N supply mediates the radiative balance of N 2 O emissions and CO 2 sequestration driven by N‐fixing vs. non‐fixing trees

N supply mediates the radiative balance of N 2 O emissions and CO 2 sequestration driven by N‐fixing vs. non‐fixing trees

Abstract Forests are a significant CO 2 sink. However, CO 2 sequestration in forests is radiatively offset by emissions of nitrous oxide (N 2 O), a potent greenhouse gas, from forest soils. Reforestation, an important strategy for mitigating climate change, has focused on maximizing CO 2 sequestrati...

Full description

Saved in:
Bibliographic Details
Published in:Ecology (Durham) 2021-08, Vol.102 (8)
Main Authors: Kou‐Giesbrecht, Sian, Funk, Jennifer L., Perakis, Steven S., Wolf, Amelia A., Menge, Duncan N. L.
Format: Article
Language:eng
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Abstract Forests are a significant CO 2 sink. However, CO 2 sequestration in forests is radiatively offset by emissions of nitrous oxide (N 2 O), a potent greenhouse gas, from forest soils. Reforestation, an important strategy for mitigating climate change, has focused on maximizing CO 2 sequestration in plant biomass without integrating N 2 O emissions from soils. Although nitrogen (N)‐fixing trees are often recommended for reforestation because of their rapid growth on N‐poor soil, they can stimulate significant N 2 O emissions from soils. Here, we first used a field experiment to show that a N‐fixing tree ( Robinia pseudoacacia ) initially mitigated climate change more than a non‐fixing tree ( Betula nigra ). We then used our field data to parameterize a theoretical model to investigate these effects over time. Under lower N supply, N‐fixers continued to mitigate climate change more than non‐fixers by overcoming N limitation of plant growth. However, under higher N supply, N‐fixers ultimately mitigated climate change less than non‐fixers by enriching soil N and stimulating N 2 O emissions from soils. These results have implications for reforestation, suggesting that N‐fixing trees are more effective at mitigating climate change at lower N supply, whereas non‐fixing trees are more effective at mitigating climate change at higher N supply.
ISSN:0012-9658
1939-9170