At forests are wide ecosystems formed by a wide variety of animals and plants, with a predominance of woody vegetation with high canopies, forming what we know as a canopy. They cover about a third of the surface of the planet and half of the area of Brazil, being extremely important for the maintenance of the biodiversity world, for climate balance and for diverse populations that depend directly on the resources obtained from them.
Read too: Deserts — areas where arid climate and low rainfall predominate
Forest summary
They are ecosystems formed predominantly by woody plants that have high crowns, forming a canopy.
In its interior there are several strata of vegetation.
They are formed by a process called ecological succession.
There are several ways to classify them, one of them by latitude. So we have tropical, temperate and boreal forests.
They are important because they harbor much of the world's biodiversity and store large amounts of carbon. In addition, many populations depend on the resources obtained from them for their subsistence.
Many economic activities also extract raw materials from them.
The area covered by forests in Brazil corresponds to half of the country's total area.
The Amazon is the largest forest in Brazil and the world.
What are forests?
forests arewide sets vegetationisthat cover very large surfaces and are formeds predominantly by woody trees, those that have stalk composed of wood, with high crowns, which, due to the proximity of its leaves, give rise to a canopy, a characteristic structure of this plant formation. This definition is presented by the National Forest Information System, the Snif.|1|
As pointed out by Snif himself, the definition of forest is not unique, nor unanimous. It varies according to the intended purpose, such as management, research and conservation, and above all according to the organization, group or entity that elaborates it. Thus, in Brazil useto two definitions, both that of the Brazilian Institute of Geography and Statistics (IBGE) and that of the Food and Agriculture Organization of the United Nations (FAO):
FAO: considers a forest as any set of vegetation that extends over 0.5 hectare (0.005 km²) and is formed by trees with a height of more than five meters, in addition to a canopy cover greater than 10%. Areas with different land uses, such as agricultural or urban areas, are not included in this definition.|1||2|
IBGE: characterizes forests as densities of plants in which it is possible to identify four well-defined strata, which are: herbaceous, shrubby, low arboreal and arboreal. The height of the predominant plant species is also taken into account, which varies between 20 m and 50 m. Depending on the height of the trees, the light from the Sun that penetrates the forest formations is limited.|3|
How are forests formed?
the natural forests form per many different phases of development until they reach their climax, reaching the forest stage. This process is called ecological succession. The way in which it takes place will depend on the edaphoclimatic characteristics of the area, that is, on the ground It's from climate, which will then influence its development time. Overall, forests take up to 100 years to form.
The first moment of forest formation is called pioneer stage, in which there is a low diversity of vegetation (herbaceous and grasses) covering a soil that is still poor in organic matter and nutrients. As the life cycle of the plants present in this first phase comes to an end, there is their soil deposition and litter formation, providing a contribution of organic matter and moisture to the ground.
The undergrowth gives way to the shrub, with the appearance of small and medium-sized shrubs that can reach up to three meters in height, in the stage called capoeirinha. Over the years, if there is no disturbance in the environment, the development of large trees and the presence of greater diversity of flora and fauna are observed. This stage is called capoeira.
The next step is known as capoeirão, in which the formation of an understory and two other different stages consisting of a greater amount of plant species, in addition to observing the beginning of the canopy development, which is not yet closed. This happens only in the last step, the climax, in which the trees exceed 20 meters in height and the forest shelters animals of different species and sizes, in addition to a wide variety of plants that are becoming more and more dense.
types of forests
Forests can be classified according to several criteria, one of them being latitude, that is, the area of the planet where they form. In view of this, three types of them are identified:
Tropical florests: occur in low latitude areas, where hot and humid climates predominate, with the absence of a dry season. They are characterized by great biodiversity, with dense vegetation consisting of all plant strata. The trees have broad, evergreen (always green) leaves, which are not lost during the year.
temperate forests: develop in mid-latitude regions, where temperate climates, characterized by alternating dry and rainy seasons, in addition to mild temperatures during most of the year. They are formed by deciduous (or deciduous) vegetation, which loses its leaves during the dry season.
Boreal forests: also known as coniferous forests, are typical of the biome Taiga, which develops in high latitude areas, where cold climates predominate with winters damp. They are formed by species of conifers, adapted to the snow.
See too: Grasslands — vegetation cover found in sub-humid temperate regions
Why are forests important?
Forests are important because they constitute ecosystems that shelter countless species of animals and plants, therefore, contêm a good portion of the world's biodiversity. Its moisture retention and evapotranspiration process help climate maintenance and in controlling the microclimate of a given region, easing temperatures and providing moisture to the air. In some cases, as in the amazon, this moisture is carried for thousands of kilometers by air currents and causes rain in other regions, a phenomenon known as flying rivers.
The importance of forests also includes the fact that they absorb a large amount of carbon dioxide (CO2) from the atmosphere to the carrying out photosynthesis, still storing the carbon in its vegetal structure and in the produced biomass.
In addition to the environment, forests have a important socioeconomic role. They are a source of raw materials, food and medicinal plants and herbs for the diverse populations that live close to them. Some of these populations survive entirely on the resources found in the forests. Raw materials for industry, such as lumber, are also taken from them.
Brazilian forests
Brazilian forests cover almost 60% of the country's surface, which corresponds to 500 million hectares, according to data from Snif. Just over 97% of these areas are formed by natural forests, while only 1.97% are planted forests. Forests are present in practically all biomes that form the Brazilian natural landscape, being predominant in the Amazon.
The Amazon Forest is the largest forest in Brazil and the world, spanning a total of nine territories. It is home to millions of species of animals and thousands of species of plants, in addition to being crossed by one of the most important rivers in the country, the amazon.
The second largest forested area in Brazil is located in the Cerrado biome. In both cases, extensive areas have been devastated for the installation of agricultural crops and for logging.
Another important Brazilian forest is the Atlantic forest, which spans 17 Brazilian states in the eastern part of the territory, from the northeast to the south of the country. It is home to thousands of species of animals, in addition to containing more than 15,000 species of plants. It is important to emphasize that the Atlantic Forest area coincides with the most populous regions of the country.
Approximately 70% of the Brazilian population live in this biome, a factor that conditioned the high rate of logging observed in the forest as a result of the expansion of urbanized areas, industrialization, exploitation for economic purposes and pollution.
forests of the world
The area of the planet covered with forests is 31%, half of it is in good condition, according to FAO data. In addition, they concentrate the largest share of the planet's biodiversity. Forests are not evenly distributed across countries, being especially concentrated in the wetter regions of low latitude.
FAO's most recent report on the world's forests shows that 50% of the forested area is concentratedm in just five countries. Are they:
Brazil;
Canada;
China;
Russia;
United States.
The main problem faced today in the world's forests is deforestation with the purpose of opening new areas for the performance of agricultural activity. The greatest losses were identified in South America, more specifically in Brazil, and in the African continent.
Grades
|1| NATIONAL FOREST INFORMATION SYSTEM – SNIF. Knowing About Forests: Definition of Forests. Available here.
|2| FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS – FAO. Global Forest Resources Assessment - 2020: Terms and Definitions. Rome: FAO, 2018. Available here.
|3| BRAZILIAN INSTITUTE OF GEOGRAPHY AND STATISTICS – IBGE. Technical Manuals in Geosciences – number 1: Technical Manual of Brazilian Vegetation. Rio de Janeiro: IBGE, 2012. 2nd ed. Available here.
By Paloma Guitarrara
Geography teacher
