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Lush Life
An Australian sand plain with wretched soil mysteriously yields more diversity than a rain forest
In Australia’s sandy southwestern corner, a barely perceptible topography stretches as far as the eye can see. Even spiny, knee-high bushes can’t cloak the skeletal soil, and in summer the heat is so intense that haze swallows the horizon, and wind is the only sound to be heard.
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But a closer look reveals one of the most diverse plant communities on Earth. In spring the land bursts into uncountable blooms of breathtaking color and shape. The Nyungar natives of Australia named this region the kwongan, and today its blossoms attract tourists from around the world.
My first view of this bizarre ecosystem came in 1973 from the seat of an Italian Moto Guzzi motorcycle I had ridden from my home in Australia’s southeast, more than 2,000 miles away. For several days I traveled relentlessly across the featureless Nullarbor Plain on a national highway that had not yet been paved. As I entered the better-watered southwest, the scenery refused to improve. The monotonous kwongan baked under a harsh sun. Many of the plants were perched on stilt roots that held their main stems a few centimeters above the surface, as if the soil had eroded under them. It hadn’t, but like most things here, no one has a satisfactory explanation for it.
Most of the bushes looked almost dead, but I could see taller growth ahead. When my eye caught a flash of brilliant orange, I eased the throttle and came up on blooms of orange banksia (Banksia prionotes), six-inch-long cones packed with hundreds of tiny spiraled flowers that turn the snowy white structure flame orange as they open from the bottom up. The cones were dripping with nectar and had attracted beetles, flies, and other insects. Beneath the flowers grew strange, stiff leaves that looked as if they had been cut with pinking shears. The flamboyance seemed out of place on this parched, dusty roadside. Why did this struggling plant expend so much precious energy on flowers, and why was it wasting so much moisture producing nectar in the midst of summer?
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| (A) Australia is home to many carnivorous plants, including members of the genus Drosera (called sundew). The plant’s sticky glands trap insects, which are slowly digested and absorbed. (B) The blossoms of Gastrolobium, a pea called prickly poison, contain toxic compounds. |
The mystery deepened as I learned about the strange pollinators that serve some of the flowers. One is a mouse-size marsupial that eats nothing but nectar, pollen, and small insects—the ecological equivalent of a flightless hummingbird. Why has such a marvel evolved? At first I believed the curiosities were unrelated, but research has shown that many stem from a single strange attribute of the region’s soils.