TY - JOUR
T1 - Root Biomass Dynamics Under Experimental Warming and Doubled Precipitation in a Tallgrass Prairie
AU - Zhou, Xuhui
AU - Fei, Shenfeng
AU - Sherry, Rebecca
AU - Luo, Yiqi
N1 - Funding Information:
The authors thank the two anonymous reviewers for their insightful comments. We would also thank Nancy Zerbach, Jesse Bell, Mike Cyrwus, Dafeng Hui, Delora Mowry, Afzal Subedar, Melissa Talley, Asfaw Tedla, Shiqiang Wan, and Tao Xu for field assistance. Watersheds and other field structures were built with much help from Cody Sheik. Afzal Subedar processed some of the soil cores. We thank Shuli Niu and Yuanhe Yang for their suggestions on the manuscript. We also thank the financial support for this project provided by NSF IRCEB grant # DEB 0078325 and DEB 0444518.
PY - 2012/6
Y1 - 2012/6
N2 - Human-induced climate change is expected to increase both the frequency and severity of extreme climate events, but their ecological impacts on root dynamics are poorly understood. We conducted a 1-year pulse warming and precipitation experiment in a tallgrass prairie in Oklahoma, USA to examine responses of root dynamics. We collected data in the pre-treatment year of 2002, imposed four treatments (control, 4°C warming, doubled precipitation, and warming plus doubled precipitation) in 2003, and observed post-treatment effects in 2004. Root biomass dynamics (for example, root growth and death) were measured using sequential coring and ingrowth coring methods. Treatment effects were not significant on standing root biomass in 2003, although root growth rate was significantly higher in the warmed than control plots. However, in the post-treatment year, the warmed plots had significantly lower standing root biomass than the controls, likely resulting from increased root death rate. Root death rate was significantly lower in the doubled precipitation and warmed plus doubled precipitation plots than that in the warmed plots in 2004. The root:shoot ratio showed similar responses to the post-treatments as standing root biomass, whereas aboveground biomass changed relatively little, indicating that roots were more sensitive to lagged effects than aboveground biomass. Our results demonstrate that root growth and death rates are highly sensitive to extreme climate events and lagged effects of extreme climate on root dynamics are important in assessing terrestrial carbon-cycle feedbacks to climate change.
AB - Human-induced climate change is expected to increase both the frequency and severity of extreme climate events, but their ecological impacts on root dynamics are poorly understood. We conducted a 1-year pulse warming and precipitation experiment in a tallgrass prairie in Oklahoma, USA to examine responses of root dynamics. We collected data in the pre-treatment year of 2002, imposed four treatments (control, 4°C warming, doubled precipitation, and warming plus doubled precipitation) in 2003, and observed post-treatment effects in 2004. Root biomass dynamics (for example, root growth and death) were measured using sequential coring and ingrowth coring methods. Treatment effects were not significant on standing root biomass in 2003, although root growth rate was significantly higher in the warmed than control plots. However, in the post-treatment year, the warmed plots had significantly lower standing root biomass than the controls, likely resulting from increased root death rate. Root death rate was significantly lower in the doubled precipitation and warmed plus doubled precipitation plots than that in the warmed plots in 2004. The root:shoot ratio showed similar responses to the post-treatments as standing root biomass, whereas aboveground biomass changed relatively little, indicating that roots were more sensitive to lagged effects than aboveground biomass. Our results demonstrate that root growth and death rates are highly sensitive to extreme climate events and lagged effects of extreme climate on root dynamics are important in assessing terrestrial carbon-cycle feedbacks to climate change.
KW - drought
KW - extreme climate
KW - global change
KW - grassland
KW - growth
KW - heat
KW - mortality
KW - root biomass
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U2 - 10.1007/s10021-012-9525-3
DO - 10.1007/s10021-012-9525-3
M3 - Article
AN - SCOPUS:84862803867
SN - 1432-9840
VL - 15
SP - 542
EP - 554
JO - Ecosystems
JF - Ecosystems
IS - 4
ER -