Natural regeneration of Miombo trees after shifting cultivation: a case study of Chibombo and Rufunsa districts, Zambia.

The objective of the study was to assess the regeneration of Miombo woodlands after shifting cultivation in Chibombo and Rufunsa districts in comparison to undisturbed woodland. The study analysed different descriptors that characterize the woodland including: species composition, diversity, richness, stem density and mode of regeneration. To achieve these objectives, three sites were selected. In each site, 40 circular plots of radius 10 meters were sampled. All trees within the plot were identified and counted. Trees that were ≥0.6cm in height were measured for height and diameter. The main stems were counted and the mode of regeneration for each shoot was recorded. The GENSTAT and Python were used to analyse the data. The Shannon Diversity Index was used to assess species diversity. The Non-Metric Multidimensional scaling (NMDS) results show that there is some separation between the sites, particularly between Chibombo and the other two sites, suggesting that Chibombo might have a distinct species composition compared to Mfunganisha and Nyampande. However, the Analysis of Similarlity (ANOSIM) like analysis suggests that the observed differences in species composition are not statistically significant (p-value is 0.10). Analysis of species diversity revealed that Chibombo had the highest species diversity with H‟=2.83 and D=0.11. The undisturbed woodland recorded H‟=2.68 and D=0.13 while Rufunsa had the lowest diversity with H‟=2.60 and D=0.12. However, the undisturbed woodland had the highest species richness (60); Rufunsa recorded 43 while Chibombo had the least with 40. Generally, the species diversity was quite high in all three sites, an indication of good recovery in terms of species. Determination of
stem density revealed that Rufunsa had the highest number of stems per hactor (10417), higher than the undisturbed woodland which recorded 9063 stems ha-1 while Chibombo recorded the lowest number of stems of 3165 stems ha-1 . An analysis of mode of regeneration showed that root sucker is the most dominant mode of regeneration, followed by stump and seed regeneration in both sites. This can be attributed to the type of shifting cultivation and the farming equipment which favours root sucker. No mature trees were recorded in both sites accounting for the low number of seed regeneration. The study revealed a potential for Miombo woodland to recover provided the fallow period is followed and the regenerating Miombo trees are not exploited for other use such as poles and fibre before maturity. Further, there is need to educate farmers on the importance of coppice with standards. While this study has provided insights into species diversity and stem density, further research should investigate additional
indicators of recovery, such as soil health, carbon sequestration, and the presence of keystone species.