A century of increasing pine density and associated shifts in understory plant strategies

Daniel C. Laughlin, Margaret M Moore, Peter Z Fule

Research output: Contribution to journalArticle

18 Scopus citations

Abstract

We analyzed one of the longest-term ecological data sets to evaluate how forest overstory structure is related to herbaceous understory plant strategies in a ponderosa pine forest. Eighty-two permanent 1-m2 chart quadrats that were established as early as 1912 were remeasured in 2007. We reconstructed historical forest structure using dendrochronological techniques. Ponderosa pine basal area increased from an average of 4 m2/ha in the early 1900s to 29 m2/ha in 2007. Understory plant foliar cover declined by 21%, species richness declined by two species per square meter, and functional diversity also declined. The relative cover of C4 graminoids decreased by 18% and C3 graminoids increased by 19%. Herbaceous plant species with low leaf and fine root nitrogen concentrations, low specific leaf area, high leaf dry matter content, large seed mass, low specific root length, short maximum height, and early flowering date increased in relative abundance in sites where pine basal area increased the most. Overall, we observed a long-term shift in composition toward more conservative shade- and stress-tolerant herbaceous species. Our analysis of temporal changes in plant strategies provides a general framework for evaluating compositional and functional changes in terrestrial plant communities.

Original languageEnglish (US)
Pages (from-to)556-561
Number of pages6
JournalEcology
Volume92
Issue number3
DOIs
StatePublished - Mar 2011

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Keywords

  • Functional diversity
  • Functional traits
  • Height
  • Leaf economics spectrum
  • Nitrogen
  • Ponderosa pine
  • Seed mass
  • Shade tolerance
  • Specific leaf area
  • Specific root length
  • Stand density

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics

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