Most protected areas in developing countries have been mismanaged due to data gaps that would be used for planning management strategies. Without ecological information it is difficult to develop and implement effective conservation plans and measure the effectiveness of management interventions. This study was conducted in Chebera Churchura National Park in southwest Ethiopia to determine species diversity, population structure, and regeneration status of woody plants across four vegetation types of the park (montane forest, riverine forest, woodland and wooded grassland). Vegetation data were collected in 2021 from a total of 137 quadrats, each measuring 10 m × 10 m, allocated proportionally across the four vegetation types. Rarefaction and extrapolation curves were computed to compare richness and diversity indexes across vegetation types. Density, frequency, diameter and height size class distributions, and IVI were used to characterize vegetation structural variables. A total of 76 woody species were recorded across the vegetation types. Species richness varied significantly among the vegetation types in the following order: montane forest (65 species) > woodland (22) > riverine forest (14) > wooded grassland (6). Sorensen’s similarity index among the vegetation types was generally low, ranging from 8.3% (between wooded grassland and montane forest) to 46.7% (between wooded grassland and woodland). The majority of the species in each vegetation type (46–71%) were found in the lower density (<20 individuals per ha), frequency, and DBH size classes, exhibiting low basal area and IVI. Although most species lacked regeneration, stand level regeneration status of woody vegetation was good (inverted J-shape pattern) in the montane and riverine forests, while fair (seedlings < saplings > adults, or seedlings > saplings < adults) in the others. In conclusion, findings of this study will serve as baseline data against which the effectiveness of conservation interventions and long-term vegetation monitoring will be evaluated.

Sampling Design

Stratified systematic sampling design was adopted for the study [34], the stratum being the major vegetation types. A total of ten, 2.4–3.0 km long transects were established systematically (spaced at a minimum distance of 200 m apart) across the four vegetation types: montane forest, riverine forest, woodland, and wooded grassland. Quadrates of 10 m ×10 m (totalling to 137 quadrats) were established along each transect at ~200 m distance interval. Sample size (number of quadrates) distribution across the vegetation types was determined proportionally, based on assumed effort required to reach data saturation point in each vegetation type. Accordingly, 46 quadrates (established along 2 transect) were sampled in the montane forest, 11 quadrates (1 transect) in the riverine forest, 50 quadrates (5 transects) in the woodland, and 30 quadrates (2 transects) in the wooded grassland.

Data Collection

Data collection took place between December 2020 and March 2021. Plots were established using a 100 m long rubber meter tape, pinned using wooden-pegs on the corners. For each woody plant encountered in a quadrate, in addition to the quadrate information (date, vegetation type, transect code and plot code), data were collected on the following variables: plant species name (local and botanical names), height, diameter at breast height (DBH), and plant age category.

Plant height was estimated using Santo Clinometers Circumference of each plant was measured by rubber meter tape at 1.3 m above the ground and DBH values were estimated by dividing the circumference by phi (3.14). Woody plants: (i) taller than 1.5 m and DBH greater than 2.5 cm were recorded as adults, (ii) taller than 1.5 m but DBH less than 10 cm as saplings, and (iii) height less than 1.5 m and DBH less than 5 cm as seedlings. For data analysis, however, to ensure valid comparisons with similar studies, we used plants with DBH >10 cm as adults, (ii) taller than 1.5 m and DBH <10 cm as saplings, and (iii) height less than 1.5 m and DBH < 5 cm as seedlings. Species identifications were made at field using floral guidebooks and further confirmed at Ethiopian National Herbarium. Species scientific names are following World Flora Online.

Data Analysis

Species Diversity and Composition. Woody species diversity was assessed using three metrics: species richness (S; the number of species observed or expected at a given site), Shannon diversity (H; a combination of richness and evenness), and the Shannon Equitability or Evenness index (H’; a measure of similarity in species abundance). Species and diversity rarefaction (accumulation) curves were computed using individual-based abundance data by summing all individual stems of a species recorded across plots within a given vegetation type.

Population Structure*.* The population structure of woody plants in each vegetation type was described based on Importance Value Index (IVI), height class distribution, and diameter at breast height (DHB) class distribution. IVI is a composite index that measures the ecological importance of a species by combining its relative frequency, density and dominance values.

Regeneration status of woody species*.* The regeneration status of woody species was assessed both at the stand level and for each species based on the ratios of density of seedlings (height less than 1.5 m and DBH < 5 cm), saplings (height taller than 1.5 m and DBH > 5 and < 10 cm), and adult plant (DBH >10 cm). At stand/vegetation type level, this was conducted based on summed individual plants across all plots of the respective vegetation type.  A species was considered to be in ‘good’ regeneration status if the density of its seedlings > saplings > adults; ‘fair’ if seedlings < saplings > adults, or seedlings > saplings < adults; ‘poor’ regeneration if a species survives only in the sapling or seedling stages; and ‘not regenerating’ if a species is present only in the adult stage.

Changes after Sep 1, 2026: Data provided were incorrect. Instead of providing vegetation data and metadata, we had provided data and information about a paper (under consideration) on mammals of the same study area. The change is therefore made to provide the correct data and metadata.