COMPETITIVE RELATIONSHIPS AMONG HERBACEOUS GRASSLAND PLANTS

The present state of the art of grassland competition is one of imminence rather than eminence. We know many fragments and bits of information, but heretofore have been unable to unite all of what we do know into an integrated system. It is possible to describe mathematically one and two species competitive systems both in terms of numbers and amount of plant material produced. Likewise, it is possible to predict the conditions under which a third species may invade and certain facts about the reproductive capacity required for particular environmental conditions. At present most of these models are derived from theoretical or experimental populations, and in some cases expansion will be necessary for application to field conditions. The goundwork is available. This survey of previous investigations provides an indication of those important aspects of plant growth which are most likely to assist in the elucidation of competitive relationships. If for any given species the seed size and number, time of germination, rate of vegetative reproduction, rate of growth, maximum number and size of individuals attained under optimum conditions, soil level at which roots operate, time of and conditions for initiation of root and shoot growth, and any allelopathic considerations are known, a reasonably good prediction can be made concerning the success of that species relative to any other for which the same information is known. © 1969 The New York Botanical Garden.