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The influence of elevated CO 2 on species phenology, growth and reproduction in a Mediterranean old‐field community
Author(s) -
NAVAS MARIELAURE,
SONIE LAURETTE,
RICHARTE JEAN,
ROY JACQUES
Publication year - 1997
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 - 10.1046/j.1365-2486.1997.00092.x
Subject(s) - phenology , biomass (ecology) , biology , reproduction , interspecific competition , mediterranean climate , growing season , old field , vegetative reproduction , botany , sexual reproduction , agronomy , ecology
We studied the effects on the phenology, growth and reproduction of 19 Mediterranean species, of elevating the atmospheric CO 2 concentration ([CO 2 ]) to twice‐ambient. Intact monoliths were taken from an old‐field and put, during a six month growing season, into growth chambers in which external climatic conditions were mimicked and [CO 2 ] was regulated. Fruit set time was significantly changed in six species under elevated [CO 2 ] and leaf and branch senescence accelerated in most species. Grasses had fewer leaves and legumes were more branched at peak production under elevated [CO 2 ] than under ambient. Plant seed number was not significantly changed under elevated [CO 2 ], whereas the reproductive effort of grasses was significantly depressed. Reproductive and vegetative characteristics showed related responses to [CO 2 ], as species with enhanced biomass had a hastened fruit set time, a higher number of fruits per plant and a higher reproductive biomass under elevated [CO 2 ] than under ambient conditions, while species with depressed biomass had a delayed fruit set time, a lower number of fruits per plant and a lower reproductive biomass. Our results also show a high interspecific variability in [CO 2 ] response, but some trends emerged at the family level: the production of vegetative and reproductive modules were depressed in grasses and slightly stimulated in legumes.