Holzner


Die Bodenkultur - Journal for Land Management, Food and Environment

W. Holzner:

Weed-Types

A Classification of Ruderals and Segetals Using Complex Biological-Ecological Criteria

Part two: The Dominant Perennials

Summary

The polycarpic perennials with a tendency to form pure stands were classified according to the principles used in part of this paper (Holzner 1991). Four types have been determined:

O. Strong vegetative reproduction by underground tillers with high regenerative capacity means special adaption to frequent soil disturbance, an environmental factor difficult to bear by perennials. The focus of reproduction is on the vegetative side. Generative reproduction plays a subordinal part.

P. High seed production and efficient dispersal over long distances brings only sporadically available stands within the reach of the species. They are afterwards occupied by the means of a subterranean tiller-phalanx.

Q. Intermediate type between O and R.

R. High seed production, dispersal by animals (and man), a seed bank, protective devices against browsing, and high nutrient requirements point to a niche of sites where the vegetation is regularly disturbed by animals.