- Last Updated on Friday, 30 December 2016 16:29
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Biological invasions are considered a major threat to biodiversity conservation.
A species is considered invasive when - once introduced into a distinguished territory of their origin and without human intervention - has a high ability to increase their populations, threatening native species and may eliminate them.
Exotic species introduced in our country amount to more than 550, about 7% of which are classified as dangerous invasive species. The severity of the problem is reflected in legislative terms since 1999, being identified the exotic species with invasive character (Decree-Law No 565/99).
Species such as silver wattle or mimosa, Long-leaved wattle, Australian blackwood and tree of heaven are very aggressive and have been expanding their populations, occupying large areas in the Bussaco National Forest, including the adernal.
At the same time, invasive species introduced by its ornamental value as cherry laurel, the sweet pittosporum, or River Spiderwort, have excessive densities and are causing conservation problems for its expansion to the adernal and other relict habitats.
Finally, species with less significant presence as locusts, the Roccella, and the Fascicularia bicolor, also pose a threat as it is evident its invasive nature.