Carbon and nitrogen in the soil-plant system along rainfall and land-use gradients in Southern Africa

C.J.W. FERAL; H.E. EPSTEIN; L. OTTER; J.N. ARANIBAR; H.H. SHUGART; S.A. MACKO; J. RAMOTSHO

JOURNAL OF ARID ENVIRONMENTS

Elsevier

Año: 2003 vol. 54 p. 327 - 343

0140-1963

We examined relationships between vegetation and soil nutrients along rainfall and land use gradients in the Kalahari. Soil organic carbon (SOC) was significantly lower where reduced rainfall and grazing lowered litter inputs to the soil. Soil organic nitrogen (SON) was significantly lower at the driest site and was higher than expected at two grazed sites. Ammonium levels at Mongu (wettest) were significantly higher, while nitrate was lower than expected everywhere. Site-averaged concentrations showed no significant differences in SOC and SON beneath plant canopies, but woody plant canopies alone showed elevated SOC at three sites and SON at one site. canopies alone showed elevated SOC at three sites and SON at one site. canopies alone showed elevated SOC at three sites and SON at one site. canopies alone showed elevated SOC at three sites and SON at one site. canopies alone showed elevated SOC at three sites and SON at one site. canopies alone showed elevated SOC at three sites and SON at one site. canopies alone showed elevated SOC at three sites and SON at one site. canopies alone showed elevated SOC at three sites and SON at one site. canopies alone showed elevated SOC at three sites and SON at one site. woody plant canopies alone showed elevated SOC at three sites and SON at one site.