Titlebar

Export bibliographic data
Literature by the same author
plus on the publication server
plus at Google Scholar

 

Patterns of CO2 exchange and productivity of the herbaceous vegetation and trees in a humid savanna in western Kenya

Title data

Otieno, Dennis O. ; Ondier, Joseph O. ; Arnhold, Sebastian ; Okach, Daniel ; Ruidisch, Marianne ; Lee, Bora ; Kolb, Andreas ; Onyango, John C. ; Huwe, Bernd:
Patterns of CO2 exchange and productivity of the herbaceous vegetation and trees in a humid savanna in western Kenya.
In: Plant Ecology. Vol. 216 (2015) Issue 10 . - pp. 1441-1456.
ISSN 1573-5052
DOI: https://doi.org/10.1007/s11258-015-0523-3

Abstract in another language

Factors governing the dynamics between woody and herbaceous vegetation in the savanna are of ecological interest since they determine ecosystem productivity and stability. Field measurements were conducted in a humid savanna in the Lambwe valley, western Kenya, to compare CO2 exchange of the herbaceous vegetation and trees and its regulation. Soil characteristics and root distribution patterns under tree canopies and in the open locations dominated by the herbaceous vegetation were profiled in 1-m-deep soil layers. Soil water content (SWC) was measured at 30 cm depth both in the herbaceous vegetation and also under the tree canopies. The mean maximum monthly gross primary production (GPPmax) in the herbaceous vegetation was determined from chamber measurements, while daily GPP (GPPday) in both the grass and tree canopies was simulated using the PIXGRO model. The highest mean GPPmax in the herbaceous vegetation was 26.2 ± 3.7 μmol m-2 s-1 during April. Seasonal fluctuations of GPP in the herbaceous vegetation were explained by soil water availability (R2 = 0.78) within the upper 30-cm soil profile. Seasonal GPPday fluctuations were larger (between 1 gC m-2 d-1 and 10 gC m-2 d-1) in the herbaceous vegetation compared to the trees, which fluctuated around 4.3 ± 0.3 gC m-2 d-1 throughout most of the measurement period. Daily tree canopy transpiration (Ec), canopy conductance (Gc), and GPPday were decoupled from SWC in the top 30-cm soil profile. On average, ecosystem GPPday (mean of tree and herbaceous vegetation) was 14.3 ± 1.2 gC m-2 d-1 during the wet period and 6.1 ± 0.9 gC m-2 d-1 during drought. Differences between the herbaceous and tree canopy responses were attributed to soil moisture availability.

Further data

Item Type: Article in a journal
Refereed: Yes
Additional notes: BAYCEER132954
BAYCEER131343
BAYCEER141160
Keywords: Canopy conductance; Canopy transpiration; Gross primary production; Hydraulic lift; Humid savanna; Soil water availability
Institutions of the University: Faculties
Faculties > Faculty of Biology, Chemistry and Earth Sciences
Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Biology
Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Biology > Chair Plant Ecology
Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Earth Sciences
Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Earth Sciences > Former Professors
Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Earth Sciences > Chair Soil Physics
Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Earth Sciences > Former Professors > Professorship Soil Physics - Univ.-Prof. Dr. Bernd Huwe
Faculties > Faculty of Biology, Chemistry and Earth Sciences > Department of Earth Sciences > Professorship Ecological Services
Research Institutions
Research Institutions > Research Centres
Research Institutions > Research Centres > Bayreuth Center of Ecology and Environmental Research- BayCEER
Result of work at the UBT: Yes
DDC Subjects: 500 Science
Date Deposited: 03 Aug 2016 05:36
Last Modified: 17 Apr 2018 09:58
URI: https://eref.uni-bayreuth.de/id/eprint/33785