مجله مرتع
سال دهم شماره 2 (پیاپی 38، تابستان 1395)

A field experiment was conducted to investigate the effects of mono and mixed culture on crude protein contents of Medicago sativa L. and Bromus tomentellus Boiss, total nitrogen, available phosphorus and potassium of soil using factorial experiment based on completely randomized design with 5 replications. Treatments consisted of three crop compositions (M. sativa, B. tomentellus or mixture of the two), three density levels (low (4 rows, row spacing 70 cm), Medium (8 rows, row spacing 30 cm) and high (16 rows, row spacing 14 cm). Results demonstrated that the forage crude protein in mixed culture was significantly higher than in monoculture of B. tomentellus (p 0.05). Percentage of plant crude protein decreased with increasing plant density both in monoculture and mixed culture. Medicago sativa monoculture and mixed culture increased soil fertility that confirms the importance of forage legumes in forage quality maintenance and preservation of soil fertility. According to the results, mixed culture of M. sativa and B. tomentellus with 8 rows density (30 cm row spacing) is recommended in dryland fields of Fereydoon-Shahr and similar areas.

This research was carried out to study the distribution pattern of Artemisia fragrant and Bromus tomentellus in Razan-Khushvash mountainous rangelands located around Noor city. Random- systematic approach was used to collect the data along three 100 meters transects within the 2200 and 2400 elevation range. Ten random points along each transect with distance of 10 m were selected and the data were collected from 30 points. The distance of to the nearest plant to the selected random points, that plant to nearest neighbor plant and distance of random point to second nearest plant were measured. One square meter plots were placed at the random points and the numbers of plant individuals were also counted. The plant distribution indices (Eberhart, Hopkins, Holgate, Johnson and Zimmer) were then calculated. The quadratic indices of species dispersal (Variance mean, Green, Lloyd, Morisita and Standard Morisita) were also calculated. One hundred percent inventories as control were conducted in 100m2 and 200m2 plots for Bromus tomentellus and Artemisia fragrant respectively. According to the calculated indices (Eberhart, variance mean, green, Morisita and standard Morisita), Artemisia fragrant had clumped pattern in the study area. Bromus tomentellus had a random to clumped pattern based on some calculated quadrate indices as it was confirmed by the one hundred percent inventory. Although the obtained results from Variance mean, Green, Morisita and standard Morisita indices showed a clumped pattern for Bromus tomentellus, Hopkins index showed a random pattern for the species. Overall, quadratic indices can be recommended to study the spatial pattern of the species in the study area compared to distance methods.

Assessing vegetation characteristics (e.g. cover and density) is an essential part of quantitative ecology and is also required for vegetation management. This research was carried out to select the most appropriate distance method for estimating density of Astragalus gossypinus in rangelands of Kurdistan. Four range sites including Khoroseh in Sanandaj, Baharestan and Zarrineh in Divandarah and Varmakan in Kamyaran were selected. In each range site, four places with size of 5000 m2 (100 × 50 m) were selected and all Astragalus gossypinus plant individuals were counted. The average number of plants in the 4 places was used as reference or control for other methods. Systematic random sampling was used to establish 100 meters transects in each place. Sample size was determined by statistical method and using data from the first 30 observations. Closest Individual, Nearest Neighbor, Random Pairs, Quarter-Point Center and Third Closet Individual techniques were used to measure A. gossypinus density. The density of A. gossypinus was calculated using Ecological Methodology software. The obtained results from each method compared with reference method and relative density difference between each method with the reference was calculated. Although measurement time did not vary between the methods, their accuracy and precision were significantly different. Random Pair and Quarter-Point Center methods were identified as the most appropriate approaches for measuring A. gossypinus density.

Geomorphological landforms play an important role in the establishment of vegetation, especially in drylands. Earth fissures are known as one of the most interesting landforms in drylands. Polygonal hydro-geomorphologic patterns are formed by fissures connections in Yazd-Ardakan plain. This study aimed to compare the Haloxylon aphyllum physiological factors such as sugar, proline, nitrogen, phosphorus, sodium, potassium and Naﲯ of aerial and underground part of Haloxylon aphyllum that grow in the mouth of fissures as treatment with the same age individuals out of fissures as controls. According to the results, nitrogen, potassium and Naﲯ content of the trees were significantly different (α= 1%). Results indicated that fissure provide more nutrients for the established species. This study indicated that fissures landforms can be considered as good places for desert reclamation activities.

Kavar (Capparis cartilaginea) is a medicinal shrub with scattered extensive branches, or up vertical, that grow in the southern and southeastern provinces of Iran. In addition to its role of stabilization and reduction of soil erosion, this species is used as traditional medicine. A factorial experiment in a completely randomized design was used to study the effects of potassium nitrate with concentrations of 0, 50, 100 and 200 mM and duration of 24, 48 and 72 soaking hours with four replications to break the seed dormancy and improve the germination components of the species. The results showed that the seed germination parameters of Kavar were affected significantly by the priming treatments. The germination rate, vigor index, shoot fresh weight and shoot dry weight of the species were increased 78.2%, 147%, 78.9% and 90% respectively compared with the control by using 200 mM potassium nitrate salt and 24 hours soaking treatment. The germination percentage of the species was increased by 72.5% compared with control in 200 mM with 24 and 72 hours soaking treatments. 200 mM concentration and 72 hours soaking treatment increased maximum rootlets fresh weight, rootlets dry weight and rootlets length by 438%, 400% and 112% respectively compared with control. Overall, the contamination levels of 200 mM and time soaking of 72 and 24 hours are suggested as the most appropriate treatments in order to improve the germination characteristics of Capparis cartilaginea.

This study aimed to study the effects of some environmental factors on distribution of Prangos ferulacea Lindl in rangelands of Ardabil province. The vegetation cover and density of the species were studied using 10 square plots (2×2 m) along three 100 meteres transects in all the seven studied sites. The soil samples from the presence and adjusent area with no Pr. ferulacea occurrence were collected from the beginning, middle and end of each transect. Altitude, slope and aspect of all samples were recorded. Soil properties including nitrogen, phosphorus, potasium, organic matter, pH, EC, and soil texture of the collected soil samples were determined in laboratory. Various analytical and classification methods (e.g. t test, ANOVA and cluster analysis) were used to compare the condition of presence and absence site of the species. According to the results, this species prefer habitats with high altitude, steep slope with high organic matter. More specifically, Pr. ferulacea habitats characterized by altitude of 1790m, slope more than 80%, precipitation of 227-358mm per year, average annual temperature of 9-11 cetigerade, and organic matter of 0.98-1.35%. The results indicated that the species prefer lomy soils with high nitrogen and potassium content. According to the disriminative analysis, the occurrence of Pr. ferulacea depends more on climate variables (e.g. precipitation and temperature), and physiographic condition (e.g. elevation and slope) than soil variabels. The results of this study can assist managers to identify appropriate sites for establishing the species in the field.

Precise estimates of plants water requirement is essential in the water, soil and plant management. Crop coefficient determination is required to prepare appropriate irrigation timing and enhance water resource management. FAO determined crop coefficient (Kc) of main horticultural and agricultural plants. This study aimed to determine crop coefficient of Medicago polymorpha, using weighing micro lysimeters in Fasa University, located at 140 km south west of Fars province. Circular micro lysimeters with 30 centimeters diameter and 40 centimeters depth were used in three replications to measure Kc of the species. According to the results, various growth stages of the species in a normal growing season including initial, developing, mid-season and late season stages take 5, 25, 35 and 15 days respectively. The crop coefficient (Kc) of these growth stages were 0.59, 0.95, 1.32 and 0.74, respectively. Results showed that Medicago polymorpha requires 541 mm of water during a growth season, therefore it has low water requirement and can be used in rangelands rehabilitation programs in arid and semi-arid regions.

Determining the nutrition values of range plant species and investigating their balance with livestock requirements is essential for grazing management. This study aimed to determine and compare the mineral contents of Hedysarum criniferum and Astragalus cyclophyllon in three phonological stages (vegetative growth, flowering and seed dispersal) in Chadegan region of Isfahan province. The plant samples were collected from 1 cm above the ground surface and their mineral elements were measured in laboratory using various methods. Factorial statistical method in the form of a randomized complete design with two treatments and three replications was used to analyze the data. According to the results, mineral contents of the species varied significantly in various growth stages (P ≥ 0.05). Comparing mineral contents of the species with sheep requirements revealed that k, Mg, Ca and Fe contents of the plant species meet sheep daily requirements, but their P and Zn contents were insufficient for sheep in the both species. The measured amount of Cu in the collected samples from Hedysarum criniferum was more than minimum requirement of the sheep daily requirements but it was insufficient in Astragalus cyclophyllon. In conclusion, most of the measured mineral elements were decreased in these species during the phonological stages and these two important native legums meet sheep mineral requirement except p and z.

The present study aimed to investigate the spatial variability of soil properties in the Taftan rangelands of Khash city. Homogeneous units were determined by overlyaing slope, aspect, elevation, and geology maps (1: 25000 scales) of the study area. Random systematic method was used to collect data by plots placed along three transects with 150 m length. Soil samples from 0 to 15 and 15 to 30 cm depths were collected by drilling 24 holes. Soil samples were analyzed and their characteristics including gravel percent, texture, saturation moisture, available water, lime, gypsum, organic matter, acidity (pH) and electrical conductivity (EC) were measured by the standard methods. Kriging analysis was used to examine and describing spatial structure by GS software version 9. Model were fitted to the variogram and model parameters were then determined. Accuracy assessment of the interpolation results was performed through cross-validation, and their Mean Bias Error (MBE) and Mean absolute Error (MAE) were calculated. According to the results, most of soil characteristics followed a spherical and exponential shape models in both surface and deep soil layers. Although some soil properties such as lime content of soil surface (with 4.70 nugget effect and 80% spatial structure), available water in the both soil layers (with 0.29, 0.1 nugget effect and 97%, 99% spatial structure respectively) and soil texture (sand, clay and silt percentage) had strong spatial structure. Some charactristics such as gypsum, saturation moisture and gravel did not show strong spatial structure in the both layers. According to the fitted model, kriging could not obtain a proper estimation of gravel amount in the first soil layer (MAE=11.93 and MBE= -0.708) and soil sand content in the second layer (MAE=10.51 and MBE= 0.15) because their high values of nugget effects and weak spatial structures resulted to the high error rate and estimation bias of these variables.

Gundelia tournefortii (L.) as a medicinal plant species grows spontaneously in the mountains and steep rocky areas. It belongs to Astraceae family. Growth and yield of this species in various ecosystems and natural habitats are affected by many environmental factors (e.g. altitude, climate and soil characteristics). The aim of this study was to investigate the impact of environmental factors on the antioxidant capacity of G. tournefortii in different growth stages in Oshtorankooh rangeland - Lorestan province. For this purpose, leaves and stems of G. tournefortii were collected from 4 sites located in various elevation ranges (1900m - 2700m from sea level with elevation intervals of 200 m) in three stages of maturity. Dried powder of aerial parts from 4 sites was extracted with methanol 80%. Antioxidant activity of the extracts were then analyzed by 2,2-diphenyl-1-picryllhyrazyl (DPPH) method. Statistical analysis of the data was performed by Multivariate Analysis of Variance (MANOVA) to compare the means. The highest antioxidant activity of leaves and stems of G. tournefortii was observed in 1900-2100 m elevation. A significant relationship (p