Biotic and abiotic effects on pollen production and allergenicity of birch and related health impacts

• Applicants: Professorin Dr. Carmen Büttner; Professorin Dr. Susanne Jochner-Oette; Professorin Dr. Claudia Traidl-Hoffmann
• Subject Area: Forestry ; Physical Geography
• Term: from 2019 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 411096677

Although higher temperatures were often found to increase pollen production and allergenicity, several studies reported decreased quantities of pollen and allergen content under warmer conditions. Up to now, little is known about additional biotic and abiotic factors that might alter these pollen characteristics. There might exist a remarkable difference in the impact of pollen on human beings depending on the overall production and allergenic potential of pollen. In this study, we focus on the most important allergenic tree species in northern, central, and eastern Europe: birch (Betula spp.). The major novelty is the analysis of biotic and abiotic impacts on pollen of cloned birch individuals free from genetic differences in their natural environment across International Phenological Gardens in Europe. In addition, studying birch pollen of cloned individuals in a seed plantation in Bavaria guarantees the exclusion of genetic diversity as well as tree age and microclimate. We further focus on birch trees along an altitudinal gradient in the northern Alps that offers a variety of climatic conditions and a great genetic and species diversity. Besides the investigation of abiotic factors (e.g., air temperature, relative humidity, air pollutants) influencing pollen production and allergen content, we also focus on biotic factors such as virus infections (Cherry leaf roll virus) or the pollen-associated microbiome and the in vivo relevance of the pollen’s allergenicity using skin prick tests. A greater knowledge gained by our study allows the prediction of future alterations under climate change conditions in more detail. An interdisciplinary collaboration between scientists of landscape ecology, phytomedicine and environmental medicine shall answer how biotic and abiotic factors impact pollen production and allergenicity and finally the allergic reactions in patients.

• DFG Programme: Research Grants