Can Livestock Alone Be the Main Source of Income from Rangelands in Poor Countries?

In many countries due to the high population of land holders, there is insufficient range area for each land holder to cover all life expenses. In such places, the income of only livestock in rangelands is not enough to cover living expenses of landholders. The ideas in this paper suggest that researchers should create and explore economic models that incorporate the multiple use concept in rangelands and show how multiple uses are compatible with livestock grazing and to sustain the livelihood of rangeland families

Variation in the Quality of Forage of Six Rangeland Species in Different Phenological Stages

An understanding of forage quality is fundamental to the measurement of grazing capacity. In addition, knowledge of forage quality is necessary for planning grazing and developing range improvement and development programmes, such as planting and seeding of rangelands. Among the different factors that affect forage quality, phenological stage is particularly important (Cook, 1972; Caballero et al.,2001). The objective of this study was to investigate the effects of plant species, phenological stages and life form on forage quality indices

Discrete least squares meshless method for modeling 2D crack problems

In this paper, Discrete Least Squares meshless method (DLSM) is developed to analyze cracked structuresin an elastostatic problem. DLSMis a new really meshless method that does not use any mesh in computation. The method is based on the minimization of the least squares functional with respect to the nodal parameters. The least squares functional are formed as the weighted summation of the residual of the differential equation and its boundaryconditions. In thismethod, the domain of problem is discretized bysome nodesthat are used to produce Moving Least Squares shape functions. This type of discretization eliminates the Finite Element Method shortcomings. In this study, diffraction method was used to produce continuous shape functions around the crack. In diffraction method, the domain of influence wrap around the crack tip and it results in continuous derivatives of shape functions. Finally, the DLSM high efficiency and accuracy is presented by comparing the analytical results with numerical ones

Comparison of a Biometric Method with Clipping and Weighing Method for Estimating the Yield of \u3cem\u3eArtemisia sieberi\u3c/em\u3e (Case Study Zarand-e-Save Region)

Forage production is a most important vegetation attribute in rangeland analysis and evaluation and use in management practices. Artemisia sieberi covered about 47% of the rangeland area in Iran and scientists need to know the best method for analysis and evaluation of this species. Clipping and weighing has high precision, but this method is time-consuming and expensive and alternative methods are required. Russian scientists developed a biometric method based on plant dimensions and suggest this method for rangelands in the Middle East (discussed by Dianati, 2003). In America, Muray (1982) used plant dimensions for yield estimation and regression models for estimating production. This method required the selection of a lot of individual plants for each species to draw curves and estimate forage production. The critical stage of this method is the determination of the relationship between plant dimensions and yield. The research showed that in A. sieberi the best relationship with yield is from height (H) and the sum of diameters (D1 +D2). This relationship should be calculated separately for each species. In this study this method was tested with the Artemisia type in Iran