Ecosystem responses to elevated CO2 governed by plant-soil interactions and the cost of nitrogen acquisition.
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
Contents Summary I. II. III. IV. References SUMMARY: Land ecosystems sequester on average about a quarter of anthropogenic CO2 emissions. It has been proposed that nitrogen (N) availability will exert an increasingly limiting effect on plants' ability to store additional carbon (C) under rising CO2 , but these mechanisms are not well understood. Here, we review findings from elevated CO2 experiments using a plant economics framework, highlighting how ecosystem responses to elevated CO2 may depend on the costs and benefits of plant interactions with mycorrhizal fungi and symbiotic N-fixing microbes. We found that N-acquisition efficiency is positively correlated with leaf-level photosynthetic capacity and plant growth, and negatively with soil C storage. Plants that associate with ectomycorrhizal fungi and N-fixers may acquire N at a lower cost than plants associated with arbuscular mycorrhizal fungi. However, the additional growth in ectomycorrhizal plants is partly offset by decreases in soil C pools via priming. Collectively, our results indicate that predictive models aimed at quantifying C cycle feedbacks to global change may be improved by treating N as a resource that can be acquired by plants in exchange for energy, with different costs depending on plant interactions with microbial symbionts.
Date Issued
2017-11-06
Date Acceptance
2017-09-05
Citation
New Phytologist, 2017, 217 (2), pp.507-522
ISSN
0028-646X
Publisher
Wiley
Start Page
507
End Page
522
Journal / Book Title
New Phytologist
Volume
217
Issue
2
Copyright Statement
© 2017 The Authors. New Phytologist © 2017 New Phytologist Trust. This is the accepted version of the following article, which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1111/nph.14872/abstract
Sponsor
AXA Research Fund
Grant Number
AXA Chair Programme in Biosphere and Climate Impacts
Subjects
CO 2
Free-Air CO2 enrichment (FACE)
N2-fixation
mycorrhizas
nitrogen
photosynthesis
soil carbon
soil organic matter (SOM)
Publication Status
Published