Using structure to model function: incorporating canopy structure improves estimates of ecosystem carbon flux in arctic dry heath tundra
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 ca...
Published in: | Environmental Research Letters |
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2023
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Online Access: | https://doi.org/10.1088/1748-9326/acceb6 https://doaj.org/article/5fc5b8e06d914e03aac0bf7c4e17d869 |
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ftdoajarticles:oai:doaj.org/article:5fc5b8e06d914e03aac0bf7c4e17d869 2023-09-05T13:17:08+02:00 Using structure to model function: incorporating canopy structure improves estimates of ecosystem carbon flux in arctic dry heath tundra Elizabeth Min Shahid Naeem Laura Gough Jennie R McLaren Rebecca J Rowe Edward Rastetter Natalie Boelman Kevin L Griffin 2023-01-01T00:00:00Z https://doi.org/10.1088/1748-9326/acceb6 https://doaj.org/article/5fc5b8e06d914e03aac0bf7c4e17d869 EN eng IOP Publishing https://doi.org/10.1088/1748-9326/acceb6 https://doaj.org/toc/1748-9326 doi:10.1088/1748-9326/acceb6 1748-9326 https://doaj.org/article/5fc5b8e06d914e03aac0bf7c4e17d869 Environmental Research Letters, Vol 18, Iss 6, p 065004 (2023) net ecosystem exchange low arctic herbivory tundra vegetation ecosystem respiration gross primary production Environmental technology. Sanitary engineering TD1-1066 Environmental sciences GE1-350 Science Q Physics QC1-999 article 2023 ftdoajarticles https://doi.org/10.1088/1748-9326/acceb6 2023-08-13T00:36:54Z 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 Directory of Open Access Journals: DOAJ Articles Arctic Environmental Research Letters 18 6 065004 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
net ecosystem exchange low arctic herbivory tundra vegetation ecosystem respiration gross primary production Environmental technology. Sanitary engineering TD1-1066 Environmental sciences GE1-350 Science Q Physics QC1-999 |
spellingShingle |
net ecosystem exchange low arctic herbivory tundra vegetation ecosystem respiration gross primary production Environmental technology. Sanitary engineering TD1-1066 Environmental sciences GE1-350 Science Q Physics QC1-999 Elizabeth Min Shahid Naeem Laura Gough Jennie R McLaren Rebecca J Rowe Edward Rastetter Natalie Boelman Kevin L Griffin Using structure to model function: incorporating canopy structure improves estimates of ecosystem carbon flux in arctic dry heath tundra |
topic_facet |
net ecosystem exchange low arctic herbivory tundra vegetation ecosystem respiration gross primary production Environmental technology. Sanitary engineering TD1-1066 Environmental sciences GE1-350 Science Q Physics QC1-999 |
description |
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. |
format |
Article in Journal/Newspaper |
author |
Elizabeth Min Shahid Naeem Laura Gough Jennie R McLaren Rebecca J Rowe Edward Rastetter Natalie Boelman Kevin L Griffin |
author_facet |
Elizabeth Min Shahid Naeem Laura Gough Jennie R McLaren Rebecca J Rowe Edward Rastetter Natalie Boelman Kevin L Griffin |
author_sort |
Elizabeth Min |
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 |
https://doi.org/10.1088/1748-9326/acceb6 https://doaj.org/article/5fc5b8e06d914e03aac0bf7c4e17d869 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Tundra |
genre_facet |
Arctic Tundra |
op_source |
Environmental Research Letters, Vol 18, Iss 6, p 065004 (2023) |
op_relation |
https://doi.org/10.1088/1748-9326/acceb6 https://doaj.org/toc/1748-9326 doi:10.1088/1748-9326/acceb6 1748-9326 https://doaj.org/article/5fc5b8e06d914e03aac0bf7c4e17d869 |
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_ |
1776198429444145152 |