Spain's 'Green Deserts' Threaten Birdlife

Vast eucalyptus plantations, a hallmark of northwestern Spain since the 1940s, are raising significant environmental concerns. These fast-growing Australian trees were favored by the paper and pulp industry over native species. However, research from the University of Santiago de Compostela and the National Research Council of Spain has established a clear link between eucalyptus expansion and a loss of native bird diversity.

The study, conducted in Galicia's Fragas do Eume Natural Park, found fewer bird species in eucalyptus forests compared to native woodlands. Even mature eucalyptus failed to provide the ecological services of native forests. Insectivorous birds and cavity nesters, such as the great spotted woodpecker and coal tit, are particularly affected due to a lack of insects and suitable nesting sites.

Scientists refer to these plantations as 'green deserts' because eucalyptus's allelopathic properties inhibit undergrowth, reducing insect populations and consequently food sources for birds. Furthermore, the typical 10-15 year harvesting cycle prevents the development of the hollow trees many birds rely on for nests.

The forestry and wood sector in Galicia generates approximately €2.5 billion annually and employs over 19,000 people, with eucalyptus being a key species. This economic importance has complicated proposals to list eucalyptus as an invasive alien species in Spain. Scientists suggest integrating strips of non-managed indigenous vegetation within plantations as a cost-effective solution to support biodiversity without halting forestry practices.

This issue extends beyond Spain, with Portugal having over 800,000 hectares of eucalyptus forests. Research continues into how large-scale eucalyptus plantations affect temperate and Mediterranean climates, exploring a balance between forestry and biodiversity protection.