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Competitive Abilities of Sparse Grass Species: Means of Persistence or Cause of Abundance
Ecology (1984)
  • Deborah Rabinowitz, University of Michigan-Ann Arbor
  • Jody K. Rapp, University of Michigan-Ann Arbor
  • Philip Dixon, Cornell University
Sparse species have chronically small local population sizes, even though they occur in
several habitats over a wide geographic range. Greenhouse de Wit replacement series with seven
species of sparse and common perennial grasses of tallgrass prairie were performed with seedlings and
tiller fragments for 5, 10, and 15 mo. As younger and older seedlings, sparse grasses overyielded and
were advantaged by the interaction with common grasses. The common grasses underyielded and
were disadvantaged in mixture with sparse grasses. As tillers, the interaction was less antagonistic,
and both common and sparse grasses either overyielded or were unaffected by the interaction. Seedlings
of sparse species were largest when planted in low proportion, surrounded by individuals of a common
grass. Because the sparse species are not disadvantaged by interactions with their common neighbors,
their competitive abilities are not implicated as a cause of their local rarity. Rather, the good competitive
abilities of these sparse grasses are best viewed as a mechanism that offsets the hazards of
low density and makes local persistence more likely.

  • Agrostis hiemalis,
  • Andropogon gerardi,
  • Andropogon scoparius,
  • competition,
  • de Wit replacement series,
  • Festuca paradoxa,
  • persistence,
  • prairie grasses,
  • rarity,
  • Setaria geniculata,
  • Sorghastrum nutans,
  • Sphenopholis obtusata
Publication Date
Publisher Statement
This is an article from Ecology 65 (1984): 1144, doi:10.2307/1938322
Posted with permission. Copyright 1984 by the Ecological Society of America
Citation Information
Deborah Rabinowitz, Jody K. Rapp and Philip Dixon. "Competitive Abilities of Sparse Grass Species: Means of Persistence or Cause of Abundance" Ecology Vol. 65 Iss. 4 (1984) p. 1144 - 1154
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