Scientific and ethical foundations - Ecological Governance - page 35

of species due to human actions. This is currently occurring at a rate that

has not been seen since the last global mass extinction event

'

. 84
The resilience of an ecosystem is not directly correlated with the
numbers of different species that it supports, but lies in the variety of
species belonging to groups that have roles in maintaining its function-
ality. 85 For example, certain functional groups enable the renewal of
coral reefs following disturbance by removing dead corals and by grazing
on algae that would otherwise prevent new corals from taking root. 86
The complete loss of a group reduces the ability of ecosystems to main-
tain existing structures and functions in the face of disturbance. 87 It is
an outcome that speci

'

ed resilience measures could be used to prevent
although a general resilience back up will always be required to account
for ignorance of species that are, or could form part of, a grouping.
Research into the role of biodiversity in maintaining ecosystem func-
tionality has identi ed the critical importance of response diversity in

functional groups. 88 Response diversity entails that a group whose mem-
bers respond differently to changes in conditions maximises the possi-
bility that functions will continue to be performed despite the inability
of particular species within a functional group to withstand systemic
change. 89 The term redundancy is also used to refer to species whose loss
may appear unimportant at a point in time, but which may become of
immense value in different circumstances. 90 These concepts point to the
desirability of maximising diversity in functional groups as we cannot
know which species will respond well to particular conditions or, indeed,
what conditions will be encountered in the future. 91
It would be prudent where we are aware of the importance of certain
functional groupings to devote attention to their protection. However, this

84 Rockström et al.,

' A Safe Operating Space ' ,473 - 4. See also N. Myers, ' Biodiversity ' ,74 - 5;

Chapin III et al., ' Consequences of Changing Biodiversity ' , 234; Chapin III et al.,

' Terrestrial Ecosystem Ecology ' ,p.333.

85

Folke et al., ' Biological Diversity ' , 1019 - 20; Folke et al., ' Regime Shifts ' , 570; Folke,

' Resilience ' , 258; Chapin III et al., ' Terrestrial Ecosystem Ecology ' , pp. 323 - 4.

86 Walker and Salt,

' Resilience Thinking ' ,pp.64 - 73.

87

Ibid .; Folke et al., ' Regime Shifts ' , 570.

88 Chapin III et al.,

' Consequences of Changing Biodiversity ' , 238; Gunderson, ' Ecological

Resilience ' , 431 - 2; Folke et al., ' Regime Shifts ' ,570 - 1; Folke, ' Resilience ' ,258;

Rockström et al., ' A Safe Operating space ' , 473 - 4.

89 Ibid .
90 Folke et al.,

' Regime Shifts ' ,570 - 1; Levin and Lubchenco, ' Resilience ' ,30 - 1; Walker and

Salt, ' Resilience Thinking ' ,p.71.

91 Chapin III et al.,

' Terrestrial Ecosystem Ecology ' ,pp.333 - 4; Walker and Salt, ' Resilience

Practice ' ,pp.93 - 4.