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A description of wetland habitats on nutrient-poor sandstone and quartzite substrates across South Africa is given. Most of these are situated in the Fynbos Biome and are dominated by sclerophyllous shrubs but there are some sedge-dominated vegetation types as well as geographical outliers found in Pondoland, the Kamiesberg, the Mpumalanga escarpment, the Soutpansberg and the Waterberg. A subset from a national survey of wetland vegetation was selected for analysis in terms of classification and ordination. This resulted in a classification of 27 communities which are summarized in eight community groups. The variation in the dataset can be largely differentiated by means of altitude and cations and the associated ordination separates a small number of plots belonging to communities that are also distributed outside of the Fynbos Biome from the rest of the dataset. Within the Fynbos Biome, there are different wetland vegetation types found on steep slopes, with shallow soils and a high sand content versus the valley bottoms with deeper soils and a higher silt and clay content. There are also small differences in the nutrient status of different communities. This research showed that wetland plant communities in nutrient-poor communities have a distinct species composition. Species originate from a diverse range of functional types and phylogenetic groups compared to the typical wetland vegetation found in nutrient-rich grassy habitats in the rest of the continent. [ABSTRACT FROM AUTHOR]

Abstract: South Africa faces growing impacts on wetlands and limited resources for conducting assessments. In response, a method for the rapid assessment of ecological condition based on the impacts of human stressors on hydrogeomorphic processes and vegetation responses was developed. The rapid assessment method, referred to as WET-Health, divides wetlands into hydrogeomorphic (HGM) units that are assessed individually. Results are then combined into a composite health score for the wetland system being evaluated. Deviation from the natural reference condition is examined for three separate but interlinked components of ecosystem health: hydrology, geomorphology and vegetation. The spatial extent of the HGM unit affected by a human impact is estimated and the intensity of the impact in the affected area is scored on a scale of 0 (no impact) to 10 (complete transformation) based on pre-determined indicators that are rated using clear scoring guidelines. Extent and intensity are combined to give an index of the level of departure from the natural reference condition. An assessment is also made in each module of the likely trajectory of change of the wetland. This paper describes the method in order to reflect on the central approach and highlight its heuristic and hypothesis generating value. [Copyright &y& Elsevier]

• South Africa has a paucity of process-based research into ecosystem services. • We used a Delphi-based method to validate an ecosystem service assessment technique. • We compared expert opinion and assessment technique scores for three wetlands. • The process led to identifying refinements that could be made to the technique. • The Delphi method has potential for solving environmental problems. Wetlands differ in their ability to provide ecosystem services, and thus there is a need to assess ecosystem service delivery in order to prioritize protection and restoration efforts. We used a Delphi-based expert-panel method to validate an ecosystem services assessment technique in a context where there is a paucity of field-level process-based research into the delivery of ecosystem services. The validation process entailed comparing scores from a panel of wetland experts to that derived by WET-EcoServices. Three wetlands were selected where detailed information relating to the supply of regulating services was available. At each site a selection of regulating services was assessed and then scored using the technique and independently by the panel of experts. The expert panel reached high levels of consensus (83%) on the scores for the three case studies used in the validation process. The consensus formed a useful basis for the validation of the technique. Statistical testing revealed no significant differences between expert and technique scores however, when considered practically, there were small differences in 53% of the scores, moderate differences in 23% and large in 20%. In most cases the technique over scored relative to the expert assessment. The results were useful for identifying specific refinements to the technique. The study demonstrates how a three-way "engagement" of a rapid-assessment technique, expert opinion and detailed research can be used to improve ecosystem services assessments in resource-limited situations. We reflected on the use of the Delphi method in a resource-constrained environment and advocate its careful application in similar contexts. [ABSTRACT FROM AUTHOR]

The common wetland vegetation types categorized as temperate grassy wetlands have tall or medium tall graminoids that are found in the Highveld and other grassland areas in South Africa, but can extend into other biomes. The data on temperate grassy wetlands were extracted from a nationwide wetland vegetation database, consisting partly of historical vegetation data and partly newly collected data. A classification of these vegetation types took place using cluster analysis. Some of the vegetation data contained detailed soil parameters, which were used in canonical ordination to illustrate which environmental variables have the most impact on these vegetation types. Temperate grassy wetlands consist of twenty-five communities, which have been summarized in this paper into thirteen community groups. These wetlands occur over a wide altitudinal range as many of the species occurring in them have broad ecological amplitudes and are competitive even outside of their optimum range. The environmental variables that were the most important in explaining both the variation in the dataset and the vegetation types were wetness and altitude. [ABSTRACT FROM AUTHOR]

This paper describes grass lawn wetlands, which are wetlands subjected to dynamic conditions, particularly highly fluctuating water tables that regularly drop deep below the ground surface. This occurs mostly in floodplain wetlands, as well as in wetlands in semi-arid regions or coastal plains. These wetlands are often dominated by short lawn grasses, particularly Cynodon dactylon , while other life forms, from taller tufted sedges to trees and shrubs, occur less frequently. A subset of data from a nationwide survey of wetland vegetation representing these grass lawn wetlands was selected for analysis using clustering and ordination techniques. Thirty-seven wetland communities are described and are further summarized into 13 community groups. Wetland communities on the coastal plains were associated with sandy soils whereas most of the other communities had a high clay fraction. Grass lawn wetlands are commonly found in a zone along the central, semi-arid part of the country and for this reason will likely play an important role in wetland monitoring in the long term. [ABSTRACT FROM AUTHOR]

In this paper, the wetland vegetation types of subtropical wetlands occurring in South Africa are discussed. The South African National Wetland Vegetation Database targeted the collation of all available wetland vegetation data consisting of species composition, Braun-Blanquet cover-abundance data and the relevant environmental parameters. A subset of this database that represented subtropical wetlands, was used for analysis by means of clustering and ordination techniques. Forty-nine wetland communities are described and these are summarized into sixteen community groups. The most important factors that account for the variation among these wetlands are the soil clay percentage and associated soil electrical conductivity. Some communities are associated with peaty or sandy soils with a very low soil electrical conductivity on the coastal plain while others that occur more in loamy soils with a high soil electrical conductivity are associated with drainage channels, at the foothills of mountains or the escarpment. A specific group of wetlands is associated with nutrient-poor substrates of the Msikaba group Sandstones in Pondoland or on coastal sands of Maputaland. Subtropical wetlands are particularly vulnerable to degradation due to cultivation as they are found in some of the most densely inhabited rural areas of South Africa. [ABSTRACT FROM AUTHOR]