BRANCHING OUT

Trees are your best antiques. ~ Alexander Smith 

     Even though they have continuously inhabited the Earth for far more than 160 million years, trees are now having a moment of prominence. This moment has nothing to do with the recent, hefty increases in the commercial lumber prices – which are now headed back towards the basement after previously occupying the penthouse for a brief time.

My fascination with dendrology – the study of wooded plants – comes after reading Suzanne Simard’s Finding the Mother Tree and Richard Powers’ The Overstory. These absorbing books are related, each has a focus on trees, forests and related land-use policies. In addition, Mr. Powers modeled one of the protagonists in The Overstory, Patricia Westerford, after Professor Simard and her notable career.

First, some botanical taxonomy. Trees reside in the Plantea kingdom. Two of this kingdom’s phyla contain trees: Coniferophyta (conifers) and Magnoliophyta (flowering plants). Currently, there are about 60,000 known species of deciduous and conifer trees. Deciduous (from the Latin term meaning “to fall”) trees shed their leaves during some parts or seasons of the year. Conifers retain their narrow, long, pointed waxy-coated leaves (aka, needles) throughout the year. They are mostly evergreens and bear seeds within their cones.

The tallest trees on Earth are coastal redwoods, Sequoia sempervirens. I gaze at a baby redwood that's planted within 100ft of our home. The loftiest of which is named Hyperion that reaches 380 feet into the sky at Big Basin Redwoods State Park north of Santa Cruz, CA. It weighs 230 tons and is a youngster of just 600-800 years old. Redwoods can live to be over 2,000 years. In contrast to their size, redwoods produce quite small, one-inch-long cones.

The heftiest trees by volume are giant sequoias, Sequoiadendron giganteum. General Sherman reaches 275 feet into the sky in Sequoia National Park, has an immense 102-foot trunk circumference, is 2,300-2,700 years old and weighs a staggering 1,350 tons. Impressivo.

On another end of the living tree spectrum, the shortest trees in the world are dwarf willows that live in the arctic and subarctic regions of northern Europe, Greenland and eastern Canada. They somehow survive through the bitter 3-4 months of dark by being ground-huggers. Petite dwarf willows grow to a height of 0.4 to 2.4 inches, less than the length of your index finger with not much at all to put Christmas decorations on. These tiny trees thus stay below their landscape’s numerous winter storms’ sub-zero winds in these willows.

The oldest living things alive today above ground are gnarled bristlecone pine trees,[1] shown below. They endure high in California's White Mountains. Even though they can and have lived for about 5,000 years, they (fortunately) haven’t qualified for millennia’s worth of Social Security or Medicare.

Bristlecone pines at 11,190ft.

Let’s leave trees’ physical characteristics and explore how they communicate with each other. Until recently, the thought of trees transferring information among each other would have been judged completely bizarre. Enter Prof. Simard, who is a professor of Forest Ecology at the University of British Columbia.

Her groundbreaking empirical research during the past 25 years has demonstrated conclusively that forested trees can and do exchange information with others nearby. This communication is facilitated via the trees’ subsurface, interlaced root and mycorrhizal (fungal) networks. These impressive, multi-layered networks between inter-dependent trees exchange carbon, water, nutrients and defense signals about drought and disease. In addition to her book, she has given several TED talks that summarize her pioneering findings.

Vital providers in forests are what Prof. Simard calls Mother Trees. They are the oldest, usually largest trees within a forest neighborhood (a stand) that act as centralized hubs. Mother Trees bolster communication and nutrient exchange among other trees. They are the proverbial adhesive that holds a forest stand together. A picture of a temperate forest Mother Tree is shown below. Mother trees carry genes from prior climates and provide sanctuary to many symbiotic creatures, increasing biodiversity.

A temperate rainforest Mother tree, far right.

 According to Prof. Simard and subsequent researchers, this communication occurs not just between the same species, but between different species of trees in the network. Who’d have guessed. Not the commercial timber industry, who was a staunch critic of her research. The industry’s myopic pursuit of single-species “free-to-grow” clear-cutting has devastated healthy forest diversity in British Columbia as well as many other places around the globe.

The Earth’s forested land has been declining for centuries. At the beginning of the 18th century, prior to the Industrial Revolution, forests accounted for 52% of the planet’s habitable land (5.5 billion hectares), 9% was devoted to agriculture (both field crops and grazing land), according to Our World in Data. During the last three (3) centuries human population and the consequent demand for agricultural acreage have grown significantly.

By 2018 just 38% of habitable land is forested, 46% is agricultural (15% cropland, 31% grazing), 1% is urban areas. World population between 1700 and 2018 increased well over 12x, to 7.59 billion people.

The 27% drop in forested land between 1700 to 2018 has been due principally to two (2) inter-related factors; increased population and enlarged agricultural (ag) land use which grew 5x as large. Half of the loss in global forested land has occurred in just the last 100 years. Urbanization has not been as prominent factor in deforestation. Urban land now accounts for 1% of Earth’s habitable land.

Largely, it’s what we eat, not where we live that’s caused forested land to drop. Modern crop technology has allowed ag land to be up to 10x more productive since 1700. In spite of this, millions still go hungry.

Burning rainforests to plant soybeans, such as Brazil has been increasingly doing, has consequences. As we learned in high-school science, trees perform the impressive feat of absorbing carbon dioxide (CO2) from the atmosphere and replenishing it with oxygen. They accomplish this fortuitous environmental miracle by photosynthesis. Trees’ leaves absorb CO2 and water and use the sun’s energy to convert this into chemical compounds such as sugars that feed the tree. Oxygen is produced as an essential by-product and released through their leaves. Tropical and temperate rainforests produce roughly one-quarter of the Earth's oxygen.[2]

Creating preferential protections for Mother-Tree laden old-growth forests is an imperative alternative to the short-term “slash-and-earn” bravado of too many timber companies. Ultimately, humanity requires biodiverse forests full of trees that are healthy and ample enough to provide sufficient oxygen for all of us O2 breathing animals

We need to protect our Mother Trees as a vital part of Mother Earth for many reasons, including this fundamental one.

 

---

[1] Glass (Hexactinellid) sponges live in very deep sea-waters in the Antarctic and Northern Pacific oceans. Some scientists guestimate a maximum age of up to 15,000 years for these sponges.

[2] The majority of the Earth’s oxygen, perhaps as much as 75%, is produced from oceanic plankton. Marine plankton are mostly microscopic in size that include bacteria, archaea, algae and protozoa. Kelp forests also create oxygen.