutrient value, forage production, disease, climate and its effects on this species were surveyed. This species has wide geographic distribution in the arid land of the world and appear in different vegetation types, also it is dominant in some of the sites in steppe region. This specimen has wide range of altitude from 1000 – 2000 m in Iran and 800 – 2000 m. in Esfahan province. This species is a shrub with 30 – 100 cm. high and in certain regions maybe reach to 1.5 m. Its phenological phenomens occur during long time and is different in different years. Chemical composition showed high protein (% 12), total digestible nutrient (TDN) 62%. Forage production is different according in ecological condition. Salsola orientalis was found in different soils (with different structure and texture) and geologic formation. It is resistant to pests and disease and heavy grazing. This species appears in regions up to 150 mm precipitation and with absolute maximum and minimum temperature, respectively +40 and -20 degree centigrade. For escaping from unsuitable condition it removes it's foliage and modifying growth period length and by this method resistant to aridity
Khosro Mirakhorlo; Zein ... Hosseini
Volume 13, Issue 2 , February 2006, Pages 127-138
Abstract
Estimating rangelandsۥ production is one of the range management tools. This requires detailed information about the present available forage of the rangelands. The assessment of the parameters is difficult and cost-intensive using clipping method. Therefore, new estimating methods are required. We ...
Read More
Estimating rangelandsۥ production is one of the range management tools. This requires detailed information about the present available forage of the rangelands. The assessment of the parameters is difficult and cost-intensive using clipping method. Therefore, new estimating methods are required. We estimated available forage using remote sensing data in the production model that it extracted from ecological parameters and remote sensing data. For quantifying evaluation of vegetation cover stratified random sampling and transect sampling methods were selected. Plot size calculated from “minimal area and species curve” method. Overall, 28 transects (50m) one transect in each site that contain 280(1m2) sample plots were measured. Modeling performed using NDVI index, animal density and effective ecological factors (altitude, slope, aspect, precipitation, temperature and evaporation) on rangelandsۥ yield. After analyzing of ecological factors of Damavand region, some ineffective factors omitted. Finally three factors namely slope, precipitation and NDVI index were entered in the model for calculating the available forage in the study area. The calculated amount of average standard predict value of forage model is 38% and its standard deviation value is 97%. They show that the validation of model for predicting of forage is fairly acceptable.
shahram Banedjschafie; Esmaeil Rahbar; Farhad Khaksarian
Volume 13, Issue 2 , February 2006, Pages 139-144
Abstract
Commercial producers of polymers claim that their polymer materials hold plentiful of water using low suction so that plants are able to have access to it. If this is true, then polymers could be used to increase desired physical characteristics of sandy soils in areas with dry climatic conditions. Based ...
Read More
Commercial producers of polymers claim that their polymer materials hold plentiful of water using low suction so that plants are able to have access to it. If this is true, then polymers could be used to increase desired physical characteristics of sandy soils in areas with dry climatic conditions. Based on this view and using a pressure apparatus, water retention curves were evaluated for a sample of agricultural silty clay soil, a sample of blown sand, and samples of the same blown sand mixed with three different amounts of polymer. The results showed that when a mixture of sand and a kind of polymer named " Super ab 200A" was provided in a way that 0.2 to 1.0 percent (% w/w) of the mixture is polymer, the condition of water in the mixture would be similar to a clay soil. When the amount of polymer reaches to 1%, the condition would be tougher than the previous one. In other words, although polymers cause more absorption of water in sand blown sand, the stored water is kept in the soil by a suction that is higher the suction in clay. Therefore, to increase the capacity of Plant-available water in blown sands to elongate irrigation interval of planted seedlings for afforestation in dry areas, adding polymer to blown sands would result in undesirable conditions. Furthermore, using polymers increase the cost of operation. They are unsustainable materials and they may have some other disadvantages. Results of this experiment suggests that usage of clay, instead of polymer, to blown sands would create a better conditions.
Hosein Arzani; Mahdi Abedi
Volume 13, Issue 2 , February 2006, Pages 145-161
Abstract
Rangeland as a dynamic ecosystem changes by accruing abundance and if cross the rangeland health threshold may be disturbed. By determination rangeland health attributes, we could judge about management practices effects. In this research for determination three attributes (soil and site stability, hydrologic ...
Read More
Rangeland as a dynamic ecosystem changes by accruing abundance and if cross the rangeland health threshold may be disturbed. By determination rangeland health attributes, we could judge about management practices effects. In this research for determination three attributes (soil and site stability, hydrologic function and biotic integrity) , seventeen indicators used include rill, water flow pattern, pedestals and terracettes, bare ground, gullies, wind scour and depositional area, litter movement, soil resistance to erosion, soil surface loss or degradation, plant composition, soil compaction, plant functional/structural groups, plant mortality, litter amount, annual production, invasive plant and reproductive capability. This method was conducted in six steps. to test this new concept in arid and semi arid zone , thus by using vegetation and soil studies in Orazan (Taleghan) region and Zarand Saveh, selected five treatment included: three grazing intensity and two cultured area and then modified indicators table categorized under three ecosystem attributes in five classes. Because of grazing and cultured treatment rangeland health attributes reduced and showed significant differences by references area. Most treatment crossed the rangeland health threshold. By increasing grazing intensity stractural plant characterestics and soil characteristic beetwin plants disturbed.inreliced cultivated area soil stability and hydrologic function attributes modified but plants health attribute in comperation with references area have a little change. Results showed that soil surface resistance decrease and water flow pattern degradation are the most important causes in rangeland health decrease.