In mid-September, wildfires swept through parts of Portugal, transforming the sky into a smoky red and devastating the landscape. Central Portugal witnessed a particularly fierce blaze that blocked a major highway, isolating regions and resulting in the tragic loss of nine lives.
Many may not realize that everyday products, such as certain brands of toilet paper and tissue, may have exacerbated these wildfires. These products often contain materials sourced from eucalyptus trees, a non-native species in Portugal.
Eucalyptus globulus, or Tasmanian blue gum, is favored for its rapid growth and high fiber yield, making it ideal for paper production. However, this species is highly flammable, which poses a significant risk as climate change intensifies fire conditions.
Originally native to Australia, eucalyptus trees were introduced to Portugal in the early 19th century. As the Portuguese paper and timber industries expanded during the mid-20th century, so did the plantations, covering nearly 2 million acres—about one-tenth of the country’s land and a quarter of its forested area.
Portugal holds the distinction of having more eucalyptus trees relative to its size than any other country. This extensive coverage has led to descriptions of the landscape as “green deserts.” The species has also proliferated in California, where it has become naturalized beyond its initial planting sites.
In response to the recent wildfires, firefighters employed hoses and buckets to protect homes from the advancing flames. Amid growing concerns, a debate has emerged regarding the role of eucalyptus in wildfire severity. Some studies suggest the trees have a limited impact, while others indicate that their bark, leaves, and twigs burn more readily than those of native species. In California, authorities have classified these trees as fire hazards.
Environmental groups in Portugal, such as Quercus, are advocating for a reduction in eucalyptus plantations and the promotion of native oak growth. Domingos Patacho, a forest engineer with Quercus, explained that eucalyptus foliage decomposes slowly in Portuguese soil, leading to the accumulation of flammable debris on the forest floor.
The structure of eucalyptus trees also contributes to their fire risk. Their split bark can detach and ignite, sending fiery pieces over long distances, which can initiate new wildfires far from the original blaze.
Adding to the fire risk in northwestern Portugal is the region’s climate. Unlike drier areas like Greece and Italy, where vegetation growth is stunted in the summer heat, northwestern Portugal’s cooler, humid conditions favor the growth of flammable plants. This combination of poor soil, challenging topography, and a conducive climate for fire fuels—such as grasses and twigs—creates a precarious environment that heightens wildfire risks.
