Bayesian Estimation of Shrubs Diversity in Rangelands under Two Management Systems in Northern Syria

Abdoul Aziz Niane, Murari Singh, Paul C. Struik

Bio-Diversity and Integrated Gene Management Program, International Center for Agricultural Research in the Dry Areas (ICARDA), Aleppo, Syria.
Centre for Crop Systems Analysis, Wageningen University, Wageningen, The Netherlands.

DOI: 10.4236/oje.2014.44017                

Abstract

The diversity of shrubs in rangelands of northern Syria is affected by the grazing management systems restricted by the increase in human and livestock populations. To describe and estimate diversity and compare the rangeland grazing management treatments, two popular indices for diversity, the Shannon index and the Simpson index, were studied for the four combinations of two sites, Hammam and Obeisan, and two grazing methods, Closed and Open, using frequentist and Bayesian approaches. We simulated the a priori and a-posteriori distributions of the Shannon and Simpson diversity indices, where from a range of values for a constant in the a priori distribution the best value normalizing the distribution of the diversity indices was chosen. The Bayesian diversity estimates were higher than their frequentist counterparts and had lower standard errors. The grazing methods at each site and sites under each grazing method delivered significant diversity of shrub species. The Bayesian estimates resulted in lower p-values than the frequentist approach for two cases reflecting in Bayesian method’s higher power. Bayesian approach is recommended as it has a wider framework for inference on diversity studies.

Keywords

Arid Rangelands; Species Abundance; Diversity; Shannon Index; Simpson Diversity Index; Bayesian Method

Conflicts of Interest

The authors declare no conflicts of interest.

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