Disturbance of grasslands Outline of the theme

Abstract

In this introduction to the theme ‘Disturbance of Grasslands’ we will review some of the relevant terminology, before going on to consider some of the more important concepts concerning responses to disturbance in plant communities. The terminology of ‘disturbance’ is very confused, firstly, because synonyms, such as ‘perturbation’, have gained popularity and, secondly, because causes (i.e. disturbance or perturbation) sometimes tend to be confused with effects (e.g. stress). Various authors have provided definitions, often with little agreement amongst them. We will try to clarify basic definitions concerning ‘disturbance’, pointing out where possible areas of agreement between authors of the present book. Disturbance is considered here largely in the context of grassland. In this chapter we shall consider responses of species in the community and interpret the mechanisms of response largely in terms of competition for resources. Finally, we will discuss the problem of reversibility of change, and the implication that a biological system can return to its original state.