Alien Species.vp - IUCN

The understorey of human dimensions in
biological invasions
George W. Staples
Abstract
People frequently tend to move species from one place to another, possibly because they
have an innate desire to have other species of organisms near them, irrespective of their
cultural origins. However, the rise of global consumerism has greatly increased the flow
of plants and animals around the world, driven by modern transportation and communications
technology. This has been accompanied by growing urbanization, where people
are disconnected from the land and the ecological processes it supports; people living in
cities may have only a very slight understanding of the native or alien characteristics of
the species around them (indeed, they may not even care). Management of IAS needs to
take into consideration the human dimensions, including cultural and political elements,
in order to overcome apathy, scepticism, and ignorance. Successfully dealing with IAS
problems will require bringing in other parties affected by the issue, including human
health, commerce, and agriculture.
Introduction
People have been moving plants and animals around the globe since the dawn of human
existence (Mabberley, 1999). Some of those species were moved intentionally and others were
accidental hitchhikers. Some survived in the new habitats; others died out. Of those that
survived, dubbed alien species because they are not native to the place where human activity
put them, some managed to survive and reproduce in populations that did not make a
discernible impact on the environment, while others, sometimes quickly, sometimes slowly,
began to spread and undergo dramatic population growth and range expansion. These latter
alien species are called invasive alien species (IAS) because of their ability to spread
aggressively, impact the environment, commerce, agriculture, human health and quality of life,
or any combination of these.
That, succinctly put, is the problem. It is the purpose of the Global Invasive Species
Programme to work toward an international approach to facing this complex and multi-tiered
problem. While scientific and government awareness have been increasing for a number of
years, the recognition that the invasive species problem is at its heart a human problem has been
a recent one. If we are to gain some understanding of the human dimensions of the IAS
problem, and then do something about it, then we must step back from the details and try to see
the larger picture. To paraphrase an analogy, “One can’t see the forest for the trees.” And so it is
with alien species issues: the upper tiers, closer to us, obscure what is underneath, much like the
canopy of a tall forest obscures the ground beneath. The understorey, where the roots are, is
hidden far below the middle and upper tiers of the canopy. It is the goal of this paper to peer
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