This exhibit is on display at Garden World from 30 July till 5 September 2010
South Africa had a very important task ahead of them this year: to maintain it’s innovative & unusual interpretations of our spectacular plant heritage. It was with excitement that designers David Davidson & Ray Hudson – designing the exhibit for the 17th time, took up the challenge to explore the theme of biological diversity, in celebration of 2010 as the International Year of Biodiversity. They produced an unusual & thought provoking exhibit for the South African National Biodiversity Institute’s (SANBI’s) 2010 Kirstenbosch – SA Chelsea entry entitled ‘Bio[logical] diversity is the variety of life’.
Intrigued by the fact that biodiversity occurs at many different levels, ‘ranging from complete ecosystems to the chemical structures that are the molecular basis of heredity’, this year’s exhibit attempts to illustrate the diversity as well as the genetic variability of the botanical wealth that makes South Africa the third most biologically diverse country in the world.
Commonly known as the “Olympics” of the industry, the Chelsea Flower Show is one of the most visited exhibitions in the world & attracts people from a wide variety of disciplines & countries. As a major tourism opportunity the Kirstenbosch-South Africa exhibit attracts wide attention & the result is many more people visiting our country to see our wonderful National Botanical Gardens (NBG’s) as well as enjoy the myriad other attractions our country holds.
In attempting to exhibit biodiversity within the South African flora at various levels, the designers created an exhibit that represents several of the different vegetation types comprising the nine biomes of South Africa, grouped in four separate nodes, each with its own cluster of interconnected, hexagonal compartments. In addition, the display included ‘fine-scale’ examples of genetic variability within a single species as well as diversity among species – & within different genera.
The four clusters featured plants from the following biomes:
- Fynbos (Cape Floral Kingdom – proteas, restios, ericas [heathers])
- Forest/Thicket [Sub-tropical] (cycads, euphorbias, strelitzias)
- Desert/Succulent Karoo (succulents)
- Savanna/Grassland (aloes, grasses & bulbs)
South Africa was consumed by soccer fever in preparation for the 2010 FIFA World Cup Soccer tournament in June/July, the design of the exhibit also revealed a fascinating consonance with the sport!
Designers David Davidson & Ray Hudson explained that using the uniform polyhedron as a design element (based on the familiar diagrams used to illustrate the chemical or structural properties of molecules) to determine the layout of the exhibit, overarched by a geodesic domed roof structure (similar to the domed climatron greenhouse of the Eden Project in Cornwall) bore uncanny results! “& as coincidence would have it”, laughed Davidson, “this same formula was also the original inspiration for the design of the soccer ball”.
According to SANBI CEO Dr Tanya Abrahamse: “This exhibit is a major way of reaching potential tourists but also, once it is recreated on home soil, offers South Africans the chance to enjoy & understand how important it is to conserve these natural resources. As SANBI’s mandated responsibility includes making biodiversity accessible to all South African’s, our Chelsea exhibit contributes to this intent in a very real & exciting way.”
The exhibit has been recreated on home soil at Garden World for the duration of their Spring Festival from 30 July to 5 September 2010, giving South Africans the opportunity to view the Silver Award Winning Exhibit that illustrates the diversity as well as the genetic variability of the botanical wealth that makes South Africa the third most biologically diverse country in the world.
THE NINE BIOMES
South Africa’s vegetation types can be grouped into the following nine biomes based on shared ecological & climatic characteristics: Fynbos, Forest, Succulent Karoo, Nama Karoo, Savanna, Albany Thicket, Grassland, Desert & Wetland vegetation. Each biome supports its own collection of plants & animals. The Karoo biomes, for example, are home to plants & animals that are well suited to hot, dry conditions while the Fynbos biome has a variety of plants that are adapted to the Mediterranean climate & nutrient-poor soils of the South-Western Cape.
FYNBOS BIOME [FEATURED]
The Fynbos Biome is synonymous with the Cape Floristic Region or Cape Floral Kingdom. However, the Biome refers only to the two key vegetation groups (Fynbos & Renosterveld) within the region.
Renosterveld used to contain the large animals in the Cape Floristic Kingdom, while Fynbos is much richer in plant species, but has such poor soils that it cannot support even low densities of big game. However, most of the endemic amphibian, bird and mammal species in the region, occur in Fynbos vegetation types.
Fynbos is characterised by the presence of the following three elements: Restios, belonging to the Restionaceae or the Cape Reed Family; Ericas or heaths & Proteas which are the dominant overstorey in Fynbos. Fire is a major influence on Fynbos community processes. Fynbos must burn at between 6 and 45 years of age in order to sustain its plant species. Many species store their fruit in fire-safe cones for release after a fire, & ants are enticed to bury fruit where they are safe from rodents and fire & can regenerate. Without fire, Fynbos becomes senescent & Forest & Thicket elements begin invading.
Some three-quarters of all plants in the South African Red Data Book occur in the Cape Floral Kingdom: 1 700 plant species are threatened to some extent with extinction!
Renosterveld is characterised by the dominance of members of the Daisy Family (Asteraceae), specifically one species – Renosterbos Elytropappus rhinocerotis, from which the vegetation type gets its name. Grasses are also abundant as well as a high species richness of geophytic or bulbous plants (chiefly in the Iris Family (lridaceae) & Lily Family (Liliaceae), but also in the Orchid Family (Orchidaceae).
SUCCULENT KAROO / DESERT BIOME [FEATURED]
The Succulent Karoo Biome is characterised by low winter rainfall & extreme summer aridity. Rainfall varies between 20 & 290 mm per year. In summer, temperatures in excess of 40°C are common.
The vegetation is dominated by dwarf, succulent shrubs, of which the Vygies (Mesembryanthemaceae) & Stonecrops (Crassulaceae) are particularly prominent. Mass flowering displays of annuals (mainly daisies) occur in spring, often on degraded or fallow lands. The number of plant species – mostly succulents – is very high & unparalleled elsewhere in the world for an arid area of this size. Tourism is a major industry: both the coastal scenery & the spring mass flower displays are draw cards.
True desert is found under very harsh environmental conditions which are more extreme than those found in the Succulent Karoo Biome and Nama-Karoo Biome. The climate is characterised by summer rainfall, but with high levels of summer aridity. Mean annual rainfall is from approximately 10 mm in the west, to 70 or 80 mm on the inland margin of the desert. The vegetation of the Desert Biome is characterised by dominance of annual plants (often annual grasses). Perennial plants are usually encountered in specialised habitats associated with local concentrations of water.
SAVANNA / GRASSLAND BIOME [FEATURED]
The Savanna Biome is the largest Biome in southern Africa, occupying over one-third of the area of South Africa, mainly in the Lowveld and Kalahari region and is also the dominant vegetation in Botswana, Namibia and Zimbabwe. It is characterised by a grassy ground layer and a distinct upper layer of woody plants.
Rainfall varies from 235 to 1 000 mm per year; frost may occur from 0 to 120 days per year; and almost every major geological and soil type occurs within the biome. Most of the savanna vegetation types are used for grazing, mainly by cattle or game. The importance of tourism and big game hunting in the conservation of the area must not be underestimated.
The Grassland Biome is found chiefly on the high central plateau of South Africa, and the inland areas of KwaZulu-Natal and the Eastern Cape. The topography is mainly flat and rolling, but includes the escarpment itself. Altitude varies from near sea level to 2 850 m above sea level.
Grasslands are dominated by a single layer of grasses. Trees are absent, except in a few localized habitats. Geophytes (bulbs) are often abundant. Frosts, fire and grazing maintain the grass dominance and prevent the establishment of trees.
The Grassland Biome has an extremely high biodiversity, second only to the Fynbos Biome. Rare plants are often found in the grasslands, especially in the escarpment area. Very few grasses are rare or endangered. The scenic splendour of the escarpment region attracts many tourists.
FOREST / THICKET BIOME [FEATURED]
Forests are restricted to frost-free areas with mean annual rainfall of more than 525 mm in the winter rainfall region and more than 725 mm rainfall in the summer rainfall region. The canopy cover of forests is continuous, comprising mostly evergreen trees, and beneath it the vegetation is multi-layered. Herbaceous plants, particularly ferns, are only common in the montane forests, whereas lianas and epiphytes are common throughout. The ground layer is almost absent due to the dense shade. On the edges of the patches are distinctive communities, the so-called fringe and ecotonal communities, which are able to tolerate fire. Some 649 woody and 636 herbaceous plant species are recorded from forests.
Partly because of their rarity, their grandeur and their setting, forests are an important tourist attraction in South Africa.
ALBANY THICKET BIOME
There is no formal “Thicket Biome” in the scientific literature. However, it is recognised that the vegetation which replaces forest – where a degree of fire protection is still evident, but rainfall is too low – does not fit within the “Forest” type – having neither the required height nor the many strata below the canopy. A conspicuous grassy ground layer is also absent.
Subtropical thicket is a closed shrubland to low forest dominated by evergreen and succulent trees, shrubs and vines, many of which have stem spines. Because the “Thicket Biome” shares floristic components with many other vegetation types and occurs within almost all the formal biomes, Thicket types are also referred to as “transitional thicket”.
The Nama-Karoo Biome occurs on the central plateau of the western half of South Africa, at altitudes between 500 and 2000 m, with most of the biome failing between 1000 and 1400 m. It is the second-largest biome in the region.
The rain falls in summer, and varies between 100 and 520 mm per year. This also determines the predominant soil type – over 80% of the area is covered by a lime-rich, weakly developed soil over rock. Although less than 5% of rain reaches the rivers, the high erodibility of soils poses a major problem where overgrazing occurs.
The dominant vegetation is a grassy, dwarf shrubland. Grasses tend to be more common in depressions and on sandy soils, and less abundant on clayey soils. Mining is important in the Biome. Biological diversity means the full range of variety and variability within and among living organisms and the ecological habitats in which they occur and encompasses species diversity, genetic diversity and ecosystem diversity.
WHY SHOULD WE BE CONCERNED ABOUT BIODIVERSITY?
Ecological diversity reflects the incredible variety of different ecosystems found on Earth, e.g. deserts, rainforests, grasslands, wetlands etc.
Species diversity is seen in huge range of different species of plants and animals that occur in an area, country or the world.
Genetic diversity (the level of biodiversity) refers to the total number of genetic characteristics in the genetic makeup of a species. It is distinguished from genetic variability, which describes the tendency of genetic characteristics to vary. Genetic diversity and biodiversity are dependent upon each other: genetic diversity within a species is necessary to maintain diversity among species, and vice versa.
Biodiversity maintains life on Earth – Healthy ecosystems provide the services upon which life depends: water purification, oxygen production, carbon dioxide absorption, soil stabilisation, soil fertility, flood control, nutrient cycling, pollination, seed dispersal, pollution breakdown, waste removal and decomposition. People are therefore, ultimately dependent on living, functioning ecosystems.
However, healthy ecosystems require that the extremely complex inter-relationships that exist between plants, animals and the non-living environment within ecosystems be maintained. The loss of a few species could have ripple effects on all the other interactions within an ecosystem. In time these losses de-stabilise the integrity of life on Earth.
Economic – South Africa’s economic growth and development also depends on its biodiversity. Our biodiversity provides a basis for the fishing industry, agriculture, horticulture of indigenous species, tourism, aspects of the film industry, medicines (both commercial and indigenous use of indigenous plant and animal resources) among others.
Aesthetic and spiritual value – Many people appreciate and are inspired by the beauty of the different kinds of plants and animals in their natural environments. Each species contributes to the richness of life on Earth.
Stewardship – We have an obligation to maintain biodiversity for future generations. We do not know what sources of food, medicines, materials and fibres living organisms might provide in the future.
PRESSURES ON SOUTH AFRICA’S BIODIVERSITY
Unfortunately, South Africa’s rich diversity is under extreme pressure resulting mainly from human demands placed on the environment: Habitat loss and degradation • Increased use of natural resources • Invasive alien plants and animals • Pollution.