Geoscience Reference
In-Depth Information
restoration became increasingly important scientifi cally and politically (e.g., Walters
and Maguire, 1995; Petts, 2001; Dobson, 2005).
The concept of 'ecosystem services' was developed to acknowledge the range of
functional processes within ecosystems that are indirectly necessary for human sur-
vival (e.g., Daily et al., 1997). These are mainly provided by biotic ecosystem com-
ponents and include (as just a few examples) regulation of climate and atmosphere,
cycling of water, sediments and nutrients, photosynthesis and production of biomass,
pest control, pollination, and soil formation. Ecosystem services contribute to the
functioning of ecosystems and ultimately human survival at a range of scales, from
local (e.g., photosynthesis or nutrient cycling within an individual plant) to global
(e.g., maintenance of the Earth's atmosphere and climate). The ecosystem services
concept had implications for the prediction of ecosystem response to disturbance
and management at different scales, and also raised questions regarding the scale
at which management is appropriate. Ecosystem management for resource acquisi-
tion or production was almost always conducted at the local scale and with limited
understanding of temporal variability. Consequently, there was very limited consid-
eration of how alterations in functioning in local ecosystems would impact regional
and global ecosystems.
The management of ecosystems for individual resources is increasingly being
recognised as unsustainable and so whole ecosystem management is becoming more
important, both for industry and conservation. This is refl ected in trends towards
land management at broad spatial scales, e.g., landscapes, regions or catchments,
as well as increased interactions between geographers, ecologists, land managers
and economists (e.g., Grumbine, 1994; Sparks, 1995). It is apparent that we need
to preserve the complexity and dynamism of ecosystems, though we still do not
know how best to achieve this. There are major gaps in our understanding of eco-
system variability and prediction that make ecosystem prediction and management
less effi cient and effective. Furthermore, the same considerations of ecosystem vari-
ability and complexity that apply to resource management in industry also apply
to ecosystem conservation and restoration. Partly because ecosystems are poorly
understood and partly because of the history of single resource management, con-
servation and restoration are often conducted with one resource or habitat in mind,
and recent lessons relating to the complexity and variability of ecosystems have yet
to be applied to this new form of ecosystem management, which is necessary if they
are to be successful (e.g., Bond and Lake, 2003). This chapter goes on to discuss
issues relating to the quantifi cation and prediction of variability in ecosystems and
the way in which this infl uences the management of ecosystem resources and
services.
Understanding Ecosystem Interactions and Variability
Ecosystems as non-linear complex adaptive systems
Ecosystems on any scale involve extensive interconnections and interactions among
their components that largely defy quantifi cation and simplifi cation. Despite the
discovery of, for example, power laws linking some ecosystem patterns and pro-
cesses over a range of scales and levels of organisation (Brown et al., 2002), eco-
systems can display substantial non-linearity. They can be understood as complex
adaptive systems (i.e., having the capacity to change). This means that they may
