Flowering phenology in a species-rich temperate grassland is sensitive to warming but not elevated CO2.
* Flowering is a critical stage in plant life cycles, and changes might alter processes at the species, community and ecosystem levels. Therefore, likely flowering-time responses to global change drivers are needed for predictions of global change impacts on natural and managed ecosystems. * Here, the impact of elevated atmospheric CO2 concentration ([CO2]) (550 micromol mol(-1)) and warming (+2 masculineC) is reported on flowering times in a native, species-rich, temperate grassland in Tasmania, Australia in both 2004 and 2005. * Elevated [CO2] did not affect average time of first flowering in either year, only affecting three out of 23 species. Warming reduced time to first flowering by an average of 19.1 d in 2004, acting on most species, but did not significantly alter flowering time in 2005, which might be related to the timing of rainfall. Elevated [CO2] and warming treatments did not interact on flowering time. * These results show elevated [CO2] did not alter average flowering time or duration in this grassland; neither did it alter the response to warming. Therefore, flowering phenology appears insensitive to increasing [CO2] in this ecosystem, although the response to warming varies between years but can be strong.
Hovenden
Mark J
MJ
School of Plant Science, University of Tasmania, Hobart, Tasmania, Australia.
Wills
Karen E
KE
School of Plant Science, University of Tasmania, Hobart, Tasmania, Australia.
Vander Schoor
Jacqueline K
JK
School of Plant Science, University of Tasmania, Hobart, Tasmania, Australia.
Williams
Amity L
AL
School of Plant Science, University of Tasmania, Hobart, Tasmania, Australia.
Newton
Paul C D
PCD
Land & Environmental Management, AgResearch, Palmerston North, New Zealand.
D000704:Analysis of Variance; D001315:Australia; D002245:Carbon Dioxide / Q000494:pharmacology*; D002980:Climate; D017753:Ecosystem; D035264:Flowers / Q000187:drug effects* / Q000502:physiology*; D006358:Hot Temperature; D006109:Poaceae / Q000187:drug effects* / Q000502:physiology*; D011891:Rain; D013045:Species Specificity; D013997:Time Factors
D002245:Carbon Dioxide