Volcanic Ash Soils of the Southern Plains

node · earth · Southern Serengeti and western Ngorongoro Conservation Area

The shallow, mineral-rich soils of the southern Serengeti plains, formed from ash deposited by the Crater Highlands volcanoes — the same deposits that make Olduvai Gorge readable. The ash is carbonatitic and leaves soils comparatively high in phosphorus and calcium, so the short grasses growing on them carry mineral concentrations that matter to a lactating female far more than bulk does. This is the standard explanation for why the herds choose the driest, least productive part of the ecosystem for calving: the grass there is not abundant, it is good.