Using structure to model function: incorporating canopy structure improves estimates of ecosystem carbon flux in arctic dry heath tundra
Abstract Most tundra carbon flux modeling relies on leaf area index (LAI), generally estimated from measurements of canopy greenness using the normalized difference vegetation index (NDVI), to estimate the direction and magnitude of fluxes. However, due to the relative sparseness and low stature of...
Published in: | Environmental Research Letters |
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Online Access: | http://dx.doi.org/10.1088/1748-9326/acceb6 https://iopscience.iop.org/article/10.1088/1748-9326/acceb6 https://iopscience.iop.org/article/10.1088/1748-9326/acceb6/pdf |
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crioppubl:10.1088/1748-9326/acceb6 2024-06-02T08:01:57+00:00 Using structure to model function: incorporating canopy structure improves estimates of ecosystem carbon flux in arctic dry heath tundra Min, Elizabeth Naeem, Shahid Gough, Laura McLaren, Jennie R Rowe, Rebecca J Rastetter, Edward Boelman, Natalie Griffin, Kevin L Division of Environmental Biology Office of Polar Programs 2023 http://dx.doi.org/10.1088/1748-9326/acceb6 https://iopscience.iop.org/article/10.1088/1748-9326/acceb6 https://iopscience.iop.org/article/10.1088/1748-9326/acceb6/pdf unknown IOP Publishing http://creativecommons.org/licenses/by/4.0 https://iopscience.iop.org/info/page/text-and-data-mining Environmental Research Letters volume 18, issue 6, page 065004 ISSN 1748-9326 journal-article 2023 crioppubl https://doi.org/10.1088/1748-9326/acceb6 2024-05-07T14:00:50Z Abstract Most tundra carbon flux modeling relies on leaf area index (LAI), generally estimated from measurements of canopy greenness using the normalized difference vegetation index (NDVI), to estimate the direction and magnitude of fluxes. However, due to the relative sparseness and low stature of tundra canopies, such models do not explicitly consider the influence of variation in tundra canopy structure on carbon flux estimates. Structure from motion (SFM), a photogrammetric method for deriving three-dimensional (3D) structure from digital imagery, is a non-destructive method for estimating both fine-scale canopy structure and LAI. To understand how variation in 3D canopy structure affects ecosystem carbon fluxes in Arctic tundra, we adapted an existing NDVI-based tundra carbon flux model to include variation in SFM-derived canopy structure and its interaction with incoming sunlight to cast shadows on canopies. Our study system consisted of replicate plots of dry heath tundra that had been subjected to three herbivore exclosure treatments (an exclosure-free control [CT], large mammals exclosure), and a large and small mammal exclosure [ExLS]), providing the range of 3D canopy structures employed in our study. We found that foliage within the more structurally complex surface of CT canopies received significantly less light over the course of the day than canopies within both exclosure treatments. This was especially during morning and evening hours, and was reflected in modeled rates of net ecosystem exchange (NEE) and gross primary productivity (GPP). We found that in the ExLS treatment, SFM-derived estimates of GPP were significantly lower and NEE significantly higher than those based on LAI alone. Our results demonstrate that the structure of even simple tundra vegetation canopies can have significant impacts on tundra carbon fluxes and thus need to be accounted for. Article in Journal/Newspaper Arctic Tundra IOP Publishing Arctic Environmental Research Letters 18 6 065004 |
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IOP Publishing |
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Abstract Most tundra carbon flux modeling relies on leaf area index (LAI), generally estimated from measurements of canopy greenness using the normalized difference vegetation index (NDVI), to estimate the direction and magnitude of fluxes. However, due to the relative sparseness and low stature of tundra canopies, such models do not explicitly consider the influence of variation in tundra canopy structure on carbon flux estimates. Structure from motion (SFM), a photogrammetric method for deriving three-dimensional (3D) structure from digital imagery, is a non-destructive method for estimating both fine-scale canopy structure and LAI. To understand how variation in 3D canopy structure affects ecosystem carbon fluxes in Arctic tundra, we adapted an existing NDVI-based tundra carbon flux model to include variation in SFM-derived canopy structure and its interaction with incoming sunlight to cast shadows on canopies. Our study system consisted of replicate plots of dry heath tundra that had been subjected to three herbivore exclosure treatments (an exclosure-free control [CT], large mammals exclosure), and a large and small mammal exclosure [ExLS]), providing the range of 3D canopy structures employed in our study. We found that foliage within the more structurally complex surface of CT canopies received significantly less light over the course of the day than canopies within both exclosure treatments. This was especially during morning and evening hours, and was reflected in modeled rates of net ecosystem exchange (NEE) and gross primary productivity (GPP). We found that in the ExLS treatment, SFM-derived estimates of GPP were significantly lower and NEE significantly higher than those based on LAI alone. Our results demonstrate that the structure of even simple tundra vegetation canopies can have significant impacts on tundra carbon fluxes and thus need to be accounted for. |
author2 |
Division of Environmental Biology Office of Polar Programs |
format |
Article in Journal/Newspaper |
author |
Min, Elizabeth Naeem, Shahid Gough, Laura McLaren, Jennie R Rowe, Rebecca J Rastetter, Edward Boelman, Natalie Griffin, Kevin L |
spellingShingle |
Min, Elizabeth Naeem, Shahid Gough, Laura McLaren, Jennie R Rowe, Rebecca J Rastetter, Edward Boelman, Natalie Griffin, Kevin L Using structure to model function: incorporating canopy structure improves estimates of ecosystem carbon flux in arctic dry heath tundra |
author_facet |
Min, Elizabeth Naeem, Shahid Gough, Laura McLaren, Jennie R Rowe, Rebecca J Rastetter, Edward Boelman, Natalie Griffin, Kevin L |
author_sort |
Min, Elizabeth |
title |
Using structure to model function: incorporating canopy structure improves estimates of ecosystem carbon flux in arctic dry heath tundra |
title_short |
Using structure to model function: incorporating canopy structure improves estimates of ecosystem carbon flux in arctic dry heath tundra |
title_full |
Using structure to model function: incorporating canopy structure improves estimates of ecosystem carbon flux in arctic dry heath tundra |
title_fullStr |
Using structure to model function: incorporating canopy structure improves estimates of ecosystem carbon flux in arctic dry heath tundra |
title_full_unstemmed |
Using structure to model function: incorporating canopy structure improves estimates of ecosystem carbon flux in arctic dry heath tundra |
title_sort |
using structure to model function: incorporating canopy structure improves estimates of ecosystem carbon flux in arctic dry heath tundra |
publisher |
IOP Publishing |
publishDate |
2023 |
url |
http://dx.doi.org/10.1088/1748-9326/acceb6 https://iopscience.iop.org/article/10.1088/1748-9326/acceb6 https://iopscience.iop.org/article/10.1088/1748-9326/acceb6/pdf |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Tundra |
genre_facet |
Arctic Tundra |
op_source |
Environmental Research Letters volume 18, issue 6, page 065004 ISSN 1748-9326 |
op_rights |
http://creativecommons.org/licenses/by/4.0 https://iopscience.iop.org/info/page/text-and-data-mining |
op_doi |
https://doi.org/10.1088/1748-9326/acceb6 |
container_title |
Environmental Research Letters |
container_volume |
18 |
container_issue |
6 |
container_start_page |
065004 |
_version_ |
1800746448536469504 |