Video:How Does a Tree Grow in Naturewith Jacob Taxis
The manner in which a tree grows in nature is very different from how it is allowed to grow in a pot or nursery. This video from About.com will explain how trees grow in nature.See Transcript
Transcript:How Does a Tree Grow in Nature
Hi, I'm Jacob Taxis for About.com. In this video, you will learn how a tree grows in nature.
Seed Begins to Germinate
The seed of a tree begins to germinate, or grow, after it has found a proper place to do so. Seeds won't grow unless they have soil nutrients, water, and a favorable temperature. Seeds are often carried by the wind, streams of water, or animals. When a seed does begin to grow, it relies heavily on the nutrients it has brought with it from its parent tree – that is, the nutrients available in the seed itself.
Tree Growth Takes Place at Branch Tips
Tree growth does not take place at the base of the tree. Rather, it occurs at the branch tips. It also occurs in the trunk but not upward. Instead, the tree increases in diameter. This happens because trees grow by producing new cells in limited spots throughout the tree, called meristems. This is where all of the cell growth takes place. The meristems at the tree's roots and at the tips of the branches are called apical meristems. This means they are located at an apex or point—like a tree bud.
Vascular Cambium is Another Meristem
If you notice that a tree in your backyard has grown taller, you can be sure this is due to apical meristems at the tips of the branches – where the cells are highly active and expanding. Likewise, you might notice that the trunk of the tree has grown in diameter – this is the result of another meristem known as the vascular cambium. The vascular cambium makes the trunk, roots, and branches grow in diameter by producing phloem and xylem every year. Xylem is a compound tissue that transports water and nutrients up from the ground to the various parts of the tree itself.
How Tree Roots Grow
As the growth process continues, the seedling's roots anchor themselves in the soil and begin to soak up water and minerals. The hairs of the roots actually wrap around single grains of soil and begin extracting the needed minerals. Over time, this strengthens both the tree itself and the soil around the tree — with so many root hairs latched onto grains of soil, the soil is held together against erosion. As the seedling is strengthened, the stem tip dives its way up through the soil and, when its leaves are large enough, it begins to produce its own food in a process called photosynthesis. Therefore, the meristem growth process continues.
Process of Tree Growth
A seedling becomes a sapling after it has grown to approximately 3 feet tall. Of course, this varies greatly according to species. A seedling does not technically become a sapling until it has surpassed, in height, the parameter determined for its species. In general, it remains in this sapling stage until it reaches about 2 3/4 inches in diameter. A young tree with a trunk that measures between approximately 2 3/4 inches and 11 3/4 inches in diameter is called a pole. A tree is considered mature when it has grown to just under 12 inches in diameter.
Difference From Trees in Nurseries
The root-systems of trees that are grown in containers at nurseries are much smaller than those of trees grown in the wild. Potted roots do not have a chance to spread and develop to their full potential – this greatly weakens the tree when it is planted in the ground. If these trees do not begin rapid root growth and expansion after they are planted in the field, they become highly susceptible to drought.
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