Five years of national airborne pollen monitoring in South Africa: Biome-specific calendars to inform allergy diagnosis and prevention

Matuvhunye, T.; Berman, D. M.; Esterhuizen, N.; Razafimanantsoa, A. H. I.; Neumann, F. H.; Gharbi, D.; Podile, K.; Mmatladi, T.; Langa, B.; Moseri, M. E.; Ajikah, L.; Effiom, A.; Ndlovu, N.; Quick, L. J.; Hilmer, E.; Marishka Govender, M.; Davids, S.; Van Aardt, A.; de Jager, L.; Sithole, J. V.; John, J.; Garland, R. M.; Hill, T.; Finch, J.; Chetty, K.; Hoek, W.; Bamford, M.; Seedat, R. Y.; Manjra, A. I.; Upton, C.; Peter, J.

doi:10.64898/2025.12.09.693198

Home/Archive/bioRxiv

bioRxiv · 10.64898/2025.12.09.693198

Five years of national airborne pollen monitoring in South Africa: Biome-specific calendars to inform allergy diagnosis and prevention

View original source ↗Export metadata ↓

Abstract

Pollen monitoring is crucial for understanding seasonal patterns, supporting allergy diagnosis and informing early-warning tools to mitigate allergic diseases. The Southern Hemisphere lacks long-term data on pollen seasons, with extremely few from Africa. We present pollen calendars based on five-year data from the South African Pollen Monitoring Network (SAPNET). Airborne pollen from 2019 to 2024 in biomes across South Africa was collected using Hirst-type volumetric spore traps and standard protocols. Daily concentrations were analysed by light microscopy. The five-year mean annual pollen integral (APIn, pollen grains/m3 per year) was calculated for each site. The five-year mean APIn was highest in the Grassland Biome (Bloemfontein, 11654 pg/m3; range 8515 to 14454 pg/m3) and lowest in the Albany Thicket Biome (Gqeberha, 1372; range 853 to 2010 pg/m3). The Grassland Biome (Johannesburg) had the highest averaged tree pollen concentration (7558; range 6575 to 8803 pg/m3). The Savanna Biome (Kimberley) had the highest average grass pollen concentration (3150; 1826 to 3785 pg/m3). The grass family (Poaceae) was the most common pollen type across all biomes. Other common contributing taxa were exotic trees Cupressaceae, Platanus, Morus and Betula. Tree seasons were July to September, whilst grass and weed pollen seasons varied across the different biomes. These five-year pollen calendars provide the first biome-specific national reference for airborne pollen exposure in South Africa. The findings provide baseline data for the clinical management of allergic disease.

Source connections

Published article ↗

Explore related subjects

ecology Preprint

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Matuvhunye, T., Berman, D. M., Esterhuizen, N., Razafimanantsoa, A. H. I., Neumann, F. H., Gharbi, D., Podile, K., Mmatladi, T., Langa, B., Moseri, M. E., Ajikah, L., Effiom, A., Ndlovu, N., Quick, L. J., Hilmer, E., Marishka Govender, M., Davids, S., Van Aardt, A., de Jager, L., Sithole, J. V., John, J., Garland, R. M., Hill, T., Finch, J., Chetty, K., Hoek, W., Bamford, M., Seedat, R. Y., Manjra, A. I., Upton, C., Peter, J.. 2025-12-11. Five years of national airborne pollen monitoring in South Africa: Biome-specific calendars to inform allergy diagnosis and prevention. https://doi.org/10.64898/2025.12.09.693198

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Operationalising the context in regenerative agriculture: decision-making and farm variability

Soil degradation is a widespread challenge that requires a broad response at the individual farm level. To ensure effectivity, the practices should be tailored to the farm context: land manager objectives and farm specific challenges. These have however been difficult to quantify. Here we demonstrate that a workable farm context can be created based on a value survey, open satellite and soil data, and published models for vegetation gross primary productivity and soil erosion. Based on the findings, despite individual differences, farmers value profitability and operational efficiency, but also biodiversity and soil health. At least the regenerative farmers surveyed also value working for the greater good more than maintaining tradition or power. In spite of wide differences in farm production orientation, we also found that each farm also had a broad variation in individual fields GPP. Most fields have a stable GPP level, which is either high or low, and that there is a 2-3-fold difference between the weakest and best producing fields indicating the potential for improving GPP by improving the growing conditions on currently weak fields. In addition, soil loss was found to be highly concentrated in critical source areas, where 10% of the field area contributed to 50% of the soil loss. Overall, open data can be linked to modelling workflows to rapidly produce a decision-making context for farmers. This facilitates benchmarking and co-learning as well as enables land managers and advisors to identify the farm context for planning effective responses to soil degradation.

ecology↗

bioRxiv2026

Fly, land, listen: Autonomous intermittent locomotion enables scalable low-noise drone ecoacoustic surveys

Ecoacoustic monitoring is enabling scientists and land managers to monitor and manage biodiversity more effectively and cost-efficiently in the face of human pressures and rapidly changing climates. Currently, most ecoacoustic surveys use manually deployed static sensors to record data, limiting the scale and reach of surveying efforts. Here we present a proof-of-concept autonomous drone platform that can use intermittent locomotion to conduct ecoacoustic surveys using an onboard sensor. Our custom prototype is able to fly, navigate, and avoid obstacles autonomously, land at a pre-determined location, record audio from an onboard microphone whilst static, before taking off and moving to the next sampling site. Autonomous navigation and operation enable greater sampling flexibility, reach, and scalability. Furthermore, by recording audio only whilst landed, noise from the drone's rotors does not mask signals or disturb animals, simplifying signal processing and downstream ecological analyses. We conducted trials in a scrubland habitat at the Knepp Estate in West Sussex, where our prototype demonstrated successful autonomous navigation and obstacle avoidance. Furthermore, we found that avian biodiversity data collected from the drone platform was comparable to that from traditional static acoustic sensor deployments, and that vocalisation patterns were not significantly impacted by the noise of the drone arriving or leaving a site. While scaled deployments of our technology would require further technical and regulatory challenges to be solved, our first demonstration of autonomous intermittent robotics-assisted ecoacoustic surveys lays the foundations for more cost-effective and far-reaching biodiversity surveys, with transformative potential for conservation, agricultural management, biosecurity, and more.

ecology↗

bioRxiv2026

Do higher-order moments improve inference of population dynamics?

Fitting mathematical models of population dynamics to microbial time-series data allows us to estimate the ecological processes and interactions taking place in the microbiome. Repeated experiments of microbial systems yield replicates which slightly differ from each other. Some of this variability arises due to the fact that births and deaths occur at random. Most prior work focuses on fitting a deterministic mathematical model to the average across replicates. We use a stochastic model to fit the variability to the observed variability across replicates. Using a simulation-driven approach, we study the conditions under which our approach allows us to infer a larger fraction of ecological parameters correctly. We observe a substantial improvement in parameter inference. Lastly, our Bayesian approach not only allows us to incorporate prior information about the system, but also provides a distribution of parameters which conveys some idea of the uncertainty of the estimates.

ecology↗