Sand Forest

Sand Forest

According to the definitive vegetational classification, there are three distinct types of forest in southern Africa. Combined, these areas occupy less than 1% of the region's land surface, whereas ‘woodland' extends over half of the subcontinent. To ecologists and botanists, ‘forest' differs from ‘woodland-savanna' in that the canopies of the trees are interlocked, and grass cover is sparse or absent.

‘Afromontane Forest' occurs in patches along the eastern escarpments of South Africa and Zimbabwe, typically in east-facing situations where rainfall from the Indian Ocean is highest. ‘Coastal Forest' formerly extended from Mozambique south to the eastern Cape (where it met Afromontane Forest) but only remnant patches of this now remain. Both of these forest types are moist and require high annual rainfall. The third and most unusual forest type is ‘Sand Forest' which is confined to the deep sands of Maputaland and Mozambique.

Growing on fossil dunes

Sand Forests are thought to be relics of coastal dune forests which have been separated by the ocean for more than a million years (the African shoreline has shifted slowly eastwards over the millennia). Today, the forests are, in effect, growing on ‘fossil dunes'. Typical elements of moist forests, such as ferns and mosses are comparatively scarce, while the appetite of the abundant termites appears to limit the accumulation of dense leaf litter. Most obvious from an aerial perspective, Sand Forest is characterised by sharply defined fringes, often delineated by narrow zones of bare or sparsely-vegetated sand.

Threatened by fire and elephants

For much of the year, Sand Forests are bone dry with a very sparse and open understorey, but they are nevertheless filled with unusual plants, birds and small animals. These extraordinary forests consist of numerous endemic or restricted-range species, but research suggests that they have no capacity to regenerate. Uncontrolled burning and excessive browsing by contained elephant populations may have irreversible impacts on this rare forest type and its unique biodiversity.

Based at Phinda Forest Lodge, ranger Ross Goode has recently won the annual &Beyond ‘Best Field Project' award for his analysis of Sand Forest plant communities, which will serve as means of assessing the impacts of the reserve's growing elephant population. Goode's report is published in the annual Ecological Journal.

Characteristic Trees

Extensive areas (up to 1000 hectares) in the north of Phinda - including the surrounds of Forest and Vlei Lodges - are comprised of this distinctive, species-rich forest. Characteristic trees include the Sandveld Newtonia, Green-thorn, False Tamboti, Small Red-heart Tree, Forest (Coldbark) Ochna, Quiver-leaf Fig and Galla-plum; the forest fringe is dominated by Stink-bushwillow, with Maputaland Ordeal Tree, Zulu Pod-berry, Flat-crown Albizia, Toad-tree and Saddle-pod well represented. Where light penetrates the forest, Sand Lemon-rope and Tonga Croton are common shrubs, while the Zulu Coshwood and Sand Canary-berry flourish in deeper shade. Epiphytic orchids, vines and lichens are abundant, and the leafless, epiphytic cactus - Rhipsalis baccifera (the only member of the cactus family in Africa and a relic of Gondwanland) - is commonly seen draped on larger trees.

Rich in birds, unnamed insects

The Phinda Sand Forest is rich in birds, with several species more-or-less restricted to it. Among the more interesting are the African Broadbill, Narina Trogon, Neergaard's Sunbird, Square-tailed Drongo, Dark-capped Weaver, Rudd's Apalis, Pink-throated Twinspot, Green Twinspot, Eastern Bearded Scrub-Robin and Blue-mantled Crested-Flycatcher. The lovely call of the African Wood-Owl is often heard after dark and African Crowned Eagle may nest in emergent trees. Rarely seen mammals such as the Red Duiker, Suni and Tonga Red Squirrel are common in Sand Forest, while Bushpig, Nyala, Aardvark and Leopard are frequently encountered. African Elephant wander in and out in search of favoured food. Among the numerous beautiful butterflies are the Mamba Swordtail, Gold-banded Forester and the diminutive Dwarf Blue. It is likely that numerous species of insects, and perhaps spiders, in the Sand Forest are new to science.

A walking safari or lodge visit at Phinda will reveal the magic of the unique Sand Forest.

- Duncan Butchart -

Posted: Other by CC Africa, Date: 21 November 2006