How urban planners' preference for male trees has made hay fever worse (2020)
3 days ago
- #urban planning
- #pollen
- #allergies
- Tom Ogren observed excessive pollen from male deodar cedars in Sacramento, a result of urban planners favoring male trees for their seedless nature.
- Male trees are preferred in urban areas for their lack of seeds and pods, but this leads to unchecked pollen production, exacerbating allergies.
- Hay fever and asthma, linked to pollen, affect hundreds of millions globally, with pollen counts rising over the past 15 years.
- Ogren developed the Ogren Plant Allergy Scale (Opals) to rank plant allergies, now used by the USDA for urban forestry programs.
- Urban areas globally, including in the US, UK, and Canada, predominantly plant male trees, a practice Ogren calls 'botanical sexism'.
- Efforts in cities like Hamilton, Vancouver, and Edmonton aim to balance tree sexes to reduce allergenic pollen, but progress is slow.
- Air pollution and higher CO2 levels worsen pollen's allergenic effects by breaking pollen into smaller, more allergenic particles and increasing bloom rates.
- Ogren advocates for public awareness and action to demand pollen-free urban landscapes as a basic human right to mitigate allergy risks.