Review:
There are a number of interesting trends in ecological texts
not all of which are helpful to beginners. There are specialised
texts of course and those that attempt more interdisciplinary
analyses but sometimes, when you just need a simple, straightforward
analysis of one ecosystem there can be little there. As deserts
and desertification are becoming more important, the need for
this background text becomes more evident. This author has sought
to provide such a book.
The
opening chapter outlines the concept of desert and the basic
locations along with some of the regional and local complexities
we are going to explore in later chapters. Chapter two provides
us with a basic geographical overview of all the major global
desert regions. This covers size, location, basic climatic parameters
and something of the key ecological components. Deserts are
more than just 'dry areas' and chapter three aims to investigate
the more complex side of climate. Starting with the surface
boundary layer and covering vapour, radiation, albedo and precipitation
(in ironically more detail than other areas!) and wind. To these
more local factors are added the regional ones e.g. ENSO which
is a major factor with the Saharan desert. Chapter four moves
on to hydrology and examines in some detail the complex movement
of water in the air, on the surface and in sub-surface conditions.
There's work on runoff, an important feature given the high
variability of precipitation. Fog can be a key component and
its impact is also noted. Finally there's the idea of cloud
seeding and a brief study of water management in the Tigris-Euphrates
area. When sufficient moisture does build up there's often a
lack of channels to carry it from the area meaning that lakes
are formed to cope with surface excess. These lakes, pans and
playas have significant value for both modern climates and past
reconstructions. After examining water systems, chapter six
has moved on to weathering and erosion processes highlighting
the specific aspects found only in deserts and the impact this
has on landscapes. Soil is the next topic. We might associate
deserts with a specific colour, usually red, but this can hide
considerable variations in both chemical and physical properties.
Soil can influence growth patterns in vegetation often controlling
the 'flush' of plants found after rapid precipitation events.
Finally, chapter 8 looks at the way in which water can shape
geomorphological events in terms of slopes, valleys, channels
and products such as alluvium. If water is a key component,
then wind processes must also be seen as crucial. Chapter 9
and 10 look at a wide range of aeolian processes from wind velocities
and their effects to landforms of both erosion and deposition.
Deserts are also ecological communities and chapters 11 and
12 dealing, respectively, with plants and animals highlight
some of the unique characteristics of desert habitats. Finally,
people get a mention. Desertification is a key environmental
issue and some of the key aspects are discussed here. An extensive
bibliography rounds out the text.
This
is a very valuable text. At a time when a lot of ecological
and environmental work focusses on a specific process it's less
common to find holistic discussions of one area. This is a pity
because it's the way that most beginners get to understand their
area and see how the various processes interact. From this,
they can then move on to consider the process alone because
they have the grounding in the known. In this text the author
has systematically covered the key ideas of desert geography
and ecology. Chapters are chosen to discuss key topics familiar
to the beginner and this adds to the ease of use. However, the
extensive bibliography shows that there is also much for the
more advanced user. Overall, an excellent guide and one sadly
all too rare.