TY - JOUR T1 - Determination of Effective Environmental Factors on Bromus tomentellus Species Establishment Using Ordination Method TT - تعیین عوامل محیطی مؤثر بر استقرارگونه Bromus tomentellus با استفاده از روش رسته‌بندی JF - JSTNAR JO - JSTNAR VL - 12 IS - 44 UR - http://jstnar.iut.ac.ir/article-1-891-en.html Y1 - 2008 SP - 347 EP - 356 KW - Bromus tomentellus KW - Ordination KW - Environmental Factors KW - Redundancy Detrended Analysis (RDA). N2 - Ordination is the part of statistical ecology which has developed and integrated in recent years. Finding environmental factors which important in ecological structure determination of plant species is the final purpose of ordination. Ordination method was used for finding the effect of important variables on Bromus tomentellus species quantitative and qualitative changes in Esfahan's Fereidan region. For this purpose, fifteen sites were studied. Density, Cover percentage and Soil factors containing EC, pH, % caco3 , % gravel and stone, % clay, % silt, % sand, Na+, Ca2+, K+, Mg2+, Cl-, SAR, C/N and % OC. In A (0-30 cm) and B (30-60 cm) horizons over a line transaction in each site, were measured. The matrix of environmental and species characteristics were prepared. The relationship between environmental and species characteristics were determined using of PC-ORD and CANOCO software's and Redundancy Detrended Analysis (RDA) method. The results show that there are meaningful correlation between Density and Cover percentage with soil factors. The results implicate that C/N factor in A horizon and SAR in B horizon have the most effect on Bromus tomentellus density and cover percentage. EC, pH and …. Factors don't have much effect on Bromus tomentellus species characteristics. M3 ER -