Evaluation of Heavy Metal Levels and the Distribution of Rhizophora racemosa and Nypa fruticans in the Niger Delta Mangrove Forest, Nigeria

Abstract

Plants react differently to pollutant levels in their substratum, and pollutant levels either positively or negatively influence their distribution. In this study, soil levels of Cr, Ni, Cd, Pb and Zn on the distribution of Rhizophora racemosa and Nypa fruticans was investigated. Soil samples were collected randomly closer to the roots at growth sites and the non-growth sites of the study plants at four selected stations in the study area and analyzed using standard laboratory methods. Findings showed that N. fruticans grew well in soils with high levels of soil Cr, Pb and Zn over R. racemosa whose growth was associated with soils with lower levels of the referenced metals and the above metals influence their distribution. The above observation was attributed to the high tolerance level of N. fruticans to Cr, Pb and Zn toxicity above R. racemosa. It is thus concluded that R. racemosa and N. fruticans distribution are influenced by the levels of soil heavy metals.

Keywords: Pollutant levels, Distribution, Mangrove.