TY - JOUR
T1 - The effect of fire history on soil nutrients and soil organic carbon in a semi-arid savanna woodland, central Namibia
AU - Nghalipo, Elise
AU - Joubert, Dave
AU - Throop, Heather
AU - Groengroeft, Alexander
N1 - Funding Information:
Acknowledgements — We gratefully acknowledge the Southern African Science Service Centre for Climate Change and Adaptive Land Management (SASSCAL) for funding the work, the Ministry of Environment and Tourism for allowing the field work to be conducted in Waterberg Plateau Park, Waterberg Plateau Park staff for their assistance, and the soil laboratory staff at the Ministry of Agriculture, Water and Forestry for their assistance with laboratory analyses. Support for Prof. Heather Throop’s participation in the project was provided by the United States Fulbright Commission and the US National Science Foundation (DEB 0953864).
Publisher Copyright:
© 2019, © 2019 NISC (Pty) Ltd.
PY - 2019/1/2
Y1 - 2019/1/2
N2 - Fire is an integral part of savanna ecosystems that has shaped these systems since the Miocene. Substantial uncertainty about fire effects in semi-arid ecosystems exists. Fire may affect ecosystem productivity directly through nutrient volatilisation, increased mineralisation and altering organic matter quantity, and indirectly through altering vegetation structure. We explored the effects of fire history and vegetation patch types (tree canopy vs inter-canopy) on soil nutrients and soil organic carbon (SOC) in a semi-arid ecosystem. We collected soil samples along transects in four treatments with different fire histories (1 to 24 years since the last burn). In the statistical analyses, tree canopy and inter-canopy samples along transects were differentiated. Fire showed an inconsistent effect on soil nutrients and SOC. There was a short-term negative influence on total nitrogen, whereas phosphorus, potassium and magnesium increased in the 1-year treatment. Sodium consistently decreased with increasing time since the last burn, whereas SOC and calcium were not affected. Calcium and magnesium were significantly higher under canopy relative to inter-canopy patches. There was no significant interactive effect between fire history and vegetation patch type on soil nutrients and SOC. Management decisions regarding fire within the frequency experienced in this system appear not to necessitate concern regarding soil resource impacts.
AB - Fire is an integral part of savanna ecosystems that has shaped these systems since the Miocene. Substantial uncertainty about fire effects in semi-arid ecosystems exists. Fire may affect ecosystem productivity directly through nutrient volatilisation, increased mineralisation and altering organic matter quantity, and indirectly through altering vegetation structure. We explored the effects of fire history and vegetation patch types (tree canopy vs inter-canopy) on soil nutrients and soil organic carbon (SOC) in a semi-arid ecosystem. We collected soil samples along transects in four treatments with different fire histories (1 to 24 years since the last burn). In the statistical analyses, tree canopy and inter-canopy samples along transects were differentiated. Fire showed an inconsistent effect on soil nutrients and SOC. There was a short-term negative influence on total nitrogen, whereas phosphorus, potassium and magnesium increased in the 1-year treatment. Sodium consistently decreased with increasing time since the last burn, whereas SOC and calcium were not affected. Calcium and magnesium were significantly higher under canopy relative to inter-canopy patches. There was no significant interactive effect between fire history and vegetation patch type on soil nutrients and SOC. Management decisions regarding fire within the frequency experienced in this system appear not to necessitate concern regarding soil resource impacts.
KW - cations
KW - fire intervals
KW - fire treatment
KW - sandy soils
KW - time since last burn
KW - vegetation patch types
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U2 - 10.2989/10220119.2018.1526825
DO - 10.2989/10220119.2018.1526825
M3 - Article
AN - SCOPUS:85059037544
SN - 1022-0119
VL - 36
SP - 9
EP - 16
JO - African Journal of Range and Forage Science
JF - African Journal of Range and Forage Science
IS - 1
ER -