Soil-vegetation relationships on the Agulhas Plain, South Africa

Thwaites, R. N.; Cowling, Richard M.

doi:10.1016/0341-8162(88)90055-0

Cited by 55 publications

(43 citation statements)

References 8 publications

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“…As the entire area was inundated by transgressions during the mid-Miocene (15 Myr (million years)) and the early-mid-Pliocene (4 Myr), most sediments and soils postdate the regression (Hendey, 1983). Despite the low topographical diversity when compared with the mountainous regions of the fynbos biome, the area has numerous contrasting soil types and land systems (Thwaites and Cowling, 1988). Table Mountain Group sandstones and quartzites, Bokkeveld Group shales, limestones, remnant silcrete and ferricrete outcrops and calcareous coastal dunes are all represented in the area.…”

Section: Study Areamentioning

confidence: 99%

Patterns of endemism in the limestone flora of South African lowland fynbos

1996

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Taxonomic and biological aspects of endemism and Red Data Book status were studied amongst the limestone endemics of the lowland fynbos in the Cape Floristic Region, South Africa. Of the 110 limestone endemics, 1.8% are widely distributed in the Cape Floristic Region and 56.4% are regional endemics. Relative to flora of non-limestone lowland fynbos (n = 538 species), the families which were overrepresented in terms of limestone endemics included the Ericaceae, Fabaceae, Polygalaceae, Rutaceae and Sterculiaceae. The Restionaceae was the only underrepresented family. The local limestone endemics were not significantly different from regional endemics in terms of their biological attributes. An analysis of the frequency of the biological traits associated with the limestone-endemic flora established a biological profile for a limestone endemic: a dwarf-to-low shrub with soil-stored seeds which are ant or wind dispersed. In terms of the species richness of limestone endemics, the De Hoop Nature Reserve was the 'hotspot' within the region. Relative to the total species richness, the Hagelkraal and Stilbaai areas contained higher-than-predicted numbers of rare species. These areas require urgent attention if the unique floral diversity associated with limestone substrata within the Bredasdorp-Riversdale centre of endemism is to be conserved.

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Section: Study Areamentioning

confidence: 99%

Patterns of endemism in the limestone flora of South African lowland fynbos

1996

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“…The mean annual rainfall is 452 mm of which 65 ~o falls between April and September. The soils are derived from the Mio-Pliocene limestone of the Bredasdorp Formation (Thwaites & Cowling 1988). Protea obtusifolia Beuk ex Meisn.…”

Section: Study Site and Study Speciesmentioning

confidence: 99%

“…are dioecious and female plants have seed borne in cones. Thwaites & Cowling (1988), Esler et al (1989), and Mustart & Cowling (in press …”

Section: Study Site and Study Speciesmentioning

confidence: 99%

“…This edaphic specificity is usually absolute, in that species do not occur off their soil type. The distinct, non-overlapping distribution of co-occurring Agulhas Plain fynbos Proteaceae on soils of different fertilities: Protea obtusifolia and Leucadendron meridianum on limestone derived soils, and P. susannae and L. coniferum on adjacent, colluvial sands Thwaites & Cowling 1988), suggested a study of the relationship between soil-type and plant reproductive traits.…”

Section: Introductionmentioning

confidence: 99%

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Reproductive traits of two closely related species-pairs on adjacent, different soil types in South African Fynbos

Mustart

Cowling

Dunne³

1994

Vegetatio

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High levels of edaphic endemism and soil-related beta-diversity in Agulhas Plain fynbos communities suggest that reproductive traits of plants growing on different fynbos soils would be related to differences in soil regime. We investigated reproductive traits in two closely related Proteaceae species-pairs growing on adjacent soil types: Protea obtusifolia and Leucadendron meridianum occurring in shallow pockets of limestone-derived soils, and P. susannae and L. coniferum on the adjacent, uniformly deep colluvial sands.We found that species growing on the limestone soil comprised smaller plants, with fewer cones and seeds per plant, than species on the colluvial sands. These differences suggest that the small soil pockets of limestone soil limit plant size, in turn limiting the number of reproductive structures. Annual variation in cones and seed was the same in all species. There were no consistent trends in degree of serotiny, or sex allocation across soil types. The higher cone and seed predation levels of both limestone species than the colluvial sands species were ascribed to the higher plant densities of the former leading to lower insect search times. It was concluded that there were no overall patterns in reproductive traits that could be ascribed to differences in soil regime, other than through size-related effects. Fire regime is likely to have played a more important role in determining reproductive traits.

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“…The Agulhas Plain is equally well known for exceptionally rich plant biodiversity. An area total of 1,751 plant species, including 99 endemics, 112 Red Data Book species and 46 vegetation types have been described (Thwaites & Cowling, 1988;Cowling & Holmes, 1992;Cowling & Mustart, 1994;Lombard, Cowling, Pressey & Mustart,1997;Privett, 2002;Raimondo, Von Staden, Foden, Victor, Helme, Turner, Kamundi & Manyama, 2009). Almost a third of the land surface area is formally protected in the Agulhas National Park, which also includes the southern tip of Africa and the Agulhas lighthouse, as well as De Hoop Nature Reserve, the Nuwejaars Wetland Private Protected Area and a handful of smaller wildflower reserves.…”

Section: Introductionmentioning

confidence: 99%

An estimate of the recreational value of the Agulhas Plain, South Africa, with special reference to the value of plant biodiversity

Conradie

García²

2013

SAJEMS

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The Agulhas Plain is a remarkable recreational site which combines the attraction of a pristine marine environment with exceptional plant biodiversity, rural tranquility and the novelty of being at the southernmost tip of Africa. The resource is a public good to which the market cannot assign a full value. This paper presents an estimated recreational value based on individual travel cost models and a sample of 370 visitors surveyed in 2010. Trip demands were estimated with zero truncated negative binomial models to account for over-dispersion. The study established a recreational value of R2.167 billion in 2010 prices for the site as a whole. By partitioning the sample into visitors who indicated having been attracted or not to the area by its nature and biodiversity, a net biodiversity value of R2 866 per trip was calculated. Allocated between marine and terrestrial resources based on the proportion of activities related to each type of resource, the value of plant biodiversity was estimated to be R2 268 per hectare in 2010to 2010 prices.

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Soil-vegetation relationships on the Agulhas Plain, South Africa

Cited by 55 publications

References 8 publications

Patterns of endemism in the limestone flora of South African lowland fynbos

Patterns of endemism in the limestone flora of South African lowland fynbos

Reproductive traits of two closely related species-pairs on adjacent, different soil types in South African Fynbos

An estimate of the recreational value of the Agulhas Plain, South Africa, with special reference to the value of plant biodiversity

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