Tree Diversity in Western Kenya: Using Profiles to Characterise Richness and Evenness

Abstract

Species diversity is a function of the number of species and the evenness in the abundance of the component species. We calculated diversity and evenness profiles, which allowed comparing the diversity and evenness of communities. We applied the methodology to investigate differences in diversity among the main functions of trees on western Kenyan farms. Many use-groups (all trees and species that provide a specific use) could not be ranked in diversity or evenness. No usegroup had perfectly even distributions. Evenness could especially be enhanced for construction materials, fruit, ornamental, firewood, timber and medicine, which included some of the most species-rich groups of the investigated landscape. When considering only the evenness in the distribution of the dominant species, timber, medicine, fruit and beverage ranked lowest (>60% of trees belonged to the dominant species of these groups). These are also use-groups that are mainly grown by farmers to provide cash through sales. Since not all communities can be ranked in diversity, studies that attempt to order communities in diversity should not base the ordering on a single index, or even a combination of several indices, but use techniques developed for diversity ordering such as the Re´nyi diversity profile. The rarefaction of diversity profiles described in this article could be used in studies that compare results from surveys with different sample sizes.

Weed species diversity in organic and integrated farming systems

“…Diversity profiles (Rényi entropy) quantify diversity as a multidimensional concept with the use of the parameter [39]. A group of indices for measuring species diversity at different levels of forms a "family", where = 0 represents the number of species, = 1 represents the Shannon-Wiener index (H'), = 2 represents the Simpson index (C), and infinity represents the Berger-Parker index [16,40]. The indices may be presented graphically by plotting a curve (a diversity profile).…”

Integrating local knowledge with tree diversity analyses to optimize on-farm tree species composition for ecosystem service delivery in coffee agroforestry systems of Uganda

“…If the profile of group A is above the profile of group B at all Renyi values, then group A is more diverse than group B. If the profile of group A inter-crosses that of group B, the two groups cannot be ordered (Kindt et al 2006). In this case, we revert to the less strict approach of a single diversity index, Shannon diversity index, to derive the 'Diversity rank'.…”

“…In this case, we revert to the less strict approach of a single diversity index, Shannon diversity index, to derive the 'Diversity rank'. We derived Shannon diversity index from, and when the Renyi value approaches one (Kindt et al 2006). The 'Needs rank' means the ordering of ES groups from most to least important as ranked by farmers and analyzed using BT model.…”

Ant community structure and response to disturbances on coastal dunes of Gulf of Mexico

“…Rényi diversity profiles were performed using Biodiversity R (Kindt and Coe 2005;R Core Team 2013) to study the differences of diversity among habitats. The Rényi profile is a useful method for diversity ordering, and can provide more information than single a diversity index (Tóthmérész 1995;Ricotta 2003;Kindt et al 2006). In the profile, each line represents the diversity of one habitat; the higher position of the line represents the higher diversity of that habitat.…”