Land use−land cover changes and Mopani worm harvest in Mangwe District in Plumtree, Zimbabwe

Abstract

Background: Mopani worms have been considered a critical food security resource as people living in Mopani woodlands depend on the worms both as a food source and as an income generating resource. These become a readily available substitute if agriculture fails and droughts loom. However the yields from these worms have been dwindling over the years and this has been associated with land use−land cover changes as the worms depend on vegetation. This research sought to investigate the relationship between land use−land cover changes and Mopani worm harvests in Mangwe District in Plumtree from the period 2007 to 2016 in Zimbabwe. Methods: Satellite imagery was collected using LandSat 5 and LandSat 8 satellite and then classified using the Semi-Automatic Classification plugin in Quantum Geographic Information System to identify trees, dams, bare soil and settlements. Thematic maps were then produced and used to quantify extent of Land Use–Land Cover changes in the period from 2007 to 2016. Ground control data was collected using hand held Global Positioning System. Harvests trends (and reasons thereof) were estimated through usage of interviewer administered questionnaires on selected Mopani worm harvesters and harvest data kept by the community leaders. Results: Results showed that settlements and bare soil cover had greatly increased from 2007 to 2016. There was a significant decline on vegetation cover from 2007 to 2016. There was also decline in the Mopani worm harvest over the years. Reasons for reduction of harvest were cited as deforestation, drought, overharvesting, cooking with lids on and occurrence of veld fires. Conclusions: Findings of this study highlight that land use−land cover changes impacted negatively on Mopani worm harvests over the period 2007 to 2016. It is also of paramount importance to note that major reasons for this decline has been associated with Land Use changes that are associated with human activities. There is need for Natural Resource Conservation Agencies to embark on awareness campaigns to encourage reforestation and also control cutting down of Mopani woodlands. Research needs to be conducted to determine the association between cultural beliefs and Mopani worm conservation and utilisation.