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Plant Ecology

, Volume 164, Issue 1, pp 29–36 | Cite as

Canopy gaps are sites of reduced belowground plant competition in a productive old field

  • James F. CahillEmail author
  • Brenda B. Casper
Article

Abstract

Whether small gaps in the aboveground vegetation of productive oldfields correspond to gaps in belowground plant biomass, and whether such“root gaps” result in a reduction of competition for soil resourcesis not known. Our study in an abandoned hayfield shows that root biomass withinsmall gaps (< 0.50 m diam) is 20% of that found withinintact vegetation, similar to the findings for shoot biomass. Associated withthe decrease in root biomass was a 25% reduction in the intensity ofbelowground competition within gaps compared to the surrounding matrixvegetation. These differences could not be attributed to variation in soilproperties, as gap and matrix soils did not differ in any of the physical orchemical properties measured. These results indicate that the increased plantgrowth commonly observed within gaps may be partly due to reduced belowgroundcompetition, independent of any advantage gained from increased lightavailability. By providing areas of low belowground competitive intensity, gapsin this field could allow poor belowground competitors to exist with in oldfields,thusincreasing community diversity.

Abutilon theophrasti Favorable microsite Root competition Root gaps Succession 

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Copyright information

© Kluwer Academic Publishers 2003

Authors and Affiliations

  1. 1.Department of BiologyUniversity of PennsylvaniaUSA

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