“I think that I shall never see A poem lovely as a tree. A tree whose hungry mouth is pressed Against the sweet earth’s flowing breast; A tree that looks at God all day, And lifts her leafy arms to pray; A tree that may in summer wear A nest of robins in her hair; Upon whose bosom snow has lain; Who intimately lives with rain. Poems are made by fools like me, But only God can make a tree.” Joyce Kilmer
Wedsworth Library celebrated Arbor Day with the Town of Cascade to honor the ancients, to celebrate nature, and of course encourage all to plant a tree today. It’s hard to overstate the importance of trees. They have been here forever it seems. Their introduction more than 300 million years ago was a “turning point for Earth to help transform its surface into a utopia for land animals.” Trees have fed, housed and otherwise nurtured countless creatures over time.
Trees are the longest living organisms on Earth. Believe it or not, trees didn’t exist for the first 90 percent of Earth’s history. Before trees, there were fungi that grew 26 feet tall. The first known tree, the Wattieza, was a leafless, fern-like plant from New York identified from 385 million-year-old fossils. Part of a prehistoric plant family; it stood 26 feet tall and formed the first known forests. It may have lacked leaves and grew frond-like branches with “branchlets” resembling a bottlebrush.
Scientists thought the Wollemia nobilis, a dinosaur-era tree, went extinct 150 million years ago, but was found growing wild in Australia. During the Jurassic Period it lived on the supercontinent Gondwana. These ancient trees were only known from fossil records. In 1994 a few survivors of one species were found living in the temperate rainforest of Australia’s Wollemia National Park. They are critically endangered and are often described as a living fossil. Only about 80 mature trees are left, plus some 300 seedlings and juveniles.
While Wollemia nobilis is the last of its genus, there are also other middle Mesozoic trees alive today. Ginkgo biloba, aka the ginkgo tree, dates back about 200 million years and has been called “the most ancient living tree.”
Dating a tree by studying its rings is called Dendrochronology. However, a tree’s rings don’t just reveal its age; they can also indicate the occurrence of natural disasters such as a volcanic eruption or a drought event. Tree rings can also predict climate change. Years of good growth results in a thick ring, whereas when resources were scarce or the tree encountered an unhealthy environment, a thin ring is seen.
Trees also help reduce the effects of climate change. A mature tree can absorb more than 48 pounds of carbon dioxide each year. In one year, an acre of trees can absorb as much carbon as produced by a car driven up to 8700 miles. In Chicago, trees remove more than 18,000 tons of air pollution each year.
Trees also reduce energy costs. Strategically planting trees and shrubs can save up to 25 percent on energy bills. A shade tree helps cool a home by as much as 20 degrees in the summertime. They provide shade in the summer and a windbreak in the winter.
Jack and his beanstalk have nothing on this reach for space. Some trees have been to the moon. “Moon trees” were grown from seeds taken to the moon during the Apollo 14 mission in early 1971. “NASA and the US Forest Service wanted to see if the moon’s orbit caused the seeds to grow differently back on earth. These trees were then donated to state forestry services in 1975 and 1976.
Trees reduce stress. Research suggests that a walk down a tree-lined street can be beneficial to our mental and social well-being. This is partly because trees release chemicals called phytoncides. When we breathe them in, it reduces blood pressure, lower anxiety levels, and increases pain threshold.
Trees can help you find your way if lost in the woods. In northern temperate climates, moss grows on the northern side of the tree trunk. The tree’s rings can help point you in the right direction too. If you’re in the northern hemisphere, you can see the rings of the tree grow slightly thicker on the southern side since it receives more light. In the southern hemisphere, the opposite is true, with rings being thicker on the north side. Just don’t forget what hemisphere you are in or you really could be lost.
More than half of all tree species exist in only one country. There are 60,000 tree species in the world and many are threatened with extinction. Brazil, Colombia, and Indonesia have the highest totals for native tree species. Until recently, there was no thorough global census of tree species. “But in April 2017, the results of a “huge scientific effort” were published in the Journal of Sustainable Forestry, along with a searchable online archive called GlobalTreeSearch. The scientists compiled data from museums, botanical gardens, agricultural centers and other sources, and concluded there are 60,065 tree species currently known to science.”
If a birdhouse is hung on a tree branch, it won’t move up the tree as the tree grows. That’s because trees grow from the top or their most distal ends, which means that a branch will always be the same height as the day it emerged from the trunk. Guess the birds won’t have to live in skyscrapers.
Trees improve water quality. Trees serve as natural sponges, collecting and filtering rainwater and releasing it slowly into streams and rivers. They also prevent soil from eroding, reduce storm water runoff, and lessen flood damage.
Trees communicate and defend themselves against attacking insects. Trees may look passive and helpless, but they’re savvier than they seem. Scientists have found that trees can flood their leaves with chemicals called phenolics when insects begin their raid. This also signals danger to other trees so they can start their defense. Willow trees, for example, emit certain chemicals when they’re attacked by webworms. Other willows then produce more tannin, making their leaves harder for the pests to digest.
Some trees emit chemicals that attract enemies of their enemies i.e. predators and parasites that kill the insects, which is essentially calling for backup. Songbirds provide valuable pest control. Trees in a forest can also ‘talk’ and share nutrients through an underground internet built by soil fungi.
Trees have symbiotic relationships with mycorrhizal fungi that live on their roots. The fungi help trees absorb more water and nutrients from the soil, and trees repay the favor by sharing sugars from photosynthesis. The fungi link each tree to others nearby, forming a huge, forest-scale platform for communication and resource sharing.
Most tree root systems stay in the top 18 inches of soil where growing conditions tend to be best. Some grow above ground or dive a few hundred feet deep. The lack of depth is offset by lateral growth. The root system of a mature oak, for example, can be hundreds of miles in length. Still, tree roots vary widely based on species, soil and climate. Bald cypress grows along rivers and swamps, and some of its roots form exposed “knees” that supply air to underwater roots like a snorkel. Similar breathing tubes are also found in the stilt roots of some mangrove trees, along with other adaptations like the ability to filter up to 90 percent of salt out of seawater.
On the other hand, some trees extend remarkably deep underground. Certain types are more prone to grow a taproot such as the hickory, oak, pine and walnut. Trees have been known to go more than 20 feet below the surface under ideal conditions. A wild fig at South Africa’s Echo Caves has reportedly reached a record root depth of 400 feet.
A large oak tree can consume about 100 gallons of water per day, and a giant sequoia can drink up to 500 gallons daily. As a bonus, trees have a knack for soaking up soil pollutants. One sugar maple can remove 60 milligrams of cadmium, 140 mg of chromium and 5,200 mg of lead from the soil per year, and studies have shown farm runoff can contain up to 88 percent less nitrate and 76 percent less phosphorus after flowing through a forest.
Trees provide food, housing and other benefits for a wide range of birds. Native trees create vital habitat for a variety of wildlife, from urban squirrels and songbirds to less obvious animals like bats, bees, owls, woodpeckers, flying squirrels and fireflies. By adding a single tree to a pasture, for example, the number of bird species was raised from near zero to 80.
One of the most fascinating things about trees is how long some can live. Clonal colonies (a group of genetically identical individuals), are known to endure for tens of thousands of years. Utah’s Pando aspen grove dates back 80,000 years, but many individual trees also stand their ground for centuries or millennia at a time. North America’s bristlecone pines are especially long-lived. One 4,848 years old pine in California was considered the planet’s oldest individual tree until 2013, when researchers announced they’d found another bristlecone that sprouted 5,062 years ago. The last woolly mammoths, for comparison, died about 4,000 years ago.
We still periodically pause to honor trees, with ancient holidays like Tu Bishvat as well as newer tributes like Arbor Day, the International Day of Forests or World Environment Day. Remember “He who plants a tree Plants a hope.”- Lucy Larcom Summer is the perfect time to sit under a tree and read a good book. From a small seed of reading, a mighty trunk may grow.