African Wildlife and Environment Issue 65

FAUNA, FLORA & WILDLIFE

FAUNA, FLORA & WILDLIFE

bearing plants that have no flowers. Gymnosperms are all classified as ‘soft-woods’ which, surprisingly, has nothing todowith the hardness of thewoodbut rather

The generic name Podocarpus literally means ‘foot ( podo ) fruit ( carpus )’! This is apt, as three of the four species all have a fleshy appendage at the base of the

The mystical, majestic YELLOWWOOD Globally there are around 150 species of Yellowwoods - mainly in the southern hemisphere, with the greatest concentration of species on the Australian plate (Australia, New Zealand and New Caledonia).

describes the anatomical structure of the wood (Gymnosperms only have trachieds and no vessels or xylem that Angiosperms have). In fact balsa, a very soft wood to work, is also classified as a ‘hard-wood’ - all very confusing to the amateur! The fruits of our Yellowwoods are all roundish and dispersed by birds and bats. Many readers may know that Cape Parrots Poicephalus robustus are strongly associated with one of our giant Yellowwoods, namely Podocarpus henkelii , which is most common in Afromontane Forest patches from the northern Eastern Cape to southern KZN (King William’s Town to just north of Pietermaritzburg). And it seems that the conservation of these parrots is hugely dependent on us properly conserving those forest patches where P. henkelii flourish.

Eugene Moll

Podocarpus latifolius fruit

Of our four species, only the Breede River yellowwood P. elongatus is a re-sprouter after disturbance; possibly because it grows in habitats that are episodically disturbed (such as river banks in the Cape Mountains that are subjected to occasional torrential flooding, and on cliffs where falling rocks can strip off the vegetation at lower levels). Thus to be able to re-sprout gives this species a great advantage for its long-term survival. This species is the smallest of the four, possibly because any big and old species were harvested historically. The next biggest is P. latifolius that tends to be most common on forest margins and in drier forest patches. Interesting enough Roddy Ward (recently deceased), one of our best field ecologists, discovered it in the Dune Forest near Isipingo – which I found most interesting. Another interesting Yellowwood distribution is that in the Swamp Forests on the Tongaland Plain (in the region of Kosi Bay) where A. falcatus can occur as very big trees. To me, who considers this species to be an Afromontane specialist, this lowland distribution is rather strangely out-of-place. While talking about size and age, it is a myth that Yellowwoods can live for 1 000 to 2 000 years; actually the oldest known specimen was from the Karkloof and was some 700 years old. In fact, except for baobabs, few South African trees are much older than 500 years; indeed many are much younger. With respect to height, maybe our two forest species, P. henkelii and A. falcatus are the tallest of our SA trees, reaching heights in the region of maybe 40 m.

fruit and only Afrocarpus falcatus is footless, and for this reason it has been placed in a separate genus (see photos). As an interesting aside, this species did not occur naturally on the Cape Peninsula where it has been introduced and today is spreading and so considered by some as an alien invasive! Years ago, when the then Department of Forestry was the custodian of the Knysna Forest and mountain catchment areas, Yellowwoods were some of the species that were sustainably harvested from the forest. To minimise the destructive impact that a felled giant can have on the surrounding vegetation, the Department had skilled people who could fell all the side branches before cutting down the main trunk. The trunk was then cut into pieces that could be safely airlifted from the forest – again minimising the destruction that slip-paths have. However, now that SANParks is the custodian of the Knysna Forest, the practice of sustainable harvesting has ceased and one has to wonder whether this new management regime is better – time for a debate on sustainable harvesting for human consumption!

The majest Podocarpus latifolius with a visible strangler fig starting its growth

Our Yellowwoods are amongst our historically most famous timber trees; but not all of the four South African species were used for timber products (the best known timber species is in fact Afrocarpus falcatus [once known as Podocarpus falcatus ] followed by P. henkelii and occasionally P. latifolius - if the trunks of the latter were not too twisted). Thus it was that the early European settlers to the Cape

very soon ran out of useable timber harvested from the forests on the Cape Peninsula, and soon had to get this from Knysna, where there was a much more abundant supply. Yellowwoods are mostly evergreen forest trees with separate male and female trees that are wind pollinated. They are in fact Gymnosperms, so more closely related to pines and cedars that are cone

Eugene Moll emoll@telkomsa.net

44 |

45 | African Wildlife & Environment | 65 (2017)