Showing posts with label climate. Show all posts
Showing posts with label climate. Show all posts

Sunday, March 6, 2022

Wild Free and Happy Sample 59

 

[Note: This is the fifty-ninth sample from my rough draft of a 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 happen to have some free time.  If you prefer audiobooks, Michael Dowd is in the process of reading and recording my book HERE.

ISLANDS

The saga of the family of life is several billion years old.  It’s a story of evolution, from single celled organisms to a fantastically complex and diverse collection of living beings.  It’s a story of climate change which, for better or worse, never tires of pulling the rug out from under eras of stability.  Craig Childs noted that drill cores of lake sediments in northern New Mexico showed droughts that lasted up to ten centuries.  Six thousand years ago, the Sahara Desert was a lush grassland.

The saga is also a story of migration and colonization.  All plant and animal species are sometimes nomadic, remaining in comfortable habitats until conditions become challenging.  When their home becomes harsh, the lucky ones are able to migrate to better locations.  The horse family originated in North America about 4.5 million years ago.  It was a wonderful place to live — until hungry humans from Eurasia arrived.  Pita Kelekna noted that the last wild American horse perished in Patagonia 9,000 years ago.  

The horse family remains alive and well today because, long ago, some adventurous herds happened to wander across the land bridge to Asia.  They migrated into new regions, and found lots of delicious places to live.  Like the horses, many other groups of megafauna species have colonized large portions of the world — the elephant-like family, and the bears, cats, canines, camels, hominins….  They migrated from one continent to the next by walking across dry land.  Of these globetrotting megafauna, only one species has a reputation for causing numerous extinctions, and severely damaging ecosystems.

Paul Martin was a pioneer in the study of megafauna extinctions.  Offshore islands were the last places to be colonized by species that did not fly or swim.  He noted that ground sloths were eventually driven to extinction from Alaska to Patagonia — except on islands.  For example, on the islands of Cuba, Haiti, and Puerto Rico, ground sloths survived 6,000 years longer than on the continental mainland.  Why?  The mainland and islands had the same climate.  The critical variable was human presence.  When watercraft technology enabled hunters to visit islands, the sloths were finally doomed.

After reading a pile of books and papers, I was convinced that climate change was not the primary cause for many of the extinctions that have happened since humans migrated out of Africa.  Martin wrote that the megafauna species that went extinct had been around for a very long time, and had survived a number of surging and fading glacial cycles.  Ongoing research largely supports the human impact hypothesis.

In his book Europe, Tim Flannery discussed the vast mammoth steppe of northern Europe.  Oddly, with the rise and fall of temperature trends, warmth loving species were not more likely to vanish during periods of frigidity.  Cold loving species were not more likely to vanish when the steppe got hotter.  Uncomfortable animals were inspired to migrate to more pleasant locations.  Unlike today, ice age climate swings happened gradually.  Living generations would not have been aware of the changes.

Earlier, I mentioned that megafauna extinctions could sometimes take a thousand years or more.  Living generations were unlikely to actually notice the slow decline of large game species in a wild frontier.  As humans colonized new regions, and unintentionally encouraged extinction spasms, the largest mammals were usually the first to blink out.  They were easy to find, provided lots of meat, and had low reproduction rates.  Thus, human impact.  A climate whammy would have hammered critters of all shapes and sizes indiscriminately.  David Burney and Tim Flannery described a 50,000 year pattern of extinctions corresponding with the arrival of humans. 

Fernando Fernandez wrote an unusually readable paper that described six significant problems with the climate change theory.  Bernardo Araujo and team agreed.  They concluded that if we disregarded all evidence of human impacts, nobody would be talking about megafauna extinctions today.

Over the years, Paul Martin rejected flimsy arguments that blamed climate shifts, but by 2005, he acknowledged that the climate could have led to a few extinctions.  Big Mama Nature may have sometimes played a direct role, and that’s OK.  We can’t complain.  She will always do whatever she wishes, because this is her circus, and we are her clowns.

Most of the world’s woolly mammoths were extinct by 10,500 years ago.  A few lasted longer.  Saint Paul Island is off the coast of Alaska.  Graham Russell and team noted that woolly mammoths survived there until about 5,600 years ago.  A warming climate had elevated sea levels, which shrank the land area of the island.  The climate got dryer, and sources of fresh water became scarce.  The thirsty mammoths vanished.  The first evidence of human presence on the island dates to just 230 years ago.  Here, climate is clearly a primary suspect.

The last mammoths on Earth perished about 4,000 years ago on Wrangel Island, north of Siberia.  DNA analysis suggests that the mammoths were wrecked by a small population and inbreeding.  Lately, new research has found evidence of human presence about 3,700 years ago.  The island is huge, and has not been thoroughly studied.  When more is learned, this story may add a hunting chapter.  Stay tuned.

I’ve been a technical writer for 35 years.  Accuracy is essential.  But in the realm of prehistory, experts express theories and factoids that are consistently inconsistent.  Truth can be a fairy mist.  This gives me endless headaches.  I still can’t understand why more than a few folks continue to believe that the primary cause of the megafauna extinctions was climate change, not human impacts.

Today, the world is buzzing with countless conspiracy theories that throw truth under the bus.  Derrick Jensen wrote the book on human supremacy, and the super-spooky mind-altering power of unquestioned beliefs.  Humans are the only things that matter, a living planet does not.  Earth is a disposable stage prop for the heroic stars of the show, the comically clever primates.

From this mindset, the human colonization of Earth (a process that has left behind a long and bloody trail of extinctions, spurred explosive population growth, rubbished countless ecosystems, and triggered an onrushing climate catastrophe) is seen as a wondrous achievement that should fill us with glowing pride.  We have blind faith that technology will always sweep aside every challenge on our path.  Indeed, the best is yet to come! 

Was I missing something important?  My muse was nervous and perspiring heavily.  She persistently insisted that I take a deeper look at island extinctions, and butt heads with my doubts.  So I did.  Wow!  It has been a mind-blowing experience.  I now have no doubt that islands have especially important stories to tell us.  So, let’s do some island hopping.  Enjoy!

Pangaea the Supercontinent

I sometimes look out my window and see an opossum.  One day, I was fascinated to discover the saga of the opossum people.  They are marsupial mammals, and humans are placental mammals (see Google).  Opossums originated in the vicinity of Australia.  Around 335 million years ago, most of Earth’s dry land was clumped together into an enormous supercontinent called Pangaea.  It began to break apart around 200 million years ago.  Over time, chunks of it drifted all over the place, and arranged themselves into the seven continents we know today.

The plants and animals that had evolved on Pangaea continued living on the drifting chunks, in varying assortments of species.  The chunks migrated in different directions, sometimes into different climate zones.  Their plant and animal communities continued adapting and evolving, creating unique ecosystems.  Opossums had lived on chunks that used to be connected, now called Australia, Antarctica, and South America.  For a long time, South America was far away from North America, but they eventually wandered close together, and opossums boogied north across the border, and into my future back yard.

Until this morning, I believed that humans were the only species associated with mass extinctions, but I was wrong.  A wise woman has now informed me that, three million years ago, when North and South America finally kissed at Panama, North American carnivores charged southward, and exterminated numerous marsupial species.

Anyway, the gradual breakup of Pangaea was rough and messy.  Offshore from the large land masses were smaller chunks that had broken away from the edges — islands.  Many islands were created.  For example, Madagascar broke away from India maybe 100 million years ago.  East of Madagascar is Mauritius, a different type of island, created by volcanic activity (like Hawaii was).

Channel Islands

Offshore from Santa Barbara, California are the five Channel Islands.  Around 20,000 years ago, when sea levels were 300 feet (91 m) lower than today, the five islands were united in one larger island that was just 6 miles (10 km) from the coast.  Over time, rising seas altered the coastlines.  Today, the islands are 22 miles from the coast.  About 80 percent of their former dry land area is now submerged.

Among the former residents were pygmy mammoths.  Their ancestors were the huge Columbian mammoths that lived on the mainland, some of whom decided to swim several miles to the islands.  Swim?  Yes!  Even when sea levels were low, there was no land bridge from the mainland to the islands.  Asian elephants have been known to swim to islands 23 miles (37 km) away.  Their large bodies are buoyant, and their trunks can be used like snorkels.  Did you know that hippos in the Old World have also been excellent long distance swimmers?  No joke!

Anyway, over the passage of thousands of years on the Channel Islands, the mammoths evolved into dwarfs, a unique new species.  Maybe this was an adaptation to limited resources.  Or, maybe it was a lack of predators.  Jumbo size improves the odds for survival when bloodthirsty carnivores live nearby.  But when predators are not good swimmers, and live far away, there is less need to be huge and powerful.

Radiocarbon dating is accurate up to 50,000 years ago, and mammoths were on the islands for at least that long.  Humans arrived on the islands around 13,000 years ago.  The mammoths went extinct between 13,000 and 12,900 years ago.  Coincidence?  Wikipedia reports that mammoths still lived on the islands when humans arrived.  Two mammoth skulls with the brains removed were found near a fire pit.  Of the 100 fire pits examined, at least a third contained mammoth bones.  Climate pleads innocent.

Mediterranean

Jacques Blondel was interested in habitat destruction on the Mediterranean islands during the last 10,000 years.  Population pressure on the mainland encouraged folks to colonize the larger islands.  Forests were pushed back to create cropland and pasture.  Humans deliberately introduced livestock, and unintentionally released pests, like rats and mice. 

Long, long ago, isolation from the mainland led several species of large animals to become dwarfs on multiple Mediterranean islands. There were pygmy hippos and deer, and at least 12 species of pygmy elephants.  The smallest elephants were 39 inches (1 m) tall.  The scarcity of predators also led to the evolution of giant rodents and flightless owls. 

Blondel wasn’t sure if the pygmies were primarily eliminated by hunting, or by feral pigs introduced from the mainland.  Either way, this was not a climate bummer, it was a human impact bummer.  Bottom line: probably all of the wild mammal species that originally inhabited the Mediterranean islands were eventually driven extinct following human colonization. 

Marco Masseti was fascinated by the mammals of the Mediterranean islands, and his report is long, exceedingly thorough, and includes cool maps and illustrations.  In the Mediterranean basin, several thousand years of civilization have been fantastically successful at rubbishing the ecosystem, taking a heavy toll on biodiversity.  Many islands were once vast jungles of oak trees, now reduced to “little more than mineral skeletons.”  It may be the most heavily destroyed region on Earth. 

The old theory was that when sea levels were low, large mammals simply walked across dry land to what are now islands.  When sea levels rose, and islands became cut off, the isolated large mammals became dwarfs.  Experts now say that the land bridges never existed.  Islands were only accessible by swimming, rafting, or flying.  Rising sea levels increased the difficulty.  Deer are capable swimmers, and hippos and elephants are champions.  Birds and bats can go where they wish.  Masseti concluded that human impacts were the primary cause of Mediterranean island extinctions.  Again, climate pleads innocent.

Caribbean

There have been two recent studies of extinctions on islands of the West Indies, in the Caribbean Sea.  The 2017 paper was written by Siobhán B. Cooke and team.  On multiple islands, it compared the dates of human arrival with the extinction dates.  It found that humans arrived on the islands in four waves.  The first three were Amerindian hunter-gatherers, and the fourth was Europeans.  Each wave generated increased eco-impacts.  Access to the full paper is not free. 

Luckily, Mindy Weisberger wrote a news release that summarized the study, and is free to one and all.  Prior to human colonization, there were 150 species of mammals on the islands, including sloths, giant monkeys, bats, and jumbo rats.  Humans colonized the Caribbean basin mainland by 12,000 years ago, but they didn’t begin colonizing the islands until 6,000 years ago.  By this time the climate was stable, well into the Holocene warm era.  Most of the extinctions on all of the islands happened after human arrival, not before. 

Early in the game, hunting was probably the cause of extinctions.  Then came forest clearance and agriculture, which eliminated wildlife habitat.  Destruction accelerated 500 years ago, when Europeans arrived, bringing invasive exotics like cats, rats, goats, and mongooses.  Indigenous rodent species got hammered.  This is not a climate story, it’s another human impact tragedy.

In 2021, a second paper was published, written by Samuel Turvey and team.  It’s online and free.  This paper tracked the data on 89 species on 118 Caribbean islands, and explored the pattern of extinctions.  All of these species were still alive at the start of the Holocene warm era, which began 11,700 years ago, and has not cooled off yet.  Conclusion: “Hunting, landscape transformation, and invasive mammal introduction by successive waves of colonists following human arrival approximately 6000 years ago are considered the primary drivers of Caribbean mammal loss.” 

Larger animals had low reproduction rates, and small populations.  They were at the highest risk of being driven to extinction by the growing human population.  The smallest animals were hard hit by the introduction of invasive predators, like black rats and mongooses.  Their extinction dates correspond to the arrival of these predators.  Again, climate pleads innocent.

New Zealand

The islands of New Zealand were the last large landmass colonized by humans.  Polynesian settlers began arriving somewhere between A.D. 1280 and 1350.  Over time, almost half of New Zealand’s original vertebrate species went extinct, including 51 species of birds.  Alexandra van der Geer wrote that nine species of huge flightless moas vanished in less than a century, zapped by hunting and habitat destruction. 

Moas shared the trait of gigantism with other flightless birds, like the ostriches of Australia, and the elephant birds of Madagascar.  In the extremely distant past, the moas lived elsewhere, and still had wings that enabled flight.  When they landed in New Zealand, maybe 60 million years ago, they were delighted to discover that there were no large ground dwelling predators eager to eat them.  The only mammals on the islands were bats and seals, and they weren’t interested in moas. 

Until this morning, I believed that the gigantism of flightless island birds was solely due to little or no predator risk.  Today I learned that there was another factor.  Isolated islands had no large herbivores that feasted on the greenery.  So, birds that could digest the greenery lived in a heavenly all-you-can-eat buffet.  They were free to grow to jumbo proportions, in a normal and healthy way.

Flying is an energy-guzzling way for an animal to explore the world.  If you live in a place where there is plenty to eat, and little or no risk of getting killed by ground-dwelling predators, then you might have little or no need for wings.  Over time, evolution completely eliminated the tiny useless wing bones of the moas. 

The largest moas stood 12 feet (3.6 m) tall, and weighed 510 pounds (230 kg).  Many collections of moa bones have been found, some containing the remains of up to 90,000 birds.  Evidence suggests that a third of the meat was tossed away to rot.  Obviously, the birds were super-abundant and super-easy to kill.  Obviously, the hunters (like modern folks) did not comprehend the vital importance of mindfully respecting limits.

Moas were the primary food source for the Haast’s eagle, the largest eagle that ever lived.  They weighed up to 33 pounds (15 kg), and their wingspan was over 8 feet (2.6 m).  Not long after the moas were hunted to extinction, the eagles lost their meal ticket and vanished forever. 

Polynesian settlers also brought with them domesticated food plants, which required cleared land.  Originally, 80 percent of New Zealand was forest.  Today, forest covers only 23 percent of the land.  Along with the trees, many forest dwelling birds also got wiped out.  Europeans stumbled upon the islands in 1642, and substantially accelerated the eco-destruction.

Folks who colonized islands sometimes brought with them rats, mice, dogs, ferrets, pigs, and so on.  Baz Edmeades noted that exotic rodents exploded in number, and drove many island birds to extinction.  Their chicks and eggs were no longer safe.  Rodents wiped out frogs, flightless songbirds, ground-dwelling bats, and large insects.  Again, climate pleads innocent.

Madagascar

Alexandra van der Geer described the ecological history of Madagascar, the world’s fourth largest island.  It’s located in the Indian Ocean, 250 miles (400 km) east of the African mainland.  Isolated from the outer world for maybe 100 million years, it was home to a unique collection of tropical fauna (see the illustrations in her report). 

Several types of exotic mammals mysteriously began arriving on the island around 60 million years ago, maybe rafting in via ocean currents — lemurs, tenrecs, fossas, and Malagasy mice.  More recently, just one or two million years ago, hippos arrived, and eventually shrank to one fourth the size of mainland hippos.

Lemurs evolved into 17 varieties, including giant sloth lemurs that could grow to the size of male gorillas.  The island was also home to the elephant bird, the heaviest bird in the world.  It was flightless, weighed up to a half ton, and stood 10 feet (3 m) tall.  Their eggs could weigh 22 pounds (10 kg).  When the European colonizers arrived in the 1600s, elephant bird eggshells still littered the beaches of the island’s southern coasts.  Conclusion: “The combined evidence suggests that all mammalian species heavier than 10 kg (22 lbs) gradually disappeared forever from Madagascar’s fauna list.”

Baz Edmeades wrote that Indonesian seafarers first visited Madagascar sometime between A.D. 670 and 920.  By the end of the fourteenth century, many mammals, birds, and reptiles were gone.  Elizabeth Kolbert wrote that the lemurs, elephant birds, and pygmy hippos survived into the Middle Ages.  All of them blinked out.  She noted that the extinction spasms in North America, South America, Madagascar, New Zealand, and elsewhere occurred in a series of pulses, each of which corresponded to the arrival of human colonists.  None of the pulses seem to correspond with unusual climate events.  Again, climate pleads innocent.

Mauritius

Mauritius is a tropical island, east of Madagascar, in the Indian Ocean, about 1,200 miles (2,000 km) from the African coast.  It is one of the four Mascarene Islands.  They were created by volcanic activity about eight million years ago.  Because of its long isolation, Mauritius was inhabited by an amazing assortment of unique species, including many flightless birds and large reptiles. 

It was home to the famous flightless dodos.  The dodo lineage was more than 23 million years old.  So, they were originally from somewhere else, and arrived in Mauritius by flying there, back when they still had functional wings.  Having no natural enemies, dodos enjoyed a wonderful life.  For this reason, evolution long ago reduced the dodo’s wings to tiny useless stubs.  Dodos were unable to fly or swim, but they did enjoy being alive.  They could grow up to 39 inches (1 m) tall, and weigh up to 37 pounds (17 kg).

When the Portuguese visited in 1507, there were zero ground dwelling mammal species on the island.  The only mammals were fruit bats and marine animals.  In 1598, Dutch sailors were the first to describe the existence of dodos.  The Dutch East India Company used Mauritius as a service station for trade vessels.  The last mention of dodos was in 1662. 

There used to be at least ten species of flightless birds on the island, all are now extinct.  Humans imported dogs, pigs, macaques, cats, and rats.  Some think the imports may have killed more dodos than humans did, by raiding their nests.  There is also the matter of habitat destruction.  When humans arrived, the island was entirely forested.  Dodos were forest birds.  Today, just two percent of the forest remains.  Again, climate pleads innocent.

There is an old saying that rude folks use to insult others, calling them “dumb as a dodo.”  Humans could simply walk up to a happy dodo and club it to death.  Dodos weren’t dumb, they were fearless.  They had no concept of predators or danger.  To them, humans were mysterious funny-looking weird-smelling space aliens.

Eight Billion Fearless Dodos

Paul Martin focused much attention on the megafauna extinctions.  They were an ongoing process that began in Africa more than two million years ago, then Australia, then Eurasia, and then the Americas.  Human pioneers migrated from continent to continent by walking (except for the soggy trip to Australia).  Fifteen thousand years ago, before the ice age softened, critters could theoretically walk north from South Africa, through Eurasia, cross the land bridge to America, and go south to Chile.

In these large interconnected continental landmasses, there were many species of carnivorous animals, of every size and shape.  They regularly enjoyed having lunch dates with delicious prey.  The endless bloody dance of predator and prey could lead to evolution and/or extinction. 

As discussed earlier, genetic evolution was something like a nonstop escalating arms race, encouraging animals to become smarter, larger, stronger, faster, and/or harder to find.  In this process, prey gradually got better (but not too good) at escape, and predators gradually got better (but not too good) at capture.  In continental ecosystems, the existence of these predators would have made it impossible for flightless moas, elephant birds, or dodos to survive.  Islands provided a far safer refuge, allowing lucky critters to enjoy a wonderful life to the fullest. 

Genetic evolution was an exceedingly slow balancing act.  For savannah elephants to evolve into tundra-adapted woolly mammoths took many thousands of years.  But for furless tropical primates to adapt to a frosty life in snow country required a different, turbulent, and high speed process called cultural evolution, which bypassed the limits set by genes.  It was driven by cleverness and technological innovation — campfires, shelters, sewn clothing, food storage, deadly weaponry, and so on. 

Cultural evolution, in countless ways, enabled folks to quickly pound the crap out of an ecosystem.  Using a short spear, a single Mbuti pygmy could kill a full grown elephant 20 times larger than the hunter.  With this clever new killing technology, the elephant’s great size and thick hide suddenly lost all of its defensive benefits, and became a serious handicap.  The improvements provided by millions of years of genetic evolution were tossed out the window.  No more safety nets.

A number of isolated islands were remarkably different from continental mainland ecosystems.  Some of them existed for millions and millions of years without humans, spears, manmade fire, religion, industry, money, cell phones, plastic garbage, and eco-catastrophes.  Imagine that! 

Island critters did not have to live in a state of high alert, in constant fear of life-threatening surprise visits from lions and tigers and bears.  Island birds could grow huge, and eventually lose their wings, because flying had no useful purpose.  On islands, there were no two ton elephants with thick hides and huge tusks, because elephants were perfectly safe — no sabertooths.  They were free to slim down to pygmy size, so they could dance with ecstatic enthusiasm.

It is very IMPORTANT to understand that the long term journey of existence for ALL species is guided by genetic evolution, but just ONE genus (Homo) has seriously fooled around with cultural evolution, which has become the curse of our existence.

Humans share 98.8 percent of our DNA with chimps, charming beings that have not been bedeviled by the juju of cleverness.  They have lived in the same place, in the same way, for maybe a million years or more.  They haven’t trashed it.  It has never occurred to them to cleverly obliterate their home and future.  Can you imagine living in a manner that could glide along for a million years? 

Like all wild nonhumans, chimps have a way of life that remains within the limits defined by genetic evolution.  In other words, they continue to live in their ancient, time-proven traditional manner.  Chimps have not forgotten how to be chimps.  The difference between humans and wild nonhumans is that cultural evolution has enabled us to bypass the limits set by genetic evolution, and become control freaks and loose cannons.  Singh and Zingg wrote a fascinating book about feral children — kids who had no language, no tools, no fire, no self-awareness, no directed thinking, no sin, no guilt, no greed.  The only thing they wanted was freedom.

Cultural evolution was born long ago, maybe ignited by the fire-making Erectus, or another early ancestor.  If they had never domesticated fire, and discovered many clever ways of exploiting its power, our ancestors may have remained something like ordinary animals — brown skinned, wild, free, and happy tropical primates.

Snow country might still be home to mammoths, sabertooths, dire wolves, short-faced bears, and so on.  Neanderthals were also addicted to cultural evolution.  So is humankind.  We can start fires, use projectile weapons, drive species extinct, travel at high speeds, live underwater, fly around the world, survive in polar bear country, and spend our lives entranced by glowing screens. 

Discovering new tricks can be thrilling — using rocks to crack nuts.  Wow!  The discovery of fire making was mind blowing!  It blasted our ancestors outside the community of ordinary animals, into a dangerously unstable realm of existence.  Cleverness snowballs over time, at an accelerating pace.  It never sleeps.  Every day, countless new gizmos and ideas pour into the world, like a devastating flash flood.  None are clean, green, and renewable.

With the emergence of plant and animal domestication, our ability to control, exploit, and rubbish ecosystems soared to astonishing new heights.  More and more people got better and better at living too hard and busting up everything.  Forests were cleared to make space for fields, pastures, cities, civilizations, freeways, landfills, and barren wastelands.  This large scale destruction was turbocharged by explosive surges in cultural evolution.

To varying degrees, every human society is addicted to clever tricks inspired by cultural evolution.  Indigenous cultures were rooted in a specific region, which set firm limits on them.  Smart groups paid close attention to reality.  If they did not live mindfully, they were on a slippery path.  Nomadic cultures were free to pack up and move.  While passing through a region, they might unintentionally damage an ecosystem without knowing it.  Consumer cultures, like the one I live in, have no foresight.  We live like there’s no tomorrow.

Low impact does not mean no impact.  The humans that colonized the mainland regions of the Caribbean basin 12,000 years ago, were what we would consider to be extremely low-tech hunter-gatherers.  So, what happened to the giant ground sloths, huge rodents, and jumbo monkeys?  They disappeared.  Then, 6,000 years later, humans colonized the offshore islands, and another extinction spasm commenced.

Sadly, low impact does not always mean safe and secure.  Back country wild folks with bows and arrows are not going to have a pleasant future when the folks with guns and diseases discover them.  In the painful words of an old proverb, cultures have no right to what they cannot defend.  The ancient Story of Ahikar says it more elegantly, “Oh my son!  Withstand not a man in the days of his power, nor a river in the days of its flood.”

Unfortunately, the serpent in the Garden of Eden encouraged the first couple to eat the forbidden fruit from the tree of knowledge.  By doing so, “your eyes shall be opened, and ye shall be as gods, knowing good and evil.”  The disobedient duo was immediately hurled out of paradise, and condemned to spend the rest of their days tilling the soil.  Bye-bye!

Unfortunately, our blind leap into hardcore cleverness also inspired the development of mining, smelting, axes, plows, swords, spears, automobiles, aircraft, toxic pollution, nuclear fission, and on and on.  We have become techno-kamikazes, skilled at using turbocharged cultural evolution to blindly zoom down a dead-end road. 

I am an American consumer, and it’s extremely painful to contemplate the enormous amount of stuff I’ve discarded during my life.  I was simply living as Americans are expected to live (like spoiled two year olds).  Other cultures are far less clever, and far less destructive.  No culture is cleverness free.  None live with the sustainable simplicity of chimps and bonobos.

In earlier chapters, I’ve mentioned many low impact cultures.  It would be great if the vast human herd could sharply downsize and return to far lighter lifestyles — deliberately, wisely, and this afternoon (or sooner).  That would blindside life as we know it.  The herd is still growing explosively, and we’re zooming toward energy limits, water limits, and soil limits, while the rapidly warming climate is preparing to serve us exactly what our blindfolded cleverness has ordered.

Wild humans had no wings, and could not fly.  So, most islands remained healthy and safe.  Unfortunately, clever innovation eventually inspired the development of technology for travelling by water.  Dodos were doomed!  Fearless flightless birds also vanished on Tonga, New Caledonia, Fiji, Hawaii, Easter Island, the Marquesas, and on and on.  Island by island, the good old days disappeared in the rearview mirror. 

Like dodos, mainstream humankind is also fearless.  Some of us are a bit aware of a few uncomfortable changes in the world.  In the preceding chapters, I mentioned the existence of swarms of growing abnormalities.  Nobody comprehends them all, including me.  The future is sure to be full of exciting surprises.

The notion that our ancestors unintentionally encouraged extinction surges is uncomfortable.  But the planet’s sixth mass extinction catastrophe is not slowing down.  I suspect that blaming climate change might be an effort to defend our reputation, and conceal embarrassing secrets.  We can act like children who don’t understand how the cookie jar mysteriously became empty.  Hey, we didn’t eat the pygmy hippos.  Honest!

Luckily, doubt fairies can be chased away with magical thinking.  We’re OK!  Miraculous technology will protect us.  We just need to make a bunch of clean green energy, buy a bunch of electric cars, and continue enjoying unlimited prosperity.  If we just maintain a positive attitude, and hope really hard, the clouds will pass.  Really?

Bon Voyage!

Congratulations, you’ve finally made it to the rear end of my long and tedious rant storm!  You now know a bit about what I’ve been contemplating for the last 25+ years.  What I’ve learned has little in common with the worldview I absorbed during 16 years in classrooms, the standard love story that celebrates our amazing genius, and perpetual progress.

This book’s core question was: “How did things get to be this way?”  Obviously, a mob of eight billion critters fearlessly rubbishing a delightful planet is not exactly a heartwarming portrait of sparkling intelligence.  Limited knowledge, clever technology, and self-centered thinking helped to conjure the monster into existence. 

In this book, my goal was to explore the human saga from a perspective that presents humans as simply one of the gang in the family of life, rather than the glorious crown of creation.  From this viewpoint, we are the family’s crazy uncle.  The dodo family enjoyed this planet for 23 million years, but the human family just stepped off the bus recently.  Humankind’s initial colonization of the planet’s ecosystems established a pattern that has never stopped.  Empire builders continue ruthlessly bulldozing their way over all obstacles in their never-ending quest for maximum domination — the Romans, Mongols, Spaniards, English, Americans, Nazis, Russians, and thousands more.

On the day you squirted out of the womb, you were a wild animal, ready to enjoy a wild life in a healthy paradise.  You were not a fatally flawed animal genetically, but the culture that taught you everything you know is a train wreck.  The good news, in theory, is that dodgy cultures can be revised and improved, or hurled off a cliff.  They are nothing but vivid ideas, fantasies, and nightmares that live between your ears, and can be highly contagious. 

As promised, I have presented no sure-fire snake oil cures for all that ails us.  I’ll let you know if I ever find any.  In this book, my objective was exploring history, not foretelling the future.  All of us accept the notion that we’ll die someday.  So will our way of life.  The sun rises every morning, the stars come out at night, and all civilizations have expiration dates.  They grow like crazy, deplete their resource base, and become ancient ruins. 

Several weeks ago, it occurred to me that Wild, Free, and Happy was a ridiculously inappropriate title for this book.  It had little to do with the flow of ideas between the covers, but it sounded nifty a few years back.  I’m going to keep it.  Discovering the islands of flightless birds radically altered my perception of reality.  These ecosystems evolved in isolation for millions of years.  They were 100% cleverness free, virgins unmolested by cultural evolution, and they actually existed on this planet.  Imagine that!

We’ve learned that it’s possible for bird species to live for millions of years without wings.  Can humans live without cleverness?  Can we forget everything we know, return to Mother Africa, throw out our clothes, and humbly start over?  Can humans survive the powerful pandemonium we have conjured into existence?  Time will tell.  Whatever happens, genetic evolution will continue, and guide the survivors down the long and winding path to healing.

Bon voyage!

 

Sources

Araujo, Bernardo, et al., “Bigger kill than chill… (megafauna extinctions),” Quaternary International, November 2015. [Link]

Blondel, Jacques, “On humans and wildlife in Mediterranean islands,” Journal of Biogeography, 2008, 35, 509-518. [Link]

Burney, David and Tim Flannery, “Fifty millennia of catastrophic extinctions after human contact,” TRENDS in Ecology and Evolution, Vol.20 No.7 July 2005. [Link]

Childs, Craig, Apocalyptic Planet, Pantheon Books, New York, 2012. [Review]

Cooke, Siobhán, et al., “Anthropogenic Extinction Dominates Holocene Declines of West Indian Mammals,” Annual Review of Ecology, Evolution, and Systematics, Vol. 48:301-327, November 2017. [Link] ($$$)

Dávalos, Liliana M., “Caribbean islands reveal a ‘lost world’ of ancient mammals,” Annual Review of Ecology, Evolution, and Systematics, November 6, 2017. [Link]

Edmeades, Baz, Megafauna: First Victims of the Human-Caused Extinction, Houndstooth Press, 2021. [Review]

Fernandez, Fernando, “Human Dispersal and Late Quaternary Megafaunal Extinctions…,” ResearchGate, July 2016. [Link]  (Readable & detailed)

Flannery, Tim, Europe: A Natural History, Atlantic Monthly Press, New York, 2019.

Graham, Russell, et al., “Timing and causes of mid-Holocene mammoth extinction on St. Paul Island, Alaska,” PNAS, August 16, 2016, vol. 113, no. 33. [Link]

Kelekna, Pita, The Horse in Human History, Cambridge University Press, New York, 2009. [Review]

Kolbert, Elizabeth, The Sixth Extinction, Henry Holt and Company, New York, 2014. [Review]

Lister, Adrian, and Paul Bahn, Mammoths, Macmillan, New York, 1994.

MacKinnon, J. B., The Once and Future World, Houghton Mifflin Harcourt, New York, 2013. [Review]

MacPhee, Ross, End of the Megafauna, W. W. Norton Company, New York, 2019. [Review]

Martin, Paul, “Africa and Pleistocene Overkill,” Nature, October 22, 1966. [Link]

Martin, Paul, Twilight of the Mammoths, University of California Press, Berkeley, 2005.

Masseti, Marco, “Mammals of the Mediterranean islands: homogenization and the loss of biodiversity,” Hystrix (Italian Journal of Mammalogy), 2009. [Link]

Singh, J. A. L., and Robert M. Zingg, Wolf-Children and Feral Man, 1939, Reprint, Archon Books, 1966. [Review]

Turvey, Samuel, et al., “Where the Wild Things Were,” Proceedings of the Royal Society B: Biological Sciences, March 2021. [Link]

Van der Geer, Alexandra, “The Late Survival of Madagascar’s Megafauna,” Paleobiology, December 13, 2017. (Cool illustrations) [Link]

Van der Geer, Alexandra, “The Lost World of Island Dwarfs and Giants,” Paleobiology, September 22, 2017. [Link]

Ward, Peter D., The Call of Distant Mammoths, Copernicus, New York, 1997. [Review]

Weisberger, Mindy, “Humans Doomed Caribbean's 'Lost World' of Ancient Mammals,” Live Science, November 7, 2017. [Link]

 

Friday, October 29, 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.