Field Trip 01: Of sand and sun: plant tales from the dunes of the Eastern Cape

In the context of the Cape’s geological history, coastal dunes are some of the youngest landscapes, with shifting extents in response to sea-level changes and glacial-interglacial cycles — during glacial periods, the extent of coastal dunes would have been much larger on the flat Palaeo-Agulhas Plain than the present-day configuration that hugs the coastline. Dunes are also extremely harsh environments: they are exposed to high levels of solar radiation and prone to strong, salt-laden winds year-round, which also blows around highly abrasive sand grains. In addition to these factors, dune plants must also cope with the unique edaphic environment of these coastal landscapes: soils are typically sandy, droughty, highly alkaline, and poor in nutrients critical for plant growth. In such a dynamic and challenging environment, we would expect the flora to be species-poor, yet coastal dunes of the Cape are remarkably species-rich. In this virtual field trip, we will share some of the fascinating features and dynamics of this poorly understood ecosystem, using the dune fynbos–thicket mosaics around Port Elizabeth to set the scene. If you’re into sand, sun, flowers and fire, come join us!

SPEAKERS

Adriaan Grobler

Adriaan is a botanist from the eastern Cape Floristic Region who, unlike Alastair, has been enamoured with dune plants for over a decade. He is happiest when leopard-crawling through the veld in search of floral peculiarities, but also enjoys applying his knowledge of plants to help answer questions about ecology, evolution, and environmental history. Over the past three years, he has spent much time in dunes along the Cape south coast, trying to figure out how the super-saturated floras of these tiny habitat slivers came to be.

Alastair Potts

Alastair is a retreaded phylogeographer who spent far too much time in the laboratory and now needs to be under the open sky conducting any type of research that doesn’t involve a PCR machine. He found nanophyllous plants too tough to identify (gasp!) and fell in love with the easier-to-identify Subtropical Thicket. He now cuddles thorny thickets while trying to figure out all the ways they aren’t fynbos, forests or savannas. He completely ignored dune vegetation for five years thinking it was “boring”. Then the fires came… And he realised the errors of his ways — he had been glibly ignorant of the amazing ecology of these systems (especially the thicket lineages), which comes to life after being burnt to the ground. He will, however, always keep one toe firmly rooted in fynbos as he digs the fynmense.