Some slides on warming, precipitation, and biomass harvesting experiments in Oklahoma Yiqi Luo Department of Microbiology and Plant Biology University of Oklahoma, USA

C3 dominant C4 dominant 14-year warming and clipping experiment 4-year warming, precipitation and clipping experiment

Long-term: 14 years Warming: 2 o C Clipping: Yearly

warming x Precipitation x Bioenergy

Plant community C 4 /C 3 species Leaf Ps Phenology Growing season Plant growth Microbial community Fungi/bacteria Plant N uptake Plant & soil C Available N Quality of bulk litter Respiration NUE Litter Decomposition Luo, Ann. Rev. Ecol. Evol. System

Plant community C 4 /C 3 species Leaf Ps Phenology Growing season Plant growth Microbial community Fungi/bacteria Plant N uptake Plant & soil C Available N Quality of bulk litter Respiration NUE Litter Decomposition Sherry et al. 2007, PNAS Zhou et al. 2007a, JIPB Zhou et al. 2006, GBC; 2007b, GCB Luo et al. 2001, Nature Zhang et al GCB Zhou et al NCC An et al. 2005, GCB Cheng et al Agric Ecosystems Wan et al. 2005, GBC Luo et al. 2009, GCB-E Sherry et al. 2008, GCB Niu et al. 2010, Ecology Sherry et al. 2010, 2011, 2012

Warming effects on C & N storages Plant C increased, but plant and soil N didn’t change Niu et al Ecology

Niu et al Contributions of N and NUE

Mechanism: species composition changes

W: +12~25% W: -26~53% W: +4~9% W: +32% W: -18~19% W: -8~18% Contrast warming effects between C3 and C4 vegetation C4 grasslandC3 grassland Niu et al. 2013

C3 & C4 composition determines warming effects! Niu et al. 2013

Mechanism: different optimum temperature Niu et al. 2013

Luo et al Nature Acclimation of soil respiration to warming

Sherry et al PNAS