What is it?
Ambrosia is a plant native to North America, introduced to Europe at the end of the 19th century, whose proliferation represents a major health, agricultural and environmental issue. Highly competitive, it rapidly colonises bare or recently disturbed ground, particularly :
- Agricultural land,
- Construction sites,
- Roadsides and wasteland.
Its dispersion is favoured by :
- Human activities,
- Soil transport (machinery that works the soil)
- Contaminated seeds
- Climate change, which is gradually extending its range.
The main risk associated with ragweed is its highly allergenic pollen: just a few grains per cubic metre of air are enough to trigger respiratory illnesses (conjunctivitis, asthma attacks, etc.) in susceptible people, leading to significant health costs.
On the other hand, in agricultural terms, the plant reduces yields and may require costly intervention to control it.
Its annual life cycle begins in spring with germination, followed by rapid growth in summer, then flowering from August to September, during which time it emits large quantities of pollen. In autumn, it produces its seeds, which are very hardy and can survive for several years in the soil, ensuring its persistence and spread.
Managing ragweed involves
- Surveillance,
- Early grubbing-up,
- Limiting bare soil
- Raising public awareness
The Local Ambrosia Referent
Each commune in the Communauté de Communes has an Ambrosia advisor whose role is to:
- Identify colonised areas and encourage those concerned to take action
- Help ensure compliance with current regulations
- Communicating and escalating information in the event of difficulties
Here is the list of local ragweed referents: