مجله مرتع
سال سوم شماره 1 (پیاپی 9، بهار 1388)

Data sampling is the first step for sustainable rangeland management. This research was conducted to investigate the efficiency of four sampling strategies: random sampling (RND), systematic sampling (SYS), systematic-random sampling (SRS) and representative stand selection (RSS) in semi-steppe ranges of southern Zagros, near Shiraz. Each sampling unit was established based on four sampling strategy and plant cover and moving time was recorded. The precision, accuracy and time of different strategies were calculated. The result showed that sampling strategies were significantly different in terms of precision, accuracy (p<0.05), and time consumption (cost) (p<0.01). Weighting and ranking the sampling strategies by AHP method showed that SRS strategy had the highest rank and also RSS strategy was the alternative method for sampling the vegetation cover of rangelands. It should be noted that if the sampler has no enough experience to select the representative stands of vegetation, it is preferable to use SRS sampling strategy.

The world meadows are the most productive kind of rangelands. The development of croplands and overgrazing decline diversity and restrict meadows. Mountain meadows have mostly occurred in north western of Iran, especially in Chaldran areas. The people of Chaldran have different uses in mountain meadows which affects directly on their forage production. The objective of this research is investigation the effects of utilization methods on forage production of mountain meadows. To sample the study locations in Chaldran, based on the current utilization methods and the soil moisture percentages, 9 study units were selected and were randomly sampled by using 25×60 cm plots. In each location, production and soil characteristics were measured and analyzed by using completely randomized design with two factors of utilization methods and soil moisture regimes. The effects of edaphic factors on utilization methods were analyzed by using CCA ordination technique. Significant differences were observed among utilization methods in different soil moisture percentages. Therefore, the forage yield increases if soil moisture increases. There was also significant difference among application of harvesting method so the forage production highly increased. The production under direct grazing method was less than other utilization methods. The analysis of CCA showed that harvesting method had high correlation with soil moisture, soil depth, and C/N.

In order to investigation of the relationships between soil characteristics and vegetation in Nodoushan rangelands of Yazd province, three vegetation types which are represent of area vegetation, were selected and key area was determined in each type. After delimitation of the study area, sampling of soil and vegetation were performed using randomized- systematic method. The area of each plot was determined by minimal area method according to kind of plant species. The topographical conditions were recorded for plot locations. soil samples were taken at 0-5 cm and 5-60 cm depths in each plot. The measured soil variables included texture, lime, gypsum, acidity (pH), EC, SAR, and soluble ions (Na, K, Ca and Mg). Multivariate methods, including principal component analysis (PCA), were used to analyze the collected data. Results showed that the vegetation distribution pattern was mainly related to such soil characteristics as texture, gypsum, soluble potassium, lime and Salinity.

Because of daily animal traffic in around of the water point, these areas more than the other areas are generally destroyed by animal. Then it is necessary to investigate of quantitative and qualitative gradients of vegetation of these areas which if there is any regressive gradient of soil and vegetation conditions, management methods should change. In this study, diversity, richness and species composition in different distances of water point and grazing gradient on steppic rangeland of Nadoushan (Yazd) were investigated. For this research, completely Randomized Block Design was used. Sampling method was stratified-systematic-random scheme. In each plots (2m2), canopy cover percentage and plant density were estimated. In order to investigation of grazing intensity on species composition, the percentage of the canopy cover of perennial grass, perennial shrub, forbs and annual plants were estimated. Species diversity was measured by calculating of diversity (Shannon-Weaner and Simpson information index), evenness (Pielou index) and richness (species number in the each site). Analyses of data were carried out using SPSS 11.5 statistical packages. Results showed that different grazing intensity can not clarify changed gradient by animal grazing. Animal grazing can’t completely omit a species, Because plants tolerate environmental stress. Since animal grazing influences on vegetation covers and follow it on dominated plant composition, it seems that because of Simpson and Shannon-Wiener indices are influenced by dominated vegetation cove and rare species, respectively; Simpson index can better describe grazing gradient in dry rangeland.

Knowledge of environmental factors and their effects on vegetation is necessary for sound rangeland management. In this study we applied multivariate analyses to determine the effects of soil and topography on upland rangeland vegetation and also the amount of variance explained by them. 30 homogenous units according to slope, aspect and elevation were determined and then vegetation was sampled in 320 plots (1x1 m). This was done along transects and cover percentage of each species present in each plot was recorded. Also, up to 3 soil samples were taken in each homogenous unit. Result of cluster analysis showed a total of 12 sub-association of vegetation and then we described them according their species composition. Thereafter, results of ordination methods showed that two measured environmental factors significantly influenced vegetation. Here we first found five groups of species in DCA analysis. Then using CCA we found how these groups were related to specific environmental factor. Also 12 sub-association of vegetation showed some correlation with environmental factors. Variance partitioning showed that 57.4% of vegetation changes in this mountain rangeland was explained by soil properties and this was only 39.4% for topographic factors. The combined effect of two factors was responsible only for 3.2% of vegetation changes.

There are 1400000 ha rangelands in Kurdistan province which produces about 520000 tons dry forage, but there is no information of quantitative and qualitative of the mineral elements in species. This study conduct to determine micro elements Cu, Mn, Zn and Fe in different phenological stages for three dominant and palatable species (Prangos ferulacea, Ferula haussknechtii and Cherophyllum macrospermum) in Saral rangelands in Kurdistan province. Basis of the area extent of Saral region, 30 repetitions including 10 samples (at least 5 plants per sample, randomly) of three phenological stages from different topographical points were collected which per each species to determine the components, A.O.A.C method after drying in open air were used. Results indicated that the three elements (except Cu) were significantly different in different species per each phenological stage. Comparisons between elements have showed that there isn’t significantly different Zn element in growth stage and Fe in seed production stage.

Mix-culture is a derived pattern of natural sustainable plant systems such as forests and rangelands which shows that the nature prefers the mixed-culture than monoculture. High yield and fodder quality of the mix-culture of Legume-Grass system which is a sustainable agricultural system has an important role on forage production for animals. Suitable management in the lands under the mix-culture such as sowing the adapted plants in good ratios will cause the conservation of resources. In this investigation, we applied different ratios of seed as 0.00:100, 33:66, 66:33 and 100:0.00 of barley (Hordeum vulgar) and two species of vetch (Vicia villosa, Vicia pregrina) in three replication. The statistical model was Randomize Complete Blook Design (RCBD). Results showed that the treatments yield and protein contents were significant at p<0.01. The comparisons of means by Duncan,s Test showed that the A2B3 (Hordeum vulgar – Vicia villosa, 33:66) with 5.267 t/ha have had the maximum yield and with 17.14% of maximum protein. Basis of this results, using of vicia villosa with Hordeum vulgar are recommended as mix-culture for these areas.

From the total 12/6 million hectares of dryfarming through the country, approximately 4 to 5 million hectares classified as dryfarming which located in steepic lands and generally having low output or known as abandoned lands. These lands have special characteristic like minimum yield, and high erosion which loose a part of fertilize top soil yearly. Since factors like annual rainfall, slope, soil depth, and landuse are effective elements in considering the proportion of dryfarmings, therefore regarding maps of Taleghan land use (2001), isorain, slope and soil depth suitable and non suitable areas for dryfarming in Taleghan were distinguished. Then field control was performed. Based on climatic investigations, it was found that there is no limitation in view point of raining for rain feeding in Taleghan. Results obtained from maps and field controls demonstrated that 28.5% of Taleghan dryfarmings is covered by areas without rain limitation. 71.5% of dryfarmings were known as non-suitable areas for rain feeding. Based on the results of this research it is emphasized that 3 conditions are very important for rain feeding; mean annual rainfall more than 300 mm, enough soil depth, and slope lower than 12%.

Analysis of the spatial variability of soil properties is important to interpret ecosystems and to improve modeling. Soil is a heterogeneous environment that its properties have spatial and temporal changes. Soil and vegetation have reciprocal relationship and influence each other. Then investigation of spatial variability of soil properties with other environmental change is essential. In order to analysis of spatial variability of soil properties in Reineh rangelands in Mazandaran Province, 300 soil samples from 0-30 cm depth were gathered and transported to laboratory. Soil properties included: pH, CaCo3, Bulk density, Particle density, total Phosphorus, total Nitrogen, absorbed Potassium, Organic Matter, Saturation Moisture, Soil Texture, Field Capacity, permanent Wilting Point, available Water Capacity and Water Holding Capacity were measured in laboratory. Afterwards, data normalization was performed statistical analysis for description of soil properties and geostatistical analysis for indication spatial analysis correlation between these properties. Finally using Kriging methods and ELWIS Software were made maps of spatial distribution of soil properties. Results indicated that in the study area has had spatial correlation between researched factors and pH and potassium had highest and lowest spatial correlation respectively.

Social capital is a new concept in socio–economical development studies. As human population increased, it is necessary to have people participation for proper use and sustainable conservation and development of natural resources. This study aims to assess the relationship between participation of ranchers in range management plans and social capital. The study was performed in summer ranges of Ballade in the north of Iran on 72 ranches. Ranches were classified according to their history of accomplishing the range management plans. The sampling method was stratified sampling with filling questionnaire. The finding of this study shows that there is a significant relationship between ranchers` participation and social capital and its dimensions including inter-individual confidence, institutional confidence, social security, and interactions among ranchers. Also analysis of variance shows a significant effect of kind of management on social capital of ranchers. Here greater social capital was found in individual ranching and the least social capital was in Council centre.

Soil erosion assessment is an important factor for determine range suitability. The objective of this research were to compare efficiency of MPSIAC and EPM models in classification soil erosion sensitivity in Ghareh Aghach watershed extends 8962.25 hectares in Semirom province. To achieve variables models, digitalize topographic map in 1:25000 scale, digital evaluation model, slope map, aerial photos of 1:40000 scale, geological, geomorphologic, vegetation cover, pedological and land use maps were used. In frequent field visits all the necessary data from MPSIAC and EPM models were collected, checked and improved in 5 Hydrological units (sampling units). Following of finalizing the information layers, all of them were integrated to create the final soil erosion sensitivity map for each Hydrologic unite and vegetation type. For levels of suitability suggested by FAO including highly suitable (S1), moderately suitable (S2), marginally suitable (S3) and not suitable (N) were applied to indicate degree of suitability. The result of MPSIAC model indicated that 3.5% of the area was classified at low soil erosion sensitivity and 64% was classified at medium soil erosion sensitivity and 32.4% was classified at high soil erosion sensitivity, respectively. According to the results of EPM model, 57% of area was classified at moderate level of sensitivity to erosion and 5.4% and 37.6% of the area were classified at high and very high level of sensitivity to erosion, respectively. The results of statistical compare of erosion of MPSIAC and EPM models in hydrologic unit (sampling unit) by real erosion measure show that, there is no significant different between erosion estimate by MPSIAC model and real erosion measure at level of 1% and 5%, but the erosion estimate by EPM model have a significant different at level of 5%. Thereafter, very high erosion class was found for EPM model under study. Due to not fully compatible tables for EPM model and its subjective nature, one can conclude that MPSIAC model may have better performance.