Population Density and Structure of Marula (Sclerocarya Birrea) in Gonarezhou National Park and Adjacent Areas, Southeast Zimbabwe

Admire Chanyandura,Victor K Muposhi,Shelly Satuku,Never Muboko,Olga L Kupika,Edson Gandiwa

doi:10.22158/se.v4n3p172

Abstract

This study assessed the population density and structure of marula (Sclerocarya birrea) in the Gonarezhou National Park (GNP) and adjacent areas, southeast Zimbabwe. Data were collected from 15 belt transects using a stratified random sampling technique (with study sites located in the northwestern Gonarezhou National Park, adjacent communal and resettlement areas) in November 2014. The study results showed that marula tree and shrub densities were highest in the Gonarezhou National Park compared to the communal and resettlement areas. The diameter size class generally showed a reverse J shape in all the land use categories implying that there was a high regeneration and low recruitment into mature marula trees. Anthropogenic uses and herbivory may likely have influenced the density and population structure of marula in the study area. Thus, continuous monitoring and adaptive management is essential in ensuring that marula species is not locally extirpated in areas of high use or damage.

Highlights

The marula tree (Sclerocarya birrea) is an iconic wild growing deciduous dioecious leafy tree species indigenous to Africa (Nerd & Mizrahi, 1993)
The present study results showed that tree, shrub, sapling densities, and tree height significantly differed across the three land use categories in the southeast Zimbabwe
The generally higher marula tree, shrub, sapling densities and tree height within the Gonarezhou National Park (GNP) compared to the adjacent areas suggest lower levels of utilisation on the marula species within the protected area than in the adjacent communal and resettlement areas

Summary

Introduction

The marula tree (Sclerocarya birrea) is an iconic wild growing deciduous dioecious leafy tree species indigenous to Africa (Nerd & Mizrahi, 1993). S. birrea caffra is a keystone African savanna tree species with high ecological, commercial and cultural value (Helm et al, 2011; Murye & Pelser, 2018) It is an abundant fruit bearing tree which plays a significant role in the lives of both humans and animals in southern African ecosystems (Hall & O'brien, 2002; Gouwakinnou et al, 2011; Mocheki et al, 2018; Sinthumule & Mzamani, 2019). Apart from sustaining rural livelihoods, the marula species acts as forage for browsing wild animals such as elephant (Loxodonta africana) and impala (Aepyceros melampus) (Gadd, 2002) and domestic animals which are potentially important seed dispersers (Gallaher & Kruger, 2012) In protected areas such as Gonarezhou National Park (GNP), southeast Zimbabwe, large herbivores and fires have a significant negative impact on vegetation structure and composition thereby threatening local extirpation of some plant species (O’Connor et al, 2007). The objective of this study was to assess the population density and structure of marula (Sclerocarya birrea) in the northwestern GNP and adjacent areas

Objectives

Methods

Conclusion