The evolution of trees

A tree is a perennial plant with an elongated stem, or trunk, supporting branches and leaves (in most species).

Strzelecki Gum Drouin

The first plants to exist on land appeared about 430 million years ago. In the Devonian period, around 400 million years ago, the first land plants were little more than a metre or two tall. Competition for sunlight ensured that the tallest plants grew best. Evolution helped for the taller plants to support their extra weight plus develop a system of delivering water and nutrients to their leaves and roots through a structure of vascular cells – a ‘tree’ is born.

Australia’s tree ferns, (while not strictly being trees), in evolutionary terms, are some of the oldest tree structures still existing today.  

 

Tree Fern Gully, Glen Nayook

Tree Fern fronds

Bushy Clubmoss, a fern ally, is another ancient descendant of a large tree that grew 300 million years ago and reached heights of 20 metres.

Bushy Club Moss, Bunyip State Park - a tree relic.

Mountain Ash trees which grow in the higher rainfall parts of the shire are the tallest flowering plants in the world, sometimes towering to 100+ metres. Many of the Mountain Ash trees in this district were killed in the devastating 1939 bushfires hence many of the E.regnans we see today in places like Noojee and Neerim, are quite young in eucalypt terms, around 80 years old.

Regal giants. Mountain Ash, Noojee

So significant, so priceless.