Showing papers in "Bulletin of the Torrey Botanical Club in 1966"

The Role of Chemical Inhibition (Allelopathy) in Vegetational Composition

Abstract: MULLER, CORNELIUS H. (University of California, Santa. Barbara.) The role of chemical inhibition (allelopathy) in vegetational composition. Bull. Torrey Bot. Club 93: 332-351. 1966.-Salvia leutcophylla, Artemisia californica, and other aromatic shrubs of Southern California contain phytotoxic terpenes which volatilize aild inhibit the establishment of seedlings of a wide variety of plants at some distance from the shrubs. Similarly, Adenosterna fascicatlata and associated shrubs of the Californiia Chaparral produce water-soluble toxins which restrict herbs from the shrub stainds. These phenomena strongly indicate that allelopathy is an important inifluence in the operation of ecological processes and that this factor must be included in any acceptable model of community dynamics. The deterioration of old Salvia stands, apparently by auto-initoxication, suggests that allelopathy could be a significant factor in plant succession in many kinds of vegetation. It is hypothesized that most phytotoxins originate in planits as metabolic by-products whose role is primarily excretory and only secondarily inhibition of neighboring competitors.