Sweet thorn encroachment in the Eastern Cape
Many years ago, people started observing that sweet thorn (Vachellia karroo) was gradually migrating out of its known habitats in a westerly direction in the Eastern Cape. A simultaneous westerly spread of kudu into areas where they were previously unknown was attributed largely to this phenomenon.
THE ROLE OF CLIMATE CHANGE
Scientists suspect that global warming, and particularly warmer temperatures, have triggered and accommodated this westerly expansion of . The saplings and seedlings of this species are vulnerable to cold nights and are killed off at what is known as the critical elimination temperature. Several nights in succession of temperatures at this level will kill the saplings and seedlings, whereas just one or two nights of these low temperatures will enable a percentage of the plants to survive.
