Subtropical Thicket

The Maputoland-Tongoland-Albany hotspot

The Maputoland-Tongoland-Albany biodiversity hotspot is the most recently recognised hotspot in Africa. It is scientifically not well known and goes under many names, but on a national level is recognised as the Albany Thicket biome (Mucina& Rutherford 2006). The Maputoland-Tongoland-Albany biodiversity hotspot concept expands eastwards, well beyond the current nationally recognised concept of the Albany Thicket biome, but even in the restricted concept this biome is well represented in the biosphere reserve.

Although there is still much scientific dispute about its extent (what should be included or excluded) this is probably one of the most ancient vegetation types in Africa (Cowling & Pierce 2009), if not globally. It occurs mostly in an ameliorated climate, and the presence of this vegetation type and the postulated origin of modern man along the coastal part of the biosphere reserve is probably not coincidental.

One of the 14 vegetation units of this biome recognised by Mucina and Rutherford (2006) is endemic to the biosphere reserve. Their contemplation of the vegetation of this biome was, however, very conservative. In a more detailed survey of the region several more distinctive vegetation units were recognised (Vlok et al. 2005; Vlok & de Villiers 2007), many of which are endemic to the region and severely threatened.

Rarely understood and recognised to date in scientific studies of the South African vegetation types is the interlinking between seemingly vastly different floras, which is perhaps the reason for the many differences of opinion about the extent of this biodiversity hotspot. It seems to be an odd linkage to both the temperate and subtropical vegetation of South Africa. This complex vegetation type was a mystery to past researchers and they swept it under the carpet. Clearly a key to better understanding of the immense biodiversity of the Cape Floristic Region lies in further research of this vegetation type.

The Maputoland-Tongoland-Albany Thicket biome. This area is adjacent to the core of the biosphere reserve (in the background). Game fences were erected recently around the property in the foreground, obstructing natural migration routes of indigenous fauna and obscuring the view of this unspoilt environment. Through sharing gratis information the biosphere reserve intends to rectify such inconsiderate management actions

(Photo: Jan Vlok). 

Characteristic species:

Typical and characteristic species are an abundance of trees that show a sub-tropical phylogenetic affiliation such as Euclea undulata and Pappea capensis and members of the Celastraceae such as Gloveria integrifolia, but none of them are endemic to the area. They merely represent the western extreme of this ancient biome that probably occurred in the Gondwanaland and later fluctuated all over the African continent.

It is important to realise that even the best scientists are still battling to understand this complex vegetation type. The scientific community only recently managed to agree to recognise this vegetation type as something unique.

Important natural processes:

Large herbivores play an important role as a disturbance agent in solid stands of this vegetation type and can only be introduced and managed once extensive conservation areas have been established.

Little is known regarding other important ecological processes, except one thing: fire is a threat to solid stands of this vegetation type, but it may play an important role to retain biodiversity pattern where this vegetation merges with the Fynbos vegetation.

Main human impacts:

In being largely a relict vegetation type, with its present occurrence mainly reflecting previous climatic regimes in the area, this vegetation type is particularly prone to the impacts of modern man and most of these impacts are very difficult, if not impossible, to reverse.

Past grazing practices by domestic stock removed many of the palatable plants, especially Spekboom (Portulacaria afra).

Harvesting of trees for fence poles, firewood etc. resulted in the loss of many typical trees of this vegetation.

Introduction of foreign game species harms the ecological integrity and functioning of the local vegetation types, while game fencing threatens the natural seasonal movement of indigenous game.

The lowering of the underground water table through water abstraction to support urban areas and other developments may well threaten the persistence of the tree component of this vegetation type.

Relevant management practices:

  •  Inform private landowners who own important remnant patches of this biodiversity hotspot about the conservation value of their land, especially with a view to linking their land-use to existing core conservation areas.
  • Engage with emerging game industry to ensure that only indigenous game species are introduced and maintained at sustainable levels. Stimulate collaboration between adjacent landowners to ensure that game fencing is kept to a minimum.
  • Support eco-friendly tourism ventures that can act as motivation for landowners to protect remnant patches of this vegetation type as a new source of income.
  • Restore disturbed areas, especially the thousands of hectares where Spekboom (Portulacaria afra) has been removed completely through grazing by domestic stock. 
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