title: Effects of three global change drivers on terrestrial C:N:P stoichiometry: a global synthesis.
abstract: Over the last few decades, there has been an increasing number of controlled-manipulative experiments to investigate how plants and soils might respond to global change. These experiments typically examined the effects of each of three global change drivers [i.e., nitrogen (N) deposition, warming, and elevated CO2] on primary productivity and on the biogeochemistry of carbon (C), N, and phosphorus (P) across different terrestrial ecosystems. Here, we capitalize on this large amount of information by performing a comprehensive meta-analysis (>2000 case studies worldwide) to address how C:N:P stoichiometry of plants, soils, and soil microbial biomass might respond to individual vs. combined effects of the three global change drivers. Our results show that (i) individual effects of N addition and elevated CO2on C:N:P stoichiometry are stronger than warming, (ii) combined effects of pairs of global change drivers (e.g., N addition + elevated CO2, warming + elevated CO2) on C:N:P stoichiometry were generally weaker than the individual effects of each of these drivers, (iii) additive interactions (i.e., when combined effects are equal to or not significantly different from the sum of individual effects) were more common than synergistic or antagonistic interactions, (iv) C:N:P stoichiometry of soil and soil microbial biomass shows high homeostasis under global change manipulations, and (v) C:N:P responses to global change are strongly affected by ecosystem type, local climate, and experimental conditions. Our study is one of the first to compare individual vs. combined effects of the three global change drivers on terrestrial C:N:P ratios using a large set of data. To further improve our understanding of how ecosystems might respond to future global change, long-term ecosystem-scale studies testing multifactor effects on plants and soils are urgently required across different world regions.
authors.affiliation: Long-term Research Station of Alpine Forest Ecosystems, Provincial Key Laboratory of Ecological Forestry Engineering, Institute of Ecology and Forestry, Sichuan Agricultural University, Chengdu, 611130, China.|Department of Biological Science, Institute of Environment Sciences, University of Quebec at Montreal, Montreal, QC, H3C 3P8, Canada.
authors.forename: Kai
authors.initials: K
authors.lastname: Yue
authors.affiliation: Agri-Food & Biosciences Institute (AFBI), Newforge Lane, Belfast, BT9 5PX, UK.
authors.forename: Dario A
authors.initials: DA
authors.lastname: Fornara
authors.affiliation: Long-term Research Station of Alpine Forest Ecosystems, Provincial Key Laboratory of Ecological Forestry Engineering, Institute of Ecology and Forestry, Sichuan Agricultural University, Chengdu, 611130, China.
authors.forename: Wanqin
authors.initials: W
authors.lastname: Yang
authors.affiliation: Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, DK-1958, Frederiksberg C, Denmark.
authors.forename: Yan
authors.initials: Y
authors.lastname: Peng
authors.affiliation: Long-term Research Station of Alpine Forest Ecosystems, Provincial Key Laboratory of Ecological Forestry Engineering, Institute of Ecology and Forestry, Sichuan Agricultural University, Chengdu, 611130, China.
authors.forename: Zhijie
authors.initials: Z
authors.lastname: Li
authors.affiliation: Long-term Research Station of Alpine Forest Ecosystems, Provincial Key Laboratory of Ecological Forestry Engineering, Institute of Ecology and Forestry, Sichuan Agricultural University, Chengdu, 611130, China.
authors.forename: Fuzhong
authors.initials: F
authors.lastname: Wu
authors.affiliation: Department of Biological Science, Institute of Environment Sciences, University of Quebec at Montreal, Montreal, QC, H3C 3P8, Canada.|Laboratory for Ecological Forecasting and Global Change, College of Forestry, Northwest A & F University, Yangling, Shaanxi, 712100, China.
authors.forename: Changhui
authors.initials: C
authors.lastname: Peng
mesh_terms: D002245:Carbon Dioxide; D057231:Climate Change; D017753:Ecosystem; D009584:Nitrogen; D012987:Soil / Q000737:chemistry*
chemical_list: D012987:Soil; D002245:Carbon Dioxide; D009584:Nitrogen
keywords: ecological stoichiometry; ecosystem functioning; elevated CO2; nitrogen deposition; stoichiometric homeostasis; warming