B51E-0481
Down-regulation of tissue N:P ratios in terrestrial plants by elevated CO2
Friday, 18 December 2015
Poster Hall (Moscone South)
Qi Deng, Tennessee State University, Nashville, TN, United States, Dafeng Hui, Tennessee State University, Department of Biological Sciences, Nashville, TN, United States, Yiqi Luo, University of Oklahoma, Department of Microbiology and Plant Science, Norman, OK, United States, James J Elser, Arizona State University, School of Life Sciences, Tempe, AZ, United States, Yingping Wang, CSIRO, Ocean and Atmosphere Flagship, Aspendale, Australia, Irakli Loladze, Bryan College of Health Sciences, Lincoln, NV, United States, Quanfa Zhang, Wuhan Botanical Garden, Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan, China and Sam Dennis, Tennessee State University, Department of Agricultural and Environmental Sciences, Nashville, TN, United States
Abstract:
Increasing atmospheric CO2 concentrations generally alter element stoichiometry in plants. However, a comprehensive evaluation of the elevated CO2 impact on plant nitrogen:phosphorus (N:P) ratios and the underlying mechanism has not been conducted. We synthesized the results from 112 previously published studies using meta-analysis to evaluate the effects of elevated CO2 on the N:P ratio of terrestrial plants and to explore the underlying mechanism based on plant growth and soil P dynamics. Our results show that terrestrial plants grown under elevated CO2 had lower N:P ratios in both above- and below-ground biomass across different ecosystem types. The response ratio for plant N:P was negatively correlated with the response ratio for plant growth in croplands and grasslands, and showed a stronger relationship for P than for N. In addition, the CO2-induced down-regulation of plant N:P was accompanied by 19.3% and 4.2% increases in soil phosphatase activity and labile P, respectively, and a 10.1% decrease in total soil P. Our results show that down-regulation of plant N:P under elevated CO2 corresponds with accelerated soil P cycling. These findings should be useful for better understanding of terrestrial plant stoichiometry in response to elevated CO2 and of the underlying mechanisms affecting nutrient dynamics under climate change.
