It is one of the most common trees on the Iberian Peninsula. In Spain you will mainly find the species in northern regions such as Galicia, Cantabria and Asturias. After initially enjoying the benefits of the tree, its harmful effects on native nature are now clear.
The tree was introduced in the late 19th century for its rapid growth and suitability for the production of cellulose, an ideal raw material for papermaking. Furthermore, the tree is used for firewood, plywood and lumber, construction and fencing posts, as well as for medicine, oil and honey production.
This fast grower is the eucalyptus. After about ten years, the trunk of the eucalyptus is sufficiently thick to use. And when the tree is cut down, a new trunk grows very quickly. The eucalyptus has now been classified as an invasive species. A lot of money is also made in Spain with 760,000 hectares of eucalyptus, but the tree turns out to be a wolf in sheep’s clothing.
Minimal maintenance and low costs
One of the reasons for the widespread presence of the eucalyptus in Spain is that many Spaniards left the countryside over the past century. To meet the growing demand for wood and paper, abandoned land was transformed into eucalyptus plantations, partly with government support. The eucalyptus tree turned out to be the best choice, especially for landowners who lived far from their (agricultural) land. The costs were low and the tree required minimal maintenance. In both Portugal and Spain, many native forests have been replaced by eucalyptus.
“Huge amount of water”
According to the Spanish Bird Protection Association (SEO/Birdlife), the eucalyptus “consumes an enormous amount of water and significantly reduces biodiversity”. In addition, the cellulose production process is highly polluting to both rivers and the atmosphere. In regions such as Galicia, Asturias, Cantabria and the Basque Country, the eucalyptus plant covers approximately 300,000 hectares of the 760,000 hectares in all of Spain. A notable example is the Souto de Retorta in Viveiro (Lugo). The tallest and oldest eucalyptus in Europe can be found there, with heights of up to 80 metres.
Hazards
The area of eucalyptus plantations continues to expand. This poses a threat to old meadows and shrublands that are of great importance for biodiversity and the landscape. “The spread of these trees threatens to transform the Cantabrian landscapes into a gigantic industrial plantation,” warns SEO/Birdlife.
Scientific judgments
A 2017 report by the Scientific Committee of the Ministry of Agriculture, Fisheries, Food and Environment classified the eucalyptus as an invasive species that threatens biodiversity and native species. The trees use so much water that other plants do not have a chance to grow. In addition, they change the chemical composition of the soil and their fallen leaves are difficult to break down. This also hinders further plant growth.
Fire hazard
Eucalyptus plantations are also highly susceptible to fire due to the accumulation of leaves and the presence of flammable oils, which increases fuel loads. Aromatic oil is extracted from various eucalyptus species. The oil is extracted from the leaves and is used for inhalation for colds to clear the airways. This oil is very flammable, especially at temperatures above 30 °C, and is often the cause of serious forest fires.
Water consumption
According to Ecologistas en Acción, eucalyptus plantations use an enormous amount of water: “Every hectare can accommodate 1,400 eucalyptus trees, which equates to a water consumption of 42,000 litres per hectare per day.” These conditions make the eucalyptus a threat not only to local flora and fauna, but also to Spain’s water supply and security. The urgent call from environmental organisations is therefore to take measures to limit the spread of these trees and minimise the impact on the environment.