title: How light competition between plants affects their response to climate change.
abstract: How plants respond to climate change is of major concern, as plants will strongly impact future ecosystem functioning, food production and climate. Here, we investigated how vegetation structure and functioning may be influenced by predicted increases in annual temperatures and atmospheric CO2 concentration, and modeled the extent to which local plant-plant interactions may modify these effects. A canopy model was developed, which calculates photosynthesis as a function of light, nitrogen, temperature, CO2 and water availability, and considers different degrees of light competition between neighboring plants through canopy mixing; soybean (Glycine max) was used as a reference system. The model predicts increased net photosynthesis and reduced stomatal conductance and transpiration under atmospheric CO2 increase. When CO2 elevation is combined with warming, photosynthesis is increased more, but transpiration is reduced less. Intriguingly, when competition is considered, the optimal response shifts to producing larger leaf areas, but with lower stomatal conductance and associated vegetation transpiration than when competition is not considered. Furthermore, only when competition is considered are the predicted effects of elevated CO2 on leaf area index (LAI) well within the range of observed effects obtained by Free air CO2 enrichment (FACE) experiments. Together, our results illustrate how competition between plants may modify vegetation responses to climate change.
authors.affiliation: Ecology and Biodiversity Group, Utrecht University, Postbox 80084, 3508 TB, Utrecht, the Netherlands.|Centre for Crop Systems Analysis, Wageningen University, Postbox 430, 6700 AK, Wageningen, the Netherlands.
authors.forename: Marloes P
authors.initials: MP
authors.lastname: van Loon
authors.affiliation: Ecology and Biodiversity Group, Utrecht University, Postbox 80084, 3508 TB, Utrecht, the Netherlands.
authors.forename: Feike
authors.initials: F
authors.lastname: Schieving
authors.affiliation: Department of Environmental Sciences, Copernicus Institute for Sustainable Development, Utrecht University, Postbox 80115, 3508 TC, Utrecht, the Netherlands.
authors.forename: Max
authors.initials: M
authors.lastname: Rietkerk
authors.affiliation: Department of Environmental Sciences, Copernicus Institute for Sustainable Development, Utrecht University, Postbox 80115, 3508 TC, Utrecht, the Netherlands.
authors.forename: Stefan C
authors.initials: SC
authors.lastname: Dekker
authors.affiliation: Forest Ecology and Forest Management Group, Wageningen University, Postbox 47, 6700 AA, Wageningen, the Netherlands.
authors.forename: Frank
authors.initials: F
authors.lastname: Sterck
authors.affiliation: Centre for Crop Systems Analysis, Wageningen University, Postbox 430, 6700 AK, Wageningen, the Netherlands.
authors.forename: Niels P R
authors.initials: NPR
authors.lastname: Anten
mesh_terms: D057231:Climate Change; D008027:Light; D008954:Models, Biological; D010788:Photosynthesis / Q000528:radiation effects; D054046:Plant Stomata / Q000502:physiology / Q000528:radiation effects; D015203:Reproducibility of Results; D013025:Glycine max / Q000502:physiology* / Q000528:radiation effects*
keywords: FACE data; canopy; gas exchange; leaf area index (LAI); modeling; optimality principle; photosynthesis; soybean (Glycine max)