Journal of Rangeland
Year:2009 | Volume:3 | Issue:3|Papers Count:22

Canopy cover data are important for range management decisions and there are different methods of estimation. Introducing a method with adequate speed and precision and low cost is important in range management studies and researches. According to development of new technologies in photography soft- wares and hardwares, it can provide an opportunity to study in a large scale at a short time and low cost. If its accuracy be fine, then it could be used in monitoring projects. This study carried out for study of accuracy and efficacy of vertical photos prepared with digital camera and application of existing soft-wares in estimations of canopy cover percentage of shrublands in Yazd province. Three sites representing Yazd shrublands were selected: 1- Nir rangelands with Artemisia aucheri as dominant species, 2- Shirkooh rangeland with Artemisia sieberi as dominant species and 3- Chahafzal rangeland with Seidlitzia rosmarinus as predominate species. Sampling was carried out in these three sites after determining sample size with drawing method and plot size according to the canopy of dominant species. Photography was performed in suitable height using a camera in the centre of plot and makes sure the photo include the whole area of plot. Simultaneously, canopy cover percent was measured directly with meter tap. Canopy cover percentage also was determined by prepared digital photos after inserting them to computer and using Arc View soft-ware. The percentage of canopy cover by species, in photography and direct methods were compared using SPSSsoft-ware and using Paired T-test. There were not significant differences between canopy cover percentages estimated by two methods at %5 level. According to the results Photography with existing soft-ware could be used for determining canopy cover percentage in shrub lands of Yazd province.

Desert grasslands are characterized by microtopography that appears to be the result of a long-term accumulation of soil around grass tussocks. Microtopography (or micro roughness) describes variations in soil surface elevation (mm or cm) for a scale of a few meters of horizontal distance and it can contain the depression or mound of the soil surface. If the microtopographgy is flattened, microcatchments are lost and water runoff transports sediments and organic materials off site. Factors that affect this fine-scale patchiness are hypothesized to be the precursor of coarse scale changes leading to desertification. Livestock have the most effect on soil microtopography and this effect will decrease with the increase of distance from critical point. Present research has considered studying microtopography fluctuations of soil surface (maximum depth between two consecutive vegetation patches) along grazing gradient and its comparison with enclosure in salt grasslands of Incheh Boroun, aimed at investigation on stability state of ecosystem. To accomplish this goal, height fluctuations of soil surface were measured through running transects away from the critical point. Grazing zones were defined using dung count method along transects. Results obtained show that depth of micro depressions around critical point is more than the depth of microdepressions in the zone of constant grazing as well as enclosure site. It seems that reduction of vegetation cover and the expansion of bare soil have happened as the result of intense and long term grazing in the area. Micromounds of soil surface have also been flattened because of livestock trampling. The continuation of intensive grazing has exacerbated the effect of erosive factors such as water or wind that cause soil surface to be eroded and microdepressions to appear on the soil surface. The rate of depression has increased or decreased in different regions of the area proportional to rate of grazing; therefore, we can state that elevation of surface microdepressions can be considered as an indicator of utilization of the ecosystem and its stability state.

In this research, habitat of Camphorosma monspeliaca was studied ecologically. This species has spread into an area of more than 3500 ha within Doto-Tangsayad in Chaharmahal and Bakhtiari Province. After identification of the stands of this species and selecting stands with and without this species; vegetation cover and environmental factors such as topography, physical and chemical properties of soil were studied Random-Systematic sampling method was considered with plots which that area was determined by minimal area method. Plant species was recorded along five transect per stand. In the present study quantities parameters of C. monspeliaca were analyzed using SPSS software. A matrix of plant stands and environmental factors was prepared and data were analyzed by the Principal Component Analysis (PCA) using PC- ORD software. Result indicated that Camphorosma monspeliacaspecies has scattered more along the second axis that plant stands were in southern aspect and had more density and cover percentage. From the results obtained on three topography position, slope aspect has significant difference on distribution of this species. In general, the most important effective environmental factors in vegetation distribution pattern were elevation, sodium, organic matter, sand, calcium carbonate and magnesium.

In order to valuation effects of rangeland improvemental practices on some parameters of soil and vegetation cover were studied (2005) in the rangelands of sirjan. In the study 4 improvemental practices include: enclosure, goorab (digging the land for water harvesting), alfalfa planting and Wheat grass planting were selected and next to every site that improvemental practices were done in it, sites were selected as controlled ones that were adjacent two by two. Vegetation cover sampling was done with 50 plots of 1m2 in every site by random systematic method and soil sampling after excavation and sampling from the depth of 0-30 and 30-60 cm of the soil were done. Vegetation cover and soil data was analyzed by means of software SPSS by using of paired t test and variance analysis (RCBD). Obtained results showed that improvemental practices done have had significant effect on increasing of canopy percentage, yield, vegetation density of I and II class and decreasing of III class vegetation (1% Level). The investigation of studied soil specification with t test showed that nutritive elements of nitrogen, phosphor, potassium and organic matter had significant difference between every treatment site and its controlled site (5% level). The results of variance Analysis of variation (ANOVA) about soil parameters in 2 depths investigated showed significant difference in OM/N/P/K and Ca% among 4 sites. In the total results of study showed that 4 improvemental practices done have had positive effect on vegetation cover and soil specification in the rangelands of sirjan region.

Study of rangeland analysis can make to able an expert to judge the degradation of management activities and ecological changes of rangeland. In order to survey of range condition of sagebrush rangeland using the rangeland health method, the steppic rangeland of Roushour was selected. Habitat vigour for each area and survey regions were determined by using of rangeland health's instructions which have 17 indicators to determining of regions health. Structural condition of three traits of rangeland health (soil and habitat sustain, hydrologic function and vigour of living things) was visionally determined. Non-parametric test for two independent samples was employed to compare between indicators and rangeland health's traits of each survey region. The results have shown that each of three traits of rangeland health in the survey region is in the critical class because of overgrazing and lack of range readiness. Hence, it shows that range traits are lower than threshold which shows unhealthy condition of rangeland. This method is not a monitoring approach which uses to surveying of rangeland as same time and spatial. Then, if a ranger wants to appoint a temperary management's decision, he can use this model to rangeland survey.

Study on grazing effects is essential in order to finding the correct management strategies and suitable stocking rate of rangeland ecosystems. This research was carried out in order to determine grazing intensity effects on some soil chemical properties in Khabr region of Kerman province for two years. Natural sites under three grazing pressures (heavy, moderate and none grazed) with same ecological factors were selected based on distance from water resources and nomad tents. Sampling was conducted under split plot blocked designs in two horizons (0-15 and 15-30 centimetre) and three temporal stages (before, middle and after grazing) using metal cylinder with 4 centimetre diameter. Soil chemical properties (PH, EC, organic matter, nitrogen content, available phosphor and potassium content) were analyzed. The results showed PH and total nitrogen contents decreased significantly on middle than before and after grazing. Organic matter was maximum on before grazing. Available phosphor content decreased 6 and 7/853 mg/kg on middle and after than before grazing, respectively. Total nitrogen, Available potassium, Available phosphorus and organic matter contents contrasting to PH decreased with increasing depth. There were not any differences in phosphor and PH contents of sites. Maximum contents of organic matters and potassium were, respectively, 1/23 % and 254/95 mg/kg in moderate grazing site, that differed to other sites. Decreasing rate of nitrogen as 18/84% was seen in heavy grazed than non-grazed site, while there wasn't significantly difference between moderate and non-grazed sites. The result showed moderate grazing immolated soil chemical properties specially potassium and organic matter contents than heavy and non-grazed sites. Therefore, the moderate grazing strategy for rehabitation of Artemisia herba-alba degraded habitat is recommended.

Knowledge of rangelands ecosystems' components are necessary element to sustain managing of these ecosystem. Animal is an element of theses system which has different diet and distinguish of nature and philosophy of it is so needful to optimum management. There are many factors for animal's diet selection that it is different under area and climate condition, kind of animal and vegetation. In order to determine of sheep's diet selection, upland rangeland of the northern Alborz was selected. First, confine of grazing area was limited and then three vegetation types and floristic list were determined. Rangeland condition, and plant composition, rangeland trend are determined by range value method and trend balance method, respectively. Diet selection of sheep is determined by direct visional method with bite-count method. Bite rate was 100 for each sheep that it uses for counting of species palatability. Results are showed that although condition categories of all types were same, climate and floristic condition are performed high role to diet selection of sheep. Sheep has preferred more bush and bushy tree against of palatable species such as grasses under fogy condition. And it has also preferred to use forbs and grasses under warm and sunny condition.

One of the most important aspects in rangeland management science is palatability and plant selection while grazing which plays an important role in determining condition, capacity and rangeland tendency. On the one hand, palatability is relative and the collection of present plant species in a field "is studied with a certain type of livestock. So far, no written results have been reported about the seasonal changes in camels grazing tendency. Considering lack of enough information about camel food in different seasons and importance of determining palatable species in correct utilize of rangeland, it's really necessary to do this research. In this regard, this research is preformed in Sarchah Ammary, a desert region located in South west of Birjand, to recognize palatable plant species from domestic point of view and expanding their growing in the region. For this purpose in study area in three different periods (spring, autumn and summer), feeding minutes method was used and plant selection was studied with regard to 5 camels. In this technique, an animal was closely followed for 30 min during feeding. Data were analyzed by helping SPSS 11.5 software. The results showed that among the available plant species Seidlitzia rosmarinus was remarkably the most utilized specie during all season. Also, Tamarix ramosissima in spring was the second specie that chosen by the livestock and in autumn it has been eaten remarkably by livestock and other species was rarely eaten in three seasons. Comparing palatability in different seasons shows that there is no seasonal difference in plant species selection by camel.

Getting aware of soil attributes of one kind of vegetation is very important. Assessment of important attributes of soil and vegetation can help us aware of rangeland potential and help us to determine the situation of it. In this research we start to assessment of soil surface according to the two-way effects of vegetation and soil surface attributes by the way of soil surface classification of rangeland (SSCC). The result of this research is the qualities comparison of soil and vegetation landscape in east and west aspects of loss topographic of Ghareghir and Maravetappe. In this research the length and width of ecological patches by the forms of lichen, lichen- Grass, forb, shrub and bare soil with litter measured. Also we measured the 11 soil surface parameters on three, 50 meters transects in east and west aspects of the two mentioned regions. These 11 parameters are belonging to 3 major attributes of soil: Stability, infiltration and nutrients. Stability, infiltration and nutrients indices of Shrub, forbs and lichen- Grass showed significant differences in both aspects of Ghareghir and Maravetappe (p<0.05). In Maravetappe especially in west aspect these indices were more but in Ghareghir the most important east landscapes were forbs and lichen – Grass and in west landscapes shrub and lichen- Grass had more importance.

Sejzi plain located in east of Isfehan is one of the arid plains under intensitive desertification processes. Limoniumiranicum, a native drought and salinity tolerant plant, is distributed sparsely in this desert. According to mentioned plant tolerance against unsuitable environmental conditions, we decided to investigate the treatments which can improve its seeds germination in order to use this plant in combating desertification projects in Sejzi plain. The treatments included pre-soaking (for 48 hours), prechilling (in 0-5°C), CS[NH2]2 (0.2%) and KNO3 (0.2%). Germination tests were carried out for 21 days in germinator with 30°C and 12 hours light period in four replications for each treatment. Germination and initial growth properties included germination percentage, rate of germination, and length of coleoptile. and radicle, and alometric index. Pregermination treatments showed that prechilling with 7 days at 0- 5°C resulted in the highest germination. Germination rates and alometric index of pregermination treatments had no significant differences.

Haloxylon aphyllumis a perennial shrub, adapted plant to arid area. It is as forage and employed to sand fixation and desert reclamation. Seed germination is a critical stage of species survival. To investigate the effect of light, temperature and salinity on seed germination a factorial experimental plan was performed in a complete randomized block design with four replications, light with two levels (light and darkness), temperature with 6 levels (5, 10, 15,20,25,30°c) and salinity with 8 levels (0, 0.2, 0.4, 0.6,0.8, 1, 1.2, 1.4 Mol/lit). No significant differences were observed between light and darkness respect to seed germination. Results showed that temperature regimes highly significantly effects on the germination percentage, germination rate, seedling dry weight and seedling length. The germination percentage, seedling dry weight and seedling length, increased with increase temperature levels from 5 to 25°c but decreased at 30°c. Salinity had high significant effect on the germination percentage, germination rate and seedling length. With an increase in salinity, there is a decrease in germination percentage, germination rate and seedling length. The germination stage of Haloxylon aphyllumseed is sensitive to salinity and temperature of above 25°c.

This study was done on four range species of Agropyron desertroum, Bromus inermis, Lotium prenne, Seeale montanum in order to evaluate the effect of the grooming of osmopriming on the tolerance against dry stress in the seeds of the plants. This study was done in the face of the factorial experiments in the form of the complete random block in 3 repeats and 3 steps of the experiment. By the use of the solution of the polyethylene glycol (PEG) in the levels of -8 , -12 , -16 bar , the load of dry stress was calculated on the primed seeds (The best level of the prime was -8 bar for all of the seeds and the best time was 48 hours for Agropyron desertroum and Lotium prenne, and the best time was 24 hours for Bromus inermis and Seeale montanum)and the non-primed seeds and the percent and the speed of the germination and the length and the dry weight of the rootlet and the plumule and then was compared with the control. The mutual effects for the plants and the prime and also the dryness, the prime and the plant and dryness in the level of the probability of 0.01 were meaningful. Each of the abovementioned pastoral plants had the highest percent and the speed of the germination in the level of zero (control) and the lows percent and the speed of the germination in the dry level in -16. Also, the percent and the speed of the germination of each plant were observed in the primed level higher than the non-primed level.

This research was conducted to determine the salinity effects on seed germination characteristics in two species of Medicago sativa and Onobrychis sativa. For each species two genotypes were used by using a factorial experimental design including five salinity levels of 0,100, 200, 300 and 400 Mm NaCl and CaCl2 treatments. The treated seeds were assessed in laboratory conditions. Data were recorded and analyzed for percentage and speed of germination, length of root and shoot, seedling length; shoot to root ratio (S/R), vigour index and seedling dry weight. The results showed significant differences among salinity treatments for all of traits and between two species for speed of germination, length of root and shoot, seedling length under higher levels of salinity stresses. Species by salinity interaction effects were significant for speed of germination, length of root and shoot, seedling length and vigour index, indicating of different response of species for higher level of salinity stress. The higher variation between two species was obtained for seedling dry weight and R/S ratios. The higher values for germination percent were obtain in Lucerne in 100 Mm salinity. In sever stress (300 Mm), the sainfoin had higher values for germination percent.

Abiotic stresses including salinity are the major limiting factors of growth and crop production worldwide. Microbial endophytes as the most important soil microorganisms, by modifying plants at genetical, physiological and ecological levels increase their yield per area unit and provide the possibility of crop production in saline and arid soils or climates with biotic and abiotic stresses. The endophytic fungus, Piriformospora indica has a pronounced growth-promoting activity and also increases plant resistance to environmental stresses including salinity, drought and plant pathogens. This research deals with the potential of P.indica to improve growth of barley (Hordeum vulgareL.) and increase its resistance to salt stress. The obtained results show that P. indica increases the biomass of aerial parts and root of inoculated plant in compared to the controls. In addition to plant growth promoting activity of P.indica, the obtained results of this research approved the effective role of this fungus to improve growth and yield of barley under salt stress conditions. Application of this fungus as a plant growth promoting agent in production of biological fertilizers and its wide utilization for crop plants plays an important role to reach the sustainable agriculture.

Many damages caused by exploiters in Iran natural resources due to incorrect and unsuitable utilization, especially in recent decade. In this research by using two questionnaires(natural resources exploiters questionnaire and involved experts in natural resources management questionnaire), effective factors on natural resources degradation have collected in 11 provinces, including: Ardabil, Gillan, Kermanshah, Hammadan, Tehran, Markazi, Khozestan, Esfehan, Yazd, Boushahr and Sistan and Balochestan. Totally 1847 completed exploiter questionnaires and 504 completed expert questionnaires, collected. Answers and opinions classified and analyzed. In order to comparison of two groups opinion, depend on their grade, arranged in two right and left columns and similar grades were lined to each others. Results showed that every group had different opinion about importance and grade of natural resources degradation factors. So, their ideas were compared and showed in a graph. Line direction from left to right and reverse indicate the difference between grade of two group opinions and line slope intensity, indicate the dept of difference of opinions between of two groups. Experts had given higher grades to some factors in their answers than exploiters and reverse. For example in 41.7% of answers, experts had given higher grades to factors and 45%, exploiters had given the higher grade. In 13%, opinions of two groups are the same about natural resources degradation factors.

Soil erosion resulted from degradation of vegetation cover and consequent water loss in Iran watersheds is one of the important managerial issues in the country. Studying water resources, soil erosion and effective factors is then very important. Gully erosion also extends in many parts of Iran and its study particularly in view point of sediment yield is therefore a vital task for watershed managers. The present study was taken place in Darehshahr city in Ilam province, Iran, in order to investigate the relationship between sediment yield from gully erosion and runoff parameters viz. runoff peak, specific discharge, runoff depth, time of concentration, runoff volume, and volume to discharge ratio and runoff velocity. For this purpose, 18 axial, frontal and degitated gullies were precisely selected and their morphometric variations were surveyed at the beginning and the end of 5 storm runoff events during November 2005 to January 2006. The important affecting factors were then determined with the help of factor and regression analyses. The results of the study verified non-significant (r<0.239) effects of study runoff factors in sediment yield by gully erosion.