Morteza Shahnori; Maryam Azarakhshi; Mehdi Bashiri; Hasan Rezaee Moghadam
Abstract
Evapotranspiration as an important component of the hydrological cycle plays a major role in the study of water balance in watersheds. The purpose of present research was to investigate the response of Atriplex canescens to different levels of water salinity and the effect of irrigation water salinity ...
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Evapotranspiration as an important component of the hydrological cycle plays a major role in the study of water balance in watersheds. The purpose of present research was to investigate the response of Atriplex canescens to different levels of water salinity and the effect of irrigation water salinity levels on actual evapotranspiration under lysimetric conditions. For this purpose, four treatments inclusive 0, 25%, 50%, and 75% of maximum salinity tolerance of Atriplex canescens with 3 replications were considered which equal as zero, 19.6, 39.2, and 58.8 ds/m of Sodium Chloride. The lysimeters were placed in greenhouse and two Atriplex canescen shrubs were cultivated in per lysimeter. 5 liters of water with mentioned salinities were added to each lysimeter every two weeks. During the vegetative period of the plant, from 6th March to 15th of August of 2019, the measurement of evapotranspiration was done by weighing the lysimeters at intervals of one week. After the end of the experiments, the weights of shoots and roots of each treatment were measured in wet and dry situation. The results showed that evapotranspiration decreased from 3.94 to 2.84 liters with increasing salinity of irrigation water from zero to 58.8 ds/m, and there was a significant difference between control and 58.8 ds/m salinity treatments at 5% level. By increasing salinity from 0 to 19.6, 39.2 and 58.8 ds/m, the dry weight of shoots increased compared to control treatment 20.13%, 41.87% and 11.55% respectively. Therefore, with the conditions of the present researchو Atriplex Canescens was produced the highest amount of dry shoot in 39.2 ds/m salinity.
moslem yazdani; reza erfanzadeh; Asghar Mosleh Arani
Abstract
Study of the effect of woody plant species on the production, diversity and richness of substratum herbaceous species, especially in the arid and semiarid regions, is essential for the proper management of these ecosystems. Therefore, the rangelands of Chenarnaz region in Khatam city in Yazd province ...
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Study of the effect of woody plant species on the production, diversity and richness of substratum herbaceous species, especially in the arid and semiarid regions, is essential for the proper management of these ecosystems. Therefore, the rangelands of Chenarnaz region in Khatam city in Yazd province were selected and then, using 0.5m×0.5m quadrats, vegetation sampling was performed under the selected 15 sites from Daphne mezerum, Amygdalus scoparia and Ebenus stellate (growing in equal topographical conditions) canopies, and outside of the canopies (as control). In each quadrat, the cover percentage of each plant species was visually estimated and the productions were measured by clipping and weighing method. The species diversity and richness indices were calculated using Past software through introducing the plant covers into the software. The results showed that the most values of Shannon-Weaner and Simpson diversity indices were found under A. scoparia (2.07 and 0.80, respectively) and the lowest values were found under E. stellata (1.010 and 055, respectively). In addition, the highest values of Menhinik and Margalef richness indices were found under A. scoparia (4.90 and 3.43, respectively) and D. mezerum (4.25 and 3.12, respectively), while the highest production was found under E. stellata (64.76 g/m2). The results of this study showed that different woody species had the desired but different effects on the herbaceous species, in such, A. scoparia and D. mezerum had significant positive effects on species diversity and E. stellata increased significantly species production; therefore, conservation of all woody species is emphasized in the region.
mahshid souri; mina bayat; Hossein Arzani; Morteza khodagholi
Abstract
Climatic factors are the most important factors affecting vegetation growth and production. The impact of each of these factors in each region varies depending on the vegetation type. The effect of climatic factors (rainfall and temperature) on the production of grazed plant species at 6 steppe sites ...
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Climatic factors are the most important factors affecting vegetation growth and production. The impact of each of these factors in each region varies depending on the vegetation type. The effect of climatic factors (rainfall and temperature) on the production of grazed plant species at 6 steppe sites in Fars province over a ten year period (1998 to 2007) was investigated. 60 plots of 2 square meters along 4 transects of four hundred meters were used to measure cover and production was measured by cutting and weighing method in 15 plots along transects. Then, using regression relationship between canopy cover (percent) and production (kg ha-1), the residual plot yield was calculated for that year. Important climatic indices analyzed in this study are: annual rainfall, growing season rainfall (March to June), plus and earlier rainfall, annual temperature, July temperature, August, maximum and minimum temperatures. The results showed that the average canopy cover was 6.3% and the average yield was 128.5 kg / ha and among the different vegetative forms of shrubs had the highest percentage of cover and production and wheat had the lowest cover and production percentage. Among the important climatic indices, annual rainfall and August temperature at all sites and the growing season rainfall at all sites except for the desired site were the most effective indicators on forage production and showed a positive and significant correlation with forage production.
majid mohammad esmaeili; mohammadreza Mojtahedi; Khironesa Mirnia
Abstract
Flooding is one of the most important environmental stresses that affect the performance of plants. The effects of flooding height on the performance of the two species A.littoralis, J.maritimus were studied. This experiment was carried out the factorial experiment in a completely randomized design with ...
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Flooding is one of the most important environmental stresses that affect the performance of plants. The effects of flooding height on the performance of the two species A.littoralis, J.maritimus were studied. This experiment was carried out the factorial experiment in a completely randomized design with 4 treatments and 8 replications. After 2.5 months of ultimate recovery tests were performed. The number and length of stolons of A. littoralis were counted separately in each treatment. The number and length of rhizome J. maritimus species in each plot (pot) were counted. The total weights of dry matter, shoot dry weight, dry weight of underground organs were measured in each experimental unit. Analysis of variance showed that the effects in controlling the height of flooding on all performance indicators studied (excluding the effects of flooding on root dry weight) of two species A. littoralis and J. maritimus is significant. Comparison of performance indicators A. littoralis species show between the two treatment groups (7 cm below the water level and water treatment) and treatment (treatment without irrigation and 15 cm below the water level) there is a significant difference. Comparison of performance indicators J. maritimus species show a significant difference in the number of rhizome, total length of underground rhizome and dry weight were observed. Comparison of dry pasture species show the highest production of the two types of treatment 7 cm below the water level.
mina bayat; Hossein Arzani; adel jalili; hassan ghalij nia
Abstract
In this study the effects of three important factors: the climatic precipitation, temperature and relative humidity on the amount of canopy cover and forage production in a period of five years (1381-1385) and 1392 in semi-steppe rangelands Reineh and Polur in the Mazandaran province studied. The statistical ...
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In this study the effects of three important factors: the climatic precipitation, temperature and relative humidity on the amount of canopy cover and forage production in a period of five years (1381-1385) and 1392 in semi-steppe rangelands Reineh and Polur in the Mazandaran province studied. The statistical models (simple and multiple regression) to find the relationship between various forms of vegetative cover and annual forage plants using climate variables in different periods of time with Minitab.14 and Excel software was used for data analysis. The results of six years of study in a semi-steppe rangelands Polur and Reineh showed an average canopy cover of 51 percent and the average yield was 372 kg per hectare. The total vegetation cover of Rineh pastures had the most relation with a total rainfall of the growth season and the March and the average temperature. The temperature was more effectively than rainfall in annual yield. And The yield affected by July temperature. The total vegetation cover of polur had not significant relation with climate factors but each of the vegetation form in Different time base had significant relation. The total grazing species yield of plour affected by growth season rainfall. So instead of one year measurement of vegetation cover and production can be estimated the production and vegetation cover fluctuation according to climate parameters. With long-term vegetation cover and production data, can be determined the available forage and pasture capacity to prevent the range degradation.
Ataollah Ebrahimi
Abstract
Canopy cover and forage production have always been two important indicators in rangeland assessment, which sometimes are applied as surrogates of each other. These two indicators are widely used in rangeland studies and have a vital role in evaluation of rangeland structure and functions. Occasionally, ...
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Canopy cover and forage production have always been two important indicators in rangeland assessment, which sometimes are applied as surrogates of each other. These two indicators are widely used in rangeland studies and have a vital role in evaluation of rangeland structure and functions. Occasionally, different sampling groups (estimators) evaluate forage production and canopy cover of different spaces and times. This research was aimed at investigation of different sampling groups and life-forms' effects on relationship between canopy cover and forage yield estimation. To do so, the impact of three sampling groups and five life forms (Fixed factors) on estimation of relationship between canopy cover (covariate) and forage yield (dependent variable) in a full factorial model in rangeland of Chahrtagh of Naghan, Chahrmhal-va-Bakhtiari Province, was estimated. Results shows that predictor variable of canopy cover is a god surrogate for forage production (P≤0.05) of different life-forms, but different sampling groups significantly (P≤0.05) effects on relationship between canopy cover and forage production estimation. Nevertheless, different life-forms do not significantly (P≤0.05) influence estimation of canopy cover and forage production relationship. By the way, interaction between sampling group and life forms considerably (P≤0.05) affects the relation. Therefore, we conclude that, although, the canopy cover is a good predictor of forage production, nonetheless, different sampling groups should not be engaged in sampling and monitoring vegetation cover and forage production estimation, specifically, if estimation of different life-forms' production is intended.
S.M Heshmatol Vaezin; S Ghanbari; ALI Tavili
Volume 63, Issue 2 , September 2010, , Pages 183-14
Abstract
Eremurus and forage are main by-products in the Khazangah rangelands of Makoo region. Eremurus is harvested and used by local people in a period of 30 days during the spring in this region. At this study, Eremurus and forage have been evaluated financially and the data were obtained through field work ...
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Eremurus and forage are main by-products in the Khazangah rangelands of Makoo region. Eremurus is harvested and used by local people in a period of 30 days during the spring in this region. At this study, Eremurus and forage have been evaluated financially and the data were obtained through field work using unstructured interviews as well as direct observation. The harvested Eremurus value was estimated based on harvest costs and by means of market price. The data were analyzed through financial evaluation, annual present net value and infinite present net value or expected value. The results showed that gross revenue, economical rent and economical benefit per household were 4564 and 348 thousand Rials/yr, respectively. The amount of net benefit through harvested Eremurus was also 16748 thousand Rials/ha/yr. The Rangeland Expectation Value per hectare was estimated 670 thousand Rials/yr and 10.5 million Rials/yr from Eremurus and feed, respectively. Total Rangeland Expectation Value per hectare was estimated 11.17 Thousand Rials while the ratio of Rangeland Expectation Value of Eremurus to Total Rangeland Expectation Value was computed 6 percent. The rangelands of this region have much more products. Among them forage and Eremurus have been considered at this study. These products play a main role in local economy of the region.
