A week of spreading awareness
The ‘invasive plant’ issue is just one of many problems facing the world’s environmental scientists. Climate change, pollution and global warming are probably the most serious challenges, but invasive plants are becoming a real concern. It was interesting to see that the Lagos câmara, the Algarve and the whole of the Iberian Peninsula have been addressing this problem head-on. The initiative is part of Invasive Species Week 2025, which took place simultaneously in Portugal and Spain between 3 and 11 May.
On 6 May, Câmara Municipal de Lagos hosted a group of environmentalists and agricultural specialists. After introductions, the first scheduled speaker was Pedro Gomes from the Polytechnic Institute of Coimbra’s Agricultural Department. His topic was the super invasive cordeira plant, known more commonly as pampas grass, originally from Argentina’s Pampas region.
The plant invaders!
This plant is often seen in clumps and its plume is not dissimilar to a feather duster. It makes a very attractive display and can often be seen as a floral arrangement in hotel lobbies and entrances in public buildings. The problem is that it spreads like wildfire and is a real problem when it takes over market gardens, farmlands and domestic gardens, causing biodiversity loss. It’s extremely difficult to eradicate. Seeds are blown from the plumage across a wide area and even a small part of the root will propagate into new growth. The best method of eradication is burning, but care must be taken because it is very flammable. The public should be aware of the damage that the cordeira plant can do and not pick it or transplant it. It can be a habitat for parasites and diseases.
The next scheduled speaker was Frederico Leite, who represented international environmental organisation the World Wide Fund for Nature (WWF Portugal). His topic was the Pennisetum species, of which there are two: Pennisetum villosum and Pennisetum setaceum. The problem with this species is that it has a negative impact on food and water security, and can be harmful to health. In other words, the species requires a lot of water and can deplete ponds and wetlands, denying fish and animals water and adding to the potential for drought.
Another pervasive invader is commonly known as the Bermuda buttercup and it’s seen in the Algarve in fields of attractive yellow. Its scientific name is Oxalis, as it contains oxalic acid. It can smother other garden and landscape plants, and can inundate lawns. If large quantities are ingested by humans or animals, the plant can be toxic. It is also hard to eradicate.
Spreading like wildfire
Perhaps the most serious invader is the eucalyptus tree. It was introduced to Portugal from Western Australia in the late 18th century and since then it has multiplied exponentially. It has thrived in Portugal and has been used for reforestation and to prevent erosion. It really took off from the mid-20th century to provide raw material for the paper and paper pulp industry. The trees consume large quantities of water and have a negative impact on biodiversity. Eucalyptus trees also have a high oil content and, as such, are a catalyst in the spread of wildfires.
A marine threat
The next speaker on the schedule was Luísa Custódio from the Algarve Centre of Marine Sciences in Faro. CCMAR is one of the main marine science research centres in Portugal. Her topic was turning a potential threat, like seaweed, into a useful resource.
Ending the morning session was Paula Vaz, from the Portuguese Environment Agency, who highlighted the need for volunteers to get involved in identifying invasive species and addressing the possibilities of mitigating their adverse effects on the environment.
Raising awareness
In the municipality of Lagos, the presence of species such as pampas grass, eucalyptus and other acacias has prompted action from the municipality and partner organisations. Bringing awareness to a problem that is likely to get worse if not addressed is the first step in mitigation.
For more information invasoras.pt/en
Many of the volunteering initiatives are led by SOMAR – Conservação & Bioacústica www.facebook.com/somarbio.pt
Photography Julian Putley
