Often the meanings of words are changed subtly for interesting reasons. The implication of the word 'community' has changed from including all the organisms in an area to only those species at a particular trophic level (and often a taxonomically restricted group), for example, 'bird-community'. If this observation is correct, its probable cause is the dramatic growth in our knowledge of the ecological patterns along trophic levels (I call these horizontal patterns) and the processes that generate...

Ecologists, although they acknowledge the problems involved, generally conduct their research on too few species, in too small an area, over too short a period of time. In The Balance of Nature?, a work sure to stir controversy, the distinguished theoretical ecologist Stuart L. Pimm argues that ecology therefore fails in many ways to address the enormous ecological problems now facing our planet.

Ecologists describing phenomena on larger scales often use terms like "stability," "balance...