Allergenic Pollen Dynamics in Continental-Climate Urban Ecosystem: Multivariate Statistical Modeling of a 24-Month...

This study is the first to assess airborne allergenic pollen in Erzincan, a continental climate region with mixed native vegetation, agricultural land, and urban areas, using volumetric sampling and comprehensive statistical models. Weekly samples from 2022 to 2023 were converted to 24 h slides and examined microscopically, and concentrations were calculated as pollen/m³ according to REA methodology. A total of 730 days of observations were evaluated. The annual pollen integrals were calculated separately for each year, and their combined total was 22,225 pollen*day/m³ (2022: 8667; 2023: 13,558). Woody pollen comprised 53.67% (2022) and 51.86% (2023); herbaceous pollen comprised 46.01% (2022) and 48.07% (2023). Thirty six pollen taxa were identified; the peak months were May 2022 (24.5%) and June 2023 (27.5%). Daily total pollen concentration was correlated positively with temperature (r_s = 0.33, p < 0.001) and weakly with wind speed (r_s = 0.17, p < 0.001) but negatively correlated with humidity (r_s = -0.26, p < 0.001). Precipitation showed no significant association with pollen levels (r_s = -0.02, p = 0.13), indicating that warmer and drier conditions favor higher pollen concentrations. The LMM showed that pollen density was affected by meteorological variables as well as interannual climatic variation, with temperature being the positive predictor (β = 0.348; p < 0.001). Canonical correlation analysis revealed a significant, multidimensional relationship between meteorological variables (temperature, humidity, rainfall, wind) and the daily densities of eight pollen taxa (Wilks' λ = 0.603; p < 0.001). Canonical Correspondence Analysis indicated that meteorological variables influenced pollen taxon composition (F = 20.235, p = 0.001), explaining 11.51% of total inertia and suggesting that additional ecological factors may also contribute. In conclusion, pollen dynamics are sensitive not only to seasonal and meteorological variables but also to interannual climate fluctuations; in particular, hot, dry periods prolong the persistence of airborne pollen, while short-term rainfall can trigger sudden pollen releases in some species.