Modeling gas exchange and biomass production in West African Sahelian and Sudanian ecological zones
(2021) In Geoscientific Model Development 14(6). p.3789-3812- Abstract
West African Sahelian and Sudanian ecosystems provide essential services to people and also play a significant role within the global carbon cycle. However, climate and land use are dynamically changing, and uncertainty remains with respect to how these changes will affect the potential of these regions to provide food and fodder resources or how they will affect the biosphere-atmosphere exchange of CO2. In this study, we investigate the capacity of a process-based biogeochemical model, LandscapeDNDC, to simulate net ecosystem exchange (NEE) and aboveground biomass of typical managed and natural Sahelian and Sudanian savanna ecosystems. In order to improve the simulation of phenology, we introduced soil-water availability as a common... (More)
West African Sahelian and Sudanian ecosystems provide essential services to people and also play a significant role within the global carbon cycle. However, climate and land use are dynamically changing, and uncertainty remains with respect to how these changes will affect the potential of these regions to provide food and fodder resources or how they will affect the biosphere-atmosphere exchange of CO2. In this study, we investigate the capacity of a process-based biogeochemical model, LandscapeDNDC, to simulate net ecosystem exchange (NEE) and aboveground biomass of typical managed and natural Sahelian and Sudanian savanna ecosystems. In order to improve the simulation of phenology, we introduced soil-water availability as a common driver of foliage development and productivity for all of these systems. The new approach was tested by using a sample of sites (calibration sites) that provided NEE from flux tower observations as well as leaf area index data from satellite images (MODIS, MODerate resolution Imaging Spectroradiometer). For assessing the simulation accuracy, we applied the calibrated model to 42 additional sites (validation sites) across West Africa for which measured aboveground biomass data were available. The model showed good performance regarding biomass of crops, grass, or trees, yielding correlation coefficients of 0.82, 0.94, and 0.77 and root-mean-square errors of 0.15, 0.22, and 0.12gkggm-2, respectively. The simulations indicate aboveground carbon stocks of up to 0.17, 0.33, and 0.54gkggCgha-1gm-2 for agricultural, savanna grasslands, and savanna mixed tree-grassland sites, respectively. Carbon stocks and exchange rates were particularly correlated with the abundance of trees, and grass biomass and crop yields were higher under more humid climatic conditions. Our study shows the capability of LandscapeDNDC to accurately simulate carbon balances in natural and agricultural ecosystems in semiarid West Africa under a wide range of conditions; thus, the model could be used to assess the impact of land-use and climate change on the regional biomass productivity.
(Less)
- author
- organization
- publishing date
- 2021
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Geoscientific Model Development
- volume
- 14
- issue
- 6
- pages
- 24 pages
- publisher
- Copernicus GmbH
- external identifiers
-
- scopus:85108631246
- ISSN
- 1991-959X
- DOI
- 10.5194/gmd-14-3789-2021
- language
- English
- LU publication?
- yes
- id
- 505e395e-1c07-4e7e-b90e-816f9ac306b6
- date added to LUP
- 2021-08-17 13:49:52
- date last changed
- 2022-04-27 03:14:57
@article{505e395e-1c07-4e7e-b90e-816f9ac306b6,
abstract = {{<p>West African Sahelian and Sudanian ecosystems provide essential services to people and also play a significant role within the global carbon cycle. However, climate and land use are dynamically changing, and uncertainty remains with respect to how these changes will affect the potential of these regions to provide food and fodder resources or how they will affect the biosphere-atmosphere exchange of CO2. In this study, we investigate the capacity of a process-based biogeochemical model, LandscapeDNDC, to simulate net ecosystem exchange (NEE) and aboveground biomass of typical managed and natural Sahelian and Sudanian savanna ecosystems. In order to improve the simulation of phenology, we introduced soil-water availability as a common driver of foliage development and productivity for all of these systems. The new approach was tested by using a sample of sites (calibration sites) that provided NEE from flux tower observations as well as leaf area index data from satellite images (MODIS, MODerate resolution Imaging Spectroradiometer). For assessing the simulation accuracy, we applied the calibrated model to 42 additional sites (validation sites) across West Africa for which measured aboveground biomass data were available. The model showed good performance regarding biomass of crops, grass, or trees, yielding correlation coefficients of 0.82, 0.94, and 0.77 and root-mean-square errors of 0.15, 0.22, and 0.12gkggm-2, respectively. The simulations indicate aboveground carbon stocks of up to 0.17, 0.33, and 0.54gkggCgha-1gm-2 for agricultural, savanna grasslands, and savanna mixed tree-grassland sites, respectively. Carbon stocks and exchange rates were particularly correlated with the abundance of trees, and grass biomass and crop yields were higher under more humid climatic conditions. Our study shows the capability of LandscapeDNDC to accurately simulate carbon balances in natural and agricultural ecosystems in semiarid West Africa under a wide range of conditions; thus, the model could be used to assess the impact of land-use and climate change on the regional biomass productivity. </p>}},
author = {{Rahimi, Jaber and Ago, Expedit Evariste and Ayantunde, Augustine and Berger, Sina and Bogaert, Jan and Butterbach-Bahl, Klaus and Cappelaere, Bernard and Cohard, Jean Martial and Demarty, Jérôme and Diouf, Abdoul Aziz and Falk, Ulrike and Haas, Edwin and Hiernaux, Pierre and Kraus, David and Roupsard, Olivier and Scheer, Clemens and Srivastava, Amit Kumar and Tagesson, Torbern and Grote, Rüdiger}},
issn = {{1991-959X}},
language = {{eng}},
number = {{6}},
pages = {{3789--3812}},
publisher = {{Copernicus GmbH}},
series = {{Geoscientific Model Development}},
title = {{Modeling gas exchange and biomass production in West African Sahelian and Sudanian ecological zones}},
url = {{http://dx.doi.org/10.5194/gmd-14-3789-2021}},
doi = {{10.5194/gmd-14-3789-2021}},
volume = {{14}},
year = {{2021}},
}