Status of Native Woody Species Regeneration in the Plantation Stands of Yeraba Priority State Forest, Amhara Region, Ethiopia

Abstract

The type of species, diversity, density, similarity and status of naturally regenerated woody plants under monoculture plantation stands of four exotic species (Eucalyptus globules, Cupressus lustanica, Acacia decurrence and Acacia melanoxylon) and the adjacent natural forest stand were investigated and compared to verify the hypothesis that plantation stands of exotic species can foster natural regeneration and to determine the status of regeneration and succession. A total of forty quadrate plots, with an area of 100m² (10 m × 10 m) for each, were established in all stands, i.e. eight plots in each plantation stand and the adjacent natural forest, independently. In each plot, naturally regenerated native species name and abundance were recorded. And numerical data on numbers of seedling were collected in a sub-plot (1m²) lay within each major plot. A total of 31 species which belongs to 23 families were recorded. The diversity of understory woody plant regenerated species (H’) is 1.96, 1.80, 1.81, and 1.53 in the Cupressus lusitanica, Eucalyptus globules, Acacia melanoxylon, and Acacia decurrence plantations respectively and 2.05 in the natural forest stand. The density was 5790, 1510, 1090, 2590 and stems/ha in Cupressus lustanica, Acacia melanoxylon, Eucalyptus globules and Acacia decurrence plantations respectively, and 7950 stems/ha in the natural forest stand. Relatively high similarity of regenerated woody species composition (0.625) was found between the under-growths of the Euc. globules and Ac. melanoxylon plantation stands. There is disturbed status of natural regeneration and succession in all stands. The findings revealed that there is significant difference in undergrowth and succession between upper story species, mainly due to crown characteristics and stand density. Generally, plantation forests can foster natural regeneration and succession provided that there is an adjacent seed source and dispersal agents, and an appropriate management to protect the regeneration.

Keywords: natural regeneration; woody species diversity, plantation forest, Yeraba state forest