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What is a tree?
A tree is a tall plant with a thick wooden stem from which branches grow, usually with leaves on them.
Most trees bloom in spring and bear fruit in summer or early autumn.
As for foliage, what can trees be like?
- evergreen when they do not lose their leaves, as in the case of pines and other conifers, and the leaves remain green all year round;
- deciduous when they shed their leaves every year, usually in early autumn, as with most fruit trees.
What are the main parts of a tree?
Trees, as other plants have:
- roots that anchor the tree to the soil and provide them with water and minerals essential for their development.
- the stem or trunk that is its main body; it bears the branches with leaves, the flowers,
and the fruit. Stems can grow straight, creep along the ground, or climb over walls and fences. There are plants that can have one or more stems.
- leaves that are basically a food-producing machine, because it is through them that the photosynthesis of chlorophyll, the pigment that gives the green colour to the leaves, takes place.
Why do trees need sunlight?
Without sunlight, green plants would not be able to fix the carbon with which they produce chlorophyll, the substance (pigment) that gives leaves their green colour.
The production of chlorophyll by the action of sunlight is called photosynthesis.
When do the trees bloom and bear fruit?
Most fruit trees bloom in spring and bear fruit in summer, others in early autumn. But there are trees that bear fruit in winter, such as citrus (orange, lemon, tangerine) and pineapples.
When did the first trees appear on Earth?
The first tree fossils found date back 385 million years. To compare with humans, one of the oldest hominid fossils, Lucy, is estimated to be between 3.22 and 3.18 million years old.
As for modern men, they only appeared about 200,000 years ago.
As you may recall, in the story Penguin and the Fig Tree, we talked about two types of trees: the pine tree and the fig tree.
Let's now learn about each of them. |
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The Fig tree
As you may remember, Penguin loved figs. Figs are the fruits of the fig tree, a fruit tree with large leaves that fall every year in early autumn. That is why we say that the fig tree, like most other fruit trees, is a deciduous tree.
The fig tree bears figs, a fleshy, sweet fruit in the shape of a pear and with plenty of eatable seeds.
A land with many fruit trees is called an orchard. |
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The Pine
Pine trees are tall forest trees with leaves like needles. The pine is an evergreen tree that belongs to the conifer family.
Pine can be both gentle and wild, and it is a very useful tree for its wood extensively used as timber, and its resin used to make varnishes, medicines and other products.
Pines may be found in a very large variety of environments, but it is well-adapted to regions with a Mediterranean climate, which is why we find it so often in Portugal; maritime pine is abundant especially on the northern coast of the country, where there is more moisture for its development.
The spruce and the fir are the Nordic "cousin" of our pine and they are abundant in the forests of Northern Europe.
A land planted with pine trees is called a pine forest. The largest pine forest in Portugal is the Pinhal de Leiria, also called Pinhal do Rei. It began to be planted in the reign of D. Sancho I, but it was under D. Dinis that this pine forest reached such a large extent.
In the beginning, its function was to sustain the coastal sands so that they did not invade the interior of the country.
Nowadays, the Pinhal de Leiria, like all forests and natural sites in the world, are some of the few "green lungs" that still exist.
Young people like you, your children, and the generations that come after them, will have the hard task of saving our planet Earth, which the 20th century generations almost managed to destroy.
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Do you know why...
conifers like pines (or spruces, or firs) keep their leaves all the time?
Well, it's because of their leaves, in the form of needles, that last a long time on the tree and don't all fall at the same time.
Conifers are plants that produce pine cones and are thought to be among the first to appear on Earth: they already existed 200 million years ago!
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Dulce Rodrigues |
