Population structure and phenological attributes of Adansonia digitata L. (baobab) in Northwestern lowland area of Ethiopia

Abstract

Adansonia digitata (baobab), a multipurpose and highly valued tree species, is facing threats due to anthropogenic factors like shifting cultivation practices and fire. The aim of this study was to examine the population structure and phenological attributes of baobab in three districts (i.e. Kafta Humera, Tselemt, and Quara district) in Northwestern Ethiopia. The study was carried out by establishing 17 plots 1 km long and 100 m wide covering a total area of 170 ha in the Quara district and five plots covering 50 ha each in the Kafta Humera and Tselemt districts. Further, plots were subdivided into 25 × 25 m and 5 × 5 m sub-plots for recording other woody species and their regeneration status, respectively. Thirty reproductively matured trees with easily visible crowns were selected to record phenological characteristics and fruit yield. The findings revealed that baobab population was significantly higher in the Tselemt district (3.15 ± 0.15) as compared to Quara (1.43 ± 0.43) and Kafta Humera (1.30 ± 0.23) sites. A bell-shaped diameter distribution was observed in the Quara district and irregular-shaped distributions were observed in Kafta Humera and Tselemt districts. Phenological periodicity and fruit production of baobab did not vary significantly among the three study sites. On average, 404 fruits per tree were recorded with a maximum of 559 fruits in mid-diameter size class trees. Due to livestock browsing, shifting cultivation practices, and uncontrolled fire, the recruitments are limited in the study areas. An in-situ conservation strategy through the plantation and proper management practices are needed to sustain baobab tree species.