Plant biodiversity effects in reducing fluvial erosion are limited to low species richness

Daniel C. Allen, Bradley J. Cardinale, Theresa Wynn-Thompson

Research output: Contribution to journalArticle

9 Scopus citations

Abstract

It has been proposed that plant biodiversity may increase the erosion resistance of soils, yet direct evidence for any such relationship is lacking. We conducted a mesocosm experiment with eight species of riparian herbaceous plants, and found evidence that plant biodiversity significantly reduced fluvial erosion rates, with the eight- species polyculture decreasing erosion by 23% relative to monocultures. Species richness effects were largest at low levels of species richness, with little increase between four and eight species. Our results suggest that plant biodiversity reduced erosion rates indirectly through positive effects on root length and number of root tips, and that interactions between legumes and non- legumes were particularly important in producing biodiversity effects. Presumably, legumes increased root production of non- legumes by increasing soil nitrogen availability due to their ability to fix atmospheric nitrogen. Our data suggest that a restoration project using species from different functional groups might provide the best insurance to maintain long- term erosion resistance.

Original languageEnglish (US)
Pages (from-to)17-24
Number of pages8
JournalEcology
Volume97
Issue number1
DOIs
StatePublished - Jan 1 2016

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Keywords

  • Biogeomorphology
  • Ecogeomorphology
  • Ecohydrology
  • Ecosystem service
  • Fl uvial erosion
  • Riparian vegetation
  • Root structure
  • Root traits

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics

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