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  • Herbarium specimens reveal that mycorrhizal type does not mediate declining temperate tree nitrogen status over a century of environmental change
Title: Herbarium specimens reveal that mycorrhizal type does not mediate declining temperate tree nitrogen status over a century of environmental change
Summary Rising atmospheric carbon dioxide concentrations (CO2) and atmospheric nitrogen (N) deposition have contrasting effects on ectomycorrhizal (EM) and arbuscular mycorrhizal (AM) symbioses, potentially mediating forest responses to environmental change.In this study, we evaluated the cumulative effects of historical environmental change on N concentrations and δ15N values in AM plants, EM plants, EM fungi, and saprotrophic fungi using herbarium specimens collected in Minnesota, USA from 1871 to 2016. To better understand mycorrhizal mediation of foliar δ15N, we also analyzed a subset of previously published foliar δ15N values from across the United States to parse the effects of N deposition and CO2rise.Over the last century in Minnesota, N concentrations declined among all groups except saprotrophic fungi. δ15N also declined among all groups of plants and fungi; however, foliar δ15N declined less in EM plants than in AM plants. In the analysis of previously published foliar δ15N values, this slope difference between EM and AM plants was better explained by nitrogen deposition than by CO2rise.Mycorrhizal type did not explain trajectories of plant N concentrations. Instead, plants and EM fungi exhibited similar declines in N concentrations, consistent with declining forest N status despite moderate levels of N deposition.  more » « less
Award ID(s):
2019518
PAR ID:
10541221
Author(s) / Creator(s):
; ; ; ;
Publisher / Repository:
New Phytologist
Date Published:
Journal Name:
New Phytologist
Volume:
242
Issue:
4
ISSN:
0028-646X
Page Range / eLocation ID:
1717 to 1724
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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