Introduction

The purpose of this chapter is to introduce the reader to the concept of monitoring ecological change and to some ecological monitoring programmes. Monitoring ecological change has considerable relevance at a time when humans are having an increasingly widespread and long-term impact on nature. I have drawn on personal experiences in defence of the value of ecological monitoring (to conservation and sustainable development) and also the value of long-term ecological research.

Terms and concepts

The aim here is not to undertake academic discussions about definitions. It is, however, necessary to distinguish between the various terms as used in this book. Recording, mapping, surveys and sampling are all methods of data collection that provide a basis for monitoring, that is the systematic measurement of variables and processes over time.

Census

The term census generally refers to population counts, which, in turn, can be used in monitoring programmes.

Surveillance

Surveillance is the systematic measurement of variables and processes over time, the aim being to establish a series of data in time.

Monitoring

Monitoring is also the systematic measurement of variables and processes over time but assumes that there is a specific reason for that collection of data, such as ensuring that standards are being met.

In a report of the Study of Critical Environmental Problems (SCEP, 1970) entitled Man's Impact on the Global Environment, there is a similar definition of monitoring: ‘systematic observations of parameters related to a specific problem, designed to provide information on the characteristics of the problem and their changes with time’.