Wednesday, May 16, 2007

Restoration ecology & the 'field of dreams'

Several restoration ecologists I have met recently have referred to the ‘Field of Dreams’ hypothesis* in relation to biodiversity conservation.

This is the notion that you can rebuild or reestablish a natural ecosystem replanting trees and so on whence the natural system will reestablish itself as organisms naturally re-colonize leading to ‘normal’ community structure and biological function. The ecologists counter that habitats will not reestablish because crucial ingredients are omitted from the reestablished mix so that key features of an ecosystem are irreversibly lost.

We value many things for their authenticity or genuineness. Most of us prefer a real diamond to a zirconium imitation, we prefer the original of a great painting to even a masterly prepared print. The same ethic runs through biodiversity conservation – those of us with a green bent have a strong preference for original, pristine habitats such as old growth forests rather than restored habitats.

Three comments are in order:

(i) There are some claims that many environmental systems can reestablished themselves. For example, NewScientist this week comments on destroyed tropical forest landscapes. Many of these that have been destroyed by forestry can be expected to regenerate with most species returning.

(ii) It is difficult to define what we mean by 'authentic' or 'pristine'. Environmental history suggests such terms are ambiguous since almost all habitats have been affected by human activities and it is difficult to decide how far we should look back.

By studying changing attitudes to nature and nature conservation over history we gain a better ability to appreciate how attitudes in the future might be unstable and change. In addition, understanding the history of the environment helps us to focus on the crucial issue of what aspects of the current natural environment we might wish to conserve. For example:
“When we talk about conservation of the Australian environment what are we really talking about? Do we mean conserving the environment as it was in 1788 –an environment which was created as a result of interaction with aboriginal people –or do we mean conserving the environment as it develops in the absence of regular, routine, low intensity burning; or do we mean conserving it in the absence of the dingo; or in the absence of foxes or feral cats; or in the absence of the rabbit, the goat, the pig, the camel and the donkey; or do we mean conserving it without any human impact whatsoever –by excluding people altogether from national parks?” (Kohen (1997, p. 128))
(iii) Generally we should seek ‘fields of dreams’ but not be disappointed should we fail. The issue is not whether authenticity can be achieved but whether at least some positive conservation outcomes can be achieved. We should be ‘satisfisers’ if restorations are inevitably inauthentic. The gloom of writers such as Stephen Meyer ('The End of the Wild') should be rejected as pointless defeatism.

(*) The notion of a Field of Dreams comes from the interesting 1989 movie of the same title starring Kevin Costner which I hadn’t watched but which I viewed this evening. ‘If you build it he will come’ is the central myth which gives rise to the key restoration hypothesis.

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