The thesis charts the development of vegetation science from its
beginnings. In the first chapter, particular attention is given to
the work of Alexander von Humboldt and to the genesis of the idea
that vegetation exists in natural units. A tradition of Humboldtian
plant geography is traced to the end of the nineteenth century and
the birth of self-conscious plant ecology. The second chapter
follows the development of different notions of the plant association,
and different forms of scientific practice,by F.E. Clements in
Nebraska and J. Braun-Blanquet in Montpelier. Chapter Three describes
the career of Henry Allan Gleason and follows the development of
his individualistic concept of the plant association. Chapter Four
examines the work of J.T. Curtis and R.H. Whittaker which revived
the individualistic hypothesis and established it as dominant in
the English-speaking world. The changing character of the
scientific practice of plant ecology is correlated with interests,
both internal and external to the discipline. A short coda indicates
that debate over the nature of vegetation continues.
The thesis is narrative history, written throughout from a
social and relativistic perspective
