Fragile environments
are one of the commonest ideas in biogeography and yet the concept
is not well defined ecologically;
Fragility is
better considered in terms of the notions of extinction (loss of
species) and origination (gaining new species);
Examination
of the concept of species loss and gain shows it to be a complex
system of the interplay of genetics, organisation and chaos dynamics;
These factors
can be placed in a model to better explain the loss and gain of
species;
Examples of
fragile ecosystems and threatened species need to be studied to
better enable us to appreciate the factors which can cause catastrophic
changes in ecosystems. It is clear that this will be one of the
most urgent tasks facing biogeographers in the twenty-first century.
Extreme
environments continue to oofer us insights into biogeographical change.
Here's a study showing that human intervention and difficult recruitment
can cause severe decline.
Arctic
areas are fragile environments and their ponds are especially vulnerable
whilst also having high biodiversity. Global warming may change all
of this.