Modern pollen–vegetation relationships and human indicator taxa at high elevation human-impacted areas of the Bale Mountains, Ethiopia

Understanding the relationships between modern pollen assemblages and vegetation patterns is fundamental for reconstructing past landscapes and assessing anthropogenic impacts in ecologically sensitive high-altitude ecosystems. While previous studies in Ethiopia’s Bale Mountains explored paleo-reconstruction, quantitative approaches remain limited. This study quantifies pollen–vegetation relationships using transfer factors (TF), evaluates ecological diversity indices, and analyzes human-indicator pollen and spores. We collected 30 pollen samples from the Ericaceous and Afroalpine biomes of the Bale Mountains and analysed the data using palynological and ecological methods. Our findings record 119 pollen types from the two biomes. The transfer factor analysis revealed strong over-representation of some taxa, while most herbaceous families were underrepresented. Spatial variation in TFs across the biomes underscored the influence of microclimatic and ecological heterogeneity on pollen–vegetation relationships. Quantitative comparison of diversity indices showed that pollen family richness and diversity significantly exceeded that of vegetation, supporting the broader source area hypothesis. The study identified multiple palynological and non-palynomorph (NPP) human indicators. Cereal-type pollens were recorded in most of the samples, while ruderal taxa such as Amaranthus/Chenopodium, Geranium, and Rumex were detected. Spores of coprophilous fungi, especially Sporormiella, were highly abundant, indicating sustained grazing pressure and historical human activity in the area. Additionally, the detection of Pseudoschizaea spores, potentially linked to anthropogenic fire, was documented for the first time in modern African surface samples. These findings underscore the taxon and pollen zone specific nature of pollen representation and demonstrate the value of integrating pollen, fungal spores, and vegetation data to build a robust multi-proxy framework for paleoecology and land-use reconstruction in the region.