Population Structure and Regeneration Status of Woody Species in Dawsura Exclosure, Central Tigray, Ethiopia for Restoration and Biodiversity Conservation

Research demonstrates that exclosures promote natural regeneration of of native species from soil seed banks, thus contributing to the rehabilitation of degraded lands. The present research was undertaken to examine the population structure and regeneration status of woody species to furnish insights into the sustainable management of the Dawsura exclosure. The methodology for data collection employed a transect line sampling approach as a design framework, with a total of 36 plots, each measuring 20 m × 20 m (400 m²), established along the transect line to assess the woody species. In every designated sample plot, all instances of woody species in the seedling, sapling, and mature tree/shrub categories were enumerated and recorded. Additionally, their diameter at breast height (DBH) was measured at a height of 1.3 meters above the ground, specifically for DBH values equal to or exceeding 2.5 cm. A cumulative total of 37 vascular plant species, classified into 33 genera and 19 families, were systematically recorded and identified across the 36 study plots. The overall density of woody plant species throughout all sampled plots within the study area was determined to be 1588 individuals per hectare. The respective total densities for seedlings, saplings, and trees/shrubs were quantified as 1082.11, 271.17, and 1588.19 individuals per hectare. Among the 37 species documented within the exclosure, only 10 species (27%) were represented at the sapling stage, whereas the remaining 27 species (72.97%) were not represented. In the seedling category, only 11 species (29.73%) out of the 37 were present, with the remaining 26 species (70.27%) lacking seedlings during the period of data collection. Only a single species demonstrated a healthy population structure among the 37 recorded woody species within the exclosure.