Healthy Forests Rely on Ancient Trees, Biodiversity

Ancient trees may be the key to a healthy forest, and therefore a healthy planet, a recent article published in the academic journal Nature Plants contends.

The age of trees is not typically defined by a particular lifespan, like with animals, but is subject to external factors, such as lightning, fire, and fungal disease. This means that trees can live for a very long time — even thousands of years.

The word “ancient” as a measure of age can be relative depending on tree species. Most trees in oak forests tend to live for less than 100 years, but the oldest of them usually live for about 1,000. Pine trees usually live for around 300 years — but some ancient pines can be over 3,000 years old.

Charles Cannon, the author of the study, decided to define an ancient tree as one which is 10 to 20 times older than the other trees in the forest.

Using data collected by foresters regarding the death rates of trees, which range from 0.5 percent to five percent annually, Cannon developed a computer program that could determine the expected age makeup of trees in a forest according to its annual death rate.

He determined that in the forests with death rates measuring over three percent each year, no trees make it to an ancient age, while only one percent of trees reach ancient status when the death rate is around 1 or two percent in a forest.

Ancient trees tend to have strong genes

This is important, as ancient trees play quite a large role in the health of a forest. Trees that have reached such an old age — measuring external threats such as climate factors and disease — likely have some sort of genetic resistance to fungus and strength against the wind.

These important genes can be inherited by younger generations of trees, making the forest stronger as a whole.

But once these ancient trees die, they are gone; Cannon tells Science: “We can’t just replant ourselves back to a healthy forest.”

Gianluca Piovesan, a co-author of the article from the University of Tuscia, notes that “Ancient trees are an irreplaceable hub of biodiversity.”

Piovesan stresses the need for conservation, stating to Science: “We absolutely must preserve old-growth forests and ancient trees to transition to an ecologically sound future.”

These trees are also homes to insect, animal, and fungal species that are essential to the life of a healthy forest.

Conserving these trees and protecting forests from deforestation, disease, and the effects of climate change are essential to not only the health of forests, but to the health of the planet.

Forests are vital in that they provide us oxygen to breathe in and absorb the carbon dioxide we exhale. This is also important in the fight against climate change, as excess carbon dioxide in the atmosphere contributes to the warming of the planet. Along with phytoplankton in the ocean, forests are an important source for clean air for life on earth.

They also are home to nearly half of all known plant and animal species on earth, making the health of forests fundamental to the health of a large part of life on Earth.