Deep Ecology - The Web of Life

Notes from the 6th class of the Big Ecology Conservation Course
by Course Volunteer Bob Herbert

From: http://www.crikey-adventure-tours.com/stromatolites.html

The final big ecology course was presented by Dana Visalli.  Dana started the course by exploring 14.5 billion years of history in a couple of hours and his final presentation was equally saturated with material for hungry minds.  If there is one thing that we can take away from the past six weeks it is the fact that we are living in a dynamic and emerging universe.  The big bang started the ball rolling (or expanding), but it is the constant evolution of the universe, the planet we live on, and the millions of species we live amongst that keeps life interesting.  In the year 2013 we coexist with single-celled organisms like the 3.5 billion year old Stromatolites, which found no need to evolve; and we are also surrounded by products of evolution that are the result of massive climate swings and catastrophic events that have occurred on our planet over the past four billion years. 

The ability to adapt has proven critical for the survival of life on earth, and thanks to the five people that lectured during the Big Ecology course we have a better understanding of how we have arrived at our place in history.  A single walled cell of bacteria that existed over four billion years ago has evolved into approximately 10 million different species.  Some of those ancient bacteria still exist as they did four billion years ago, but the rest of its relatives chose to evolve into roses, garlic, butterflies, cougars, and humans, to name a few.  The attendees of the Methow Conservancy’s Big Ecology all have a better understanding of how that process occurred, and the many bumps that have altered the road of evolution.
  
The source of all life on our planet has been determined to be a bacteria named Archaea.  It is also referred to as LUCA, the last universal common ancestor.  The three domains of life that have emerged from LUCA are Archaea, Bacteria and Eukaryotes.  Birds, animals, humans, fish, insects, fungi, plants, and algae are all Eukaryotes.  The visible world is filled with millions of species of Eukaryotes, and the microscopic world is where mold, bacteria, and Archaea thrive.  The fact that over 6,000 different types of bacteria live inside our gastrointestinal tract is proof alone that we haven’t strayed too far from our ancestors.  It is the microscopic bacteria found everywhere on the planet that is responsible for recycling dead and decaying matter.  There is a perfect system of reclamation that naturally exists on our planet, which is why life has survived for over four billion years.  Bacteria are able to break down compounds into their individual elements making them ready for reuse in the system.  One study tagged a phosphorous molecule and they discovered that it passed through 46 different species before it arrived in the ocean and was recycled into the tectonic plate.

The energy produced by the sun is consumed by plants and it is converted through photosynthesis into consumable and usable energy for the remainder of the species on the planet.  Herbivores consume plants and in turn they provide food for the carnivores that exist above them on the food chain.  Each time that we move up the food chain, however, 90% of the energy is lost.  By the time you arrive amongst the top predators (humans) there has been an energy loss in the order of one thousand times that of photosynthesis.  The human brain is the pinnacle of evolution (just ask us), and even though it only makes up 3% of our mass, it consumes 25% of our energy.   

Lupine by Mary Kiesau

Forests evolve after fires through the process of ecological succession.  The fire provides potassium and other nutrients for the soil.  The newly exposed forest floor receives much more light than it previously did when the forest canopy was alive, and wildflowers like fireweed and lupine move into the newly burned area.  They fix nitrogen from the air and transfer it to the soil.  This process provides another critical nutrient necessary to grow tall trees and a new forest.  Over time the humus is restored and the size of the trees continue to grow until a mature forest returns to the burned site.  The trees provide dimension to the landscape and homes for birds and animals of all kinds.  Coniferous forests also provide protection from snow and their dark color helps to speed up the snow melt in the spring. 

Earth’s landscape has continuously been carved and shaped through the following naturally occurring events: fire, ice, water, wind, earthquakes, volcanoes, climate swings, and asteroids.  Some of these events were so catastrophic that they forced massive change upon the planet in a relatively short period of time.  Some of the super volcanoes and asteroid strikes have emitted so much ash and debris into the atmosphere that the sun’s rays were blocked out and the earth plunged quickly into another ice age, causing another mass extinction of species.

We also learned about the many ways that human intervention has upset regional ecosystems.  The brown tree snake was accidentally released on the island of Guam and within a short period of time they had eliminated 10 of the 12 native species of birds on the island.  As the continents drifted and separated they created individualized ecosystems and species that coexist in a balanced manner.  Human intervention is perhaps the biggest threat today to the delicate balance of these ecosystems; just ask the birds on Guam. 

The rainforests are responsible for 50% of the rainfall on the planet, but will that continue to be the case when the forests are all stumps?  The sun is currently producing 25% more energy than it did 4 billion years ago, but the temperature on earth has remained relatively stable.  The planet is obviously capable of maintaining balance and equilibrium when it is left to its own devices, regardless of what is thrown at it.   

After six weeks of Big Ecology we learned that the evolution of the planet has been a wild and bumpy ride if you step back and review four billion years of development.  We are all descendants of the stars, and although humans have only occupied a tiny fraction of the planet’s evolutionary calendar, our impact appears to be approaching that of the catastrophic natural disasters.  We are living in a time of mass extinction (other than humans), rapid climate change, and we don’t have a super volcano or asteroid to blame.  Thanks to Big Ecology, we all have a better understanding of where we came from and who are cousins really are.  Armed with the knowledge of our planet’s history and evolution we can all make better decisions about the future of our community and our planet.