Volume 25, Issue 3 , November 2018, Pages 0-0
leila Avazpour; Mehdi Ghorbani; Reza Erfanzadeh
Volume 25, Issue 3 , November 2018, Pages 465-474
Abstract
The present study seeks to measure indicators influencing the resilience of users of Hagh-o-Al-Khaje village, whose rangelands are degraded. The research method is descriptive-analytic and the size of sample was defined 24 rangeland users according to Morgan table. Following a review ...
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The present study seeks to measure indicators influencing the resilience of users of Hagh-o-Al-Khaje village, whose rangelands are degraded. The research method is descriptive-analytic and the size of sample was defined 24 rangeland users according to Morgan table. Following a review of literature around resilience, the level of different kinds of resilience of users encountered with rangeland degradation was measured applying questionnaire and SPSS software. It was found out that the average reilience of Hagh-o-Al-Khaje rangeland users was 2.21, which is lower than average and indicates an unpleasent condition. It was as well found that human indicators had the most impact on resilience (impact factor, 0.662), but physical indicators had the least impact upon resilience (impact factor, 0.108). It can therefore be said that users were in good state regarding human indicators but not in the case of physical indicators. Needless to say, planning and resource allocation strategies must pay due attention to improving the resilience of Hagh-o-Al-Khaje rangeland users.
seyed Habibian; Hossein barani; Ahmad Abedi; Adel Sepehri
Volume 25, Issue 3 , November 2018, Pages 475-488
Abstract
Considering the role and importance of rangelands for supplying animal feeds of the nomads, a study was conducted on the Qashqaee-Tribe (Clan Sesh-Boloki) ecosystem during 2014 and 2015 to determine the dependence of their livestock to the feeding sources including rangelands, crop residues and manual ...
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Considering the role and importance of rangelands for supplying animal feeds of the nomads, a study was conducted on the Qashqaee-Tribe (Clan Sesh-Boloki) ecosystem during 2014 and 2015 to determine the dependence of their livestock to the feeding sources including rangelands, crop residues and manual feeding separately in winter and summer seasons/rangelands, and in the wet and dry years. The method for collecting the data was the field survey based on the library review via questionnaires and interviews, respectively. Cochrane’s criterion/methodology was used to determine the sample size. The validity-reliability of the questionnaires was controlled by the conventional methods. The data were collected through filling in questionnaires and interviews with 405 samples from nomadic households. Then, using statistical software, the data were statistically analyzed. According to the results, the animal dependence of families of nomadic clans of Shesh-blouki tribe on various feeding sources (the rangeland, the crop residues, and manual feeding) in the wet and dry years showed a significant difference (P<0.01). The animal of nomadic families studied was 53.36 percent dependent on the rangelands in the wet years, and 34.8 percent in dry years; the dependence on crop residues in the summer rangeland in the wet years was 25.6 percent and in the dry years was 30.5 percent; the livestock dependence on manual feeding in the winter area in the wet years was 20.9 percent and in the dry years was 34.6 percent. Additionally, in this study, it was found that despite the severe degradation of rangelands, the percentage of livestock dependence of nomadic families to the rangelands is still significant and it seems that this issue has led nomads to continue traditional migrations.
Seyed Farzad Sajadi; Mohamad Badsar; Gholamreza Mojaradi
Volume 25, Issue 3 , November 2018, Pages 489-499
Abstract
Rapid population growth and ever-increasing demand for food lead to increase the exploitation of natural resources compared to the previous period and the continuation of this trend could lead to negative consequences and environmental crises, threatening human security and ecosystems. ...
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Rapid population growth and ever-increasing demand for food lead to increase the exploitation of natural resources compared to the previous period and the continuation of this trend could lead to negative consequences and environmental crises, threatening human security and ecosystems. Therefore, this study was conducted to investigate the status of natural resources in West of Kurdistan Province and the role of defense actions on natural resources crisis management. The population of this study consisted of the villagers of West of Kurdistan Province (N = 133837). The sample size was calculated to be 220 using Cochran's formula. The data were collected using a questionnaire. The face and content validity of the questionnaire was confirmed by panel of experts and the reliability of instrument was confirmed by conducting a pre-test and calculating a Cronbach's alpha coefficient more than 0.70 for different sections of the questioner. The data analysis was performed using SPSs20 software. The findings showed that from the perspective of 95% of respondents, the degradation of natural resources is evaluated at a high level. The results also showed that the defense actions including passive defense and the level of satisfaction from defense operating actions had a significant negative effect on the degradation of natural resources in the study area. Also, the results showed that 41.7% of the variations of the natural resources degradation was explained by defense activities.
zhila ghorbani; Kiomars Sefidi; farshad Keivan Behjou; Mehdi Moameri
Volume 25, Issue 3 , November 2018, Pages 500-511
Abstract
This study was conducted to assess the effects of different grazing intensities on the biomass amount of Agropyron libanoticum and Festuca ovina in summer rangelands of southern Sabalan, Ardabil province. After determining three sampling areas as different livestock grazing treatments ...
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This study was conducted to assess the effects of different grazing intensities on the biomass amount of Agropyron libanoticum and Festuca ovina in summer rangelands of southern Sabalan, Ardabil province. After determining three sampling areas as different livestock grazing treatments (light, moderate, and heavy grazing), plant sampling was performed by a random-systematic method in 25 plots along 600-m transects. A linear regression was used to determine the relationship between aerial and underground biomass. To assess the effects of different grazing intensities on biomass of these species a one-way ANOVA and Tukey test were used. The results showed that there was a significant relationship between aerial and underground biomass of two species in different treatments. Moreover, increasing the livestock grazing intensity resulted in a significant decrease in the aerial and underground biomass and total biomass of both species. In addition, increasing grazing intensity leads to decreasing aerial biomass in moderate and heavy grazing treatments compared to the light grazing intensity (26.31% and 42.24, , for Festuca ovina, respectively, and 22.04% and 48.76% for Agropyron libanoticum, respectively. Increasing grazing intensity leads to decreasing underground biomass in moderate and heavy grazing treatments compared to the light grazing intensity (25.14% and 42.75 for Festuca ovina, respectively, and 9.39% and 35.30% for Agropyron libanoticum, respectively. Generally, grazing intensity reduced the aerial and underground biomass of Agropyron libanoticum and Festuca ovina.Therefore, grazing control in rangeland management is necessary to prevent the destruction of these species.
Mansoureh Kargar; Zeynab Jafarian; Reza Tamartash; Seyed Jalil Alavi
Volume 25, Issue 3 , November 2018, Pages 512-523
Abstract
Ecologists and environmental managers emphasize the use of predictive models to examine the species distribution patterns. The purpose of the present study was to investigate the efficiency of the generalized linear model (GLM) and generalized additive model (GAM) in determining the ...
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Ecologists and environmental managers emphasize the use of predictive models to examine the species distribution patterns. The purpose of the present study was to investigate the efficiency of the generalized linear model (GLM) and generalized additive model (GAM) in determining the relationship between vegetation and environmental factors in Khetteh Riz Rangelands. Environmental factors studied included soil characteristics, topographic factors and climatic factors. A classified-random sampling was performed and three dominant species, Bromus tomentollus, Ferula ovina, and Agropyron repens, were identified. The results showed that in the GLM model for Ferula ovina species, the variables of phosphorus content and slope were effective. For species Bromus tomentollus and Agropyron repens, the variables of annual moisture, rainfall, silt, and slope were effective. In the GAM model, the available moisture, silt and organic matter were the factors affecting the distribution of Ferula ovina. The silt, potassium, pH, and annual moisture content were the factors affecting the distribution of Agropyron repens. In addition, slope and silt were the variables affecting the distribution of Bromus tomentollus in the GAM model. The values of AUC, calculated for the GLM (0.63) and GAM (0.70), indicate the accuracy of the model to be acceptable.
Mahshid Souri; Ehsan Zandi Esfahan; Nadia Kamali
Volume 25, Issue 3 , November 2018, Pages 524-535
Abstract
Investigating the effect of environmental factors on the yield of forage plants is one of the necessities for improvement, rehabilitation, and development of rangelands. Festuca ovina is of perennial grasses. This species is found to be abundant in the semi-steppe rangelands of the country due to its ...
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Investigating the effect of environmental factors on the yield of forage plants is one of the necessities for improvement, rehabilitation, and development of rangelands. Festuca ovina is of perennial grasses. This species is found to be abundant in the semi-steppe rangelands of the country due to its adaptability to dehydration and low temperatures of -20 ° C. This rangeland species plays an important role in providing forage, soil stabilization, erosion prevention, and soil conservation in semi steppe rangelands. Therefore, the purpose of this study was to investigate the effect of salinity and pollutant factors on the performance of Festuca ovina. This experiment was conducted in greenhouse conditions in a factorial arrangement based on a completely randomized design under the influence of the first factor of copper oxide treatment at two levels (50 and 100 mg / l), copper nano-oxide at two levels (50 and 100 mg / l), and control treatment, and the second factor of sodium chloride treatment at three levels (0, 200 and 400 mM) in five replicates on Festuca ovina in a hydroponic greenhouse. After two months of stress, changes in chlorophyll, potassium and air length were measured. Data were analyzed using a factorial experimental design and SNK multiple range test in SPSS.18 software. According to the results of this study, the Festuca ovina species, in addition to the ability to establish and grow in each of the conditions of salinity and pollutant stress, has the ability to establish in both conditions (salinity + pollutant). Therefore, it can be of particular interest to planners, managers of natural resources and the environment and recommended as a consistent species to improve the rangelands of these regions.
Seyed Mehrdad Kazemi; Hamidreza Karimzadeh; Mostafa Tarkesh Esfahani; Hosein Bashari
Volume 25, Issue 3 , November 2018, Pages 536-546
Abstract
Soil serves as an important rangeland ecosystem component and evaluating the effects of management practices on structure and function of range ecosystems can assist managers to select the best option in their reclamation plans. This study aimed to compare the effects of long-term ...
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Soil serves as an important rangeland ecosystem component and evaluating the effects of management practices on structure and function of range ecosystems can assist managers to select the best option in their reclamation plans. This study aimed to compare the effects of long-term exclosure (33 years) and rest-rotation grazing system on some soil physicochemical properties in semi-arid rangelands of Hamzavi research station, Hanna- Semirom in Isfahan province. Six transects were established in each area and three plots of 2m2 were placed along each transect randomly and 72 soil samples were collected from five points of the plot at the soil depth of 0-10 and 10-30 cm. Soil properties such as pH, EC, CaCO3, organic carbon, absorbable phosphor, total nitrogen, K, Ca, Mg, soil saturated percentage, cation exchange capacity, soil clay, silt, sand, and fine sand contents were measured in the soil laboratory. Independent t-test was used to compare soil properties in both areas. Results revealed that soil properties were more appropriate in areas under long-term rest-rotation grazing system compared with exclosure area. According to the results, most soil properties were differed significantly (α = 5%) due to rest-rotation grazing system in both areas, except pH, Mg, soil saturated percentage, silt, sand, and fine sand contents. This study showed that rest-rotational grazing systems can maintain ecosystem health condition in semi-arid area as well as decrease the costs of animal husbandry and is a more appropriate management option for ranchers compared with long-term grazing exclosure.
Elham Banihashemi; Pezhman Tahmasebi; Esmael Asadi
Volume 25, Issue 3 , November 2018, Pages 547-561
Abstract
Livestock grazing is one of the most important factors influencing on the structure and dynamics of the rangeland vegetation. The aim of this study was to identify the plant functional traits as the indicators for the effects of grazing management on Karsanak semi-steppe rangelands ...
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Livestock grazing is one of the most important factors influencing on the structure and dynamics of the rangeland vegetation. The aim of this study was to identify the plant functional traits as the indicators for the effects of grazing management on Karsanak semi-steppe rangelands of Chahar Mahal Va Bakhtiari province. A randomized-systematic sampling method was used to survey vegetation in seven grazed and enclosure sites by estimating plant cover in five plots of 4 m2 along a 100-m transect in each site. Then, the plant traits were measured and compared among grazed and enclosure sites. The results showed that there were significant differences between grazed and enclosure sites in several functional groups including plant height, leaf area, total plant weight , palatability class I and II, annuals and perennials, therophytes , and geophytes (P<0.05). The results also showed that the mean value of leaf length, the plant cover of species with palatability class II, forbs, and therophytes were significantly increased in non-grazed area compared to grazing area. The results of PCA showed that the most affecting factors responsible for overall changes in vegetation were plant weight, perennial and annual plant species, shrub growth form, chaemophytes, phanerophytes and phanerophytes forms, leaf length, leaf width, leaf area, and palatability class II and class III, justifying 60% of total variation in plant community composition. Combining the results of t-test and PCA, the results indicate that plant traits including total plant weight, leaf length and width, leaf area, palatability class, and life form are among the most important indicators to evaluate the effect of grazing managements on the structure and dynamics of vegetation in semi- steppe rangelands.
Samaneh Mohammadi; Hossein Barani
Volume 25, Issue 3 , November 2018, Pages 562-576
Abstract
The purpose of this study was to evaluate the socio-economic impacts of range management plans in the Mashhad County. Accordingly, 16 range management plans, approved during 1993 to 2012, were studied in three categories including executed, unexecuted and under execution plans. To ...
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The purpose of this study was to evaluate the socio-economic impacts of range management plans in the Mashhad County. Accordingly, 16 range management plans, approved during 1993 to 2012, were studied in three categories including executed, unexecuted and under execution plans. To achieve this purpose, some questionnaires were prepared with respect to the number of the beneficiaries in 15 range allotments and 48 samples were selected at random. The questionnaires were answered by the beneficiaries and the data were analyzed by descriptive and inferential statistics in the SPSS software. The results showed that the beneficiaries considered the implementation of these plans to be effective; however, they also face a lot of problems. In areas where range management plans are not implemented, beneficiaries believe that these plans cannot solve many of their problems. However, despite all these problems, they hope that the implementation of these plans will reduce the problems of rangelands, including rangeland ownership. Finally, according to the beneficiaries' responses and many interviews conducted, range management plans are evaluated positively from a socio-economic point of view.
Farid Dadjou; Ardavan Ghorbani; Mehdi Moameri; Mahmoud Bidarlord
Volume 25, Issue 3 , November 2018, Pages 577-593
Abstract
The purpose of this study was to investigate the relationship between rangeland aboveground production based on total aboveground production and life forms of grasses, forbs, and shrubs with 25-year temperature and precipitation data, the year before sampling, and the year of sampling in Hir and Neur ...
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The purpose of this study was to investigate the relationship between rangeland aboveground production based on total aboveground production and life forms of grasses, forbs, and shrubs with 25-year temperature and precipitation data, the year before sampling, and the year of sampling in Hir and Neur rangelands in Ardabil province. To determine the aboveground production, the amount of production was estimated using the harvesting method in one square meter plots (totally 330 plots) in three elevation classes under the range of 1446-2750 meters. Temperature and precipitation were calculated for each plot. Aboveground production maps were prepared in a GIS environment using extracted regression equations. The results showed that over the years, precipitation decreased and temperature increased, and aboveground production also decreased in relation to those climatic factors. Moreover, there is a significant relationship (P<0.01) between the aboveground production of life forms and total aboveground production with climatic factors, and aboveground production of grasses and total have a direct relationship with precipitation; however the maximum aboveground production of forbs was recorded in the middle ranges and maximum aboveground production of shrubs was recorded in the higher ranges of annual precipitation. Grasses and total aboveground production had an inverse relationship with temperature, and the maximum aboveground production of forbs and shrubs was recorded in the middle and lower ranges of annual temperatures, respectively. According to the accuracy of derived regression equations, the maps prepared by climatic data of 1394 and 1395 were better than 25-year climate data. The results of this study can be used for the supply-demand balance of aboveground production, biomass accounts, and ecosystem carbon balance indicator that is potentially an important tool for sustainable development.
Ali Akbar Nazari Samani; leila Biabani; Hamidreza Abbasi; Hasan Khosravi
Volume 25, Issue 3 , November 2018, Pages 594-612
Abstract
Wind, as a major driving factor on soil erosion in arid and semi-arid areas, needs to be investigated precisely to prevent its undesirable effects. The main purpose of this research was to determine the spatial variability of wind erosivity and sand drift around Urmia Lake. For this aim, ...
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Wind, as a major driving factor on soil erosion in arid and semi-arid areas, needs to be investigated precisely to prevent its undesirable effects. The main purpose of this research was to determine the spatial variability of wind erosivity and sand drift around Urmia Lake. For this aim, the anemometry data of eight synoptic stations adjusted to the Lake were analyzed for the whole period time. Annual wind-roses showed that despite the very high spatial and temporal changes of wind variables (speed and direction), major prevailing winds were blown from the East and West, respectively. Also, annual storm-roses depicted that the erosive winds blew mainly from South and Southwest direction. These winds had a unidirectional regime in summer and spring, while in fall and winter, a multi directional regime was observed. The results of calculated sand drift power by Fryberger and Dean Formula indicated a low to moderate class of wind erosion potential and the final direction of sediment transport was mainly to northeast. According to the Letu-Letu equation, sand transport flux is varied between 0.05 to 0.76 Ton/m/year. Although the windiness of study area is moderate, the Tsoar sand mobility index is less than one, indicating inactive sand dunes. However, due to the low vegetation established on the sand dunes surface, it can be drawn that the role of human factors (especially cattle grazing and trampling) as well as the salinity caused by the drying of the Lake are responsible for this situation.
Mohammadamin Soltanipour; Saeedeh Nateghi; Mohammad Fayaz
Volume 25, Issue 3 , November 2018, Pages 612-626
Abstract
This research was aimed to determine the grazing behavior of Tali goat, as the dominant livestock, in the Zaminsang rangelands of Hormozgan province for four years starting from 2006. The indices examined in this study included the time of livestock entry to and exit from rangelands, the daily distance ...
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This research was aimed to determine the grazing behavior of Tali goat, as the dominant livestock, in the Zaminsang rangelands of Hormozgan province for four years starting from 2006. The indices examined in this study included the time of livestock entry to and exit from rangelands, the daily distance moved by the livestock, the livestock path, maximum and average livestock speed, and the time spent for livestock rest, movement and grazing. To determine the mentioned indices, the GARMIN GPS was used and closed with a special belt behind a three-year-old goat. The GPS was activated when the livestock exited the barn. Then, at the end of the day, its data were extracted in the Ilwis software. The path of livestock movement was determined by the shepherds. According to the results, significant differences were found for the average speed of livestock in the fourth year, and the movement time and rest time in the fourth and fifth months, while no significant difference was found for other behavioral characteristics of livestock grazing. Moreover, during the study period, 31 to 39 percent of the time the livestock moved in the rangeland was dedicated to grazing.
Hasan Yeeganeh; Mohammadreza Shariati; Adel Sepehri
Volume 25, Issue 3 , November 2018, Pages 527-543
Abstract
Valuating the non-market environmental functions and services including tourism is important for many reasons including understanding the ecological benefits, providing the country's environmental issues to the planners, modifying the national computing system such as gross national product and preventing ...
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Valuating the non-market environmental functions and services including tourism is important for many reasons including understanding the ecological benefits, providing the country's environmental issues to the planners, modifying the national computing system such as gross national product and preventing the destruction and excessive exploitation of natural resources. The aim of this research is the estimation of the recreational value of Abar watershed using a contingent valuation method. To investigate the factors affecting willingness to pay of individuals, the logit model was estimated using maximum likelihood estimation. Required data were collected through questionnaires and interviews. The results showed that overnight stay, family cost, and satisfaction of welfare services were significant (P<0.05), affecting the WTP. The mean of WTP for recreational value of this rangeland was calculated to be 8096 Rials per visitor. According to the results, the Abar Watershed has considerable recreational values. Thus, these values provide enough justification for policymakers to maintain the quality of natural resources and avoid degrading rangeland resources.
Roham Rahmani
Volume 25, Issue 3 , November 2018, Pages 644-656
Abstract
The aim of this study was to identify the factors affecting ranchers' participation in the conservation activitiesof range management projects in Fars province. Using stratified random sampling method, 89 rangeland projects were selected based on the climatic conditions, vegetation cover, and the number ...
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The aim of this study was to identify the factors affecting ranchers' participation in the conservation activitiesof range management projects in Fars province. Using stratified random sampling method, 89 rangeland projects were selected based on the climatic conditions, vegetation cover, and the number of range management projects implemented. Data were collected using designed questionnaires and interviewing with 267 active ranchers in the rangelands. Poisson regression model and quasi-maximum likelihood estimation were used to identify the factors affecting participation of ranchers in the conservation activitiesof range management projects. According to the results, variables such as experience of ranchers and the number of ranchers in each range management project had a negative effect on the participation of ranchers in the conservation activitiesand it was significant at 1% level. Variables such as the level of formal education, the number of households employed in the agricultural sector and the relation with Natural Resources Offices and the relevant organizations had a positive relationship with participation in conservation activities; however, it was not statistically significant. Variables such as the amount of information passed to the ranchers after their involvement in range management projects, duration of grazing, the area of rangeland allocated to each rancher in the project, and the number of sheep and goats had a significant positive effect (P < 0.01). Based on these findings, it is necessary to express the importance of conservation programs and activitiesto the ranchersbased on theindigenous and scientific knowledge. Moreover, through empowering ranchers and providing the opportunities for investment in appropriate complementary activities, their participation in conservation activities and using rangeland services is enhanced, which would lead to sustainable livelihood.
Hosein Arzani; Javad Motamedi; Taghi Mirhaji
Volume 25, Issue 3 , November 2018, Pages 657-670
Abstract
Knowledge of the animal daily requirement in rangelands is one of the essential requirements to calculate the grazing capacity in rangeland plans. In this regard, the daily metabolizable energy requirements of different Sangesary sheep (ewe, ram, and lamb) were investigated. For ...
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Knowledge of the animal daily requirement in rangelands is one of the essential requirements to calculate the grazing capacity in rangeland plans. In this regard, the daily metabolizable energy requirements of different Sangesary sheep (ewe, ram, and lamb) were investigated. For this purpose, according to the average values of forage quality indices and the proportion of species in the plant composition, the amount of metabolizable energy in one kilogram of dry forage at different growth stages was estimated, and considering the daily metabolizable energy requirement, the amount of forage that supplies the animal was estimated. The daily metabolizable energy requirement was calculated according to the proposed MAFF (1984) equation under grazing condition regarding the physical properties of the rangelands, water distribution intervals, plant density, and applying an incremental coefficient of 70%. Based on the results, the amount of forage needed to meet the daily needs of the ewe of the Sangesary sheep with a mean weight of 37 kg in the early, mid, and late growing season was estimated to be 1.6, 2.1 and 2.3 kg dry matter, respectively. The values for adult rams with an average weight of 48.75 kg were estimated to be 1.9, 2.5 and 2.9 kg in different growth stages. The lambs' daily requirement with an average weight of 19.88 kg was estimated to be 1.3, 1.7, and 1.9 in each growing season. The results showed that considering the amount of 1.5 kg of dry matter forage to meet the daily requirements of different kinds of animals grazing in rangelands is not correct and animal requirement need be determined based on forage quality in phenologiacal stages.In addition, the results emphasize that in order to adapt the daily requirements of animal to the forage quality, it is necessary to consider the values of forage quality indices and the proportion of all species grazed in the plant composition, so that the results should not be limited to the species in animal diet. Otherwise, as in the present study, the estimated requirement is more than the daily intake of animal grazing on rangelands.
Azadeh Kavandi; Ali Ashraf Jafari; Mojtaba Jafarzadeh
Volume 25, Issue 3 , November 2018, Pages 671-685
Abstract
In order to study the effects of storage conditions and osmopriming on the seed germination and seedling growth of sainfoin (Onobrichis vicifolia), two factorial experiments were conducted based in a completely randomized design with three replications in the laboratory and greenhouse ...
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In order to study the effects of storage conditions and osmopriming on the seed germination and seedling growth of sainfoin (Onobrichis vicifolia), two factorial experiments were conducted based in a completely randomized design with three replications in the laboratory and greenhouse of Research Institute of Forests and Rangelands, Tehran, Iran in 2015. The first factor was accessions origin (Khonsaer, Karaj, Ardebil, and Tehran), the second factor was seed storage conditions at two levels: basic storage (-18ºC) and active storage (+4ºC), and the third factor was seed priming at six levels, including soaking in different concentration of PEG 6000 solution for 24 hours to produce 0, -3, -6, -9 and 12 Bar osmotic potential and control (no priming). The seeds samples of 15 to 20 years ago that were kept in gene bank storages were examined. In the laboratory experiment, seeds were sown in Petri dishes, irrigated and placed in germinator in standard conditions (20°C) for two weeks. Germinated seeds were counted every two days and after two weeks seed germination was recorded. In the greenhouse experiment, 25 seeds were sown in each one-liter pot filled by an equal amount of soil, sand, and compost. Data were collected for germination traits as germination rate, radicle length, shoot seedling length, vigor index, root/shoot length ratio (RS), and seedling fresh weight. The results showed that the seeds in basic storage (-18ºC) had higher germination percentage, germination rate, and vigor index as compared with active storage. The effects of different priming levels showed that seed germination and germination rate were increased by application of hydropriming (distilled water), whereas, for radicle length, shoot seedling length, vigor index and seedling fresh weight and RS, the higher values were obtained by osmopriming in both laboratory and greenhouse condition.
Nadia Kamali; ahmad sadeghipour; Alireza Eftekhari
Volume 25, Issue 3 , November 2018, Pages 686-698
Abstract
This study was conducted to investigate the changes in the soil seed bank of Sisab region due to the pit-seeding operation. To recognize the seed bank potentials, sampling was done using a randomized-systematic method at tow depths of 0-5 and 5-10 cm in winter 2016. Two transects of 500-m length were ...
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This study was conducted to investigate the changes in the soil seed bank of Sisab region due to the pit-seeding operation. To recognize the seed bank potentials, sampling was done using a randomized-systematic method at tow depths of 0-5 and 5-10 cm in winter 2016. Two transects of 500-m length were stablished in the pit-seeding region and in the control area and 10 plots of 1m2 were used along each transect. To study the effects of pit-seeding and soil depth as well as their interaction on the soil seed bank characteristics, a factorial design was applied. In the case that the interaction between pit-seeding and depth was significant, the unpaired T-test was applied to study the seed bank characteristics in each depth of the pit-seeding and control regions. A paired T-test was also used to compare the seed bank characteristics between the two depths. The results showed that pit-seeding had significant effect on soil seed bank characteristics and caused to increased density, diversity, and species richness of seed bank. In addition, all characteristics of the soil seed bank were significantly higher in the top soil. Our results clearly showed that the pit-seeding operation not only increased the forage production in the study area but also increased the diversity and seed density, whose ultimate result could improve the rangeland ecosystem function.
Rostam Khalifezadeh; Reza Tamartash; Mohammadreza Tatian; Mohammadreza Sarajian Maralan
Volume 25, Issue 3 , November 2018, Pages 699-712
Abstract
Organic carbon is one of the most important soil quality indices, affecting almost all physical, chemical and biological properties of the soil. The purpose of this study was to investigate soil spectral and morphometric factors to estimate the organic carbon of topsoil, using factor analysis ...
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Organic carbon is one of the most important soil quality indices, affecting almost all physical, chemical and biological properties of the soil. The purpose of this study was to investigate soil spectral and morphometric factors to estimate the organic carbon of topsoil, using factor analysis and multiple regression methods in semi-steppe rangelands of Lazour. Soil samples were taken with a stratified random method. For this purpose, 157 training sites were selected in homogeneous units. Of these, 127 sites were used to calibrate the model and 30 sites were used to validate the model. In each of the training site in a random manner, a soil sample including nine observations was taken from a depth of 0 to 20 cm of soil surface. Soil Organic Carbon (SOC) was measured using Walkley-Black titration method. The results showed that the variables of Albedo, Clay Index (CI), NDVI, Relative Relief and Tasseled-Cap's Brightness and Greenness indices had a significant correlation with the SOC (p<0.05). Also, the result of factor analysis by Principal Component Analysis (PCA) method with eigen-values greater than one indicated that the total cumulative variance, explained by the six variables, was equal to 81.1%.This variance was explained by two components. Using multiple regression model, an appropriate regression equation was calculated to predict SOC (R2=0.789). The Root Mean Square Error and the Mean Absolute Relative Error of the proposed model were calculated as 0.24 and 0.10, respectively. Due to the direct relationship between the SOC and the factors such as soil fertility and sustainability against erosion, a spatial distribution model of SOC could be an important sub-model to design other complex models such as the terrestrial ecosystems biomass and soil erosion models.