Okach, DO; Ondier, Joseph O; Kumar, A; Rambold, G; Tenhunen, J; Huwe, B; Otieno, DO: Livestock grazing and rainfall manipulation alter the patterning of CO2 fluxes and biomass development of the herbaceous community in a humid savanna, Plant Ecology, 220(11), 1085–1100 (2019), online: 2019-11-20, doi:https://doi.org/10.1007/s11258-019-00977-2 [Link]
Abstract:

Overgrazing by livestock and the changing patterns of rainfall, characterized by severe drought and floods during dry and wet seasons, respectively, threaten the sustainable productivity of the savannas. To understand the implications of such changes in Lambwe Valley—Kenya, we simulated 50% decrease (50%) and increase (150%) in ambient rainfall (100%), respectively, in grazed (G) and ungrazed (U) sites during dry and wet months. CO2 exchange and biomass production were quantified using chamber method and direct biomass sampling technique, respectively. Plots were named by combining the first letters of the sites followed by rainfall amount, i.e., U150%. Soil moisture (VWC) increased along a rainfall gradient of 50–150%. Grazing reduced the VWC, net ecosystem exchange (NEE), and total biomass by 19.07%, 57.14%, and 37.03%, respectively, with severe effects during the dry months. 50% rainfall strongly influenced the VWC, NEE (negative and positive signs indicate CO2 uptake and net carbon loss, respectively), and biomass compared to 150% rainfall. The U150% plot reported the highest mean NEE (– 8.80 ± 2.26 µmol m−2 s−1), AGB (1208.41 g m−2), and total biomass (1589.06 g m−2) during the wet months. Lower VWC in the G50% plot triggered a net carbon loss of 3.68 ± 0.81 µmol m−2 s−1 (NEE). Our results show that livestock grazing during the dry months hinders herbaceous CO2 uptake and standing biomass. Proper understanding of the interaction between livestock grazing and rainfall variability in humid savannas is essential for sustainable management strategies to regulate the herbaceous productivity.

Upcoming ...

Fr. 2020-07-10 now
12th BayCEER Workshop 2020: "Call for Abstracts" is open
BayCEER Colloquium:
Th. 2020-10-22
Extreme redox oscillations in freshwater re-flooded acid sulfate soil wetlands: Effects on Fe, S, and trace metals geochemical behavior
Th. 2020-10-29
Dissolved organic matter quality in differently managed forest ecosystems
Th. 2020-11-05
Signaling of rhizosphere microbiome: key for plant health, development and nutrition
Workshop:
Th. 2020-10-29
BayCEER Workshop 2020
BayCEER Blog
13.01.2020
Why Science Communication?
24.05.2019
Stoichiometric controls of C and N cycling
07.05.2019
Flying halfway across the globe to dig in the dirt – a research stay in Bloomington, USA
16.04.2019
Picky carnivorous plants?
RSS Blog as RSS Feed
Weather research site
Luftdruck (356m): 972.9 hPa
Lufttemperatur: 16.7 °C
Niederschlag: 0.0 mm/24h
Sonnenschein: <1 h/d
Wind (Höhe 17m): 2.1 km/h
Wind (Max.): 4.3 km/h
Windrichtung: S

...more
Globalstrahlung: 98 W/m²
Lufttemperatur: 19.8 °C
Niederschlag: 0.1 mm/24h
Sonnenschein: <1 h/d
Wind (Höhe 32m): 0.0 km/h

...more
This site makes use of cookies More information