FORBES - With spring in the Northern Hemisphere in full bloom, forests are again beckoning hikers onto paths that wend their way through thousands of acres of old growth trees. Such forests not only offer salve for the soul, but their role in Earth’s ecology is arguably crucial to the health of our planet.
But can we expect anything resembling trees on an extrasolar Earth?
An Earth Without Trees
But Earth has been without trees for most of its history. In fact, they’ve only been in existence for some 400 million years, about a tenth of Earth’s history. There are even species of sharks older than the oldest tree species.
There were no trees here for most of the history of life on Earth and, indeed, for most of the history of photosynthesis, Edward Schwieterman, an astrobiologist at the University of California, Riverside, told me via email. Geologically speaking, trees are a relatively recent development, arising in the Devonian period about 385 million years ago, he says. Yet planets with trees are more likely to host robust and diverse land-based ecosystems, says Schwieterman.