Quantifying the Rate of Environmental Factors Effect on Astragalus verus and Agropyron trichophorum Using Decision Support System and Multivariate Analysis of PCA

Document Type : Research and Full Length Article


1 Range management, IUT.

2 Faculty of Natural Resources, Isfehan University of Technology.

3 Range management, Gorgan Agricultural and Resources University.


Vegetation cover over time and space is the result of interactions between
vegetation cover and environmental factors. Changes occurred in range covers are caused by
matrix dominance, one of the most important environmental factors. Decision support system
(DSS) could be used for determining the rate and importance of each factor. Actually, in
methods based on DSS, relations between input and output factors are identified. Up to now,
various methods have been used in analyzing multivariate decision that includes binary
comparison method that has been used in this study. This method has become one of the most
commonly used methods of multivariate decision making and has been used for resolving
unstructured issues in various human areas such as agriculture and natural sciences. In this
study, nine sites were selected in west of Isfahan, Iran, then different vegetation cover and
environmental factors were examined in each of these sites. By analyzing main components,
effective factors and impact of range were identified, finally using analytical hierarchical
pattern (AHP) model, the quantity of effective factors on Yellow Astragalus and grass sites
was determined. The rate of limestone of soil and slope factor in Yellow Astragalus were 14.4
and 14.2%, respectively, which have the greatest effect and with regard to grass transmittal,
Soil limestone and soil acidity influenced 20 and 13.2% of variation, respectively.