Magical Maputaland

[Lisbeth]

If, as they say, the continents broke up, then they were closer to each other and a bird could have flown, but were there birds in those days?

[Richprins]

How fascinating, Klippies!

I would go for the sailor one!

[Flutterby]

Very interesting.

[Klipspringer]

Chemical Warfare in the Sand Forest

Maputaland sandforests occur in discrete patches in a north-south trending line from Tembe Elephant Park down to False Bay. The patches of sand forest are chracterised by very sharp boundaries towards the surrounding vegetation. Directly adjacent to the forest margin is usually an area of bare sand or sparse grass. These zones are called "streets", run north-south and are 1 - 2 m wide.
The reason for these distinct sharp boundaries is what scientists call the allelopathic effect of the sand forest.

All living beings have developed over time strategies to successfully compete and survive. Trees in ecological systems share the environment
with many other plants and are all competing for the same resources, often in less-than-favourable conditions. There are many losers and many
winners. Allelopathy is one of the many plant adaptations which acts as a strategy for survival.

The term allelopathy is derived from the Greek allelic, who is from one to another, and patheia, which means suffering, i.e. one party suffers as a result of another party. It refers to the active or passive effects of bio-chemicals released by one plant species in the environment that directly affects other organisms. In plants, the secretion of toxins happens to either suppress the growth of another (competing) species or promote the growth and therefore survival of their own species. Many of these agents are bio-chemical secretions and are used as a defence mechanism in plants.
Allelopathy is therefore a method of bio-chemical warfare in the plant kingdom.
Plants with these allelopathic abilities prevent other plants on an equal footing to compete for available resources. In this way, the evolution and distribution of the species that do not have the ability to allelopahatise are by nature manipulated. So one can say that allelopathic plants in a way ‘control’ the environment in which they occur.
These biochemical substances usually evolves in the seeds, fruits, flowers, pollen roots, stems and leaves and act as a powerful herbicide agent which affects the survival of other plants. The presence of these bio-chemical agents in nature play a very important role in the seed germination, root growth, symbiotic efficiency between species, susceptibility to infections and can also increase environmental stress on the plant. All these
factors ultimately contribute to the plant's ability to survive and to reproduce.
The best example of these bio-chemicals at work can be seen in the Sand Forest of Maputaland.
In this instance a unique habitat has been created, not only making the soil more suitable for trees naturally occurring in the sand forest, but also directly influencing the surrounding vegetation through manipulation. It also has an effect on the spread of fires from neighbouring woodland and grassland into the sand forest because virtually no undergrowth occurs in the Sand Forest compared with other forest types. The absence of young Newtonia hildebrandtii (Lebombo wattle) and Cleisthantus schlechteri (False Tamboti) plants, which are endemic to the Sand Forest leads to the thought that the germination of these trees is naturally manipulated and inhibited by chemical warefare. The immidiate soil next to the sand forest patches inhabits the emergence of seedlings. The allelopathic substances benefit the sand forest because it can actively exclude competitors from the habitat. But eventually this sand forest will also inhabit the regeneration of its very own kind when old trees die.
That's why the sand forest is able to maintain itself but it can not expand or regrow after distruction. When you destroy it, it's gone forever :-

[Lisbeth]

Not only in the animal world but also in the plant world, the strongest survive or rather the best "equipped" one, which at the end is the same thing if you do not only look at size

the sand forest is able to maintain itself but it can not expand or regrow after destruction. When you destroy it, it's gone forever

and that's where conservation comes in and has its most important role

[Richprins]

How fascinating, Klippies!

There is a similar chemical warfare story somewhere about overstressed trees poisoning browsers with tannins!

[Klipspringer]

That's a similar defence.

But the important point here is, that the sand forest is the only type of forest that can not regenerate. Afromontane forest or dune forest will regrow, sand forest won't. A forest at war with itself if you like

[Richprins]

[Lisbeth]

In this case, maybe humans can help out