Ecological world

W e find it ironic that so much effort and so many resources are put into the exploration of outer space, at a time when humans are progressively using resources to depletion and when so little is known about the biological diversity of the earth. Why is there all this publicity about ancient life discovered on the planet Mars when there are regions of the Earth where life has yet to be explored? Life at the extremes of environmental conditions are to be found on the Earth. For example, studies of life atgreat depths in the oceans has hardly begun. Recently, an entire new kingdom of deep organisms, the Archaea, has been recognised; although discovered some decades ago, genetic analysis has shown them to be quite unlike any other kind of life (Earle, 1996). We have been concerned to read of proposals for using deep oceans for disposal of global  waste that is inert or rich in metals or even in organic compounds (but not industrial organic compounds). Quite rightly, ...

      H ow often have you seen those wonderful advertisements inviting you to have a holiday on a tropical island ( Fig. )What is it about islands, whether in the tropics or polar regions, that suggests romance, excitement and adventure? Is it because of a sense of escape from the pressures and stress of a bustling way of life, or the opportunity to savour sun-soaked beaches, or the adventure of rocky unexplored shores, or perhaps the chance of seeing unique island wildlife? It is for all these reasons that there is a growing tourist industry for many islands around the world. The wildlife of islands, especially oceanic islands , has long been of special significance in biology , ecology , conservation and biogeography. Studies of island species have also been of historical significance for evolutionary biology. Many of the world's islands have high levels of endemic flora and fauna; that is, taxa found only on a particular island and no other place.  Isla...

    B iogeography has had a very important role to play in the development of our understanding of biology. For example it was biogeography that was the key to developing the theory of the evolution of life.  Today, not only does biogeographical research have important applications in a world of rapidly increasing human population densities and diminishing resources, it has crucial applications for conservation and sustainable use of many levels of biological diversity. If we are to make the best uses of limited resources for conservation we must know much more about the geography and ecology of the many kinds of biological diversity. Some questions in biogeography may seem rather academic.  For example, why are certain species and certain groups of organisms foundinrid scale? localities and nowhere else? What has caused these patterns on a world Why is it that for many groups of organisms there are fewer and fewer species in the north and in the south com...

E cology and biogeography  In 1870, the German biologist Ernst Haeckel (1834-1919) first coined the term 'ecology' and defined it as 'the total relations of the animal both to its inorganic and organic environment'. In some ways that encapsulated what ecology is today; the study of the interactions between organisms and their environment; but also including (1) the study of the abundance of organisms in space and time and (2) the processes in biological communities. Early in the 20th century, ecology emerged from natural history and wildlife manage-ment as a science.  Developments in early ecology occurred simultaneously in both North America and Europe. Landmarks in early animal ecology text-books included Arthur Pearse's Animal Ecology (published by McGraw-Hill in 1926) and the work of Charles Elton (Animal Ecology, published by Sidgwick & Jackson in 1927).  Much of the stimulus for the emergence of plant community studies came from the work of Tansle...

B iogeography : the nature of the subject, its history and its applications  In 1994, an article in the journal New Scientist proclaimed that 'Since biogeography holds the key to the survival of life, it deserves more attention' (Bowman, 1994). That statement is a very fitting opening to this first chapter. Biogeography is about the geography of plants, animals and other or-ganisms, that is, the study of the geographical distribution of plants, animals and other organisms.  Biogeographical research helps us to understand the patterns and processes of distribution and the factors that cause and maintain those patterns and processes. The patterns of distribution that we find today amongst living organisms have been determined by many things, including the following: Evolution Physiological and behavioural adaptations Dispersal mechanisms and levels of dispersal abilities Competition between species Ecological succession Climate change Sea level changes Moving conti...