From The Life & Love of Trees, Lewis Blackwell, Chronicle Books (2009). Click to view slideshow
Four hundred million years ago, an aerial view of the continents would have shown barren landmasses rimmed with barely discernible greenery. The tallest of these first land plants would have brushed our ankles, and perished if they grew far from water. But in just a few million years, their evolution took a series of pivotal steps that would drastically change Earth’s landscape. Frail stems generated tough woody tissues, allowing plants to grow taller without buckling under their own weight. Large flat leaves radiated out from branches, trapping sunlight and carbon dioxide with unprecedented efficiency. Roots burrowed deep into the hard crust, cracking the rocks and creating the first true soils. These early plants became the first trees, and their arrival around 370 million years ago paved the way for other life forms to continue the conquest of land.
It’s nearly impossible to overstate the significance of this evolutionary innovation. Forests helped regulate weather cycles while their networks of deep roots prevented the erosion of soils. Their dense canopies created nurturing cocoons where complex ecosystems flourished. More critically, they became one of the most efficient carbon reservoirs in nature. Just 70 million years after they arrived on the scene, atmospheric levels of CO2 dropped by as much as 95 percent, cooling the steamy, swampy planet to ice-age temperatures. The carbon trapped during this time is now found in vast coal deposits across the northern hemisphere.
In The Life & Love of Trees, Lewis Blackwell—writer, artist, environmentalist, and former creative director of Getty Images—marries award-winning photography of one of the most successful organisms on Earth with a thought-provoking reflection on the ties that binds us to them. After all, we spent most of our evolutionary history dwelling in the green canopy—from the time the first small shrew-like mammals ascended trunks and branches around 50 million years ago, to when the first hominids descended back to the ground more than 40 million years later.
Now more than three billion of us live in cities, where daily access to trees is limited. Nevertheless, as Blackwell writes, “we may still intuitively know that trees are a central part of the universal life cycle. Somewhere deep in our subconscious, we just may depend on trees.”
Originally published December 17, 2009