Regeneration Response of Juniperus procera and Olea europera subsp cuspidata to Exclosure in a Dry Afromontane Forest in Northern Ethiopia

background

This study investigates the natural regeneration of Juniperus procera and Olea europeaea subsp. cuspidata after 3 years under protection from livestock, human interference, and under open management systems in a dry Afromontane forest in northern Ethiopia.

Research Goals & Methods

32 random plots were laid out to investigate and compare the seedling bank/abundance at the protected area and the adjacent open sites. The following indices were used: Importance Value Index to determine relative abundance of all woody species; Shannon Weiner diversity index; and the Simpson Index to determine species diversity.

Conclusions & Takeaways

The results show that species richness and diversity were higher in the protected than the open sites. Although J. procera was the most abundant species in the overstory there was no significant difference in the understory at the open sites and the protected site but there was for O. europaea, the protected sites had significantly higher levels of regeneration. Structural composition analyses of J. procera indicated it was less represented in the lower diameter classes, in which higher regeneration and recruitment are needed for a viable population of the species. The authors conclude that J. procera as supported by other studies have poor germination capacity under field conditions and this may require additional manipulation to remove competition from weeds and limiting light availability. In contrast the abundance of O. europea in the protected site indicate that livestock browsing negatively impacts species as well as other microsite characteristics such as shade.