The analysis of the national wetlands vegetation database: freshwater lowland palustrine wetlands
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Date
2015-12
Authors
Mtshali, Hlengiwe
Journal Title
Journal ISSN
Volume Title
Publisher
University of the Free State
Abstract
The South African wetlands vegetation is not well known. Number studies were
conducted to classify vegetation focusing mostly in small areas throughout the country.
Data from all studies were collated and used to build the National Wetlands Vegetation
database. This study was aimed at grouping the similar vegetation plots in the NWVD
into plant communities, to find what extent environmental factors can explain patterns
in plant species composition, to find which species can be used as environmental
indicators in wetlands and to determine how the species respond to the environmental
variables that drive the ecosystem. The database contains eight Main Clusters that are
further subdivided into communities. Each of these Main Clusters is used as a starting
point for further, more detailed analysis. Two of the Main Clusters, Sclerophyllous
Wetlands Vegetation and Temperate Grassy Wetland vegetation w~re used for the
purpose of the study. In order to understand the various types of wetlands and their
environmental drivers, data analytical data analytical techniques were used to reveal
patterns in species composition and their correlation with environmental factors. The
multivariate methods used for the analysis of the database were cluster analysis,
indicator species analysis, ordination, group testing, and species response curves. All
of the above-mentioned methods make use of similarity measures among sample
units. S0renson similarity measure was the measure of choice. Analysis was performed
using the two data analytical I packages PC-Ord 6 and HyperNiche 2. The most
contrasting influential environmental variables for South African wetlands are Soil
texture, Hydrogeomorphic type and the Wetness index. This study also contributes to
the management and conservation of water resources. Recommendations are made as
to how the vegetation can be used in the assessment of wetlands health/quality and
monitoring of wetlands, as well as management.
Description
Keywords
Classification, Environmental conditions, Group testing, Indicator species, Ordination, Species response, Wetlands -- South Africa, Wetland plants, Wetlands ecology, Dissertation (M.Sc. (Plant Sciences))--University of the Free State, 2015