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The type of vegetation cover affects the contents of organic matter and other soil features that can lead to variability of soil microbial processes, which play a key role in the nutrient cycle. This issue is especially important in mountainous semi-arid ecosystems, which have been introduced as fragile and vulnerable habitats. In the present study, labile contents of soil organic matter (SOM), microbial and enzymatic indices under the influence of forest and rangeland cover [i.e. natural forest with dominant species of Zelkova carpinifolia (Pall.) K. Koch. And three rangeland covers, converted form forest site almost 30 years ago, with dominant species of Festuca ovina L. Dactylis glomerata L. and Stachys byzantina K. Koch.] in Northern Ir
In seed priming studies, seeds usually are sown directly in the field or stored for short periods of time. Priming provides controlled hydration of seeds to a level that allows pre-germination metabolic activity to proceed, but prevents the actual emergence of the radicle after priming, the seeds can be dried back to the initial moisture content. The objective of this study was to determine the effects of storage on the primed seed of tall fescue. Hydropriming and osmopriming methods were used in this study to prime the seeds. The water osmotic potential for osmopriming was between-1.5 and-2.2 MPa. After drying, the seeds were first divided into two groups. For the first group, the seeds were sealed in aluminum foil bags and stored at 25 C
Seed priming is known as method which improves germination performance in seeds, under stress conditions. The objective of this study was to compare the effectiveness of Hydropriming and Halopriming on germination performance of Secale montanum growing under the NaCl-salinity stress. For the Halopriming treatments, Concentrations of 125, 250 and 500 mM of sodium chloride was applied. This experiment was carried out in the four levels of salinity stress. Germination percentage in Halopriming showed the significant reduction with increasing durations and concentrations of treatments. Longer root and shoot length of S. mountanum was observed in Hydropriming treatment. S. montanum appears to be moderately salt-tolerant. The results of this stud
Land management is one of the most important factors affecting the protection and carbon sequestration of natural ecosystems. If the ecosystem is maintained naturally, it will have suitable vegetation and soil stability. One of the important factors that affects land management is livestock grazing. In order to evaluate the impact of exclosure rangeland on carbon sequestration (CS) in salty rangelands, the study was carried out in Inchehboroun rangelands of Golestan province, Iran. The main purpose of current research was to evaluate the effectiveness of management of salt rangeland on CS by topsoil and halophytes species. For this purpose, 40 plots (with 2 m2 area) were located along 8 transects of 100?m in exclosure rangeland (ER) and gra
This study evaluated the effect of priming on germination, emergence, yield and quality of Festuca arundinacea in both laboratory and greenhouse conditions. Previous priming studies have evaluated only germination and seedling emergence for fescue but priming treatment effects on forage quality have not been assessed. A wide variety of priming treatments have been used to enhance seed germination. Hydropriming and osmopriming are commonly used methods to prime the seeds. Hydropriming is the simplest method to hydrating seeds and minimizes the use of chemicals. The Seeds were treated by hydropriming (distiller water) and osmopriming in polyethylene glycol 6000 (PEG) and KNO 3 solution for 1, 3 and 6 day with osmotic potential-1.5 and-2.2 MPa
The effect of vegetation types at mountainous sites on the relationships between soil biota and environmental variables applicable for the evaluation of soil quality and functions are barely studied and remain almost unknown. In the present study, the effect of forest degradation and vegetation types changes [i.e. natural forest with dominant species of Zelkova carpinifolia (Pall.) K. Koch. and three rangelands with dominant species of Festuca ovina L. Dactylis glomerata L. and Stachys byzantina K. Koch.] on the dynamics of soil properties and density of soil organisms in northern Iran has been considered. For each studied vegetation types, three different sites (at a distance of 4–6?km) with 1?ha area were selected. In summer (August), l
The presence of plant species together causes biotic interactions. These interactions are very complex and variable among species which facilitation and competition have the highest impact on ecosystem function. Disturbances including fire are among the environmental factors affecting the biotic interactions. This study aimed on understanding the effect of fire on biotic interactions of cushions and grassland species. Therefore, to survey the effects of fire on the biotic interaction, 30 individuals of non burned Onobrychis onobrychis Subject Category: Organism Namessee more details cornuta and also 30 individuals of burnt patches were selected. In addition, 30 paired plots for each individual was randomly established close to each patches.
Investigation on the shape of the curve for responses of plant species to environmental gradients is one of the basic topics in the science of rangeland ecology. The objective of this study was investigation on the response of Bromus tomentellus and Festuca ovina species to some environmental variables using the generalized additive model (GAM) in the rangeland of Galandrood watershed in Mazandaran province. Towards this attempt, 153 quadrates of 1m 2 along altitudinal gradient were taken. The sampling method was randomized-systematic. In the area sampled, presence of B. tomentellus and F. ovina, altitude, slope and aspect were recorded. Soil samples were taken from 0-20 cm in each quadrate. In each quadrate, soil properties including: pH,
Salinity is one of the major environmental stresses that limit plant growth and productivity. In this study, the effects of salt stress on physiological and biochemical parameters were investigated in Hedysarum coronarium L. and Hedysarum criniferum species The NaCl treatments in Hoagland's nutrient solution were: Control (no salt: 0.81 ds/m NaCl), 10.67, 20.33, 22.66 and 26.59 ds/m. Plants were irrigated with Hoagland's nutrient solution during 4 months. Salt treatments were applied for 37 days. Gas exchange parameters, relative water content, proline, chlorophyll, carotenoids and stomata characteristics were measured. Data analysis showed that the measured parameters except intercellular CO2 concentration in both species were affected by
Present study was conducted to evaluate the effect of pre sowing exposure of gamma rays on seeds of Bromus inermis with doses of 15, 20, 30, 50, 100 and 150 gray, on germination, morphological traits and biochemical parameters. Irradiated seeds were sown in a completely randomized design in laboratory and greenhouse conditions. The seed germination, emergence parameters, growth, yield, chlorophyll, proline and total soluble protein content of leaves were measured. The results showed that the 15 gray doses caused the most positive effects on emergence parameters, growth, yield and chlorophyll content. Also gamma ray exposure on seeds of B. inermis caused significant decrease (P<0.01) in proline concentration. There was no significant differe
see more details with an arid and semi-arid climate and specific species is one of the most suitable areas for camel breeding. Despite the importance of camel in the province, no research has been conducted on species selection by camel as well as its relation to chemical factors of plants plants Subject Category: Organism Names
Behzad.–Germination is a most salt-sensitive plant growth stage and severely inhibited with increasing salinity in both glycophytes and halophytes. In the present study, the effect of three levels of a salt (NaCl) and polyethylene glycol 6000 (PEG) on the germination of Lolium perenne L. and Bromus tomentellus Boiss. seeds was studied. The object was to reveal factors responsible for seed germination due to salt toxicity or the osmotic effect. The electrical conductivity (EC) values of NaCl solutions were 0, 5, 7, and 9 dSm-1. PEG 6000 induced drought conditions at the same osmotic potential of 0,-2,-3, and-4 bar. Our results showed that NaCl and PEG treatments had significant (p= 0.05) effect on the germination percentage and recovery of
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 maps Subject Category: Publications
There is some evidence that allelopathic interference on the establishment of plants can be attributed to the effect of essential oils from Artemisia herba-alba. For this purpose, chemical composition essential oil and allelopathic effects of Artemisia herba-alba were evaluated to determine inhibitory or stimulatory effects of essential oils on seed germination and early seedling growth of two legumes (Medicago sativa L. and Onobrychis sativa Lam.) and three grasses (Lolium perenne L., Secale montanum Guss. and Bromus tomentellus Boiss.) in a laboratory experiment. The essential oils of aerial parts of Artemisia herba-alba were obtained by steam distillation and analyzed by GC-MS. Seed germination test was carried out on filter paper moiste
This study was conducted to investigate allelopathic effect of the essential oil of Artemisia herba-alba Asso., on seed germination characteristics of Agropyron desertorum and Agropyron cristatum in a laboratory experiment. Essential oil was extracted from the aerial parts of Artemisia herba-alba using a Clevenger-Type apparatus. The volatile chemical compositions of Artemesia herba-alba were determined with gas chromatography–mass spectrometry (GC–MS). The crude essential oil was diluted with ethanol to a final concentration of 100 ppm, 500 ppm, 1000 ppm, 1500 ppm and 2000 ppm. Seed germination test was carried out on filter paper moistened with 5 ml of different dilutions of essential oil or distilled water as control. The results sho