Redwoods: Earth's Gigantic Botanical Marvels Quiz

Answer:

Officially a coast redwood, but most commonly just called a redwood, the trees are members of the conifer group - a division of plants that reproduces using cones rather than flowers. Specifically, it belongs to the cypress family, Cupressaceae, and its full genus scientific name is Sequoia sempervirens. It is the only living species in this genus. The native home of the coast redwood is strictly limited to a narrow 450-mile (724 km) strip from Southern Oregon to Central California. Interestingly, these trees are actually a type of refugee. Millions of years ago, their ancestors grew across much of the Northern Hemisphere, including Europe and Asia. Climate changes, specifically the Ice Ages, pushed them back until they found their final home in the foggy climate of the California coast.

A coast redwood is the tallest tree species in the world. The tallest living individual (in 2026 when this quiz was written), a coast redwood named Hyperion, stands at over 380 feet (116 meters) tall in Redwood National Park, California. The tree has many unique features in order to achieve these jaw-dropping heights. The first is interlocking roots. Unlike many tall trees that use a deep root system, redwoods have a shallow root system. However, these roots can extend up to 100 feet (30 m) radially from the trunk. These roots then literally intertwine with the roots of their neighbor redwoods. This creates a massive network underground that allows a grove of trees to stand firm.

They also have a structural core and unique cellular system to aid them in their growth. At the center of every redwood is the heartwood, which is essentially a pillar of xylem cells. As the tree grows, the innermost cells die and become packed with a complex polymer that acts as a natural biological plastic. This gives immense strength to the center of the tree. Meanwhile, tracheid cells are surrounding the core and aiding in the transportation of water, much like a complex plumbing system.

To get the water that the cells transport, the tree relies on its environment and the thick fog that rolls in from the nearby Pacific Ocean. The process is called fog drip. The tree's huge numbers of needles catch microscopic water droplets from the air, which then turn into larger drops. These large drops then fall, creating a "local rain" under the canopy. This not only gives life-saving water to the tree but to the ecosystem around it.

Beyond just letting the water fall to the roots, redwoods are capable of foliar uptake. This means they absorb moisture directly through the surface of their needles instead of pulling it from the roots up its immense height. This "drinking" through the leaves allows the topmost branches to stay hydrated.

Coast redwoods are among the oldest living things on Earth, with some individuals confirmed to be at least 2,200 years old, and estimates for others reaching over 3,000 years! Thick bark and tannin help in keeping the redwood safe so it lives so long. The bark is extremely thick--up to 1 foot or .3m--which acts as insulation and a fire protectant. Tannin, a chemical compound, not only gives the tree its beautiful coloring but is an insect repellent (as it is toxic to most bugs) and a natural fungicide.

The tree also supports a unique ecosystem both in the canopy and on the forest floor. On the floor, large animals like bears and deer forage. Amphibians and invertebrates, like banana slugs and Pacific giant salamanders, make their home. Streams running through redwood forests provide critical, clean water for a variety of aquatic creatures. Up in the canopy, a whole different world exists. Over centuries, organic debris accumulates on large branches, forming thick, spongy soil mats. On these mats, hundreds of plants grow and a variety of animals (such as the spotted owl) call them home.

Unfortunately, these magnificent trees face challenges such as climate change, reduced fog, wildfires, habitat loss, and illegal poaching of the wood. National parks work to protect many of these old-growth forests. There are also conservation groups working to purchase vulnerable forestlands from private individuals. Second-growth forests are also being maintained to ensure that these trees last for even more centuries.