Skip to content
PaperFren

Carbon cycle

Canopy nitrogen and tree carbon uptake

Nair RK, Perks MP, Weatherall A, et al. · Global change biology · 2016

Open access · cc by · source: Europe PMC

Canopy-applied 15N is recovered aboveground about three times more than soil-applied N.

Study at a glance

Design
Animal / in-vitro — 15N tracer mesocosm comparing canopy vs soil nitrogen targeting in Sitka spruce
N
Potted Sitka spruce mesocosms; mean aboveground biomass 370 g/tree — exact tree N not primary in stored text
Population
Potted Sitka spruce trees
Outcome
Aboveground and wood recovery of canopy-applied vs soil-applied 15N

Structured fields used in claim comparison tables when every cited study has a complete layer.

Key findings

Canopy N uptake recovered about three times more tracer aboveground and four times more in wood than soil-targeted deposition; needle δ15N reached about 120‰ versus 38‰.

Methodology

Traced 15N applied to Sitka spruce canopies versus soil in potted mesocosms from February 2013 to March 2014, then harvested trees.

Limitations

Does not measure whole-forest C stocks or prove that canopy uptake changes landscape-scale carbon sequestration.

How this study connects

Role on claims

Each row is a claim on a concept or method page where this paper supports, challenges, or qualifies the statement. Roles are hand-checked — not a model guess.

  • SupportsCarbon cycleconcept

    This library holds 10 empirical papers on carbon cycle with measured outcomes rather than reviews.

    Evidence for the claim as stated.

  • SupportsCarbon cycleconcept

    Canopy-applied 15N is recovered aboveground about three times more than soil-applied N.

    Evidence for the claim as stated.

  • SupportsCarbon cycleconcept

    A mesocosm, a peat profile or a shrub plot does not close the global carbon budget.

    Evidence for the claim as stated.

  • SupportsMesocosm Experimentmethod

    Potted Sitka spruce mesocosms received ¹⁵N on canopies versus soil from February 2013 to March 2014. Canopy N uptake recovered about three times more tracer aboveground and four times more in wood than soil-targeted deposition; needle δ¹⁵N reached about 120‰ versus 38‰. The harvest does not measure whole-forest carbon stocks or prove that canopy uptake changes landscape-scale sequestration.

    Evidence for the claim as stated.

  • SupportsMesocosm Experimentmethod

    These mesocosms do not test one carbon-cycle claim. Litter tanks show aromaticity cutting bacterial production 14.5% with lake-colour differences in respiratory cost versus photo-oxidation. Canopy ¹⁵N recovers 3–4× more tracer in wood than soil targeting but does not scale to forest C stocks. Everglades inoculum effects on trunk diameter appear only under unconstrained flooding. Coralline algae are more sensitive to the rate of the pH drop than to low pH as a level, and live thalli at stable pH 7.7 increased daytime calcification. 'Mesocosms show carbon or OA effects' is not a single result.

    Evidence for the claim as stated.

Open questions

Tensions this paper is part of

From concept pages' “where studies disagree.” Disagreement means the same question; scope means different assays, populations, or outcomes.

  • Scope difference — different assays, populations, or outcomes

    SupportsCarbon cycle

    A mesocosm, a peat profile or a shrub plot does not close the global carbon budget.

    Also on this tension

  • Scope difference — different assays, populations, or outcomes

    These mesocosms do not test one carbon-cycle claim. Litter tanks show aromaticity cutting bacterial production 14.5% with lake-colour differences in respiratory cost versus photo-oxidation. Canopy ¹⁵N recovers 3–4× more tracer in wood than soil targeting but does not scale to forest C stocks. Everglades inoculum effects on trunk diameter appear only under unconstrained flooding. Coralline algae are more sensitive to the rate of the pH drop than to low pH as a level, and live thalli at stable pH 7.7 increased daytime calcification. 'Mesocosms show carbon or OA effects' is not a single result.

Related papers in this topic

Same topic cluster — not a recommendation engine.