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It’s not easy to live in southern Africa’s Namib Desert.
It’s one of the oldest and driest deserts in the world, and many of the plants and animals
that survive there have bizarre adaptations—and are only found in this desert.
One of these is the nara melon, which not only builds its own habitat in this harsh
environment, but also forms the base of a whole desert ecosystem.
Deserts aren’t known for being the coziest habitats, but even so, the Namib is extreme.
It’s been around for at least 55 million years, and it’s been hyper-arid—or extremely
dry—for the last five million or more.
It has an average annual rainfall of just ten centimeters, and sometimes years pass
without any rain at all.
As a result, the sandy, dry soil gets easily blown around by the desert’s strong winds,
and it contains very little of the nutrients plants need to grow.
Even so, there are plants here—and the nara plant does so well that it grows a melon—a
big, juicy fruit—in the desert!
It’s the only plant that grows fruit in the whole region, and to pull it off, it has
to be extremely resourceful.
The nara plant creates its own stable habitat by building a mound of sand called a .hummock
Initially, its seeds sprout on flat land, but as the plant grows, grains of sand and
organic material get blown around it and cover up the bottom layer.
That gives the plant a strong anchor in the sand,
while the top layers keep photosynthesis going.
Over time, these hummocks can get up to ten meters high and 40 meters across!
Scientists haven't studied nara hummocks in depth, but they can draw conclusions about
them based on what they know about plant species in Chile’s Atacama Desert that use a similar strategy.
The sand mounds they build capture organic matter blowing around in the wind as well
as moisture from fog, both of which help nourish the plants’ growth in the sandy soil.
So nara hummocks may play a similar role.
But the plant itself also has some incredible adaptations.
For one, its roots go as much as 50 meters below the sand, where they can pull up groundwater.
Scientists also think it’s possible that the plant harvests water from fog that rolls in from the coast.
Little cone-shaped spines all over the plant may help concentrate the fog into dew-like
droplets, which either get absorbed directly or run down grooves in the stem into the ground below.
Then, to avoid losing water in the super-dry air, the plant has just… done away with
leaves, which lose a lot of water to evaporation.
Instead, its green stems and spikes take care of its photosynthesis.
With these tricks, scientists estimate that nara plants can live more than a century,
including years without rain.
But they don’t just survive—they also make the desert more livable for a lot of other creatures.
At least 26 vertebrate species depend on the plant for shade, water, or food, including
jackals, antelope, and mice.
Beneath the plant, microbial communities also flourish in the nara’s shade and provide
the plant with vital nutrients in return.
And to this day, the people who live in the region depend on these melons and seeds for food and income.
Yet, as hardy as these melons are, they won’t survive if you try to grow them yourself,
and scientists don’t quite know why.
Maybe they’ve just carved out a niche that’s too specific to replicate.
So for now, they remain a unique element of the Namib desert ecosystem!
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