Australian acacias: Weeds or useful trees?
Abstract
By promoting Australian acacias to the
developing world, aid and development agencies are
failing to learn from the mistakes made with mesquite
(Prosopis juliflora) and jatropha (Jatropha curcas)—
two plants with weedy attributes that have done more
harm than good when promoted in Africa as aid. The
belief in ‘‘miracle’’ plants that can lift people quickly
out of poverty is problematical, because such plants
have the attributes of weeds—vigorous growth in
degraded conditions—and often escape human control,
degrading rather than improving land. Other
problems are costs that are less obvious than benefits,
discounting of the future, and a belief that anything
green is good. The main biological problem with
Australian acacias is copious crops of long-lived seeds
which make eradication very difficult, binding future
generations to acacia-dominated landscapes. Drawing
on papers presented at a workshop on Australian
acacias as introduced species around the world held at
Stellenbosch University, I examine the different
perceptions of Australian acacias by invasion biologists
and the aid and development community. The
latter has redefined ‘‘sustainability’’ to give it social
rather than ecological goals. To manage Australian
acacias sustainably, precautionary risk assessment
should take precedence over adaptive management,
because mistakes are often irreversible and can take
many decades to become obvious.
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- RESEARCH: CIB Associates [228]