Assessment and Comparison of Different Methods for Estimating Forage Production (Case Study: Rangeland of Kurdistan Province)

Today, in the rangeland management science and determination of range capacity, accurate and true information about range production is crucial. In fact, range production is considered as a basis for range management. The aim of this study was to compare different methods for the estimation of forage production with four sampling methods in the rangelands of Kurdistan province, Iran. The sampling methods were Adelaide technique, double sampling, estimating method, clipping and weighting method (control). A two-way analysis of variance was made to compare the methods and vegetation types. The estimating methods and plant vegetation types were considered as treatments and blocks, respectively. The results showed that Adelaide method had no significant difference with control method and was selected as the best method for estimating the plant production in the rangelands of study area with dominant shrub plants. A significant difference was obtained between control and estimation methods. Therefore, this method had lower accuracy for estimating the production of range plants. The results showed that the composition of range plants was an effective factor on the accuracy of estimating methods and also paying attention to ecosystem variability was an important key to achieve a suitable method in order to estimate the range production. A significant difference was obtained between double sampling method and clipping and weighting method (control). It was due to various plant combinations of the study area. Therefore, the double sampling had lower efficiency than clipping and weighting method to estimate various plant species such as grasses, shrub and herbaceous plants.