Transcript

NARRATOR

One of the charms of the [? team ?] catchment is that it encompasses a wide-range of natural and semi-natural habitats, tumbling rivers wind their way through wooded valleys. And as the land rises, small lush pastures criss-crossed by wildflower festooned hedge banks give way to bracken-clad upper slopes, while the hilltops may be covered with purple heather moorland or heaths bright with golden gorse.

It's clear to even the most casual observer that animal and plant species are not distributed evenly in space. Some species are widely scattered, while others are only rarely encountered. Furthermore, individuals of a species tend to form clusters that are more or less isolated from one another. So the question arises, what factors determine the spatial distribution and abundance of species?