Effects of Ground Preparation and Microenvironment on Germination and Natural Regeneration of Juniperus procera and Afrocarpus gracilior in Ethiopia

Background

This study assesses the net effect of seed supply and seedbed changes on germination and natural regeneration of J. procera and A. gracilior in the Afromontane forests of Ethiopia.

Research Goals & Methods

The authors selected 4 sites with good natural regeneration and 1 site with no regeneration. Plots were estalished for recording natural regeneration and microenvironment. Tree seedlings were counted and photosynthetic photon flux (PPF) transmission, litter depth, and percentage cover of grasses, forbs, and shrubs were sampled.

Conclusions & Takeaways

Artificial regeneration of J. procera increased significantly in percent germination and survival by raking, burning and cultivation. A. gracilior seeds increased slightly with raking, but were significantly decreased by burning and cultivation. Seedling height growth of both species was affected by ground preparation and significantly by raking. In addition, ground preparation had a significant effect on the natural regeneration of J. procera on tree stumps or partially burned logs but there was no sign of A. gracilior natural regeneration. The authors conclude that management for the regeneration of J. procera should involve more complete disturbance of the forest floor to remove barriers for both rooting and seedling emergence aboveground. Clearcutting in narrow strips is recommended to provide adequate seed supply. Site preparation such as raking and controlled burning that exposes mineral soils are preferred.