Document


Title

Causes of increased nutrient concentrations in post-fire regrowth in an East African savanna
Document Type: Journal Article
Author(s): Claudius A. D. M. Van De Vijver; Pieter Poot; Herbert H. T. Prins
Publication Year: 1999

Cataloging Information

Keyword(s):
  • Africa
  • ash
  • biomass
  • calcium
  • carbon
  • distribution
  • ecosystem dynamics
  • fire
  • grasses
  • grassland
  • grazing
  • K - potassium
  • magnesium
  • national parks
  • nitrogen
  • nutrient concentrations
  • nutrients
  • phosphorus
  • plant nutrients
  • post-fire recovery
  • precipitation
  • pyric herbivory
  • roots
  • savannas
  • site treatments
  • soil
  • soil management
  • soil nutrients
  • Tanzania
  • wildfires
Region(s):
  • International
Record Maintained By:
Record Last Modified: June 1, 2018
FRAMES Record Number: 18053
Tall Timbers Record Number: 20288
TTRS Location Status: In-file
TTRS Call Number: Fire File
TTRS Abstract Status: Okay, Fair use, Reproduced by permission

This bibliographic record was either created or modified by the Tall Timbers Research Station and Land Conservancy and is provided without charge to promote research and education in Fire Ecology. The E.V. Komarek Fire Ecology Database is the intellectual property of the Tall Timbers Research Station and Land Conservancy.

Description

The aim of the present study was to investigate the causes of increased macronutrient concentrations in above-ground post-fire regrowth in an East African savanna (Northern Tanzania). Experiments were set up to discriminate between the following possible causes: (1) increased soil nutrient supply after fire, (2) relocation of nutrients from the roots to the new shoots, (3) rejuvenation and related changes in plant tissue composition and (4) changes in nutrient uptake in relation to above-ground carbon gains. N, P, K, Ca and Mg concentrations in post-burn graminoid vegetation were compared with clipped and with unburned, control vegetation during the post-burn growth season. One month after burning and clipping, nutrient concentrations in live grass shoots in the burned and clipped treatments were significantly higher than in the control. This effect, however, declined in the course of the season and, except for Ca, disappeared three months after onset of the treatments. There were no significant differences in live grass shoot nutrient concentrations between burned and clipped treatments which suggests that the increased nutrient concentration in post-fire regrowth is not due to increased soil nutrient supply via ash deposition. The relatively low input of nutrients through ash deposition, compared to the amount of nutrients released through mineralisation during the first month after burning and to the total nutrient pools, supports this suggestion. There was no difference between burned and unburned vegetation in total root biomass and root nutrient concentrations. Relocation of nutrients from the roots to the new shoots did not, therefore, appear to be a cause of higher post-fire shoot nutrient concentrations. The present study shows that in this relatively nutrient-rich savanna, the increased nutrient concentration in above-ground post-fire regrowth is primarily due to increased leaf:stem ratios, rejuvenation of plant material and the distribution of a similar amount of nutrients over less above-ground biomass.

Online Link(s):
Citation:
Van de Vijver, Claudius A. D. M.; Poot, Pieter; Prins, Herbert H. T. 1999. Causes of increased nutrient concentrations in post-fire regrowth in an East African savanna. Plant and Soil 214(1-2):173-185.