Aerobiological fingerprint of a continental steppe in Anatolia: biphasic seasonal dynamics and atmospheric transport of herbaceous pollen

High-altitude continental steppe ecosystems remain understudied with respect to biological air quality, limiting our understanding of pollen exposure dynamics in semi-arid regions. This study characterizes the aerobiological fingerprint of the Central Anatolian steppe (Yozgat, Türkiye) using 2 years (2018–2019) of volumetric pollen data. Arboreal (50.98%) and herbaceous (49.02%) pollen were nearly equivalent in overall contribution. Herbaceous taxa exhibited a distinct biphasic seasonal pattern: an early intense Gramineae peak in late spring exceeding environmental exposure thresholds, followed by a late-summer peak dominated by Amaranthaceae and Ambrosia. Cyperaceae also emerged as a notable component of the atmospheric pollen spectrum, indicating a distinctive regional signal within the steppe biome. Atmospheric transport analysis (HYSPLIT) showed that early-season peaks were influenced by long-range transport, whereas main-season concentrations were primarily associated with regional sources. These findings provide a baseline for monitoring bioaerosol dynamics and assessing environmental change in semi-arid ecosystems.