There are many, many different types of trees found around the world. Recent studies have suggested that there are at least sixty thousand unique tree species on Earth. This is amazing! Another interesting statistic is that of all these different species, more than half of them can only be found growing in one single country somewhere. However, some species are very diverse and can be found in many countries.
There are also a lot of tree species that are currently threatened with extinction, because they are only found in very small areas. This is very unfortunate. When people think about a species going extinct, they usually think of different types of animals. Trees can go extinct too. There is a project called the Global Tree Assessment project, which hopes by the year 2020 to classify the extinction risk of every one of the different tree species found around the world. After that is done, it will be easier to start deciding how to protect each of the species that are at risk.
Just as there is a lot of variety in the appearance of different species of trees, there can be a lot of variety in the size and growth rates. People often ask, “How fast does a tree grow?” Well, the answer is, “It depends.” Some trees grow very quickly, and some grow very slowly. The main two things that determine the growth rate are the species and the location of the tree.
When we say that the location of a tree affects the rate of growth, this is because the location influences several factors. On a large scale or “macro” level, the location of a tree determines the climate that the tree grows in. In general, trees and other plants grow faster in warmer climates. Many species of trees that grow near the equator can grow several meters per year. Many trees at the equator reach maturity in as little as ten to twenty years. In contrast, trees in northern latitudes usually grow a lot more slowly, often less than a meter or two per year. In addition, for a tree to reach maturity in the boreal forests of Canada or parts of Europe, it usually takes 80-120 years!
The tree’s location can also be considered in a site-specific context. A tree that is growing in the shade may grow more slowly than a tree that is growing in open sunlight a few meters away. A tree growing at the top of a hill may grow faster or more slowly than a similar tree of the same species at the bottom of the hill.
Many factors affect the growth rate of a tree. Trees at the equator have the benefit of a much longer growing season (twelve months long) compared to trees at latitudes of sixty degrees (three months long). Equatorial trees benefit from having so much sunlight for photosynthesis. Related to sunlight is heat. Higher temperatures often lead to faster growth. This means that trees in Costa Rica would usually grow faster than trees in Norway. Temperature is also affected by elevation. Trees growing at low elevations often grow faster than those high on slopes in alpine regions.
The most important factor affecting the growth of trees is the amount of precipitation that they get. Warm rains are great, but colder rains work too. If you look at the west coast of North America, parts of British Columbia and the western United States are in what is called a “temperate rain forest zone.” This area gets a lot more rain than the rest of North America. And guess what? Some of Earth’s tallest trees grow there, such as the Redwood, the Giant Sequoia, the Douglas Fir, and the Sitka Spruce. Of course, the amount of precipitation affects the rate of growth, not just the eventual height.
In the end then, there really isn’t any one answer to how fast a tree grows, because the answer is different for every species. The trees that Ten Tree plants in different countries all grow at different rates. Make a comment on our post. Tell us what species grow where you live, and how fast they seem to grow.
To see some of the projects that Ten Tree is involved in, visit: www.tentree.ca/pages/projects
