Islands have held our fascination for centuries whether it be
for colonisation or tourism. Of course, in an ecological sense
they have also been seen as ideal places to study, not least
because of their isolation from continental areas. It's in this
context that islands continue to be seen as crucial laboratories:
isolation can be a field as much as an ocean and 50 metres can
be a greater hurdle to overcome than 50km for many terrestrial
species. There's also the conservation angle to consider - an
island can represent a nature reserve.
in these contexts that we get the second edition of this text.
Subtitled 'ecology, evolution and conservation' we are given
an immediate insight into the perspectives of the authors. The
book is divided into four parts, each dealing with a specific
element of current concern in island biogeography. The first
deals with the paradigm of the natural laboratory for which
the opening chapter provides us with further detail. We are
reminded that whereas this is true it can also be misleading
- islands come in a wide variety of shapes, sizes and locations.
Just how diverse is the focus of chapter two which starts by
trying to classify (or at least outline the range of taxonomies)
of islands and shows how environmental forces can shape their
development. Chapter three turns to biodiversity and the arguments
surrounding islands and hotspots. This has as much to do with
how/where/when species arrive or become extinct and the surrounding
conservation value and although much has been done in this area
there is still some way to do to get an overarching model. Part
two turns to island ecology starting with an analysis of the
equilibrium theory of island biogeography and the development
of notions of macroecology. One element here is the way in which
species arrive and which ones continue to exist - i.e. assembly
rules and dynamics. Although it seems an obvious that there
should be some order to this, it has yet to be proven beyond
doubt that there are specific pathways to ecosystem development.
Chapter six addresses some of these doubts specifically starting
with a critique of the dynamic equilibrium hypothesis and then
looking at some alternative explanations. Part three explores
another element - the evolution of islands in terms of biology.
Chapter seven starts with an analysis of species arrival and
subsequent development in the ecosystem. Chapter 8 turns to
look specifically at the way in which islands can promote/affect
speciation events and what we can learn from them. Finally,
chapter 9 describes a range of models and hypotheses that have
been used to describe island speciation. What's interesting
here is that examples are not just islands but also other isolated
areas such as the African lakes. Part four takes a practical
perspective by examining the links between islands and conservation.
Conservat8ion has been affected profoundly by the idea of islands
not least because of the idea of fencing off nature (the reserve)
from the other areas (the 'ocean' or isolating influence). Chapter
10 takes up this theme examining population numbers and reserve
design. Again, what seems simple in theory becomes far more
complex in practice. Chapter 11 analyses extinctions caused
by human activity - numbers, causes and trends. A final chapter
considers how such issues might be addressed.
is an excellent review of current ideas. It describes the key
concepts whilst at the same time allowing for debate where issues
are far from clear. It's wealth of detail will provide cases
that all can use (and an extensive bibliography will help with
more specialised needs). Although too detailed for general educational
use it should be a standard text in all undergraduate biogeography
and conservation courses.