Biology

Deforestation: definition, causes, consequences and types.

What is deforestation?

The deforestation is primarily to the destruction of the forest area or in other words the destruction of the area occupied by forests for other uses area.

Deforestation occurs mainly in two ways: slash and burn and poaching.

Slash and burn

Slash and burn is a traditional method of searching for new crops that makes sense when population density is low as it is very aggressive for forests.

This method consists of cutting down the forests and vegetation in general in a certain area, letting it dry and then burning it so that all the resulting ash acts as nutrients to be able to cultivate and harvest. It is used mainly in tropical areas such as the Amazon or Indonesia where soils are usually poor in nutrients. The ash contribution creates the ideal conditions for cultivation.

This system makes sense and is integrated into nature when there is little population and large-scale cultivation is not sought. When it is persecuted on a large scale, it is one of the main forms of deforestation since large forest areas are changed at a great speed. This is what has been happening with palm oil in Indonesia .

Types of deforestation

Although the concept of deforestation is identified as an impact produced by human activity, there is also another part, smaller and less impactful, that is due to natural causes. Therefore, it can be classified into two types : natural deforestation and human deforestation.

Natural deforestation

Natural deforestation corresponds to the natural dynamics of certain regions. Naturally occurring storms, volcanoes, floods, and fires are part of the ecosystem.

There are forests adapted to fire , such as the Mediterranean forest where some of the most frequent species are perfectly adapted to fire and are called pyrophytes. This is the case of pine: when fires break out, the cones that contain the seeds explode, dispersing the seeds at great distances.

At this point, and according to the latest IPCC report, it may not be entirely accurate to assign certain natural catastrophic events as natural deforestation, since climate change is having a great influence on the frequency and extent of forest fires (you can read more here)

Human deforestation

Human deforestation is that which is produced by humans with the aim of changing land use. Deforestation as a consequence of human activity is due to the causes that will be discussed in the next section.

Causes of deforestation

The objective of deforestation is to use the land occupied by forests for other uses such as to gain agricultural and livestock land, exploitation of mining deposits and the growth of cities, construction of infrastructure (roads) and the extraction of wood.

A more exhaustive list of the causes of deforestation is the following:

  • Cattle raising
  • Large-scale agriculture
  • Small-scale agriculture
  • Tree plantations
  • Large-scale logging
  • Small-scale logging
  • Firewood and charcoal
  • Mining
  • Transport infrastructure
  • Hydroelectric power
  • Urban sprawl
  • Fires

Depending on the regions and the needs, the causes and forms of deforestation vary, making it a problem that does not have a single solution for all regions.

For example, in Latin America one of the main causes of the loss of forest land in general for the entire region is the change in land use for livestock, while the second reason varies according to the area: in some places it is for small-scale agriculture while in others it is large-scale agriculture.

In other regions the picture is different, in the African continent the main cause of deforestation is large and small-scale agriculture, as is the case in Indonesia. Livestock as a cause of deforestation is very secondary.

According to WWF , around 43 million forested hectares, an area the size of Morocco, have disappeared between 2004 and 2017.

Consequences of deforestation

The consequences of forest destruction can be catastrophic. When a forest disappears, not only a group of trees disappears, but a very complex ecosystem disappears : from animal species, including microorganisms and insects, and plants, to the soil surface and the evapotranspiration dynamics of water and the rest of the hydrogeology of the area where the forest has disappeared.

Destruction of the soil by erosion and desertification

Deforestation brings with it the loss of soil dynamics and its protection, accelerating erosion and desertification processes. The vegetation on the surface of the soil protects it from rain by slowing down the impact speed of the water droplets and also holding the soil by its roots. In this way, when heavy rains occur, not all the soil is washed downstream, but much of it remains in place.

The loss of surface vegetation has the consequence that the impact of the water on the ground has a greater force and that, as there are no fastening elements, a large part of the soil is dragged downstream, causing flooding of water and mud, and leaving the ancient forest without topsoil that can be reproduced more quickly.

Loss of habitats and biodiversity

What is Deforestation
What is Deforestation

Deforestation is named as one of the main causes of loss of both animal and plant species by the IUCN as destruction of habitats along with the introduction of invasive species.

In particular, the logging of tropical forests such as those of Indonesia or the Amazon has a serious impact on the loss of global biodiversity as they are home to a large number of species.

Increase in global warming

Forests act as a carbon sink by conserving carbon in woody trunks and stored in the soil. When a forest is deforested to change the use of the land, or when there is an intentional fire, all that carbon stored in the forests is released into the atmosphere in the form of CO2, increasing the concentrations of this greenhouse gas. Also, you lose a place to continue storing carbon.

According to the 4th IPCC report (2007), deforestation could account for up to a third of global CO2 emissions.

Changes in hydrogeological dynamics: pattern of rainfall and runoff

In tropical areas it has been observed that deforestation influences the precipitation of the place and adjacent areas. The changes in the evapotranspiration of the water and therefore in the humidity of the environment are important after deforestation since this aspect depends to a great extent on the vegetation.

Not only the abundance of rainfall can be affected, but it also affects water runoff and the time spent on the soil surface. The vegetation cover slows down the circulation of water at high speed and therefore allows the water to be absorbed by the soil, improving its composition.

Effects on human health

The narrowing of the boundaries between wildlife and humans facilitates zoonoses (diseases transmitted by animals). When there is not a large enough area with hardly any buffer areas between the places where humans and wild animals live, there is a contact between species that can facilitate the spread of new diseases unknown to date.

Not only does it affect unknown diseases, but already known diseases such as malaria can be facilitated by deforestation.

How to fight deforestation

The fight against deforestation is not easy since, as we said before, depending on the regions, the causes and forms of deforestation are different, so there cannot be a single solution to this serious problem. The solution has to come from governments and large economic entities, but also on a small scale, actions and measures can be taken to try to solve it.

International collaboration: REDD +

REDD is the name of the United Nations Program for Reducing Emissions from Deforestation and Degradation. It is managed through FAO, UNEP and UNDP. The objective is that through monetary or other incentives, reverse deforestation and be able to carry out sustainable forest exploitation practices that do not contribute to CO2 emissions.

Tree plantation

Reforestation and afforestation is one more weapon in the fight against the loss of forest area. Either at the governmental level, carried out by the different countries, or at the individual or small association level.

An example is that of Sebastião Salgado and his wife, who have planted more than two million trees in 20 years in the Brazilian Amazon, on a farm they own where the tropical forest previously existed.

It is convenient to clarify the terms of reforestation and afforestation. It is called reforestation to planting trees in an area where there were trees in the last 50 years and disappeared for various reasons. It is called afforestation to when the trees in places where in the past 50 years there were planted.

The power of the consumer

Consumers have an undeniable power to change certain things, but not all. The campaign against palm oil has led many manufacturers to eliminate palm oil from their products and many others to obtain it from sustainable sources. However, there is still a great deforestation due to this cause.

Making informed decisions is very important, since for example, the coconut oil that has become so fashionable can be another cause of deforestation, and the use of other types of oils with lower yields such as rapeseed or soybeans could require a lot more forest area.

Finding out about the different options and the different impacts is very important. Sustainable palm oil could be a great alternative to curb deforestation.

In general, a good alternative is to buy wood products or sustainably managed crops where the evolution of the forests has been taken into account for their exploitation. In addition, using recycled materials instead of virgin materials reduces unsustainable logging.

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