Tropentag 2010, September 14 - 16, Zurich, Germany "World Food System - A Contribution from Europe"

Similarity and Diversity Indices in Sugar Beet Weed Communities

¹Islamic Azad University - Mashhad Branch, Department of Agronomy, Iran
²Ferdowsi University of Mashhad, College of Agriculture, Department of Agronomy, Iran

Abstract

A common method in calculating β plant diversity is by using evenness and unevenness coefficients. Jaccard and Sorensen coefficients are examples of evenness indices usually used for qualitative data and Steinhaus or Czekanowski indices and coefficient of Squared Euclidean Distance are suitable for both quantitative and qualitative data. These indices are based on number of present species or unique species comparison within community and suited for different habitats. Jaccard and Sorensen coefficients are based on common species within two communities. Steinhaus coefficient is based on species frequency and calculation of numerical (quantity) differences of a community with more precision. In weed ecology, Shannon-Wiener index is a common method for plant community diversity evaluation. This index is valid when sampling can be done and identify all species within the ecosystem. The Shannon-Wiener equation is based on species richness and frequency.
In this research, Jaccard Similarity Index, Sorenson Coefficient, Steinhaus coefficient (Czekanowski Coefficient), Shannon-Weiner, McIntosh, Margalef, Simpson Dominance and Evennes indices were studied in major sugar beet production fields in different cities of Khorassan Razavi and Khorassan Shomali provinces, Iran. The results showed that Chenaran and Khauf had the most (27 species) and the least (5 species) species richness. Sorenson and Steinhaus similarity indices were showed that Chenaran and Ghouchan had the highest similarity (0.9%) whereas, Ghouchan and Khauf showed the least similarity index (0.2%). The comparison of weed community in Bojnord fields showed the most relationship with Shirvan. In these cities, Stainhous index was 59% and Sorenson was 67%. Chenaran and Fariman also had high similarity coefficient (78% for Stainhouase & 62% for Sorenson). Sorenson and Stainhouse coefficient for Shirvan and Ghouchan were 65% and 59% respectively. Since the climate of each area is one of the major factors that affect on weed population diversity, it seems that microclimatic similarities have an important effect on similarity of the weed population comparison.

Keywords: Diversity, dominance, evenness, similarity, sugar beet, weed diversity

Contact Address: Leila Alimoradi, Islamic Azad University - Mashhad Branch, Department of Agronomy, Azadi Square, 91775-1163 Mashhad, Iran, e-mail: lealimoradiyahoo.com