Environmental Engineering Reference
In-Depth Information
It is not my task to consider the political and personal changes to human activities
that would eventually remedy the climatic problems we are causing. The focus,
instead, will be on what ecological managers can do to mitigate the worst effects of
climate change - because it is not just human populations that will be disrupted.
Nature reserves already set up for key species may turn out to be in the wrong places
and species currently appropriate for restoration projects may no longer succeed.
Moreover, each region of the world is likely to be subject to a new set of invaders,
pests and diseases. So where precisely do ecologists fi t into this picture? Our role
is to take the physical predictions (temperature, precipitation, extreme climate
events, ocean currents, etc.) and envision the consequences for species and ecosys-
tems. Only then can we properly work out plans to manage biodiversity.
Future species distributions can be expected to be determined in line with their
niche requirements (Chapter 2), life-history features (Chapter 3) and ability to move
from where they are now to where their optimal niche conditions will be in future
(Ch apter 4). Some of these species are ones deserving of conservation effort (Chapter
5) or merit attention for their harvest value (Chapter 6). Others are the focus of
biosecurity (invaders) or pest control (Chapter 7). Sometimes our predictions about
ecological change will depend on an understanding of community and ecosystem
functioning, such as successional processes (Chapter 8), food-web interactions and
ecosystem services (Chapter 9). And always a landscape perspective (Chapter 10)
will be appropriate, because managers must envision how global climate change will
reorganize regional landscapes. In other words, understanding and managing our
ecological future needs to be underpinned by all the aspects of ecological theory
you have met so far in this topic.
Box 11.1 gives a taste of how the climate change modelers go about their business,
producing predictions upon which ecological managers can base their work. This
chapter then follows the logical structure of the topic as a whole. First, I consider
examples where managers can base their plans on our knowledge of individual
organisms - their niche requirements, life-history features and dispersal powers
(Section 11.2). Then I turn to the guidance provided by an understanding of popula-
tion dynamics - when managers plan for the conservation of endangered species,
the harvest of animals and plants, and the control of pests (Section 11.3). You will
discover that an understanding of community and ecosystem processes can also
guide managers (Section 11.4) and fi nally, at the largest scale, I will take out my
macroscope again and adopt a landscape perspective of ecological management in
our rapidly changing world (Section 11.5).
Box 11.1 Predicting the
ecological effects of
global climate change
The human activities that have changed the composition of the atmosphere, and the links between
atmospheric change and climate change, were explained in Chapter 1. Here, I present some of the
observational evidence of a changing climate that already exists, and then outline the modeling
process used to indicate the pattern and scale of changes we can expect in future. The models of
the physical scientists are simplifi cations of a very complex reality. It is important to consider a
variety of models, each based on a different set of reasonably realistic but imperfect assumptions,
to provide not a single defi nitive (and probably wrong) result, but rather a range of change that
encompasses the probable truth of the matter. The transformation of these likely climate scenarios
into ecological consequences is a further step. This is based either on what is known about current
species distributions in relation to climate or, alternatively, on an understanding of the biological
consequences of climate change for reproduction, growth and survival.
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