Hovenden et al 2019 Nature Plants_as accepted.pdf (905.5 kB)
Globally consistent influences of seasonal precipitation limit grassland biomass response to elevated CO2
journal contribution
posted on 2023-05-19, 23:51 authored by Mark HovendenMark Hovenden, Leuzinger, S, Newton, PCD, Fletcher, A, Fatichi, S, Luscher, A, Reich, PB, Andresen, LC, Beier, C, Blumenthal, DM, Chiariello, NR, Dukes, JS, Kellner, J, Hofmockel, K, Niklaus, PA, Song, J, Wan, J, Classen, AT, Langley, ARising atmospheric carbon dioxide concentration ([CO2]) should stimulate biomass production directly via biochemical stimulation of carbon assimilation and indirectly via water savings caused by increased plant water use efficiency. Because of these water savings, the CO2 fertilisation effect should be stronger in drier sites, yet large differences among experiments in grassland biomass response to elevated CO2 appear unrelated to annual precipitation, preventing useful generalisations. Here we show that, as predicted, the impact of elevated CO2 on biomass production in 19 globally-distributed temperate grassland experiments reduces as mean precipitation in seasons other than spring increases but, unexpectedly, rises as mean spring precipitation increases. Moreover, because sites with high spring precipitation also tend to have high precipitation at other times, these effects of spring and non-spring precipitation on the CO2 response offset each other, constraining the response of ecosystem productivity to rising CO2. This explains why previous analyses were unable to discern a reliable trend between site dryness and the CO2 fertilisation effect. Thus, the CO2 fertilisation effect in temperate grasslands worldwide will be constrained by their natural rainfall seasonality such that the stimulation of biomass by rising CO2 could be substantially less than anticipated.
Funding
Australian Research Council
History
Publication title
Nature PlantsVolume
5Pagination
167-173ISSN
2055-026XDepartment/School
School of Natural SciencesPublisher
Nature Publishing GroupPlace of publication
United KingdomRights statement
Copyright 2019 The Authors, under exclusive licence to Springer Nature Limited. The post-print version of the article is subject to Springer Nature's terms of reuse available at https://www.nature.com/authors/policies/license.html#termsRepository Status
- Restricted