Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Accueil du site → Master → Afrique du Sud → 2006 → The effect of burning frequency on invertebrate and indigenous flowering forb diversity in a Drakensberg grassland ecosystem

University of KwaZulu-Natal (2006)

The effect of burning frequency on invertebrate and indigenous flowering forb diversity in a Drakensberg grassland ecosystem

Arnott, Wendy Lynn.

Titre : The effect of burning frequency on invertebrate and indigenous flowering forb diversity in a Drakensberg grassland ecosystem

Auteur : Arnott, Wendy Lynn.

Université de soutenance : University of KwaZulu-Natal

Grade : Master of Science (MS) 2006

Résumé partiel
The KwaZulu-Natal Drakensberg, South Africa, is predominantly a grassland ecosystem maintained by fire. The effect of the current burning regime on invertebrate and flowering forb diversity in this ecosystem is poorly understood. The overall aim ofthis study was to contribute towards the development of an effective burning regime for the KwaZulu-Natal Drakensberg that will conserve invertebrates and indigenous forbs, two major components of biodiversity. The objectives were to examine the effect of fire and fire frequency on flowering forb and invertebrate species diversity, to determine whether fire frequency, time since last burn or locality were influencing species composition, and to identify potential biodiversity indicators that reflect overall species richness for use in monitoring of invertebrates and forbs. Sampling took place in March, September and November of 2002 at Giants Castle Game Reserve. Invertebrates were sampled using sweep netting and targeted netting along transects, yellow pan traps and soil quadrats. Invertebrate taxa sampled were ants (Formicidae), butterflies (Lepidoptera), grasshoppers (Orthoptera), leafboppers (Cicadellidae), bees (Apoidea), bee flies (Bombyliidae), hover flies (Syrphidae), robber flies (Asilidae), spiders (Araneae), earthworms (Oligochaeta) and millipedes (Diploda). These were identified to species level with the assistance of taxon experts. Flowering forbs were sampled using five replicates of five by five metre quadrats randomly placed in each site. Overall flowering forb and invertebrate species diversity was higher in grasslands that were burnt for two consecutive years in 2001 and 2002 than in grasslands that were not burnt during those two years. Frequently (annual) and intermediately (biennial) burnt grasslands had significantly higher invertebrate and flowering forb diversity than infrequently (five years without burning) burnt grasslands.

Présentation

Version intégrale (6,51 Mb)

Page publiée le 9 janvier 2021