Forests

We explain what forests are, how they are classified and the flora and fauna they present. Also, what are its characteristics and its importance.

What are forests?

Forests are biomes that are characterized by the presence of trees and shrubs as the predominant vegetation.. They contain a good part of the planet's biodiversity and are spread over the five continents, except Antarctica. Their specific characteristics depend on the climate, relief and soils of the place where they are located. For this reason, there are forests of very varied composition and biodiversity in different parts of the Earth.

Forests play a fundamental role for the ecological balance of the planet and for human and animal life in general. Their environmental services are very varied: they produce oxygen and capture carbon dioxide through photosynthesis, they are the natural habitat of a great diversity of species, and they provide raw materials and resources for human societies.

Throughout history, human beings have used forest resources, but exploitation is often carried out without taking into account the biological cycles of the ecosystems that make them up. This has produced environmental problems that have destroyed large areas of forests and threaten the existing ones due to high levels of deforestation and pollution.

See also: Biomes

Forest characteristics

Forests have the following characteristics:

• Its predominant vegetation is trees and bushes.
• They appeared on Earth approximately 400 million years ago.
• They are found on all continents of the planet, except Antarctica.
• They play a fundamental role in the ecological balance of the planet.
• They house a great variety and diversity of animal and plant species.
• They can be classified according to their foliage, their type of vegetation and their climate.
• Its surface area has been reduced in recent years due to forest fires and deforestation.

Origin of forests

Forests emerged on the planet almost 400 million years agowhen the first plant organisms left the sea and adapted to life on land. In this process, they took advantage of the rains to develop and absorbed carbon dioxide from the atmosphere to produce oxygen.

Competition for sunlight and soil resources led to the development of taller plant species, such as trees, which continued to evolve and adapt to the ecological changes that occurred over geological time on the planet, including the movement of continents and climate changes. This gave rise to diverse types of forests in different places, with varied climates, soils and altitudes.

Forest distribution

Forests are found on all continents of the planet, except Antarctica.. They are located in the most diverse latitudes and climatic regions, and occupy about 4,000 million hectares, which represents 30% of the Earth's surface.

Regarding the distribution by country, it is estimated that the largest forest areas are found in Russia, Brazil, Canada, the United States, China and the Democratic Republic of the Congo.

Types of forests according to the foliage of the trees

Forests can be classified according to the presence or absence of leaves on their trees during autumn and the arrival of cold weather. According to this characteristic, there are:

• deciduous forests. They are forests whose trees lose their foliage during part of the year, generally in the coldest months.
• Evergreen forests. They are forests whose trees maintain their foliage throughout the year.

Types of forests according to their vegetation

Depending on the type of vegetation that predominates and the shape of the tree leaves, forests can be classified into:

• Hardwood forests (broadleaf). They are forests whose trees have large leaves and usually have dense branches, with a lot of competition for sunlight. Because of this, the trees are usually very tall and developed. They are typical of hot and rainy areas.
• Coniferous forests (acicular leaf). They are forests whose trees have thin and pointed leaves. In general, these are perennial species that grow in cold and rainy environments.
• Mixed forests. They are forests that combine leafy and coniferous tree species, in transition regions between cold and warm climates.

Types of forest according to climate

Forests can be classified according to the climate in which they develop. According to this characteristic, there are:

• boreal forests. They predominate in polar or subpolar climates. They are usually coniferous with evergreen leaves, adapted to low temperatures.
• Temperate forests. They are found in temperate and continental climates, especially in the warmest regions. They can be broad-leaved deciduous or coniferous evergreen, adapted to regions of great thermal amplitude, with warm summers and cold winters.
• Subtropical forests. They proliferate in humid or dry subtropical regions and mixed vegetation predominates.
• Tropical forests or rainwater. They are found in regions around the equator, where rainfall is abundant and it is hot almost all year round. They are also called jungles. They present an enormous variety of species of trees and shrubs adapted to humidity and high temperatures.

Forest flora and fauna

In the tropical and subtropical foreststhe flora is characterized by the presence of broad-leaved trees, such as mahoganies and palms, and an abundance of epiphytic plants, such as orchids and lianas. These forests are known for their extraordinary biodiversity. Fauna includes monkeys and lemurs, exotic birds such as macaws and toucans, and also amphibians and reptiles.

In the boreal foreststhe flora is dominated by conifers, such as spruces and firs, along with mosses and lichens that adapt to low temperatures. As for the fauna, there are mammals adapted to the cold, such as reindeer and elk, migratory birds and a variety of insects resistant to low temperatures.

The temperate forests They are home to a mix of broadleaf and coniferous species, such as oaks, maples, firs, and pines. The fauna is varied and includes mammals such as deer and foxes, a diversity of birds and a wide range of insects and invertebrates.

Environmental importance of forests

Forests play a vital role in the development of life on Earth:

• Oxygen production. Forests allow the replenishment of atmospheric oxygen, since they take in carbon dioxide (CO²) and release oxygen through photosynthesis.
• Carbon storage. Forests act as carbon sinks, absorbing carbon dioxide during photosynthesis. This helps mitigate climate change, since the amount of CO is reduced² in the atmosphere.
• Biodiversity. Forests are habitats rich in biodiversity and are home to a wide variety of plant, animal and microorganism species.
• Habitat for wildlife. Forests provide shelter, food and breeding habitats for numerous animals. They are essential for the survival of many species, from mammals and birds to insects and fungi.
• Regulation of the water cycle. Forests play a fundamental role in regulating the hydrological cycle. They absorb water through their roots, release it into the atmosphere through transpiration from the leaves, and contribute to the formation of clouds and precipitation. This helps maintain river flows, prevent flooding and recharge aquifers.
• Soil protection. The roots of trees and other plants help prevent soil erosion by acting as anchors and retaining soil through their roots.
• Resource supply. Forests provide a wide range of natural resources essential for human life, medicine and industry.
• Recreation and cultural value. Forests have cultural and recreational value. They are used for sports and tourist activities, and constitute cultural and spiritual sites for many communities.

Economic importance of forests

Forests play an important role in the economy, providing a wide variety of environmental services and natural resources:

• Wood products. Wood is a fundamental resource from forests and is used in various industries, such as construction, furniture and paper manufacturing. It is an activity that creates employment for millions of people around the world.
• Non-wood products. Forests provide a wide variety of non-timber products, such as fruits, resins and medicinal plants. These products are essential to ensure food security and income for local communities residing near or within forests.
• Tourism and recreation. Forests attract tourists and nature lovers, generating income through ecotourism and recreational activities. The scenic beauty and biodiversity make forests valuable destinations for tourism.

Forest threats

The main environmental problems that threaten forests today are:

• deforestation. Deforestation is one of the main causes of the reduction of the Earth's forested areas in recent centuries, and the most important threat today. It is mainly produced by the expansion of agricultural frontiers, that is, forests are deforested in order to expand crop and livestock farming areas.
• forest fires. Forest fires destroy huge areas of forest every year. Some occur naturally and others are the product of human accidents, but most are explained by intentional human causes. This means that people set forests on fire in order to carry out some economic activity or real estate business.
• pollution. Air and water pollution produced by human activities carried out in forests affects soil quality, plant growth and animal health.
• Climate change. Climate change affects forests by altering weather patterns, increasing temperatures and modifying the distribution and reproduction of species. This causes changes in the composition of flora and fauna, as well as more frequent extreme weather events, such as floods.

References

• Educate. (sf). Jungles, forests and wetlands in danger. Ministry of Education of the Argentine Nation. https://www.educ.ar/
• National Geographic. (2015). Threats to rainforests. https://www.nationalgeographic.es/
• Seguí, P. (2019). Forests. What they are, geographical location and types of forests. Ovacen. https://ecosystems.ovacen.com/