An overview of consequences
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Introduced species issue |
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Introduced
species have, in the past years, increasingly become a concern to the people of Haida Gwaii. It is now recognized that introduced species are a major threat to The threat posed by introduced species to the living communities of Haida Gwaii can be particularly acute as island communities have fewer species than mainland ones and have species that are often genetically pecular. The spacial limitations imposed by islands also limit the opportunities for species to The limited size of island animal or plant populations can also diminish their resilience to invasives. |
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The above photos show the difference between forests of Haida
Gwaii on an island with deer (left) and on an island without deer (right).
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Introduced species that spread beyond their
point of introduction without human aid are said to be "naturalized". It is estimated that only between 1% and 10% of introduced species become naturalized. They are the species with the potential to cause problems. |
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It is estimated that the US alone
spends $US137 billion each year fighting non-native flora and fauna, a
figure that rises to $US336 billion when Britain, Australia, India,
South Africa and Brazil are included.
Scientists estimate that up to 5 per cent of the world's gross domestic product is being destroyed as a result of foreign pests and other invasive species, like this Japanese knotweed (introduced to Haida Gwaii). The invaders can also destroy habitats and drive endemic species to extinction. |
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1. Ecological impacts 2. Economic impacts and 3. Cultural impacts |
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What does this mean on Haida Gwaii ? |
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On Haida Gwaii the main concerns associated to introduced species are:
For specifics see the links below: |
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to the geographic isolation, species that evolve on islands are often
genetically unique. This makes them especially vulnerable to impacts of
introduced species. The space limitations of islands means that species are less able to move away from changes brought by introduced species. Islands generally have fewer species and smaller populations, therefore less resilience to invasive impacts. |
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