Hupperts, Stefan and Gerber, Stefan and Nilsson Hegethorn, Marie-Charlotte and Gundale, Michael
(2021).
Empirical and Earth system model estimates of boreal nitrogen fixation often differ: A pathway toward reconciliation.
Global Change Biology. 27
, 5711-5725
[Article Review/Survey]
![]() |
PDF
1MB |
Abstract
The impacts of global environmental change on productivity in northern latitudes will be contingent on nitrogen (N) availability. In circumpolar boreal ecosystems, nonvascular plants (i.e., bryophytes) and associated N-2-fixing diazotrophs provide one of the largest known N inputs but are rarely accounted for in Earth system models. Instead, most models link N-2-fixation with the functioning of vascular plants. Neglecting nonvascular N-2-fixation may be contributing toward high uncertainty that currently hinders model predictions in northern latitudes, where nonvascular N-2-fixing plants are more common. Adequately accounting for nonvascular N-2-fixation and its drivers could subsequently improve predictions of future N availability and ultimately, productivity, in northern latitudes. Here, we review empirical evidence of boreal nonvascular N-2-fixation responses to global change factors (elevated CO2, N deposition, warming, precipitation, and shading by vascular plants), and compare empirical findings with model predictions of N-2-fixation using nine Earth system models. The majority of empirical studies found positive effects of CO2, warming, precipitation, or light on nonvascular N-2-fixation, but N deposition strongly downregulated N-2-fixation in most empirical studies. Furthermore, we found that the responses of N-2-fixation to elevated CO2 were generally consistent between models and very limited empirical data. In contrast, empirical-model comparisons suggest that all models we assessed, and particularly those that scale N-2-fixation with net primary productivity or evapotranspiration, may be overestimating N-2-fixation under increasing N deposition. Overestimations could generate erroneous predictions of future N stocks in boreal ecosystems unless models adequately account for the drivers of nonvascular N-2-fixation. Based on our comparisons, we recommend that models explicitly treat nonvascular N-2-fixation and that field studies include more targeted measurements to improve model structures and parameterization.
Authors/Creators: | Hupperts, Stefan and Gerber, Stefan and Nilsson Hegethorn, Marie-Charlotte and Gundale, Michael | ||||||
---|---|---|---|---|---|---|---|
Title: | Empirical and Earth system model estimates of boreal nitrogen fixation often differ: A pathway toward reconciliation | ||||||
Series Name/Journal: | Global Change Biology | ||||||
Year of publishing : | 2021 | ||||||
Volume: | 27 | ||||||
Page range: | 5711-5725 | ||||||
Number of Pages: | 15 | ||||||
Publisher: | WILEY | ||||||
ISSN: | 1354-1013 | ||||||
Language: | English | ||||||
Publication Type: | Article Review/Survey | ||||||
Article category: | Scientific peer reviewed | ||||||
Version: | Published version | ||||||
Copyright: | Creative Commons: Attribution 4.0 | ||||||
Full Text Status: | Public | ||||||
Subjects: | (A) Swedish standard research categories 2011 > 1 Natural sciences > 105 Earth and Related Environmental Sciences > Climate Research (A) Swedish standard research categories 2011 > 1 Natural sciences > 105 Earth and Related Environmental Sciences > Environmental Sciences (social aspects to be 507) | ||||||
Keywords: | boreal, bryophyte, diazotroph, Earth system model, elevated CO2, nitrogen deposition, nitrogen fixation, nonvascular | ||||||
URN:NBN: | urn:nbn:se:slu:epsilon-p-113455 | ||||||
Permanent URL: | http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-p-113455 | ||||||
Additional ID: |
| ||||||
ID Code: | 25945 | ||||||
Faculty: | S - Faculty of Forest Sciences | ||||||
Department: | (S) > Dept. of Forest Ecology and Management | ||||||
Deposited By: | SLUpub Connector | ||||||
Deposited On: | 25 Oct 2021 08:45 | ||||||
Metadata Last Modified: | 25 Oct 2021 08:51 |
Repository Staff Only: item control page