Dispersal and Invaders

Abstract

The Whole Terrestrial and freshwater ecosystem that has been analysed into its component parts in the previous chapters has two outstanding characteristics: its complexity and its comparative stability. Most ecological work has to be concerned with relatively small parts of a population or a community, and this is a sound procedure, up to a point, for obtaining the solid material for building up knowledge of the whole. I have approached the matter from the opposite point of view: looking at the whole ecosystem as a piece of ecological machinery, breaking it down into component parts according to a set of consistent ideas, and then using what information exists to fit these components again into an integrated whole. By treating the problem this way, one is forced to consider the scale on which species mixtures are organized, and the relationships between the different component communities. But doing this is a formidable job that could still only be attempted for a place like Wytham Woods which has a wealth of information — not just information about animals, but information organized in the right way and collected at the two levels of population and community. I remember two friends of my youth who decided to take the family piano to pieces while their parents were out of the house one evening, and were very disconcerted to find that they could not put it together again, so that it just lay about in twanging tangled heaps.