فصلنامه تحقیقات مرتع و بیابان ایران
سال شانزدهم شماره 4 (پیاپی 37، زمستان 1388)

Information about animal requirement, available forage and its quality is fundamental for successful range forage and livestock management. Since sheep is dominant grazing animal on rangelands in Iran and there are about 27 sheep breeds and each breed has special body size and physiological condition, different daily nutrition requirements need to be considered. It is necessary daily requirement of each breed based on quality of available forage be determined which was the main objective of this research for Moghani sheep breed in Kalibar rangelands in eastern Azerbaijan province of Iran. Vegetation composition was formed by 11 species including Hordeum glavum, Aegilops sylindrica, Artemisia fragrans, Agropyron trichophorum, Festuca ovina, Dactylis glomerata, Stipa barbata, Sinapis arvensis, Bromus tectorum, Bromus tomentellus and Kochia prostrata. Among them Hordeum glavum, Aegilops sylindrica, Artemisia fragrans, Stipa barbata, Sinapis arvensis, Bromus tomentellus, and Kochia prostrata were existed in lowland, and other species were observed in highlands. Samples were collected from an exclosure about 25-31 of May in flowering stage and 4-6 of July in maturity stage. Forage quality was evaluated based on chemical combination including crude protein (CP), acid detergent fiber (ADF), dry matter digestibility (DMD) and metabolizable energy (ME). For comparison of results One-Way Analysis of Variance (ANOVA) was used. Duncan test was used to determine inside changing sources and comparing species and location with p<0.01level. There were significant differences (p<0.01) between CP, DMD, ME & ADF contents among species and different phenological stages and different areas. Higher forage quality was obtained from Festuca ovina and lowest forage quality was obtained in Hordeum glavum. Among two Phenological stages of (flowering & maturity) the higher percent of CP, DMD and rate of ME were obtained in flowering stage and the lowest percent were belonged to maturity stage. The higher percent of ADF was measured for maturity stage and the lowest Percent of ADF was obtained in flowering stage. Thus there were significant differences (p<0.01) between ADF, CP & ME of species. There were also significant differences between chemical components of species in different phenological stages and areas. Moghani sheep daily requirement based on MAFF equation considering forage quality and physical condition of the areas in two phonological stages and maintenance condition with 40% additional requirement were 1.39 kg DM and 2.14 kg DM in flowering and maturity plant growth stages respectively. Generally considering average metabolizable energy of species daily animal requirement in highland and lowland were 1.53 and 1.95 kg DM respectively.

Antecedent soil moisture is one of runoff and sedimentation crucial factors affected by parameters such as soil properties, topographic-, climatic-, and coverage circumstances etc. The work aimed at determining effects of soil properties and rainfall on runoff and sediment load at various antecedent moisture levels. Heavy, medium and light textured field soils were selected, exposed to a constantly intensified 80mm/hr rainfall under air-dried, air-dried to field capacity point, field capacity point and nearly saturated conditions, and two slopes of 5 and 15%. Recording runoff and sedimentation values every 2-5 min; populated values were calculated within 10, 20 and 30 min. intervals. All experiments were carried out with simulated rainfall technique in a 1×1×0.1m flume. Treatments showed most significant differences within first 10min. decreased with increasing rainfall duration. Maximum runoff coefficients increased as 2-5 folds as minimum ones with all durations. When moisture increased to field capacity point, light, medium and heavy textured soils had the lowest to the highest values of runoff coefficient, respectively. Under nearly saturated condition, increasing runoff trend decelerated with heavy textured soils and decreased to a lesser extent as compared to medium textured samples. Also, sedimentation process was consistent with runoff fluctuations. Medium textured soils showed a significant level of sedimentation under nearly saturated conditions. Runoff coefficients were unnoticeably different with 5 and 15% slopes; however, a more significant sedimentation increase occurred with 15% slope.

Species richness and biological diversity have been declined throughout the world as a result of human activities. Protected areas are an attempt to conserve the remaining species. Measuring species richness is important for understanding resource condition but heterogeneity in plant distribution make inventories difficult. Salok National Park with 6000 ha space located in North-west of Esfarayen County, Iran. In this study, species richness was measured by Modified – Whittaker plot for this National Park. For analysis of this richness a regression model as have been used. Totally, 184 plant species was found belonging to 137 geniuses and 40 plant family which Poaceae, Asteraceae, Fabaceae and Lamiaceae families with 28, 26, 19 and 17 plant species, respectively had the most species richness abundant among the others. As a biological spectral and life form, prevailing relations in studied area were HC>TH>GE>CH>PH and herbaceous Forbs>Grass>Bush>Shrub, respectively. The most plant species are perennial totally.

Nowadays, desertification as a great problems affect most of the countries in the world especially developing countries. Desertification phenomenon that occurs in arid, semi-arid and dry semi-wet regions will reduce the land potential. For evaluation and mapping of desertification many researches have been conducted leading to regional and local models. In this study MEDALUS model because of easy style and data accessibility and also compatible with the effective indices on land degradation was applied for land degradation intensity mapping with emphasis on soil criterion in Hablerood catchment. So in this study, soil criterion and 6 indices including: EC, Rock fragment, depth and texture of soil, slope, and percentage of soil organic matter were assessed. At the first work units was prepared; in each work unit, one soil profile was dogged (10 profiles) and desired indices were measured in laboratory. Finally, sensitive map of region was extracted using assigned score to each index and geometric average of all indices. Data were analyzed by using spss software and analysis method of various one- way ANOVA. The results showed that, about 4.16 percent of the area is classified under low class and in the level of 0.05 there was no significant differences between indices, and the only significant difference was in the gravel percentage of soil surface in 0.01 levels.

Investigation on vegetation and soil charactristics of marl lands is important in management programs.The study area was Birjand plain. First, geomorphplogical units were identified using topographic, land usability, lithology maps and aerial photoes. After field controlling, sampling was done on homogenic units by systematic-randomized method. Size and number of plots were determined by minimal area and statistical methods respectively. Vegetation and soil samples were taken in each plot. Soil parameters such as texture, pH, EC, SAR, lime and gypsum were measuered in the laboratory. Differences between plant communities and reaction to soil variations were determined by analysis of variance and CCA using SPSS and Canoco 4.0 softwares. Results showed that the different plant communities had different reactions to soil charactristics. Suaeda fruticosa, Chenopodium album, Salsola rigida and Aellenia glauca had the highest correlation with SAR but Salsola rigida and Aellenia glauca shown high correlation with EC, silt and gypsum amount. Also, entrance of invador species (Cousinia eryngium) caused to low reaction of plant communities to edaphic factors. Other species had negative reaction to soil salinity and none of them responsed to pH.

As the documents and reports reveal, the condition of rangelands of Iran is poor or very poor in most areas; therefore, the percentage of invader species is dominant. The study of vegetation changes under strict exclosure and grazing is critical to understand the extreme problems of rangelands of Iran. The effect of exclosure and grazing was studied on the direction of vegetation changes of rangelands at Arquin site of Zanjan province at 1450 meter above sea level from 2001 to 2006. Three fixed pairs of transects with a total number of 60 plots were established inside of exclosure area and outside too. The annual forage production was measured by randomized plots. Comparison of the data in first and last years of the study were done by T student sample test. The results showed that the total canopy cover of Arquin exclosure is increased inside in comparison with outside, and it is statistically significant (P<0.01). The response of growing forms to exclosure and grazing was different, and the canopy cover of Astragalus achtalensis (P<0.05) and Stipa barbata (P<0.01) increased significantly in 2006 in comparison with 2002. The vegetation composition changed also in the study area. The relative increase of increasers in last year, was by 160 percent to that of the first year inside the exclosure; whereas the changes were not apparent. The rate of plant production was specially depended on precipitation fluctuation and the amount of organic mater and nitrogen content at 0 to 15 cm of soil depth inside and outside of the exclosure and that of 15-30 cm outsid has been increased significantly.

This study was conducted to assess the effect of rangeland dedication. The research population included all the rangeland owners (N=45) and all the pasture experts (N=32). Moreover, data was gathered through two main methods, i.e. library, documentary and field methods. The viewpoints and suggestions of professors, researchers and experts were used for the purpose of determining the validity of questionnaire. Based on Kerenbakh Alpha Coefficient, the results of questionnaire reliability was determined 0.89 and 0.91 for the questions relating to pasture owners and experts, respectively. The result of Spearman correlative coefficient indicated that the relation between the variables of: beneficiary literacy, beneficiary training, improving economic capability of beneficiary family through granting credits, improving economic capability of beneficiary family through breeding and reclamation of pastures, and improving economic capability of exploiters’ family through combination of cultivation and animal husbandry, decreasing livestock, executive effective regulations, and improving economic capability of exploiters’ family through productive plans with variable of level of success in rangeland privatization in the form of pasture management plans is positive. The results gained from Man - Whitney examination indicate that there is no meaningful difference between the viewpoint of experts and pasture owners concerning the level of success in rangeland privatization in the form of pasture management plans and both groups have similar opinion. The results gained from multivariable regression in stepwise method show that the variables of improving economic capability of beneficiary capability had have positive effect on level of success in rangeland privatization in the form of pasture management plans by combination of cultivation and animal husbandry, beneficiary training, improving economic capability of exploiters’ family through pastures breeding and reclamation and decreasing the number of livestock.

In order to compare yield and forage quality, six local genotypes of common vetch (Vicia sativa) were sown in two separate experiments under irrigated and dry land farming system using randomize complete block design with three replications in khorramabad agricultural research station during 2005 and 2006. Data were collected for Forage fresh and dry matter (DM) yield, plant height and quality traits as: dry matter digestibility, (DMD), crude protein (CP), water soluble carbohydrates (WSC), crude fiber (CF), acid detergent fiber (ADF), neutral detergent fiber (NDF) and total ash. Results of combined analysis showed significant differences between two conditions for all of traits except DMD. The average values of DM (2.76 and 2.35 ton/ha), CP (24.8 and 21.6%), and WSC (10.9 and 12.9%) were obtained for Irrigated and drought condition respectively, indicated higher values of both DM yield and CP and lower values of WSC in Irrigated conditions. Genotype effect was significant for forage yield, plant height, WSC and NDF. Results of correlation coefficients showed that forage yield had positively correlated with plant height, WSC and CF and negatively correlated with CP. Whereas, WSC had positively correlated with DM yield, plant height and DMD and negatively correlated with CP, ADF, NDF and total ash. Using cluster analysis, 6 genotypes were classified into two groups. Using biplot diagram based on 5 drought resistance indices, six genotypes were scattered. Talarizan (Azna) with average values of 3.1 and 2.7 ton/ha DM yield for optimum and dry condition, respectively had higher values in both conditions and recommended for cultivation in more rainy regions of Lorestan province. Genotypes of Torshabad (Doruod) and Fahre (Aligudarz) with average values 2.55 and 2.72 ton/ha DM yield, respectively for drought condition, were identified as tolerant to dryness and identified for cultivation in dry land farming system. Genotypes of Doruod and Bawki (Azna) with average values of 2.39 and 3.01 ton/ha forage production in irrigated condition recognized as sensitive to dryness and recommended for cultivation in irrigated conditions. Among the productive genotypes, Fahre with average values of 12.74% WSC had good forage quality.

As animals graze selectively, prediction of their nutrient intake and intensity of the impact on rangelands vegetation needs an understanding of the animals’ foraging decisions. Therefore, a study area was selected in steppe rangelands in Qom province and one enclosure (1ha. area) was contracted in which forage plants production and intake were measured during grazing period. The feeding behaviour of 3 Zandi ewes (1, 3 and 5 years old) in free grazing system was evaluated considering the plant palatability and preference value based on close observation method in each month of grazing season. Then diet composition and preference index for each plant species were calculated and compared. Grazing cycle, distance and motivation speed and time spent for grazing / resting or walking were assessed using GPS equipment mounted on the back of the sheep. The results showed that during grazing season Buffunia macrocarpa and Annuals (grasses and forbs) had the highest preference index and diet composition. Diet selection and time spent on forage plants varied slightly among three ewe ages (p<0.01). There was no correlation between two evaluation methods of preference (paired plots and close observation). Considering the plants phenology and soil moisture conditions, middle Farvardin (April) for entrance and late Aban (November) for exit of livestock were proposed. The highest percentage of grazing time occurred in Farvardin and the lowest one was in Tir(June). Because of low species diversity, in arid rangelands, livestock diet selection will be restricted. Animal experience, plant’s flavor, plant cover and composition were the most effective factors on sheep preference. Due to high diversity and grazing on shrubs, grasses and forbs, Zandi sheep could be classified as Intermediate feeders, in Yekke bagh rangeland.

Diversity is one of the main subjects in ecosystem researches. It is also important in recognition of ecosystem health. Plant diversity or taxonomic diversity is medial level of biodiversity rank system. This research was done to compare Shannon diversity indices in different taxonomic levels. The study area was mountain rangelands of Ziarat in south Gorgan, Golestan province. Random quadrates, (1 m2) were used to define plant species list and their canopy cover percentage. Dependency of each plant to family, life form, biological type and vegetative life period were studied. Shannon diversity index was calculated for taxonomic level of species and family as well as life form, biological type and vegetative life period in existed vegetation communities of the study area. Results showed that diversity in species and family level carry the same amount of information thus in these levels different communities can better be compared than other levels of life form, biological type and vegetative life period.

One of the apparent characteristics of soil is color which shows high correlation with soil characteristics and spectral reflectance. Soil color is identified using visual comparison of sample and colored chips of Munsell color charts. In arid regions due to the prolonged sunny days, low soil moisture, sparse vegetation cover and close relation between land units and soils, there is an ideal condition for application of remote sensing data especially for study of relation between satellite data and color of surface features. The soil color and the most effective factors on color and spectral reflectance of soil are explained in brief. Color composite images produced from TM7, TM4 and TM2 as red, green and blue respectively used in order to choose sample sites. The 20 sample sites were chosen based on resample 3×3 pixels (90×90 m). In each site, the soil surface conditions and the munsell color of the soil surface were investigated in the field. Some physico-chemical properties of soil samples were also determined in the laboratory. The results of this study indicates that munsell notation of hue, value and Chroma are significantly correlated to the visible bands of Landsat (TM) data. From this study it may be concluded that visible reflectance of Landsat can be used to estimate soil color, if very precise result is not expected. More investigation are necessary in order to improve the obtained results.

The purpose of this research was to compare the amount of N, P and K in the soil under three rangeland species i.e. Agropyron tauri, Astragalus ammodendron and Bromus tomentellus and (with) the soil properties of the control area. After identifying the habitats (sites) of the mentioned species, soil sampling was done in all key areas at the end of the growing season based upon randomized systematic method. In order to study the features of the mentioned species, 10 plots (1 m2) were established along 4 transects.Soil sampling was carried out in the beginning and in the end of all transects from 0-10 and 10-40 cm soil depths. Soil sampling was also done in the control area and then N, P and K were measured. All data were analyzed and compared by T test. The results indicate that the amount of N, P and K in the first soil depth beneath Agropyron tauri is more than that in Astragalus ammodendron and Bromus tomentellus. In most cases the amount of N and K in the soil beneath (under) the species are more than that in the control area which indicates the increase of fertility in the soil beneath the species in comparison to the control area and it can be due to the litter fall or intensified biological activities of the organisms.