Eucalyptus plantations are biological deserts

Eucalyptus trees cause “dramatic reduction” of biodiversity, with researcher at the University of Coimbra concluding that “eucalyptus leaves prevent the growth of roots of other plant species.”

An international study undertaken by the university and published in the journal Global Ecology and Biogeography,* concludes that “the eucalyptus trees generate authentic ‘deserts’ around them, causing a dramatic reduction of the biodiversity of the territory.”

Daniel Montesinos, of the Centre for Functional Ecology at the Faculty of Science and Technology of the University of Coimbra joined researchers from Australia, Chile, USA and India.

The experts evaluated the plant biodiversity present in eucalyptus areas both in the tree’s native area, Australia, and in countries around the world where the species was introduced industrially, including Portugal.

“The chemical substances present in the leaves of the eucalyptus prevent root growth in other native species, which is why eucalyptus plantations contain very little biodiversity outside their native area in Australia,” said Montesinos.

The main result of this work, says the researcher, “was to show, for the first time and on a world scale, how the biodiversity beneath the eucalyptus tree is reduced and how extracts from eucalyptus leaves prevent root growth of other plant species.”

Eucalyptus plantations are “highly detrimental”, warns Daniel Montesinos, stressing that “the impoverishment of species triggered by eucalyptus has an impact on the whole ecosystem, for example, in the control of soil erosion and in the maintenance of biodiversity.”

The reduction of biodiversity does not occur in Australia, because “numerous species have been able to develop a tolerance to the chemicals present eucalyptus leaves throughout the centuries,” explains the report.

Outside Australia, “ironically, some of the species that can survive under the eucalyptus also are exotic species, creating a vicious circle of reduced biodiversity and invasive species,” said Daniel Montesinos.

“The results of the work show, without any doubt, the impoverishment of the areas planted with eucalyptus, which even if they may look green, in fact are deserts,” concluded the researcher.

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* ‘Global Ecology and Biogeography’ is a bimonthly peer-reviewed scientific journal that was established in 1991. It covers research in the field of macroecology. The current editor-in-chief is Brian McGill. According to the Journal Citation Reports, the journal has a 2010 impact factor of 5.273, ranking it first among 42 journals in the category “Geography, Physical” and 7th out of 129 journals in the category “Ecology”, and 4th in the category “Biodiversity and Conservation”.

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