The term “root system” refers to all the plant parts that are attached at one point or another to the ground, including stems, leaves, flowers, fruits and seeds.
Trees with root systems have two main types of roots: primary (or vascular) and secondary (or non-vascular). Primary roots are those which grow directly from the parent stem into the soil. Secondary roots grow outwards from other plants but do not originate within them.
They may extend up to several feet away from the parent stem.
Many species of trees have both primary and secondary roots. For example, most oaks, ash, birch and poplars have primarily vascular roots while many firs and spruces have mainly non-vascular roots. There are exceptions however; some conifers such as white pines and western red cedars are entirely non-vascular.
A common misconception is that all trees have non-vascular roots. However, there are a few exceptions. For example, the maple tree does not have any vascular roots.
Other than these exceptions, almost every tree has some type of vascular root system.
Some species of trees are able to regenerate their roots after they die naturally or if injured. These regeneration processes can take place over long periods of time or even spontaneously when conditions are right.
In some species of trees, the roots naturally grow very close to the surface. These are called shallow-rooted trees. Others have their primary root system several inches or even more than a foot under the surface.
These are known as deep-rooted trees.
Most trees have both shallow and deep-rooted varieties. The exception to this is the eucalyptus tree, which only has shallow-rooted varieties.
Trees with shallow-rooted systems tend to thrive better in areas where the soil is loose, well-aerated and fertile. They are more likely to be damaged in dense, compacted or low-nutrient soils. In comparison, deep-rooted trees are able to access water and nutrients in low-moisture, low-nutrient or even hard soils.
The majority of trees in an area influence how other plants grow in that particular location. Trees with deep-rooted systems tend to allow other plants with shallow-root systems to grow under them. On the other hand, areas with many shallow-rooted trees tend to restrict the growth of deep-rooted trees due to the fact that they use up more water and nutrients.
Trees help prevent soil erosion and even turn raw dirt into fertile topsoil. The leaves that fall from trees help the soil by slowly breaking down and becoming nutrients for smaller plants to use. Without these leaves, the nutrients would be lost completely.
The size of a tree’s root system depends mainly on the species but other factors have an effect as well. One of these factors is the environment in which the tree is growing. Some trees, such as the eucalyptus and coconut, are able to grow in moist sand while others cannot.
Other factors, such as the age of tree and the surrounding vegetation, influence the way a tree grows as well.
The average size of an adult tree’s root system is about 90,000 miles of roots with a combined weight of about 890,000 pounds. Most of these roots are located within the top seven inches of soil. This means that most trees depend on a fairly small amount of soil for nutrients and water.
There are several ways to increase the growth potential of trees which involve altering the environment. One way is to provide shade to the roots, which will allow them to grow faster and stronger than they would in direct sunlight. This can be done by placing concrete, boards or an old carpet over part of the area you wish to plant.
Tree roots require oxygen to thrive. If you are growing trees in sandy or compacted soil, then you should leave holes in the covering you put over part of the area to allow air to reach the roots. This will also encourage the growth of more deep-rooted trees.
The best way to plant trees is in rows. Plant the rows parallel to the direction of the wind in your area. This way, the trees will be able to use the wind to sway back and forth against one another.
This action will cause the roots of each tree to rub against each other, which will strengthen them for times of stronger winds. It will also lessen the chances of a single strong wind causing the trees to topple.
Make sure that you plant at least 50% of the trees’ roots below the topsoil layer. This will prevent the roots from being dried out by quick loss of rainfall. It will also encourage deeper rooting and more sturdy trees.
In order to do this, it may be necessary to dig a trench deep enough for you to place the roots within before you backfill.
Now that you’ve learned how to help your trees grow better, it’s time for you to apply what you’ve learned. Think carefully about where you want to plant and why. Then, go out and get started!
Sources & references used in this article:
Instrumental methods for studies of structure and function of root systems of large trees by N Nadezhdina, J Čermák – Journal of Experimental Botany, 2003 – academic.oup.com
Towards developmental modelling of tree root systems by B Tobin, J Čermák, D Chiatante, F Danjon… – Plant …, 2007 – Taylor & Francis
Assessing and analyzing 3D architecture of woody root systems, a review of methods and applications in tree and soil stability, resource acquisition and allocation by F Danjon, B Reubens – Plant and Soil, 2008 – Springer
Assessing the applicability of the earth impedance method for in situ studies of tree root systems by J Urban, R Bequet, R Mainiero – Journal of Experimental Botany, 2011 – academic.oup.com
Roots of pioneer trees in the Amazonian rain forest by J Pavlis, J Jeník – Trees, 2000 – Springer