تعيين شكل و سطح پلات بهينه براي برآورد توليد علفزارهاي نيمه استپي شمال شرق استان گلستان

Determination of optimal plot shape and size for estimation of forage production at semi-steppic grasslands of northeastern of Golestan province

The efficiency of different plot shape and sizes for estimation of forage production were compared in the semi-steppic grasslands at northeastern of Golestan province. The plot shapes were square, rectangular, and circle and plot sizes were 0.25, 0.50, 0.75, 1.0, and 1.25 mʹ. in the representative stand of grassland type along each of five systematic transects, 5 plots were selected randomly and the weight of clipped plots and time of clippings on the basis of life form and total forage production were estimated. in spite of significant differences between plot shapes, different sizes and the interactions of size and shapes were not significant. The highest efficiency gained based on the Wiegertʹs method that the optimal shape and size of plots were circle and 0.75 mʹ respectively that can be recommenced for semi-steppic grasslands in most parts of frail.