“But down deep, at the molecular heart of life, the trees and we are essentially identical.” – Carl Sagan

There are approximately 3 trillion trees on earth as of May, 2017. (Published in Nature News, 9/2/15 – a global count of tree species was compiled by a team of scientists and databases from around the world.)

Trees play an important role in removing the greenhouse gas carbon dioxide from the atmosphere. One large tree can supply a day’s supply of oxygen for four people.

4.6 billion BCE – Earth became a stationary planet.

385 million BCE – Trees began to populate earth. The first modern trees were tall plants with fern-like leaves of the genus Archaeopteris.

250 million BCE – Gymnosperms (naked seed) first appeared as primitive cone-bearing conifers, which began in the late Permian to Triassic period. Dinosaurs lived between 230 and 65 million years ago, during the Mesozoic Era.

150 million BCE – Angiosperms (enclosed seed) are flowering trees that began growing during the early Cretaceous Period when the continent of Pangaea began dividing. Angiosperms multiplied and diversified on each new continent.

95 million BCE – Magnolias, laurels, maples, sycomores, oaks and other angiosperms began to proliferate and dominate the world. Hardwoods became the predominant tree species from mid-latitudes through the tropics while conifers were often isolated to the high-latitudes or the lower latitudes bordering the tropics.

70 million BCE – Palm trees, another type of angiosperm began to appear.

65 million BCE – Dinosaurs & ammonites became extinct.

14 million BCE – The first great apes appeared on earth.

2.5 million BCE – Genus Homo began to evolve in Africa.

300,000 BCE – Most Anthropologists and DNA experts believe that homo sapiens originated in Africa.  They have traced our DNA back to a single female they named “Eve” and a male they named “Adam.”  They appear to represent the beginning point of our “Family Tree.”

150,000 BCE – Some homo sapiens formed tribes that moved out of Africa and started populating the earth. There are approximately 7.6 billion people living on earth as of 10/17.

Tree Census

There are a little over three trillion trees on Earth, according to a new assessment. (Published in Nature News, 9/2/15 – a global count based on a team of scientists and data bases from around the world.)

1.39 trillion trees or 43% of the world’s tree live in the tropics and sub-tropics

610 billion trees live in temperate regions.

750 billion trees live in the boreal forests.

We are removing about 10-15 billion trees a year, with perhaps only five billion being planted back.

Since the onset of agriculture about 12,000 years ago, the number of trees worldwide has dropped by 46%.

Tree Species

There are 60,065 species of trees in the world. (according to a comprehensive study of the world’s plants. Botanical Gardens Conservation International in April 2017.)

All trees are defined by two primary groups within the Plant Kingdom:

Angiosperms (enclosed seed) – These are flowering trees whose seeds form in ovules contained in ovaries, which are enclosed by fruits which developed from the pistol of a blossom. Some refer to angiosperms as hardwoods. They constitute approximately 80% of all tree species living in the world today.

Gymnosperms (naked seed) – Non-flowering trees, whose seeds are not enclosed in an ovary, but are exposed on the surface or held in a structure such as a cone or naked berry. Some refer to gymnosperms as softwoods. They constitute approximately 20% of all tree species living in the world today.

Brazil has the greatest number of tree species at 8,715 varieties.

Apart from the polar regions, which have no trees, the near-Arctic region of North America had the fewest number of species, with less than 1,400.

58% of all tree species were found in one country, suggesting that they were vulnerable to potential threats, such as deforestation from extreme weather events or human activity.

300 species have been identified as critically endangered as they had fewer than 50 individuals remaining in the wild.

Lifespan of Trees

Trees, on average, live longer than humans, which is another reason they are so revered. The average human lifespan is between 70-85 years, whereas a white oak tree can live between 300-600 years. The lifespan of a tree varies by species and location. Because they are one of the few constants in our lives they can feel like an extension of our family. They are quiet guardians holding space for us to explore and grow.

The oldest known tree is the Bristlecone Pine.

Trees are also their own record keepers. The rings of a tree are directly related to the number of years they have lived on earth. Each ring represents one solar year and records the environmental conditions in which that tree lived.

A sample list of average lifespans for a small variety of trees. (Source: Loehle, C. (1988). “Tree life history strategies: the role of defenses.” Canadian Journal of Forest Research 18(2): 209-222)

From shortest to longest lifespans.

Peach – 10-20 years

Acacia – 15-30 years

Palm – 50 years

Black Willow – 70-80 years

Palo Santo – 80-90 years

Black Locust – 60-100 years

Birch – 50-140 years

Balsam – 100-150 years

Apple – 100-200 years

Black Walnut – 150-250 years