Environmental controls on peak carbon uptake across four Kenyan dryland ecosystems

Semi-arid and dry sub-humid landscapes dominate much of Kenya, yet their role in the regional carbon cycle is poorly quantified, particularly how peak ecosystem photosynthesis responds to variable wet-season rainfall. We synthesized eddy covariance observations from four contrasting sites: Kapiti, a...

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Autores principales: Odongo, Vincent O., Leitner, Sonja, Räsänen, M., Omondi, J.O., Pellikka, P., Vesala, T., Heiskanen, J., Rinne, J., Dowling, T.P.F., Korczynski, J., Wooster, M.J., Mauder, M., Merbold, Lutz
Formato: Póster
Lenguaje:Inglés
Publicado: International livestock research Institute 2025
Materias:
Acceso en línea:https://hdl.handle.net/10568/176869
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author Odongo, Vincent O.
Leitner, Sonja
Räsänen, M.
Omondi, J.O.
Pellikka, P.
Vesala, T.
Heiskanen, J.
Rinne, J.
Dowling, T.P.F.
Korczynski, J.
Wooster, M.J.
Mauder, M.
Merbold, Lutz
author_browse Dowling, T.P.F.
Heiskanen, J.
Korczynski, J.
Leitner, Sonja
Mauder, M.
Merbold, Lutz
Odongo, Vincent O.
Omondi, J.O.
Pellikka, P.
Rinne, J.
Räsänen, M.
Vesala, T.
Wooster, M.J.
author_facet Odongo, Vincent O.
Leitner, Sonja
Räsänen, M.
Omondi, J.O.
Pellikka, P.
Vesala, T.
Heiskanen, J.
Rinne, J.
Dowling, T.P.F.
Korczynski, J.
Wooster, M.J.
Mauder, M.
Merbold, Lutz
author_sort Odongo, Vincent O.
collection Repository of Agricultural Research Outputs (CGSpace)
description Semi-arid and dry sub-humid landscapes dominate much of Kenya, yet their role in the regional carbon cycle is poorly quantified, particularly how peak ecosystem photosynthesis responds to variable wet-season rainfall. We synthesized eddy covariance observations from four contrasting sites: Kapiti, an open grassland rangeland; Choke, a wooded savanna; Maktau, a smallholder cropland; and Ausquest, a commercial cropland. All experience distinct wet and dry seasons but differ in rainfall, vegetation structure, and management. We focused on the wet season, when most annual carbon uptake occurs, to identify climatic and biophysical controls on maximum CO₂ uptake (NEEmax). Specifically, we assessed how rainfall and soil moisture regulate uptake, how temperature and vapor pressure deficit (VPD) constrain uptake under high light, and how land cover and management mediate water-carbon coupling. Comparing across this land-use gradient improves understanding of carbon-water exchange in East African drylands and their likely responses to future climate and land-use change.
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spelling CGSpace1768692025-10-08T01:02:57Z Environmental controls on peak carbon uptake across four Kenyan dryland ecosystems Odongo, Vincent O. Leitner, Sonja Räsänen, M. Omondi, J.O. Pellikka, P. Vesala, T. Heiskanen, J. Rinne, J. Dowling, T.P.F. Korczynski, J. Wooster, M.J. Mauder, M. Merbold, Lutz environment carbon drylands ecosystems Semi-arid and dry sub-humid landscapes dominate much of Kenya, yet their role in the regional carbon cycle is poorly quantified, particularly how peak ecosystem photosynthesis responds to variable wet-season rainfall. We synthesized eddy covariance observations from four contrasting sites: Kapiti, an open grassland rangeland; Choke, a wooded savanna; Maktau, a smallholder cropland; and Ausquest, a commercial cropland. All experience distinct wet and dry seasons but differ in rainfall, vegetation structure, and management. We focused on the wet season, when most annual carbon uptake occurs, to identify climatic and biophysical controls on maximum CO₂ uptake (NEEmax). Specifically, we assessed how rainfall and soil moisture regulate uptake, how temperature and vapor pressure deficit (VPD) constrain uptake under high light, and how land cover and management mediate water-carbon coupling. Comparing across this land-use gradient improves understanding of carbon-water exchange in East African drylands and their likely responses to future climate and land-use change. 2025-10-05 2025-10-07T18:00:56Z 2025-10-07T18:00:56Z Poster https://hdl.handle.net/10568/176869 en Open Access application/pdf International livestock research Institute Odongo, V., Leitner, S., Räsänen, M., Omondi, J., Pellikka, P., Vesala, T., Heiskanen, J., Rinne, J., Dowling, T. P. F., Jackowicz-Korczynski, M., Wooster, M. J., Mauder, M. and Merbold, L. 2025. Environmental controls on peak carbon uptake across four Kenyan dryland ecosystems. Poster prepared for the 9th International Greenhouse Gas & Animal Agriculture Conference, Nairobi, 5-9 October 2025. Nairobi, Kenya: ILRI.
spellingShingle environment
carbon
drylands
ecosystems
Odongo, Vincent O.
Leitner, Sonja
Räsänen, M.
Omondi, J.O.
Pellikka, P.
Vesala, T.
Heiskanen, J.
Rinne, J.
Dowling, T.P.F.
Korczynski, J.
Wooster, M.J.
Mauder, M.
Merbold, Lutz
Environmental controls on peak carbon uptake across four Kenyan dryland ecosystems
title Environmental controls on peak carbon uptake across four Kenyan dryland ecosystems
title_full Environmental controls on peak carbon uptake across four Kenyan dryland ecosystems
title_fullStr Environmental controls on peak carbon uptake across four Kenyan dryland ecosystems
title_full_unstemmed Environmental controls on peak carbon uptake across four Kenyan dryland ecosystems
title_short Environmental controls on peak carbon uptake across four Kenyan dryland ecosystems
title_sort environmental controls on peak carbon uptake across four kenyan dryland ecosystems
topic environment
carbon
drylands
ecosystems
url https://hdl.handle.net/10568/176869
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