Comparison of reproductive potential and biomass determinants of five plants in Pelmis region (North Khorasan, northeast of Iran)

Study of rangeland vegetation in order to recognize and introduce of rangeland forage species with high growth and reproductive potential, is one of the important issues of proper range management. In this research, Reproductive potential and biomass determinants of five rangeland species was studied. These species were orchard grass (Dactylis glomerata L.), crested wheat grass [Agropyron cristatum (L.) Gaert], Agropyron gigantea, stiff-hair wheat grass [Agropyro trichoforum (Link) Richter] and Bromus tomentellus Boiss. Samples were selected by systematic random sampling method along the 5 fifty meter transects. Above ground biomass, height, number of tillers, length and weight of inflorescence, length and weight of leaf, stem weight, basal area, node length and reproduction effort were measured for each sample. Data were analyzed by one- way analysis of variance (ANOVA) and Duncan’s multiple range tests in SPSS 16 software. Results showed that the biomass difference between reproductive and above ground vegetative organs among the five species was significant (P < 0.01). Agropyron gigantea had the most height, inflorescent length and leaf weight respectively with means of 86 and 32.82 centimeters and 4.24 grams and Agropyron cristatum had the least height, inflorescent length and leaf weight respectively with means of 35.60 and 6.31 centimeters and 1.86 grams. Accordingly, Agropyron gigantea and Agropyron cristatum had the most and least above ground biomass and reproductive potential respectively.