This preprint is under consideration at Forest Ecosystems. A preprint is a preliminary version of a manuscript that has not completed peer review at a journal. Research Square does not conduct peer review prior to posting preprints. The posting of a preprint on this server should not be interpreted as an endorsement of its validity or suitability for dissemination as established information or for guiding clinical practice.
Learn more about In Review
A new preprint design is coming!
We have improved readability, clarity, accessibility, and opportunities for engagement.
Research
Joannie Beaulne
Université du Québec à Montréal
Corresponding Author
ORCiD: https://orcid.org/0000-0002-5889-6757
License:
This work is licensed under a CC BY 4.0 License. Read Full License
Background Paludification is widespread in the boreal biome, inducing tree growth decline in forested peatlands following the development of thick organic layers over the mineral soil. However, the ecophysiological processes involved remain poorly documented and little is known about the interactions between tree growth mechanisms and site conditions in these ecosystems. We investigated changes in stem growth and main ecophysiological processes in a black spruce forested peatland in eastern Canada by combining peat-based and tree-ring stable isotope analyses. These were conducted at three sampling sites located along a paludification gradient with different peat thicknesses.
Results Organic layer thickening induces black spruce growth decline without altering tree ecophysiological mechanisms. A 40% increase in water use efficiency, or the ratio of carbon assimilated to water losses, was observed at the three sites from 1920 to the 1980s, but did not translate into enhanced tree growth. A clear shift in the 1980s revealed a decline in black spruce sensitivity to climate and rising atmospheric CO2 concentration, regardless of the organic layer thickness. Water table reconstructions revealed an important drawdown in the last few decades at the three sites, but we found no evidence of an influence of water table variations on stem growth.
Conclusions This study shows that paludification induces black spruce growth decline without altering tree metabolism in boreal forested peatlands. This underlines that changes in water use efficiency are decoupled from changes in carbon allocation, which are constrained by site, or even tree-specific strategies to access water and nutrients from belowground. Our findings indicate that dynamic changes in edaphic conditions need to be considered in process models. Otherwise, failing to account for the degree of paludification can lead to misleading forest productivity predictions and result in considerable overestimations of aboveground carbon stocks from trees in the boreal regions.
Keywords
black spruce growth, boreal biome, climate-growth relationships, ecophysiological response, forested peatland, paludification, stable isotopes, water use efficiency
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
The full text of this article is available to read as a PDF.
This is a list of supplementary files associated with this preprint. Click to download.
Loading...
Badges
Prescreen
This manuscript passed our Prescreen assessment
Complete author information
Appropriate declaration statements
Potential risks to human health
Prescreen
Peer Review Timeline
CURRENT STATUS: Under Review
The most recent version of this article is available here.
No community comments so far
Editorial decision: Minor Revision
On 24 Jan, 2021
Review #1 received
Received 20 Jan, 2021
Review #2 received
Received 17 Jan, 2021
Reviewer #2 agreed
On 10 Jan, 2021
Reviewers invited
Invitations sent on 09 Jan, 2021
Reviewer #1 agreed
On 09 Jan, 2021
Editor assigned
On 04 Jan, 2021
Submission checks complete
On 04 Jan, 2021
Editor invited
On 04 Jan, 2021
Version 1
Posted 13 Aug, 2020
No comments provided
Editorial decision: Major Revision
On 18 Oct, 2020
Review #2 received
Received 15 Oct, 2020
Review #1 received
Received 20 Sep, 2020
Reviewer #2 agreed
On 10 Sep, 2020
Reviewer #1 agreed
On 09 Sep, 2020
Reviewers invited
Invitations sent on 18 Aug, 2020
Editor assigned
On 11 Aug, 2020
First submitted
On 10 Aug, 2020
Submission checks complete
On 10 Aug, 2020
Editor invited
On 10 Aug, 2020
Metrics
Comments: 0
PDF Downloads: ...
HTML Views: ...
Subject Areas
Forestry
Learn more about our company.
A new preprint design is coming!
We have improved readability, clarity, accessibility, and opportunities for engagement.
This preprint is under consideration at Forest Ecosystems. A preprint is a preliminary version of a manuscript that has not completed peer review at a journal. Research Square does not conduct peer review prior to posting preprints. The posting of a preprint on this server should not be interpreted as an endorsement of its validity or suitability for dissemination as established information or for guiding clinical practice.
Learn more about In Review
Research
Joannie Beaulne
Université du Québec à Montréal
Corresponding Author
ORCiD: https://orcid.org/0000-0002-5889-6757
Badges
Prescreen
This manuscript passed our Prescreen assessment
Complete author information
Appropriate declaration statements
Potential risks to human health
Prescreen
Peer Review Timeline
CURRENT STATUS: Under Review
The most recent version of this article is available here.
No community comments so far
Editorial decision: Minor Revision
On 24 Jan, 2021
Review #1 received
Received 20 Jan, 2021
Review #2 received
Received 17 Jan, 2021
Reviewer #2 agreed
On 10 Jan, 2021
Reviewers invited
Invitations sent on 09 Jan, 2021
Reviewer #1 agreed
On 09 Jan, 2021
Editor assigned
On 04 Jan, 2021
Submission checks complete
On 04 Jan, 2021
Editor invited
On 04 Jan, 2021
Version 1
Posted 13 Aug, 2020
No comments provided
Editorial decision: Major Revision
On 18 Oct, 2020
Review #2 received
Received 15 Oct, 2020
Review #1 received
Received 20 Sep, 2020
Reviewer #2 agreed
On 10 Sep, 2020
Reviewer #1 agreed
On 09 Sep, 2020
Reviewers invited
Invitations sent on 18 Aug, 2020
Editor assigned
On 11 Aug, 2020
First submitted
On 10 Aug, 2020
Submission checks complete
On 10 Aug, 2020
Editor invited
On 10 Aug, 2020
Metrics
Comments: 0
PDF Downloads: ...
HTML Views: ...
Subject Areas
Forestry
License:
This work is licensed under a CC BY 4.0 License. Read Full License
The most recent version of this article is available here.
Background Paludification is widespread in the boreal biome, inducing tree growth decline in forested peatlands following the development of thick organic layers over the mineral soil. However, the ecophysiological processes involved remain poorly documented and little is known about the interactions between tree growth mechanisms and site conditions in these ecosystems. We investigated changes in stem growth and main ecophysiological processes in a black spruce forested peatland in eastern Canada by combining peat-based and tree-ring stable isotope analyses. These were conducted at three sampling sites located along a paludification gradient with different peat thicknesses.
Results Organic layer thickening induces black spruce growth decline without altering tree ecophysiological mechanisms. A 40% increase in water use efficiency, or the ratio of carbon assimilated to water losses, was observed at the three sites from 1920 to the 1980s, but did not translate into enhanced tree growth. A clear shift in the 1980s revealed a decline in black spruce sensitivity to climate and rising atmospheric CO2 concentration, regardless of the organic layer thickness. Water table reconstructions revealed an important drawdown in the last few decades at the three sites, but we found no evidence of an influence of water table variations on stem growth.
Conclusions This study shows that paludification induces black spruce growth decline without altering tree metabolism in boreal forested peatlands. This underlines that changes in water use efficiency are decoupled from changes in carbon allocation, which are constrained by site, or even tree-specific strategies to access water and nutrients from belowground. Our findings indicate that dynamic changes in edaphic conditions need to be considered in process models. Otherwise, failing to account for the degree of paludification can lead to misleading forest productivity predictions and result in considerable overestimations of aboveground carbon stocks from trees in the boreal regions.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
The full text of this article is available to read as a PDF.
This is a list of supplementary files associated with this preprint. Click to download.
Loading...