Finding the Mother Tree

 

Suzanne Simard wrote an unforgettable book, Finding the Mother Tree.  She was born and raised in the rainforests of British Columbia, and is now a professor of forest ecology.  Her grandfather was a logger who worked back in the low-tech days, when the industry ran on manpower, horsepower, and waterpower. 

At age 20, Simard’s first job was with a logging company.  By that time, the industry was using fossil powered machines — chainsaws, bulldozers, skidders, loaders, trucks, etc.  Selective cutting was being replaced by devastating clear-cuts.

At age 23, she was hired to do research for the British Columbia Forest Service.  They wanted to determine the most effective way to plant seedlings on a clear-cut site.  Government regulations required “free to grow” stocking.  So, prior to planting, herbicides were sprayed to exterminate natural plant life.  Only the moneymaking seedlings were free to grow.

In those days, much of what is now known about forest biology had not yet been discovered.  Consequently, standard industry practices were often based on a blind faith in unproven assumptions.  This wasted a lot of money, and unnecessarily damaged the ecosystem.  The most important business goal was to maximize short-term profits. 

Simard preferred critical thinking to blind faith, and she asked questions that the good old boys never considered.  Vital clues can often be very hard to see.  She paid close attention to the incredibly intricate ways in which forests function.  “My instinct has always been to listen to what living things were saying.”

One of her assignments was to investigate a mysterious situation.  A number of clear-cut sites had been planted with seedlings, and none were healthy.  Plantation after plantation was dying.  She found that all of them had been planted exactly as the rules required.  Seedling roots had to be inserted in mineral soil (sand, silt, clay) because it retained more water and supposedly boosted survival.  Rules prohibited inserting seedling roots in humus.  Humus is a nutrient-rich component of topsoil in old growth forests.  It’s loaded with fungi, worms, bugs, and decomposed organic material. 

Simard noticed that in the dying plantations, seedlings were failing to produce healthy root systems.  On the other hand, in nearby uncontrolled natural woodland, mature trees dropped seeds from which young trees sprouted.  The youngsters grew in humus, and they developed fantastically extensive root systems, intertwined with dense mats of yellow, white, and pink fungi.  This was a crucial discovery! 

So, she created an experimental plantation.  Half of the seedlings were planted in mineral soil (all died), and the other half in humus (all thrived).  Ongoing research confirmed her suspicion that healthy fungi networks were essential for the survival of healthy forests.  Very important!

Industry traditions perceived that the fundamental force of nature was competition — survival of the fittest.  So, industrial forestry was a game of nurturing the most valuable trees, and obliterating everything else.  The downside of this belief was that it was remarkably counterproductive in the real world.

Industry traditions believed that low value alders could reduce the vitality of high value lodgepole pines.  So, alders were chopped down.  Actually, pines loved alder, because alders transformed nitrogen into ammonium, a potent fertilizer that pine roots absorbed via the fungal networks.  Pines not growing near alders were more vulnerable to pine beetles that bored into their bark.  A fungus carried on beetle legs infected the pines, and it prevented water from flowing upward in the trees.  Countless pines died of thirst.

Industry traditions declared birches to be low value junk trees, because they were thought to slow the growth of high value Douglas firs.  Large birch leaves performed more photosynthesis than fir needles, so they were able to convert more sunbeam energy into chemical energy — sugar and other carbs.  As birch foliage expanded, fewer sunbeams could reach the firs.

Birches stored surplus carbs in their roots, where networks of fungi allowed fir trees to tap into it.  The more shade the birch cast, the more sugar it shared with the fir.  Simard eventually realized that this relationship was not a problem.  It was beneficial.  They were working together, like a system.  Healthy birches promoted healthy firs.

She wrote, “Fir can’t survive without birch due to the high risk of infection from Armillaria, and birch can’t survive in the long run without fir because too much nitrogen would accumulate in the soil, causing the soil to acidify.”  When firs are grown alone, up to a third are killed by a root disease. 

In one experiment, Simard grew birch and fir trees together in some stands.  In other stands, firs were grown without birches.  Twenty-one years later, the forest where birch and fir had been grown together had almost twice the productivity of stands with no birches.

The findings of Simard’s research inspired doubts about the validity of some traditions.  She began to suspect that the real life force of forest ecosystems was more like cooperation.  Over time, diverse communities of forest dwelling species apparently coevolved ways of establishing mutually beneficial win/win relationships.  Year after year, her experiments confirmed these suspicions.

She suspected that networks of fungi played a major role in this magic act.  Seeking evidence, she designed experiments to discover how nutrients and moisture were transferred from one tree to another.  This involved using carbon isotopes as tracers, unique identification tags.

The C-12 isotope is natural, C-13 is unnatural but not radioactive, and C-14 is unnatural and radioactive.  Simard inserted C-14 into birch leaves, expecting to find that it flowed into Douglas firs.  It did!  She inserted C-13 into the firs to see if nutrients also flowed from fir to birch.  They did!

When trees are able to intermingle with neighboring trees, they develop lots of beneficial fungi interconnections.  There may be more than 100 species of fungi in a forest.  Some retrieve phosphorus from humus.  Others retrieve nitrogen from decaying wood.  Some carry water.  Others send or receive sugar.  The function of most fungi is unknown.

Simard found that giant trees played an especially important role in healthy forests.  She called them Mother Trees because they nurtured others.  Fires generally roasted understory vegetation, while the taller overstory trees were more likely to survive.  Their bigger crowns captured more sunbeams and produced more carbs.  Larger trees shared their surplus carbs with nearby smaller trees, including those of other species.  Young trees might grow for decades in the shadows. 

Some of the seeds dropped by Mother Trees remain nearby, germinate, and emerge as young trees.  Mothers seem to recognize their genetic offspring, and give them top priority when sharing nutrients.  Unrelated trees, and trees of different species, also receive gifts from Mother Trees.  There seemed to be something like tree to tree communication.  Simard studied a stand of Douglas fir.  Fungi networks connected the older trees to all of the younger trees around them.  Some were as far as 20 meters away (22 yards). 

Simard’s book is a chatty discussion of her life, work, and family.  Its target audience is forestry students, and industry professionals.  Her unconventional ideas remained controversial for a number of years.  Today, her work has been peer reviewed, and is widely accepted.

General readers (like me) will stumble into the unfamiliar names of many plant and fungi species.  I didn’t know the meanings of “mycorrhiza” and “mycelium.”  Both are important categories of fungi species. 

The relationship between mycorrhizal fungi and living trees enabled the survival of both.  Fungi contributed water and soil nutrients to the tree roots.  In return, tree roots provided the fungi with carbs produced by photosynthesis.

Peter Wohlleben fondly described mycelium, the largest living organisms yet discovered.  One in Oregon weighs 660 tons, covers 2,000 acres (800 ha), and is 2,400 years old.  They provide trees with water, nitrogen, and phosphorus — in exchange for sugar and other carbs.

Around the world today, relentless industrial scale forest mining is causing far more catastrophic destruction than ever before.  The global economy has no plans to slam on the brakes.  Humankind demands unlimited lumber, paper products, firewood, etc.  We will eventually win the War on Forests — an idiotic Pyrrhic victory.  My short overview on the history of deforestation is HERE.

Simard, Suzanne, Finding the Mother Tree, Random House, New York, 2021.  

Grassland Rewrite

Greetings!  The following is a rewrite of samples 23, 24, and 25, which were originally posted way back in 2019, when I was young and innocent.  The revised version is shorter, clearer, and adds new factoids.  I hope that as my editing process moves into newer sections, fewer tweaks will be needed, and the blessed finish line will arrive before the sun burns out.

MOTHER GRASSLAND

The family of life is solar powered.  Incoming solar energy is received by green plants, who use it to produce sugar.  This process is photosynthesis.  It converts solar energy into a form of chemical energy that plants and animals must have to survive.  Animals acquire this energy by eating plant material, or by dining on plant-eating animals. 

Photosynthesis splits water molecules (H₂O) into hydrogen and oxygen atoms.  Then, in a fancy magic act, hydrogen is stirred together with CO₂ to make a sugar called glucose (C₆H₁₂O₆).  The process results in some leftover oxygen atoms, which are released to the atmosphere.  Notice that animals exhale the CO₂ needed by plants, and plants exhale the oxygen needed by animals, a sacred circle dance.  Plants use the sugar to fuel their daily life, or they can convert it to starch, and save it for later.  Plants can also make fat, protein, and vitamins.  They’re much smarter than they look.

The act of snatching carbon from the air, and incorporating it into living plant tissues, is called carbon fixation, or carbon sequestration.  As more carbon gets sequestered into the plants and surrounding topsoil, then less of it remains in the atmosphere.  This is great, because too much carbon in the atmosphere can lead to catastrophic climate juju, like the freaky changes that are beginning to bludgeon the family of life right now.

There are four primary terrestrial biomes: grassland, forest, desert, and tundra.  Grasslands are communities of different plants — primarily grasses, mixed with a wide variety of sedges and leafy forbs (wild flowers and herbs).  These mixed communities maximize the capture of solar energy, make better use of soil resources, and create rich humus.  Humus boosts soil fertility, and helps retain moisture.  Some plants also convert atmospheric nitrogen into a form that is essential for all living things.  Others are good at retrieving essential mineral nutrients.

There are maybe 12,000 species of grass, and they grow in many tropical and temperate regions.  Some are able to survive extended droughts, or long winters.  Grasslands have two modes, productive and dormant.  In warm climates, they are dormant during the dry season, and recover when the rains return.  In temperate climates, they are dormant during the frosty months, and green when the soil thaws. 

Following an intense disturbance, grasslands can recover in 5 to 10 years — far faster than a wrecked forest.  Evolution has done a remarkable job of fine-tuning grasslands for rugged durability.  They can recover more easily after wildfires because only a third of grassland biomass is above ground, and most vulnerable to flames.  Plants send roots far underground, to acquire moisture and nutrients.  Some roots grow as deep as 32 feet (10 m).  The seeds of many grassland species can remain dormant for an extended period, postponing germination until appropriate conditions return.  Some seeds can survive a hot and slippery ride through an herbivore’s gut and remain fertile, enabling the colonization of new locations.

Grass and Herbivores

Grassland communities run on carb energy that moves from species to species, up and down the food chain, and enables the existence of the family of life.  Large grass eating herbivores were a favorite source of nutrients for our prehistoric ancestors.  For the effort invested in hunting, they provided the biggest jackpots of meat.  Our strong desire for these animals, and our ongoing dependence on them, eventually resulted in some hominins evolving into Homo sapiens, the last surviving hominin species.

It’s important to understand that herds of large herbivores do not usually reside in forests or jungles.  Large body size can be an important advantage on grasslands, but a disadvantage in dense woodlands.  In terms of vegetation, forests contain much more plant biomass than grasslands, but most of it is elevated out of the reach of hungry herbivores.  On the other hand, grasslands annually produce much more new biomass per acre than forests, and it’s conveniently located close to the ground.

To herd critters, grassland looks like a candy store where all the goodies are free and delicious.  Grasslands are the best place to dine on high quality greenery, hang out with friends and relatives, produce cute offspring, and enjoy a wonderful life of fresh air, travel, and adventure.  Consequently, grasslands are home to far more large animals.  I would expect that most land-dwelling megafauna species originated in grasslands.

Grass and Hominins

The Miocene Epoch spanned from 23 to 5.3 million years ago.  It seems that the early Miocene was wet and warm, and many ecosystems were forests.  Much of Antarctica was covered with temperate forest 20 million years ago.  Later, maybe six to eight million years ago, it got cooler and dryer, and a different type of ecosystem evolved and expanded — grasslands.  Compared to forests, grasslands generally need less precipitation to survive.  Today, the Earth’s forest area is 80 percent smaller than it was in the Miocene’s golden age of trees.

This transition had a significant impact on the human saga.  As forests shrank, there was less habitat for our tree-dwelling ancestors.  A number of forest species tumbled off the stage forever.  Some primates moved onto the savannah, and figured out how to survive as ground-dwelling primates, in open country.  They included the ancestors of baboons and humans.  Humans are hominins, primates that walk on two legs.  About four million years ago, hominins originated on the savannah grasslands of tropical Mother Africa. 

Our tree-dwelling ancestors were primarily frugivores, fruit eaters.  They ate stuff that grew or lived in trees.  When they became ground-dwelling critters, they needed a new diet.  Large herbivores became a popular choice.  Hunting was the path to success, and grassland was the place to be.  Consequently, as humans migrated out of Africa, and colonized the world, they preferred to select routes that majored in grasslands.  Their journey took them to grasslands in the Middle East, and then Europe. 

Barry Cunliffe noted that a vast steppe grassland began in Hungary and ended in Manchuria, providing a grassy highway that was 5,600 miles (9,000 km) long.  As an added bonus, the steppe was largely carpeted with vegetation that was drought-resistant and frost-tolerant.  Once established in northern Asia, intrepid pioneers were eventually able to wander from Siberia, over the Beringia land bridge, and then explore the incredible Serengetis of the Americas.

In 1872, Kansas senator John James Ingalls celebrated the power of grass.  He wrote: “Grass is the forgiveness of nature — her constant benediction.  …Streets abandoned by traffic become grass-grown like rural lanes, and are obliterated.  Forests decay, harvests perish, flowers vanish, but grass is immortal.  …The primary form of food is grass.  Grass feeds the ox: the ox nourishes man: man dies and goes to grass again; and so the tide of life with everlasting repetition, in continuous circles, moves endlessly on and upward, and in more senses than one, all flesh is grass.”

Super Grass

And now, the plot thickens.  There are several ways that photosynthesis fixes carbon in plants.  The conventional process is called C₃.  It produces a compound that has three carbon atoms.  The turbocharged process is C₄, and it produces a compound that has four carbon atoms.  Maybe 85 percent of the plant species on Earth are C₃.  Their method of carbon fixation is simpler and less efficient than C₄.  Both types are very old, but when climate change favored the expansion of grassland, C₄ species got an important boost.

Elizabeth Kellogg studied C₄ plants.  In one experiment she found that, under ideal conditions, C₃ plants could theoretically capture and store up to 4.6 percent of the solar energy they received, while C₄ plants could get up to 6 percent (30 percent more).  In other words, provided with the same inputs of sunlight and water, C₄ produces more calories than C₃ — carbs that fuel the family of life.  They also produce more root biomass, which increases their tolerance for drought and fire.

Kellogg calls the C₄ process a turbocharger.  While only 3 percent of flowering plant species are C₄, they account for 23 percent of all carbon fixation in the world.  Of the 12,000 grass species, 46 percent of them are C₄, and they include corn (maize), sugar cane, millet, and sorghum.  (Mad scientists are now trying to alter DNA to make rice C₄ too.)

There are four conditions under which C₄ plants have a big advantage — high temperature, high light, low moisture, and low nutrients.  Because they need less water, C₄ plants better conserve soil moisture, so their growing season is longer in arid regions.  Kellogg wrote, “In the last 8 million years, C₄ grasses have come to dominate much of the earth’s land surface.” 

C₃ grasses are better adapted to moist forest floors and limited sunlight.  They are less able to thrive in arid grasslands.  Out on the savannah, C₄ grasses enjoy some important advantages.  When conditions are right, they are able to manufacture generous amounts of chemical energy (sugar), and this increases their odds for survival.

[Important!]  The big picture here is that climate change radically altered the family of life.  It encouraged the substantial expansion of grassland, which boosted the expansion of C₄ grasses, which propelled the evolution and expansion of large grazers and carnivores, which boosted the global tonnage of living meat, which set the stage for the arrival of our hominin ancestors.  Today’s climate crisis seems likely to unleash far bigger changes in something more like the blink of an eye.

Grasslands can support more large animals than forests.  Grassland megafauna migrated and settled on five continents (not Australasia).  Around the world we find varieties of horses, bison, elephants, antelope, deer, hyenas, wolves, bears, and so on.  Grasslands support far less biodiversity than rainforests, which are home to fantastic numbers of different species.

Graham Harvey, a grass worshipping wordsmith, noted that growth is actually stimulated by grazing and fire.  In a brilliant design, new blades of grass emerge from growing points located close to the ground, where they are less likely to be damaged by hungry teeth or passing flames.  The faster that grasses can send up new blades, the more sunlight they can capture, the more sugar they can make, and the happier the whole ecosystem becomes.  Joy!

Another benefit of grazing is that herbivores often nip off the rising shoots of woody vegetation.  If trees and brush were allowed to grow and spread, they would compete for sunlight with the grasses.  Then, the herds of hungry herbivores would have less to eat, and so would the carnivores that adore red meat.  Herds religiously offered their deep gratitude to the grass people by lovingly depositing nutrient rich manure and urine all over the place.

Grass eaters are called grazers.  Browsers are critters that eat leaves, woody shoots, bark, and saplings.  Some species are both.  The elephant family loves to dine on young green leaves, and they sometimes knock trees down to get them.  Each day, elephants eat 550 pounds (250 kg) of grass and leaves, and then turn it into magnificent fertilizer.  Giraffes are top feeders that specialize in leafy vegetation that elephants and rhinos are too short to snatch.

Browsers can limit the expansion of trees and woody brush, but they aren’t fanatical mass murdering exterminators.  Savannah ecosystems are grasslands dotted here and there with trees and shrubs.  Grass provides food for the grazing herds, and woody vegetation nourishes the browsers — and it provides shade and hiding places.  Home sweet home!

Harvey concluded that, in many ways, humans are creatures of grass country, like the bison, hyenas, and vultures.  We still are.  We take immense pride in the brilliant triumph of humankind, but if we turn off the spotlights and loudspeakers, and pull back the curtains, we see that the Green Mother of this grand and goofy misadventure is our intimate and enduring dependence on grassland ecosystems.  Grass is Superman’s momma.

Manmade Grassland

All flesh is grass, but grass is not limitless.  In the old days, there were no hunting licenses, rules, bag limits, or game wardens.  The hunting fad was able to grow until it eventually smashed into rock solid limits.  Flesh is not limitless.  Folks began missing dinners, and going to bed with growling tummies.  Overshoot is never sustainable.  Too many hominins spoil the party.  The 100% guaranteed, always effective, least popular cure for overshoot is die-off.

Another cure is migration, pack up and move.  This medicine worked for thousands of years, as folks colonized the regions uninhabited by humans.  Eventually, the happy hunters learned a painful new lesson: Earth is not limitless.  Shit!  What now?  Cultural taboos that limited reproduction could provide some pressure relief.  So could perpetual inter-tribal warfare, bloody the competition whenever possible.  Cleverness is the persistent gift and curse of humankind.  It conjured another idea, a magic wand call the firestick.

Shortgrass prairie grassland needs between 10 and 30 inches (25 to 76 cm) of annual precipitation.  Most of its plants are less than one foot (30 cm) tall.  Tallgrass prairie needs more than 30 inches (76 cm) of annual precipitation.  In tallgrass, prairie plants can sometimes grow up to 13 feet (4 m) high — tall enough to hide a horse.  Tallgrass can produce far more food for grazing animals, which enables larger herds.  However, the precipitation needed by tallgrass is also adequate for the survival of forest.  While browsing and grazing helps to maintain open grassland, it’s not enough to fully prevent the existence and spread of forest. 

When Big Mama Nature gets in a stormy mood, she sometimes ignites wildfires with lightning bolts.  Fire can be a good tonic for the health of grass.  It burns up accumulated dead foliage and debris, allowing more solar energy to empower the grass people.  Also, with the dead junk burned away, the exposed ground warms up faster when the snows melt, enabling the growing season to begin earlier.  Soon after fires end, tender green shoots emerge from the ashes.  Fresh greenery looks heavenly to the grazing critters, and hunters love grazing critters. 

Jill Haukos noted that fire happily stimulates the growth of fresh new grass, but it has zero concern for the health and safety of trees and shrubs.  Grass productivity is 20 to 40 percent higher on burned land, compared to unburned.  When tallgrass prairie is deliberately burned every few years, it will not transition to forest, because the seeds, sprouts, and saplings can’t survive the cruel abuse.  Natural wildfire doesn’t faithfully follow regular burn schedules, but regular manmade fire is able to trump the tree people.

Wild folks clearly understood that maintaining extensive grasslands improved their hunting.  By deliberately controlling nature, they could eat better, and feed more bambinos.  So they did.  For hunters, fire was a powerful beneficial servant.  For the rodents, birds, and insects of the grassland, fire could be a viciously powerful master.  Shepard Krech mentioned that when the first humans settled Hawaii and New Zealand, they cleared the land with fire, driving many bird species extinct.  Is it OK to rubbish a thriving ecosystem for selfish reasons?  Only human desires matter?

Haukos wrote about bison grazing in tallgrass prairie.  Hungry herds have little interest in seeking un-grazed locations that are covered with lots of old and skanky low calorie grass.  They much prefer fresh new grass, and they pay close attention to recently burned landscapes.  “Bison maintain large grazing lawns.  They return again and again to the same ‘lawns’ to eat the new growth of grass, which is highly nutritious.  These areas may look overgrazed but actually have new growth continually, providing the nutritious grass bison need, even if only one inch high (2.5 cm).”

The practice of using periodic burns to maintain and expand superb grazing land is often called firestick farming, because it uses burning to increase the harvest of life-giving meat.  It is a powerful, easy, low tech way to benefit large game.  Alfred Crosby noted that firestick farming had transformed much of six continents long before the first field was planted.  Let’s look at a few examples.

North America

The chilly Pleistocene ended about 11,700 years ago, with the arrival of the warmer and gentler Holocene era that we currently enjoy.  Ice sheets melted and retreated, creating space for tundra.  As the climate further warmed, expanding prairies displaced regions of tundra.  Prairie ecosystems can support more complex biodiversity, as different communities of species adapt to different mixes of soil types, moisture, and climate.  Where changing conditions favored the existence of trees, forest expanded.  Forests tend to trump grassland, because they allow less sunlight to reach the ground.  Once established, a forest can thrive for thousands of years, if not molested by murderous terrorists.

One way or another, Native Americans learned the benefits of grass burning.  They understood that regular burning could inhibit forest regeneration.  As centuries passed, tallgrass regions expanded, much to the delight of large herbivores, and hungry hunters.

Stephen Pyne wrote that when white colonists were settling in the eastern U.S., the western portion of the Great Plains was shortgrass prairie, too dry to support forest.  But much of the eastern portion was tallgrass prairie.  It had rainfall and soils suitable for forest, but over the centuries, Native Americans had gradually pushed back forest territory to greatly expand the prairie.  They maintained this highly productive prairie by burning it every few years, to kill young saplings.  It provided excellent habitat for bison and other delicacies.

Burning was a common practice in many regions of North America.  By A.D. 1000, the expansion of manmade tallgrass prairie had enabled bison to migrate east of the Mississippi River watershed for the first time.  By the 1600s, several million bison lived in a region spanning from Massachusetts to Florida. 

Shepard Krech wrote that along the east coast, there were oak openings (meadows with scattered trees) as large as 1,000 acres (404 ha).  Manmade grasslands in the Shenandoah Valley covered a thousand square miles (2,590 km²).  He noted that Indian fires sometimes had unintended consequences, when they exploded into raging infernos that burned for days, sometimes killing entire bison herds, up to a thousand animals. 

Lamar Marshall described the relationship between the Cherokee people and the bison.  The tribe resided east of the Mississippi River, and lived by farming and hunting.  Legends suggested that bison did not live there until sometime around A.D. 1400.  By then, the natives had significantly expanded grassland for hunting, and cleared forest for farming.  Game was especially attracted to rivercane pastures (canebrakes) that were burned every 7 to 10 years.  Marshall provided a map showing how huge North America’s bison range was in 1500. [Look]

Michael Williams noted that as the diseases of civilization spread westward, Indians died in great numbers.  They had zero immunity to deadly and highly contagious Old World pathogens.  Diseases spread westward far faster than the expansion of settlers.  Consequently, the traditional burning was sharply reduced, and forests were returning.  In 1750, they may have been bigger and denser than they had been in the previous thousand years.  When whites eventually arrived to create permanent agricultural communities, the happy regrown forests had to be savagely euthanized.

Arlie Schorger wrote about the vast manmade tallgrass prairies of southern and western Wisconsin, and the last bison killed there in 1832.  Some prairies spanned 50 miles.  Prairie was almost continuous from Lake Winnebago to the Illinois border.  Natives had been expanding and maintaining grassland for a very long time.  In 1767, white visitors observed “large droves of buffalos” on the fine meadows along the Buffalo River. 

By and by, devastating epidemics hammered the indigenous people who had maintained the grassland and hunted the bison.  Regular burning sputtered out.  The last bison seen crossing the Mississippi River, and entering Wisconsin, was in 1820.  By 1854, dense groves of 25 year old trees were joyfully reclaiming their ancestral homeland.  Unfortunately, these recovering forests had a bleak future, because they stood directly in the path of a rapidly approaching mob of merciless pale-faced axe murderers.  Shit!

Over the passage of centuries, the tallgrass prairies created topsoil that was deep and remarkably fertile.  Then came the settlers, with their plows and ambitions.  Plows are magnificent tools for destroying soil, and creating permanent irreparable damage.  Walter Youngquist wrote, “In the United States, half the topsoil of Iowa is now in the Mississippi River delta.”  Today, tallgrass prairie ecosystems are in danger of extinction, maybe one percent of them still survive.  Exotic freak show grasses like corn and wheat are far more popular and profitable than the indigenous tallgrass.

In his book Collapse, Jared Diamond mentioned his visit to a wee remnant of the ancient prairie that had somehow survived the plowman invasion, an old churchyard in Iowa.  It was surrounded by land that had been farmed for more than 100 years.  He wrote, “As a result of soil being eroded much more rapidly from fields than from the churchyard, the yard now stands like a little island raised 10 feet (3 m) above the surrounding sea of farmland.”

Australia

Bill Gammage described the Australia that British colonists observed in 1788, when they first washed up on shore.  That landscape was radically different from what it is today.  Early white eyewitnesses frequently commented that large regions looked like parks.  In those days, all English parks were the private estates of the super-rich.  Oddly, the Aborigines who inhabited the beautiful park-like Australian countryside were penniless illiterate bare-naked Stone Age antifascist anarchist heathens.  Their wealth was their time-proven knowledge.

In 1788, large areas of Australia had been actively managed by firestick farming, which greatly promoted habitat for the delicious critters that the natives loved to have lunch with.  The Aborigines used both hot fires and cool fires to encourage vegetation that was fire intolerant, fire tolerant, fire dependent, or fire promoting.  Different fires were used to promote specific herbs, tubers, bulbs, or grasses.  When starting a fire, the time and location was carefully calculated to encourage the desired result.  According to Gammage, most of Australia was burnt about every one to five years.  On any day of the year, a fire was likely burning somewhere.

The natives generally enjoyed an affluent lifestyle.  They had learned how to live through hundred-year droughts and giant floods.  No region was too harsh for people to inhabit.  Their culture had taboos that set limits on reproduction and hunting.  During the breeding seasons of important animals, hunting was prohibited near their gathering places.  Lots of food resources were left untouched most of the time, a vital safety net.  The Dreaming had two rules: obey the Law, and leave the world as you found it.

The white colonists were clueless space aliens.  Their glorious vision was to transfer a British way of life to a continent that was highly unsuited for it.  Australia’s soils were ancient and minimally fertile, and the climate was bipolar — extreme multi-year droughts could be washed away by sudden deluges.  But, they brought their livestock and plows and gave it a whirl.  They believed that hard work was a virtue.  The Aborigines were astonished to observe how much time and effort the silly newcomers invested in producing the weird stuff they ate.

The new settlers wanted to live like proper rural Brits — permanent homes, built on fenced private property.  They freaked out when the natives set fires to maintain the grassland.  Before long, districts began banning these burns.  This led to the return of saplings and brush.  So, in just 40 years, the site of a tidy dairy farm could be replaced by dense rainforest.

Without burning, insect numbers exploded.  Without burning, fuels built up, leading to new catastrophes, called bushfires.  The Black Thursday fire hit on February 6, 1851.  It burned 12 million acres (5 million ha), killed a million sheep, thousands of cattle, and countless everything else.

Mark Brazil shared a story that was full of crap.  In Britain, cow manure was promptly and properly composted by patriotic dung beetles, which returned essential nutrients to the soil.  In Australia, none of the native dung beetles could get the least bit interested in cow shit.  It was too wet, and too out in the open.  Cow pies could patiently sit on the grass unmolested for four years, because nobody loved them.  This deeply hurt their feelings.  Adding insult to injury, Brook Jarvis noted that fussy cattle refused to graze in the vicinity of neglected pies, so the herd needed access to far more grazing land than normal.

Australian flies, on the other hand, discovered that cow pies made fabulous nurseries for their children.  Each pat could feed 3,000 maggots, which turned into flies — dense clouds of billions and billions of flies — which the hard working Christians did not in any way fancy.  Being outdoors was hellish.  In the 1960s, folks imported British dung beetles, which loved the taste and aroma of cow pies.  Oddly, this is one example where an introduced exotic species apparently didn’t create unintended consequences.  When they ran out of pies to eat, the beetles simply died.

Anyway, a continent inhabited by Stone Age people was substantially altered by firestick farming and hunting.  The Australia of 1788 was radically different from when the first humans arrived.  We’ll never know if continued firestick farming would have eventually led to severely degraded ecosystems.  Some serious imbalances can take a long time to fully develop.  Many attempts to deliberately control and exploit ecosystems have spawned huge unintended consequences over time.  The ultra-conservative indigenous kangaroos and wallabies were not control freaks, they simply adapted.

Gammage was fond of the Aborigines, because they were highly successful at surviving for a long time in a challenging ecosystem.  He was much less fond of the British colonists who, with good intentions, combined with no wisdom, were highly successful at rubbishing it. 

Baz Edmeades viewed the entire Australian experience through ecological glasses.  Fire reshaped the continent.  When humans first arrived, the north coast was home to dry forests that majored in araucaria trees.  Before long, they were displaced by fire-promoting forests that majored in eucalypts.  The original dry forests went up in smoke.  Extremely low-tech Stone Age people substantially altered the ecosystem.  We may never have a clear understanding of the early extinctions of the vertebrate megafauna and giant reptiles. 

Wild Free and Happy Sample 42

[Note: This is the forty-second sample from the rough draft of my far from finished new book, Wild, Free, & Happy.  The Search field on the right side will find words in the full contents of all rants and reviews.  These samples are not freestanding pieces.  They will be easier to understand if you start with sample 01, and follow the sequence listed HERE — if you have some free time.  If you prefer audiobooks, Michael Dowd is in the process of reading and recording my book HERE.]

SACRED ENERGY

Sunbeams

Alfred Crosby wrote a fascinating history of energy use.  There are two primary sources of energy, nuclear fusion from the core of the sun, and heat that rises up from the molten magma within the Earth.  Almost all of the energy used by the family of life traces back to the solar source.  Every day, the sun reliably provides clean energy for our planet, and it never sends us a bill.  Solar energy will very likely continue to be delivered for millions of years.  It is genuinely sustainable.

Energy arriving via incoming sunbeams is captured by the living solar panels built into a wide variety of green plants.  The solar panels contain chlorophyll, which uses sunbeam power to assemble simple carbohydrates by combining molecules of carbon dioxide (CO₂) and water (H₂O).  This magic act is called photosynthesis, and it enables the existence of the entire family of life.  The carbs it produces include sugars, lignin, and cellulose.  They are used for the plant’s basic survival, growth, and reproduction.  Some plants store carbs for later use.  The byproduct emitted by photosynthesis is a gas called oxygen.

By a remarkable coincidence, living organisms called animals require both carbohydrates and oxygen in order to survive.  Animals burn (oxidize) carbs and release a byproduct called carbon dioxide, the gas that plants need to perform photosynthesis.  Animals consume food from plant and/or animal sources and use it for growth, reproduction, daily activities, and so on.  The portion of their food intake that’s not utilized is emitted in wastes called pee and poop, which are highly nutritious substances for plants.

Finally, all living plants and animals. sooner or later, become dead plants and animals, and dead stuff is a highly nutritious source of food for the recycling crew of wee beings.  They convert dead stuff into humus.  This organic matter sequesters essential nutrients and improves the fertility of topsoil, much to the delight of the entire family of life.  Under ideal conditions, the fertility and depth of topsoil can improve continuously for thousands of years.   

Ladies and gentlemen, please stand up and give an enthusiastic round of applause for the amazing magic of life — a brilliant, intricate, functional process that has been perfectly sustainable for several billion years, successfully rolling with the many powerful punches of change!  Hooray!  All lives matter!  All deaths matter!  The dance goes round and round.  Woo-hoo!  Big Mama Nature rocks!

Here’s something I didn’t know before.  Earth is an unusual planet, because its land surfaces include accumulations of carbon-rich organic matter, stuff left behind by the family of life.  This matter enables the possibility of fire.  Three things are needed for fire: oxygen, heat, and fuel.  A living forest can burn, and so can collections of dead dry stuff.  Crosby suspected that Earth might be the only planet where fire is possible.

Carboniferous Period

The family of life is sunbeam powered.  Soil organisms are children of the sun.  Plants and trees are children of the sun.  Everything that swims, flies, crawls, or walks is a sunbeam critter, including you and me.  Fossil energy is hydrocarbon compounds originally created by ancient sunbeams.

Coal is fossilized sunshine from tropical swamp forests that lived during the Carboniferous Period, which was roughly 360 to 300 million years ago, long before dinosaurs.  This fossil biomass accumulated over the course of 60 million years, largely in the vast swampy rainforests of Europe, Asia, and North America.  The rainforests absorbed sunshine and carbon, and used it to create carbon-rich biomass, via photosynthesis.

Today, tree trunks are roughly 1 part bark to 4 parts of wood.  During the Carboniferous, the trees trunks were more like 8 parts bark to 1 part of wood (up to 20 to 1).  Back then, there were no microorganisms capable of decomposing the lignin in the bark of dead trees, so nothing rotted for 60 million years.  The biomass in the rainforest swamps eventually became carbon-rich peat.  Over time, pressure and heat transformed the peat deposits into coal.  In some locations, coal beds are up to 39 feet thick (12 m). 

Because so much carbon was buried, there was far less of it in the atmosphere.  Consequently, the oxygen content in the air soared to 35 percent (now it’s 21 percent).  So, for the animals living in that oxygen-rich air, many things grew to giant proportions.  Dragonflies had wingspans of 29 inches (75 cm), and millipede-like bugs grew up to 9 feet long (2.7 m).  Some amphibians were almost 20 feet long (6 m). 

 Finally, the Carboniferous Period was brought to an end by climate change.  Wet and warm became cool and dry.  Glaciers grew, sea levels dropped, and many rainforest species went extinct, including most of the forests.  In the new climate, many reptiles adapted well, because the eggs they laid on land had shells that prevented the embryo from drying out.  Eventually, this enabled the emergence of the dinosaur era, which included the ancestors of modern birds.

It took many millions of years to transform the woody biomass into coal.  Over the passage of time, Big Mama Nature buried most of the sequestered carbon.  The family of life had no need for it.  So, the fossil sunshine took a long and pleasant nap.  Much later, when human miners rudely began drilling and blasting, the coal spirits were totally infuriated.  They cast malevolent spells against the screw-brained primates.  Their curses loaded the atmosphere with carbon, jerked the rug out from under a stable climate, and blindsided ecosystems everywhere.  Leave the coal where it is!

Jurassic Period

Petroleum and natural gas are buried sunshine that began in bodies of water during the Jurassic Period, the age of dinosaurs.  In those days, the climate was very warm, creating perfect conditions for teeny-tiny plants called phytoplankton that float around in oceans, seas, and lakes.  They absorbed Jurassic sunshine, and used it to create carbohydrates (their food), via photosynthesis. 

Today, phytoplankton are the most numerous organisms in oceans.  It is estimated that they comprise one percent of global biomass, yet most of them are too small to see with the naked eye.  They are the foundation of the oceanic food chain, and all sea life depends on them for survival.  Of all the photosynthesis performed on Earth, they do half of it.  They produce half of the oxygen in the atmosphere, the stuff you’re breathing now.  They asked me to tell you that they are really pissed off about the climate crisis and ocean acidification.  Leave the oil and gas where it is!

During the Jurassic, countless gazillions of these floating organisms lived happily.  When they died, they sank to the bottom.  In some locations, large deposits accumulated faster than the material could decompose.  These deposits formed between 260 and 10 million years ago.  Once they were buried under layers of sediment, heat and pressure stimulated chemical reactions.  Oil and gas were created when the deposits were cooked for millions of years at temperatures ranging from 180° to 280°F (82° to 137°C).  In many locations, large concentrations of these hydrocarbons (oil and gas) have survived to modern times.  (So, oil is not dinosaur juice, it is phytoplankton stew.)

It took 250 million years for the biomass to accumulate at the bottom of the sea, and additional millions to finish pressure cooking it into oil and gas.  During this extremely slow process, 90 tons of ancient biomass was transformed into oil from which one U.S. gallon of gasoline (3.8 l) could be refined.  Over the passage of time, Big Mama Nature deeply buried most of the sequestered carbon, because the family of life had no need for it.  The world continued to live happily, and the air remained fresh and clean.

Vicious Circle

Our hominin ancestors appeared maybe four million years ago.  Like all other animals, they needed food, air, and water to survive.  Plants made their own food via photosynthesis, so they needed sunbeams, air, and water. 

As mentioned earlier, the invention of the fire drill, and the domestication of fire was a major turning point in the human saga.  Our early hominin ancestors may have lived for a million years or more prior to fire making.  It wasn’t necessary for biological survival, but it eventually enabled civilizations to develop the deadly technology needed to destroy entire ecosystems, and destabilize the climate.  We do know that, sooner or later, our ancestors became seriously addicted to using fire.  At that point, they developed a never-ending interest in fuel — dried organic matter like grass, leaves, dung, peat, and wood. 

Fire enabled them to better defend themselves against man-eating carnivores, so fewer brothers and sisters became cat food.  It also enabled cooking, which sharply increased the number of potential food resources from which they could extract solar energy.  So their addiction to sunbeam energy now expanded beyond the food they ate, to the solar power stored in the fuels they burned.

Humans are walking sunbeams.  We absorb sunbeam energy when we eat nuts, berries, fruit, tubers, and other digestible plant substances.  We can’t acquire it by eating grass, but we can absorb it when we eat grass-loving herbivores.  We can encourage the expansion of their herds, and increase our food resources, by deliberately expanding herbivore habitat — grasslands.  This can be done via firestick farming or deforestation.  For humans, grasslands provide more food than deserts, wetlands, forests, or brushy scrub. 

Wild herbivores are far less likely to overgraze than are herds of domesticated livestock, because a herder’s wealth and status is based on the number of critters he owns, not the condition of the grassland.  More is better.  For this reason, herders also have a long history of aggressively exterminating the wild carnivores that also cherish their herds.  As mentioned earlier, some ecosystems have been reduced to wastelands when overgrazing leads to catastrophic erosion over time.

Cropland can produce far more food per unit of land than grazing land, so it was often expanded in regions that were suitable for agriculture.  The healthy community of wild vegetation was ripped off the face of the land, the soil was tilled, seeds were planted, and sunbeams nurtured a generous banquet of nutrients we could digest.

Like herding, agriculture also has a long history of degrading ecosystems over time, in a number of ways.  Each crop removes nutrients from the soil that are often not returned — nitrogen, phosphorus, potassium, and other stuff.  When sunbeams heat up exposed soil, they stimulate microbial life that degrades the humus, causing precious carbon in the soil to float away as carbon dioxide.  This long term carbon loss is even greater when cropland was originally created via deforestation.  Wild forests and unmolested topsoil are two huge treasure chests of precious carbon.  In a later chapter, we’ll take a closer look at the serious harms and challenges related to agriculture today.

Once again, attentive readers will see that the hunter-gatherer way of life had far less impact on ecosystems.  It wasn’t consistently harmless, but it kept humans alive for 300,000 years, and our hominin ancestors for several million years.  In comparison, the lifespan of civilization will be more like a quick flash in the pan, a train wreck.  Prior to the dawn of herding and farming, the planet remained in far better condition than it is today. 

Human cleverness, motivated by good intentions, and handicapped by ecological ignorance, has spectacularly backfired — and this failure is not understood by billions of folks who know little or nothing about environmental history.  Catastrophe is invisible to them.  Their virtual reality headsets stream images of a high standard of living, wondrous prosperity, amazing genius.  Let’s go shopping!

Craig Dilworth described the ongoing rise and fall of civilizations as a vicious circle.  Clever innovation enabled folks to control and exploit more sunbeam energy, and this enabled population growth.  More mouths needed access to more sunbeams, which required more cleverness, and on and on.  It was a merry-go-round that kept spinning faster and faster, until it ran into solid limits to growth that cleverness could not sweep aside.  Then, the merry-go-round shifted into reverse, and the game got slower, simpler, and quieter.  Societies strangled by scarcity, or bulldozed by stronger outsiders, tumbled into the tar pits of oblivion, while new merry-go-rounds began spinning elsewhere.  What goes up must come down.

Albert Bartlett tirelessly preached that growth in population and resource consumption is undesirable, unwise, and unsustainable.  Therefore, the super-trendy buzzword “sustainable growth” is an oxymoron.  Unfortunately, it seems that the majority of educated people in the world are radicalized believers in an absurd oxymoron.  It’s like the neon sign in the tavern window, “Free Beer Tomorrow.”  Our obsession with perpetual growth is batshit crazy.  Luckily, ignorance is curable, in theory.

By removing the forests, and growing crops, orchards, and livestock, the incoming solar energy could generate far more digestible nutrients.  More nutrients enabled the survival of more primates, so more forests were converted into manmade nutrient factories, and the primate mob grew even more.  The trees cleared could be processed into many useful products.  The charcoal could be used to smelt ores, and produce metal tools.  Metal tools made it much easier to remove forests, build things, plow cropland, and kill enemies and other animals.  This merry-go-round of cleverness has never spun faster, with greater fury — a vicious circle indeed.

Muscle Power

Throughout the four million year era of hominins, muscle power has been a primary source of energy for doing stuff.  Muscle power is highly versatile, able to run on a variety of edible fuels — grains, beans, meat, eggs, fruit, nuts, roots, insects, and so on.  Clive Ponting noted that until 1800, about 75 percent of the mechanical energy needed to run civilization came from human muscles, and most of the rest was from animals (wind and water were minor sources). 

Prior to 1492, the indigenous Americans had enslaved zero extra-large beasts of burden (beside humans).  The grand cities of the Incas, Mayans, and Aztecs were built entirely with human labor.  Much human energy was used to create Egypt’s pyramids.  The Great Wall of China was constructed by one million workers, half of whom died in the process.  The Greek and Roman city states held large populations of slaves.  Slavery was common from the dawn of civilization until the nineteenth century, and so was forced labor for “free” peasants.

Pita Kelekna wrote that horses were wild and free until maybe 4000 B.C., when humans began enslaving them.  Wild horses had been popular large game for many thousands of years.  Several scholars have speculated that domestication probably saved horses from extinction.  You can only eat a horse once, but you can force it to perform heavy work month after month, year after year.  They could be used to pull stuff, haul loads, and carry riders.  Four legged slaves enabled a tremendous expansion of soil mining, forest mining, mineral mining, bloody empire building, and economic growth.  They helped unlock the gateway to industrial civilization.

Humans produce less muscle power than horses, but we need less feed, and can digest far more types of foods.  We have bodies and brains that allow us to perform a much wider variety of physical tasks.  People can travel across deserts, up rugged mountains, and through dense rainforests.  Horses are less adaptable to hot climates and arctic regions.  Each one requires five acres (2 ha) of good grassland, and the supply of good grassland is not infinite.

By 1900, the global population of humans had soared to about 1.5 billion, and the era of horse power was wearing out its welcome.  Eric Morris wrote a fascinating essay to help us remember life in the Peak Horse era.  The streets of big cities were jammed with horses, carriages, and wagons, squishing through a deep layer of manure and urine, past rotting horse carcasses, amidst dense clouds of flies and overpowering stench.  Cities were rapidly growing, as hordes immigrants moved in to enjoy miserable industrial jobs, while living in crowded, filthy, disease ridden slums.  Each horse emitted 15 to 30 pounds (7 to 14 kg) of manure daily — 3 to 4 million pounds (1.3 to 1.8 million kg) in New York City each day.

(To be continued…)

Wild Free and Happy Sample 23

[Note: This is the twenty-third sample from my rough draft of a far from finished new book, Wild, Free, & Happy.  I don’t plan on reviewing more books for a while.  My blog is home to reviews of 202 books, and you are very welcome to explore them.  The Search field on the right side will find words in the full contents of all rants and reviews, if you are interested in specific authors, titles, or subjects.]

 Super Grass

I previously mentioned the notion that humans are creatures of the grass.  Recently, I stumbled on information that added a deeper dimension to this theme.  It all began when I read that the area of global forest cover has been sharply reduced since the early Miocene Epoch.  This stimulated my curiosity, and led to an exciting wild factoid chase.  The Miocene spanned from 23 to 5.3 million years ago.  It seems that the early Miocene was wet and warm, and many ecosystems were forests.  I was surprised to learn that as late as 20 million years ago, much of Antarctica was covered with temperate forests.

Anyway, later in the Miocene, maybe 6 to 8 million years ago, it got cooler and dryer, and a new type of major ecosystem emerged — grasslands.  They can thrive where it’s too dry for trees.  Over time, expanding grassland displaced large areas of forest.  This shift was an important turning point in the human saga.  As forests shrank, there was less habitat for tree-dwelling primates, causing a number of species to tumble off the stage.  Some primates moved out onto the savannah, and figured out how to survive in open country as ground-dwelling primates.  They included the ancestors of baboons and humans. 

So, it was a gradual but substantial shift in climate patterns and ecosystems that made it possible for our ancestors to invent a new career path as hunters of large herbivores.  As the climate got cooler and dryer, grass species more tolerant of arid conditions rose in importance.  At this point, we need to take a brief side trip into some technical stuff.  I’ll keep it as short and simple as possible.

The entire family of life is solar powered.  Incoming solar energy is received by green plants, who use it to produce sugar.  This process is photosynthesis.  It converts solar energy into a form of chemical energy that plants and animals must have in order to survive.  Some animals acquire it directly by eating plant material, and others get it indirectly by dining on plant-eating animals.  Thus, photosynthesis is the foundation of life on Earth.

The process begins by splitting water molecules (H₂O) into hydrogen and oxygen atoms.  Then, in a fancy magic act, hydrogen is stirred together with CO₂ to make sugar (C₆H₁₂O₆).  The process results in some leftover oxygen atoms, which are released to the atmosphere.  Notice that animals exhale the CO₂ that plants must have, and plants exhale the oxygen needed by animals, a sacred circle dance.  Plants can use the sugar to fuel their growth, or they can convert it to starch, and save it for later.  Plants can also make fat, protein, and vitamins.  They’re much smarter than they look.

The act of snatching carbon from the air, and incorporating it into living plant tissues, is called carbon fixation, or carbon sequestration.  As more carbon gets sequestered into the plants and surrounding topsoil, then less of it remains in the atmosphere.  This is great, because too much carbon in the atmosphere can lead to catastrophic climate juju, like the freaky changes we’re now just beginning to experience.

I should also mention that petroleum and coal are substances made of sequestered carbon that accumulated over the course of 500 million years.  Big Mama Nature wisely stored it away in a safe place deep underground, where it could cause no mischief.  Unfortunately, it has become very trendy for ignorance-powered societies to retrieve enormous quantities of this ancient carbon and foolishly burn it up, in order to indulge in a decadent joyride of self-destructive childish whimsy.  Big brains can make big mistakes.  It’s so embarrassing!

And now, (gasp!) the plot thickens.  There are two categories of plant species, based on the mode of photosynthesis they use: C₃ or C₄.  C₃ produces a compound that has three carbon atoms, and C₄ produces a compound that has four carbon atoms.  Both types are very old, but the shift to a cooler and dryer climate greatly boosted the expansion of C₄ species.  Maybe 85 percent of the plant species on Earth are C₃.  Their method of carbon fixation is simpler and less efficient than C₄. 

Elizabeth Kellogg studied C₄ plants.  In one experiment she found that, under ideal conditions, C₃ plants could theoretically capture and store up to 4.6 percent of the solar energy they received, while C₄ plants could get up to 6 percent (i.e., 30 percent more than C₃).  While only 3 percent of flowering plant species are C₄, they account for 23 percent of all carbon fixation in the world.  In other words, they produce much more of the precious chemical energy (sugar) that the family of life depends on.  Kellogg calls the C₄ process a turbocharger.

There are four conditions under which C₄ plants have a big advantage — high temperature, high light, low moisture, and low nutrients.  Because they use much less water, C₄ plants better conserve soil moisture.  They also produce more root biomass, which increases their tolerance for drought and fire.  Of the 12,000 grass species, 46 percent of them are C₄, and they include corn (maize), sugar cane, millet, and sorghum.  (Mad scientists are now trying to alter DNA to make rice C₄ too.)

When critters consume C₄ grasses, this diet leaves behind physical tracks.  Spencer Wells wrote that the bones of Native Americans revealed whether they were corn farmers or hunter-gatherers.  Because corn is a C₄ grass, the bones of corn eaters contained molecular C₄ markers.  Baz Edmeades talked about the ferocious dirk-tooth cats (Dinofelis), a species that went extinct about 1.4 million years ago.  We know they were creatures of the savannah, not the forest, because analysis of their tooth enamel indicated that they dined on herbivores that ate C₄ grasses.

And now, dear reader, at long last, we are ready to proceed to the exciting conclusion of this tedious jabber.  It’s time to turn the spotlight on the heroes of this story, the C₄ grass species.  Kellogg noted that in the last 8 million years, as climate change drove the retreat of tropical forests, the domain of C₄ grasses has greatly expanded.  They are now significant components of major grasslands around the world.

C₃ grasses were better adapted to moist forest floors and limited sunlight.  They were less able to thrive on arid grasslands.  Out on the savannah, conditions were ideal for C₄ grasses, because they needed less water to enjoy a happy life.  Here they moved from the sidelines to the center stage.  Receiving many hours of direct sunlight every day, they were able to manufacture generous amounts of chemical energy (sugar), and this gave them the ability to grow rapidly. 

And so, these highly nutritious grasses became a highly desirable food source for the animals that were able to digest them, which required some adaptations.  Baz Edmeades noted that the blades of these grasses were tough, highly fibrous, and coated with abrasive silica.  Evolution responded by providing some animals with new and improved teeth that were more tolerant of abrasion, and better able to pulverize the plant fibers.  Other critters were issued new and improved digestive tracts, populated with bacteria that were fine-tuned for chemically breaking down fibrous glop.  The critters that succeeded in adapting to the new banquet made big gains in size and diversity.

Of course, too much of a good thing will have consequences.  If herds got way too large, the vitality of the grassland would be degraded, leading to starvation.  So, evolution came to the rescue by promoting a variety of big strong bloodthirsty carnivores, who delighted in inviting large herbivores to join them at lunchtime.  To make this sacred dance more sporting, evolution also encouraged the development of herbivores who could boogie across the grassland at high speeds.

Edmeades concluded that the rise of highly productive C₄ grasses radically changed the world.  It spurred the evolution and spread of an astonishing variety of grassland herbivores and their predators.  It led to the emergence of spectacular Serengeti-like ecosystems in Africa, Eurasia, and the Americas — fantastic wonderlands of abundant life.

Graham Harvey noted that the herds of grass-eating critters benefitted the grasses.  Grazing actually stimulated plant growth.  In a brilliant design, new blades of grass emerge from growing points located close to the ground, where they are less likely to be damaged by hungry teeth.  The faster that grasses can send up new blades, the more sunlight they can capture, the more sugar they can make, and the happier the whole ecosystem becomes.

Grazing also benefitted grasses by regularly nipping off the rising shoots of woody vegetation.  If trees and brush were allowed to grow and spread, they would compete with the grass plants.  Then, the herds of hungry herbivores would have less to eat, and so would the carnivores that adored red meat.  Herds religiously offered their deep gratitude to the grass people by lovingly depositing nutrient rich manure and urine all over the place.

The big picture here is that the shift to a cooler dryer climate encouraged the substantial expansion of grassland, which boosted the expansion of C₄ grass species, which propelled the evolution and expansion of large grazers and carnivores, which boosted the global tonnage of living meat.  These megafauna migrated and settled on five continents (not Australasia).  Around the world we find species of horses, bison, elephants, antelope, deer, hyenas, wolves, bears, and so on.  The moral of this story is that climate change can radically alter the face of the planet, and the family of life.

Later in this amazing transformation, another powerful agent of radical change joined the cast of the grassland soap opera.  These critters walked on two legs, and resembled what you see in the mirror.  They eventually assumed the role of apex predators, something that no other primate had ever attempted.  Our ancestors did not wait patiently for evolution to provide them with the speed, strength, fangs, and claws that are customary for natural born carnivores.  Instead, they invented hunting weapons, learned how to make fire, and began experimenting with a way of life that no other animal in the history of the planet had ever attempted.  It’s notable that every other animal species continues to live like they did a million years ago — ultra-conservative, and perfectly sustainable.

The advance of the new critters marked the emergence of an extremely spooky, highly contagious, multi-drug resistant virus known as cleverness fever.  For a few million years, its mind-altering effects gradually intensified.  Ten thousand years ago, they surged.  Today they are skyrocketing.  Humankind is now engaged in full scale warfare against the entire family of life, including itself.  A lively and entertaining soap opera has shape shifted into the mother of all horror shows.  Will the current swing to a much warmer climate provide the miraculous silver bullet cure for the mass hysteria of cleverness fever?  Stay tuned.