It’s very strange to know how long trees have actually been on the earth for. In fact, the team here at Ashley Tree Services think that many people would be shocked to discover how much developing the trees we know today had to go through in order to become to large organisms we know today. Over the past couple of months, we have been carrying out a blog series on this very topic in order to educate our readers. In part four, we’re going to go over evolutions…

Decline of Carbon Dioxide

Archaeopteris, a now extinct tree like plant, were the first to evolve deep rooting. Roots are adapted to eat away at rocks in the ground, burrow into them and even dissolve them with acidic qualities in the search for nutrients. Over a very long period of time, this material is washed into the vast oceans of the world where it is able to mix with dissolved carbon dioxide (CO2) in order to create sediments. Eventually, these sediments would be sub-ducted into the interior of the earth as a result of tectonic activity. It is said that this process, which took place over hundreds of thousands of years, helped to reduce the amount of carbon dioxide in the ocean and air, leaving consequences for the climate. Between the start and end of the Devonian era, the levels of gas rose by 95% and greenhouse conditions disappeared, leaving behind an ice age. All this occurred around 300 million years ago however it saw glaciers near the tropics…all thanks to the pesky evolution of trees!

Deep Roots and Large Leaves

On the other hand, it was this climatic upheaval that brought about another tree development; larger leaves! In fact, science believes that the removal of CO2 from the Devonian atmosphere helped to remove an inhibitor that had been preventing the evolution of large leaves. Whilst large leaves are perfect for photosynthesis, they are hard to keep cool and in order to prevent overheating, a leaf will release water vapor via pore-like stomata. In simple terms, the plant version of sweating. However, the number of stomata a plant has is regulated genetically in a way that responds to the levels of CO2 so the more carbon dioxide in atmosphere, the lower the stomatal density. It is thought that large leaves were inhibited during the Devonian period because the high levels of CO2 prevented this overheating evolution. In fact, if large leaves were to have appeared, they would have boiled. It was only due to the lowering CO2 levels that plants could develop a high stomatal density in order make large leave viable.

The team here at Ashley Tree Services like to be considered the experts when it comes to all things tree related.  If you have a tree that could use an expert, get in contact with a member of the team today. As the best tree surgeon in Manchester, you can be sure your tree is in the best hands possible!