Heuweltjie

Like other phenomena, such as Mima mounds and fairy circles, from which they have been poorly distinguished, particularly in early literature, they have been the subject of a wide range of speculation and of debate that has not yet been settled conclusively.

For another, they differ in nature; some for example have been seen as improving soil fertility, an opinion documented at least as long ago as the early 20th century.

[6] Yet another theory is that heuweltjies are caused by differential erosion in places where the availability of water limits the growth of vegetation, creating natural patterns such as tiger bush.

[7] In 2017 Corina Tarnita and colleagues published a paper in Nature which explained these and other related self-organised vegetation patterns by means of a general theory which integrates scale-dependent feedbacks and the activities of subterranean ecosystem engineers such as termites, ants, and rodents.

[8] Heuweltjies modify their local environment, creating a patchwork of habitats in the Nama Karoo ecosystem.