INVASION OF THE CROCODILES - Rethinking Invasion Ecologies from the Environmental Humanities - page 240

Definitions
Article 8h of the Convention on Biological Diversity (Convention on Biological
Diversity, 1993) requests contracting parties to: 'Prevent the introduction of,
control or eradicate those alien species which threaten ecosystems, habitats or
species.' As Mooney notes, 'a strictly ecological definition' of invasion refers 'only
to the rate of spread' (2005: 5). If only those invasive species which are a threat (a
subjective judgement) are to be targeted, then these would seem to fit the criteria
for 'pests' or in the case of animals, 'vermin' - criteria which are defined without
reference to origin. Indeed, so-called native species (on a continental level certainly)
may prove invasive, and harmful, e.g. Acacia ataxacantha in South Africa's Eastern
Cape, or native daphne ( Pittosporum undulatum ) in the states of Victoria and New
South Wales in Australia.
While Article 8h concerns threats to 'ecosystems, habitats or species', in practice,
most targeted invasive alien species threaten local economies, and the 'goods and
services provided by natural systems on which society depends' (Mooney, 2005: 5).
These include cloggers of waterworks, destroyers of grazing land, and forests, stimu-
lators of fire, crop decimators, promoters of animal diseases, and so forth (ibid.: 6).
The Convention's definition was subsequently expanded, as outlined in
McNeely's IUCN collection on 'human dimensions of invasive alien species' (see
Box 15.1).
These definitions are still not straightforward. Some key aspects to be unpacked
include what timescale will be used to assess 'normal past or present distribution',
how experts judge which species are economically and environmentally harmful
BOX 15.1 DEFINITIONS OF ALIEN, INVASIVE AND
NATIVE SPECIES
'Alien species' are 'a species, subspecies, or lower taxon introduced outside its
normal past or present distribution . . .'
'Invasive alien species' are 'an alien species whose establishment and spread
threaten ecosystems, habitats or species with economic or environmental
harm.'
'Native species' are 'a species, subspecies or lower taxon living within its natural
range (past or present), including the area it can reach and occupy using its
own legs, wings, wind/water-borne or other dispersal systems, even if it is
seldom found there.'
McNeely (2001: 3).