what is restoration? the goals, objectives, targets and endpoints of restoration can be difficult to...

What is Restoration?

The goals, objectives, targets and endpoints of restoration can be

difficult to define. The following slides give a brief introduction to this

complex topic

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National Riverine Restoration Science Synthesis

http://www.americanrivers.org/default.htm

Restoration Trajectories

Restoration is:

“returning a system to a close approximation of its condition prior to disturbance, with both the structure and function of the system recreated”.

(National Research Council 1992)

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Restoration vsRehabilitation• As the prior graph illustrates, it is important to

distinguish restoration (in the direction of the pre-existing, undamaged state) from rehabilitation (seeks only to improve conditions)

• Targets are necessary to distinguish restoration from rehabilitation

• Indicators are needed to measure progress• Goals may be much broader than specific targets,

and might include social goals such as stakeholder involvement

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Restoration Definitions• Lake (2001) provides an excellent review of

restoration definitions. One common definition is:• “The process of inducing and assisting abiotic and

biotic components of an environment to recover to the state that they existed in the unimpaired or original state” (Bradshaw 1997)

• However,– in many cases knowledge of such a state is not available

and return to that state is not possible

– restoration may be carried out passively (degrading forces are abated) or actively (also driven by intervention)

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More RestorationDefinitions• An intentional activity that initiates or accelerates

the recovery of an ecosystem with respect to its health, integrity and sustainability

• the process of assisting the recovery of an ecosystem that has been degraded, damaged, or destroyed

• attempts to return an ecosystem to its historic trajectory (but perhaps not to its former state)– established from historical, reference,

comparable ecosystems and other information

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(Society of Ecological Restoration 2002)


Goals &Targets• clear and achievable goals are essential• goals or targets may be set by reference areas,

historical data, or compilation from many fragments of an idealized scenario– this language emphasizes historical condition (and is to

some extent contradicted by the following)

• should be forward-looking– desired characteristics of system of future, not what

existed in the past (“sensible goals”)

• should consider a range of options– implies societal evaluation of alternatives

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(Hobbs and Harris 2001)

Goals (some pragmatic considerations)

• Will need to be determined iteratively by matching restoration potential against societal desires

• as much process (considering perspectives of stakeholders) as product-oriented (adaptive)

• need to be economically possible and achievable• will be basis for recognizing success• success will depend on process of arriving at mutually-

agreed upon goals

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(Hobbs and Harris 2001)

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The Iterative Process

Goals, Objectives& Performance• Goals are ideals• Objectives are concrete measures taken to achieve

goals• Performance standards (aka design criteria and

success criteria) are used to evaluate whether objectives are met

• The more explicit the objective, the easier it is to determine if objectives (and thus goals) are met– eg, plant riparian vegetation at 20 stems/m2

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Reference Sites• May be critical to setting goals• Might this better be termed, “sources of knowledge

about the natural state”?– ie, does an emphasis on reference sites conjure up images

of past, pristine, equilibrium, etc?

• Sources of knowledge about the natural state– natural analogue (aka reference site)– historical reconstruction– best professional judgement– desired future state

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Appropriate Restoration EndpointsFrom a community ecology perspective, an appropriate

restoration endpoint might be based on any of the following:

• structural (species richness, focal groups)

• functional (processes, eg production)

• biodiversity and ecosystem function linkage

• keystone species

• natural disturbance regime

• enhancement of succession and dispersal to reach endpoint sooner

• initial conditions

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(Palmer et al. 1997)

Ecological Restoration Glossary• Restoration: to bring back into a former or original

state. • Rehabilitation: any restoration of elements of

structure or function (aka “repair”)• Reclamation: rehabilitation of severely degraded

sites• Re-creation: reconstruction of a system that is so

severely disturbed that nothing is left to restore• Ecological recovery: leaving a system alone, to

recover on its own

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