Title: Elevated carbon dioxide is predicted to promote coexistence among competing species in a trait-based model

Abstract

Differential species responses to atmospheric CO₂ concentration (C_a) could lead to quantitative changes in competition among species and community composition, with flow-on effects for ecosystem function. However, there has been little theoretical analysis of how elevated C_a (eC_a) will affect plant competition, or how composition of plant communities might change. Such theoretical analysis is needed for developing testable hypotheses to frame experimental research. Here, we investigated theoretically how plant competition might change under eC_a by implementing two alternative competition theories, resource use theory and resource capture theory, in a plant carbon and nitrogen cycling model. The model makes several novel predictions for the impact of eC_a on plant community composition. Using resource use theory, the model predicts that eC_a is unlikely to change species dominance in competition, but is likely to increase coexistence among species. Using resource capture theory, the model predicts that eC_a may increase community evenness. Collectively, both theories suggest that eC_a will favor coexistence and hence that species diversity should increase with eC_a. Our theoretical analysis leads to a novel hypothesis for the impact of eC_a on plant community composition. In this study, the hypothesis has potential to help guide the design and interpretation of eC_a experiments.

Authors:

Ali, Ashehad A. ^[1]; Medlyn, Belinda E. ^[2]; Aubier, Thomas G. ^[3]; Crous, Kristine Y. ^[4]; Reich, Peter B. ^[5]

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+ Show Author Affiliations

1. Division of Earth and Environmental Sciences, Los Alamos National Laboratory, Los Alamos New Mexico USA, Department of Civil and Environmental Engineering, University of California, Irvine California USA, Department of Biological Sciences, Faculty of Science, Macquarie University, North Ryde NSW 2109 Australia
2. Department of Biological Sciences, Faculty of Science, Macquarie University, North Ryde NSW 2109 Australia, Hawkesbury Institute for the Environment, University of Western Sydney, Locked Bag 1797 Penrith NSW 2751 Australia
3. Department of Biological Sciences, Faculty of Science, Macquarie University, North Ryde NSW 2109 Australia, UMR 5175, Centre d'Ecologie Fonctionnelle et Evolutive, 1919 route de Mende 34090 Montepellier France, UMR 7205, Muséum National d'Histoire Naturelle, CP50 45 rue Buffon 75005 Paris France
4. Hawkesbury Institute for the Environment, University of Western Sydney, Locked Bag 1797 Penrith NSW 2751 Australia
5. Hawkesbury Institute for the Environment, University of Western Sydney, Locked Bag 1797 Penrith NSW 2751 Australia, Department of Forest Resources, University of Minnesota, St. Paul Minnesota USA

Publication Date:

2015-10-06

Research Org.:

Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

1223042

Alternate Identifier(s):

OSTI ID: 1222601; OSTI ID: 1223043

Grant/Contract Number:  

DOE/DE-FG02-96ER62291; FC02-06ER64158; DP1094791; FG02-96ER62291; 0322057; 9411972; 0080382; 0620652; 0716587

Resource Type:

Published Article

Journal Name:

Ecology and Evolution

Additional Journal Information:

Journal Name: Ecology and Evolution Journal Volume: 5 Journal Issue: 20; Journal ID: ISSN 2045-7758

Publisher:

Wiley Blackwell (John Wiley & Sons)

Country of Publication:

United Kingdom

Language:

English

Subject:

54 ENVIRONMENTAL SCIENCES; elevated CO₂; plant competition; species diversity; species traits