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Woody overstorey effects on soil carbon and nitrogen pools in South African savanna
Author(s) -
Hudak A. T.,
Wessman C. A.,
Seastedt T. R.
Publication year - 2003
Publication title -
austral ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.688
H-Index - 87
eISSN - 1442-9993
pISSN - 1442-9985
DOI - 10.1046/j.1442-9993.2003.01265.x
Subject(s) - biome , litter , soil carbon , herbaceous plant , environmental science , plant litter , biogeochemical cycle , woody plant , understory , agronomy , agroforestry , ecology , ecosystem , soil water , soil science , biology , canopy
Woody plant encroachment in savannas may alter carbon (C) and nitrogen (N) pools over the long‐term, which could have regional or global biogeochemical implications given the widespread encroachment observed in the vast savanna biome. Soil and litter %C and %N were surveyed across four soil types in two encroached, semi‐arid savanna landscapes in northern South Africa. Litter at sampling points with a woody component had a higher %N and lower C : N ratio than litter at solely herbaceous points. Severely encroached areas had lower C : N ratios throughout the soil profile than less encroached areas. Soil %C and %N were highly influenced by soil texture but were also influenced by the presence of a woody overstorey, which increased surface soil %C on three soil types but decreased it on the most heavily encroached soil type. Soil C sequestration may initially increase with bush encroachment but then decline if bush densities become so high as to inhibit understorey grass growth.