Decadal biomass increment in early secondary succession woody ecosystems is increased by CO2 enrichment

• DOI: 10.1038/s41467-019-08348-1
• Publication Date: 2019-02-14T11:03:38Z
• Authors: Anthony P. Walker; Martin G. De Kauwe; Belinda E. Medlyn; Sönke Zaehle; Colleen M. Iversen; Shinichi Asao; Bertrand Guenet; Anna Harper; Thomas Hickler; Bruce A. Hungate; Atul K. Jain; Yiqi Luo; Xingjie Lu; Meng Lu; Kristina Luus; J. Patrick Megonigal; Ram Oren; Edmund Ryan; Shijie Shu; Alan Talhelm; Ying-Ping Wang; Jeffrey M. Warren; Christian Werner; Jianyang Xia; Bai Yang; Donald R. Zak; Richard J. Norby
• Keywords: [SDE] Environmental Sciences; 0301 basic medicine; 570; TREE MORTALITY; 550; Science; Climate; Biophysics; Plant Biology; Biochemistry; 333; SWEETGUM PLANTATION; Article; Trees; 03 medical and health sciences; atmospheric carbon dioxide; XXXXXX - Unknown; ddc:550; Biomass; Photosynthesis; forest ecology; plant biomass; Biochemistry, Biophysics, and Structural Biology; Ecosystem; photosynthesis; Ecology; Q; FOREST PRODUCTIVITY; Forestry; Biological Sciences; Carbon Dioxide; 15. Life on land; woody; decadal biomass; Wood; [SDE.BE] Environmental Sciences/Biodiversity and Ecology; NITROGEN; CLIMATE; 13. Climate action; [SDE]Environmental Sciences; and Structural Biology; GROWTH; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; ELEVATED CO2; SOIL CARBON; ecosystems; CARBON ALLOCATION; RESPONSES

AbstractIncreasing atmospheric CO2 stimulates photosynthesis which can increase net primary production (NPP), but at longer timescales may not necessarily increase plant biomass. Here we analyse the four decade-long CO2-enrichment experiments in woody ecosystems that measured total NPP and biomass. CO2 enrichment increased biomass increment by 1.05 ± 0.26 kg C m−2 over a full decade, a 29.1 ± 11.7% stimulation of biomass gain in these early-secondary-succession temperate ecosystems. This response is predictable by combining the CO2 response of NPP (0.16 ± 0.03 kg C m−2 y−1) and the CO2-independent, linear slope between biomass increment and cumulative NPP (0.55 ± 0.17). An ensemble of terrestrial ecosystem models fail to predict both terms correctly. Allocation to wood was a driver of across-site, and across-model, response variability and together with CO2-independence of biomass retention highlights the value of understanding drivers of wood allocation under ambient conditions to correctly interpret and predict CO2 responses.