1. Trees are producers
Tree structure
The main parts of a tree are the roots, the trunk and the leaves. The tree attaches itself into the ground with its strong roots. They can reach several meters down into the ground. Horizontally, the roots can stretch over tens of meters away from the tree's trunk. By doing so, the branching roots create a vast underground network.
The tree uses its roots to collect water. The tree also receives nutrients that have dissolved into the water. The most important nutrients for trees are nitrogen, phosphorus and potassium. Plants need these nutrients to grow and thrive.
The trunk of the tree reaches up towards the sky. By growing its trunk, the tree makes sure that its leaves have enough access to sunlight. The trunk is made of a durable material. The trunks of some trees can grow over 100 meters tall!
Narrow tubes run inside the tree's trunk, connecting its leaves and its roots. Water and nutrients travel through these tubes into the leaves of the tree.
The route of water in a tree is therefore: roots → trunk → leaves.
The leaves of the tree produce all the energy that it needs. They do this in a process known as photosynthesis.
There are many different kinds of trees in the world. The leaves of broadleaf trees are large and flat. The leaves of broadleaf trees grow during the spring and fall during the autumn.
The needle-like leaves of coniferous trees remain attached through the winter. Despite this, these leaves only photosynthesise during the summer months.
Photosynthesis
Photosynthesis takes place in the plant's leaves.
The chemical formula of photosynthesis is:
6 CO2 + 6 H2O + sunlight ➞ C6H12O6 + 6 O2
carbon dioxide + water + sunlight ➞ sugar + oxygen
6 CO2 + 6 H2O + sunlight ➞ C6H12O6 + 6 O2
carbon dioxide + water + sunlight ➞ sugar + oxygen
The cells of tree leaves contain a large number of green chloroplasts (see the microscopic image below). These chloroplasts receive carbon dioxide from the air and water collected by the roots from the ground.
Using the energy from sunlight, the plant uses carbon dioxide and water to produce sugar. This chemical reaction is known as photosynthesis.
In photosynthesis, the energy contained in sunlight is transmitted into sugar. The plant uses this sugar as its energy source. The plant uses the energy to fulfill its many functions, such as growth and reproduction.
At the same time as the plant produces sugar, the reaction also releases oxygen into the air. This makes photosynthesis an important process for all living organisms.
When we eat, we gain energy from the sugar plants have created in photosynthesis. At the same time, we breathe in oxygen that has been created during the same process.
Using the energy from sunlight, the plant uses carbon dioxide and water to produce sugar. This chemical reaction is known as photosynthesis.
In photosynthesis, the energy contained in sunlight is transmitted into sugar. The plant uses this sugar as its energy source. The plant uses the energy to fulfill its many functions, such as growth and reproduction.
At the same time as the plant produces sugar, the reaction also releases oxygen into the air. This makes photosynthesis an important process for all living organisms.
When we eat, we gain energy from the sugar plants have created in photosynthesis. At the same time, we breathe in oxygen that has been created during the same process.
Food chains
Because plants produce all the sugar and oxygen used by animals, they are considered the producers of the ecosystem. All life on Earth is made possible by the presence of producers.
Animals, on the other hand, are consumers. This means that they have to eat other organisms, such as plants, to gain energy.
Together, producers and consumers form food chains and food webs.
For example, an aspen tree produces sugar in photosynthesis during the summer months. When winter arrives, the tree stores some of this sugar in its bark and roots. A mountain hare eats the leaves and bark of the aspen. By doing so, it gains some of the sugar stored in the aspen. This makes the mountain hare a herbivore. A fox, on the other hand, is a predator. It can eat the mountain hare, and receive the energy the hare has gained from the aspen.
Therefore, the energy created by the producer (aspen) is transferred first into the herbivore (mountain hare) and finally into the predator (fox). This is an example of a food chain. Together, the food chains of a ecosystem form an intricate food web.
Animals, on the other hand, are consumers. This means that they have to eat other organisms, such as plants, to gain energy.
Together, producers and consumers form food chains and food webs.
For example, an aspen tree produces sugar in photosynthesis during the summer months. When winter arrives, the tree stores some of this sugar in its bark and roots. A mountain hare eats the leaves and bark of the aspen. By doing so, it gains some of the sugar stored in the aspen. This makes the mountain hare a herbivore. A fox, on the other hand, is a predator. It can eat the mountain hare, and receive the energy the hare has gained from the aspen.
Therefore, the energy created by the producer (aspen) is transferred first into the herbivore (mountain hare) and finally into the predator (fox). This is an example of a food chain. Together, the food chains of a ecosystem form an intricate food web.
The arrows of the food chain show how energy moves from a producer to a herbivore, and finally to a predator.
When predators and other organisms die, decomposers arrive at the scene. These decomposers, such as fungi and insects, gain their energy from breaking down the material contained in dead organisms. At the same time, they release the nutrients contained in these organisms back into the ground, where they can be collected by plants.
Terminology
| Term | Explanation |
|---|---|
| photosynthesis | An important chemical reaction that takes places in the chloroplast of plant leaves: carbon dioxide + water + sunglith ➞ sugar + oxygen. |
| producer | A plant that produces sugar and oxygen during photosynthesis. |
| food web | The combination of all the food webs (producer → herbivore → predator) in a specific ecosystem (such as a forest). |