The conservation value of artificial ponds in the Western Cape Province for aquatic beetles and bugs
Date
2007-12
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH ABSTRSACT: Freshwater insect species and their host ecosystems are widely threatened,
particularly within agricultural and urban landscapes of Mediterranean areas,
including that of the Western Cape Province, South Africa. The study here
determined the biodiversity value of nineteen artificial ponds (temporary and
permanent) and two river margin sites in the Cape Floristic Region (CFR). The aim
was to determine aquatic beetle and bug abundance and species richness in these
ponds, a topic which has been hardly explored in South Africa. Sites were sampled
from September 2005 to September 2006. A total of 18 677 aquatic beetle and bug
individuals were sampled, representing 43 genera (28 beetle and 15 bug genera), 64
species (44 aquatic beetle and 20 bug species). Different pond types had distinct
species assemblages. The associated physico-chemical characteristics of these sites
were also investigated. The key environmental variable affecting aquatic beetle and
bug distribution was naturalness (no human and environmental impact on
waterbody). The results showed that the most important determinant of aquatic
beetle and bug species richness across all sites was emergent macrophytes, such as
Typha capensis and Persicaria decipiens. Artificial ponds in the CFR clearly increase
the area of occupancy for insects, and therefore play a major role in conserving
them. This is especially so when the ponds are at moderate temperatures (i.e. 19ยบ
C). Although all ponds contributed to the aquatic beetle and bug diversity in the
region, they differed in relative value, depending on the combination of environmental
variables affecting each pond.
Description
Thesis (MScConsEcol (Conservation Ecology and Entomology))--University of Stellenbosc, 2007.
Keywords
Conservation, Ponds, Insects, Theses -- Conservation ecology and entomology, Dissertations -- Conservation ecology and entomology