Every so often a text is published which makes the reader stand
back and start to question some very fundamental points. This
is the case here. The book starts with a deceptively simple
idea: given a blank planet, what are the necessary and sufficient
conditions for life to flourish? Now, take any of the standard
texts on ecology and start to wade through the various chapters.
Which ones might be included/excluded? Would there be an order
this is the wrong way to go about it. Start again and add the
most basic processes one at a time until duplication of function
or process appears. It's at this point we join the author in
his "thought experiment". The first chapter sets the
question and suggests a few ways in which we might tackle the
question. Next, we come to a section subtitled "the fundamental
processes" i.e. the arguments for those systems without
which life could not exist. First one up for discussion in chapter
two is energy. Starting with a brief look at thermodynamics
we are asked to consider energy as the key factor. Given that
ecosystems can be described purely in energy terms (think Odum
here) then one can see the justice of the case. Next we need
to add a range of organisms (referred to here as guilds). The
object would be to create waste such that it could be recycled.
It would also be necessary to have some checks in the system
e.g. parasites. Here, biodiversity is a way of getting energy
recycled and having some redundancy in the system to cope with
failure (extinction). Chapter four adds biodiversity to the
list. Of course, biodiversity requires energy and is therefore
a tradeoff between large numbers of a few species and fewer
numbers of a large range of species. The argument comes down
in favour of the latter. Chapter five moves on to consider self-reinforcing
systems - the idea that ecosystems alter the environment for
the benefit of other species. If we take this one stage further
then this biological alteration with have physical ramifications
(chapter six). Although one might argue that it should have
been mentioned earlier, photosynthesis comes in as vital in
chapter seven. The value of oxygen-release and use of "external"
energy sources is key to colonising a planet. Although global
warming is such a key topic currently, the basic idea - that
the levels of CO2 control temperature - is vital especially
as it also regulates plant growth. So, these are the fundamental
eight processes. Now, these processes interact and in so doing,
new properties emerge from this new system. The final part of
the book studies puts forward the key ones. First is nutrient
cycling - a follow-on from biodiversity. History is also important.
As the system develops so historical processes will become more
important in shaping the biosphere. A final chapter reviews
some of the key points.
is a remarkable book at many levels. It can be used as a guide
to produce a simple ecology course although the idea of 'simple'
in the context of the ideas presented here might need some explanation!
More importantly it forces the reader to question the most fundamental
assumptions about what is really important in ecology. As the
author states one might agree or disagree with any choice or
explanation but the key point is that one is thinking. It is
this that gives the text its edge. Put simply, this should be
seen as a key text in any undergraduate ecology/environment
course. It's one of the most interesting texts published for
some time - a must-buy for the library.