Patches

Apparent monoculture patches in fynbos and regionally related veld are sometimes short-lived, caused for instance by recent fire. Soil type or content, water availability and elevation may also result in gradual or abrupt switches in observed vegetation.

So can alien invasion, and other disturbances caused by people change veld parts. The too well-known examples include Australian pines, hakeas, wattles and gums that create monocultures where their natural enemies are absent, to the extent of excluding fynbos entirely. Genetic monocultures mostly refer to crops with little to no genetic variation, from using cultivars. Such populations can be susceptible to disease.

In nature certain leucadendrons may “take over” in deep sandy soil for a time, a protea may take a liking to a shale band, or some restios can form dense swards in wet seeps. But fynbos generally tends to strong diversity of numerous species coexisting in tight ecological niches. Barriers to entry are usually low. This reduces single species dominance to limited phases in the veld, when not stressed by poor management practices (Wikipedia).