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Response to CO 2 enrichment of understory vegetation in the shade of forests
Author(s) -
Kim Dohyoung,
Oren Ram,
Qian Song S.
Publication year - 2016
Publication title -
global change biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.146
H-Index - 255
eISSN - 1365-2486
pISSN - 1354-1013
DOI - 10.1111/gcb.13126
Subject(s) - understory , vegetation (pathology) , biomass (ecology) , environmental science , ecosystem , plant community , leaf area index , agronomy , forestry , ecology , canopy , biology , geography , ecological succession , medicine , pathology
Responses of forest ecosystems to increased atmospheric CO 2 concentration have been studied in few free‐air CO 2 enrichment ( FACE ) experiments during last two decades. Most studies focused principally on the overstory trees with little attention given to understory vegetation. Despite its small contribution to total productivity of an ecosystem, understory vegetation plays an important role in predicting successional dynamics and future plant community composition. Thus, the response of understory vegetation in Pinus taeda plantation at the Duke Forest FACE site after 15–17 years of exposure to elevated CO 2 , 6–13 of which with nitrogen (N) amendment, was examined. Aboveground biomass and density of the understory decreased across all treatments with increasing overstory leaf area index ( LAI ). However, the CO 2 and N treatments had no effect on aboveground biomass, tree density, community composition, and the fraction of shade‐tolerant species. The increases of overstory LAI (~28%) under elevated CO 2 resulted in a reduction of light available to the understory (~18%) sufficient to nullify the expected growth‐enhancing effect of elevated CO 2 on understory vegetation.