Herbaceous species diversity patterns across various treatments of herbivory and fire along the sodic zone of the Nkuhlu exclosures, Kruger National Park

Koedoe - African Protected Area Conservation and Science


 
 
Field Value
 
Title Herbaceous species diversity patterns across various treatments of herbivory and fire along the sodic zone of the Nkuhlu exclosures, Kruger National Park
 
Creator van Coller, Helga Siebert, Frances Siebert, Stefan J.
 
Subject Botany; Ecology; Environmental management; Conservation biomass; fire; herbivory; nutrient hot spots; riparian zone; sodic zone; species diversity; species richness
Description Understanding relationships between large herbivores and plant species diversity in dynamic riparian zones is critical to biodiversity conservation. The Nkuhlu exclosures in the Kruger National Park (KNP) provided opportunity to investigate spatial heterogeneity patterns within riparian zones, as well as how these patterns are affected by fire and herbivory. A monitoring project was initiated to answer questions about the dynamics of the herbaceous layer and was aimed at determining, (1) whether there exists meaningful variance in herbaceous plant species richness and diversity across different treatments in the ecologically sensitive sodic zone and (2) whether an increase in herbaceous biomass, an artefact of herbivory and fire exclusion, suppresses herbaceous plant species diversity and richness. Herbaceous vegetation was sampled in two 1 m2 circular sub-plots in the eastern and western corners of 81 fixed plots. The biomass of each plot was estimated with a disc pasture meter (DPM) diagonally with the plot. DPM-readings were converted to kg/ha, according to the latest conversions for the Lowveld Savanna. Species richness and biomass showed significant variance across treatments, whereas no significant variation in herbaceous species diversity was perceived. Combined treatment of fire absence and herbivore presence contributed to higher forb species richness in the sodic zone. Biomass is significantly higher in fully fenced areas where herbivores are excluded, as opposed to the open and partially fenced areas. Although no significant variation was recorded for diversity across treatments, lowest diversity was recorded in the absence of all herbivores, especially in combination with fire treatment. Therefore herbivores are essential in sustaining herbaceous plant species richness in the sodic zone, whilst no significant results were found with regard to their effect on species diversity. Although statistically non-significant, fire seems to suppress species richness.Conservation implications: This study could be used as framework to advance and develop science-based management strategies for, at least, the sodic zones of the KNP. Research in these exclosures will create better understanding of these landscapes, benefit ecosystem conservation planning of national parks and also provide valuable long-term information on key ecological processes.
 
Publisher AOSIS Publishing
 
Contributor SANParks, Research Unit: Environmental Sciences and Management, North-West University
Date 2013-03-18
 
Type info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion — Survey; Plot methods
Format text/html application/octet-stream text/xml application/pdf
Identifier 10.4102/koedoe.v55i1.1112
 
Source Koedoe; Vol 55, No 1 (2013); 6 pages 2071-0771 0075-6458
 
Language eng
 
Relation https://koedoe.co.za/index.php/koedoe/article/view/1112/1467 https://koedoe.co.za/index.php/koedoe/article/view/1112/1468 https://koedoe.co.za/index.php/koedoe/article/view/1112/1469 https://koedoe.co.za/index.php/koedoe/article/view/1112/1466
 
Coverage South-Africa; Kruger National Park — Biomass (kg/ha); Species richness; Species diversity
Rights Copyright (c) 2013 Helga van Coller, Frances Siebert, Stefan J. Siebert https://creativecommons.org/licenses/by/4.0