Destruction of the rain forests

Definition: Ecosystems of diverse plant and animal species that develop in regions receiving average annual rainfall of 50 to 800 centimeters (20 to 315 inches)

Rain forests are the world’s most biologically diverse terrestrial ecosystems. They also play an indispensable role in the preservation and maintenance of global climate. Logging, mining, agriculture, urbanization, and a host of other pressures related to human activity have drastically reduced the extent of rain forests, and their area continues to decline dangerously.

The world’s largest rain forest, located mostly in Brazil, covers most of the Amazon River basin. Other countries with large rain forests include Indonesia, Cameroon, and Malaysia. Countries with smaller rain forests include Australia, China, Côte d’Ivoire, and Nigeria and countries of the Caribbean Islands, northern South America, and the Pacific Islands. Biodiversity in these forests is very high for both plants and animals. In the tropical rain forests, a few hundred species of plants may be found within a hectare of land. Many scientists believe that the tropical rain forests, which covered only about 6 percent of the earth’s surface in 2022, may house more than half of the earth’s plant and animal species. Because of this, tropical rain forests constitute important laboratories for scientists worldwide. Many chemicals with important pharmaceutical properties have been found in rain forest plants. These include quinine, long used in the treatment of malaria, and vincristine and vinblastine, used against pediatric leukemia and Hodgkin’s disease.

Trees in tropical rain forests may grow to more than 90 meters (300 feet) in height. These tall trees, along with their middle-layered or middle-storied plants, have leaves that spread like a sea to form what is generally called the forest canopy. Large buttress roots such as those of the kapok trees of Brazil and the fig trees in Sabah, Malaysia, anchor the large trees while at the same time functioning to absorb essential nutrients and moisture from the soil. Nutrient recycling is critical to the luxuriant growth of plants in tropical rain forests. It is also essential for the numerous epiphytes (plants that grow non-parasitically on trees) present in the lower to middle stories of the rain forests.

Although temperate rain forests have not received the same level of media attention as tropical rain forests, they are just as fascinating and are similarly threatened with regard to loss of biodiversity. These forests, which occur in places such as the Pacific Northwest and southeastern United States, are characterized by deciduous tree species (species that shed their leaves during the winter months) or by evergreen pine tree species. Among the many important species of trees are the large redwoods (sequoias) of Northern California. These giant trees can grow to heights of more than 90 meters and are among the oldest trees in the world. Other temperate rain forests may be found in central and northern Europe, temperate South America, and New Zealand.

Importance and Destruction

The luxuriant growth of the plants in tropical rain forests gives the impression that rich and fertile soils underlie them. However, as slash-and-burn agriculture and other production techniques have demonstrated, the soils are generally infertile. The luxuriant growth is the result of the tremendous amount of nutrient recycling that takes place among species in a humid environment. Thus, the removal of native plants to clear space for agriculture depletes necessary biomass for recycling and eventually exposes the soils to rapid erosional forces. After a few years of high crop productivity, yields decline dramatically, leading to further clearing of more forests.

Despite this productivity problem, the tropical rain forests play significant roles in the lives of the people who inhabit them, and they are a source of important materials for economic development. Indigenous peoples have developed the means to cohabit with other living organisms in these unique environments. However, civilization, industrialization, and population growth are gradually threatening the homelands and the very existence of these native peoples.

Rain forests exert a major influence on rainfall patterns, so that land clearance in such forests causes these areas to become drier. Perhaps most important, the abundant plant life in rain forests enhances the global environment through photosynthesis, an ongoing biological process that removes carbon dioxide from the atmosphere and produces oxygen. This process is an important factor in the prevention of global warming.

Rain forest destruction began occurring in the mid-1900s. The process, which first started in the temperate rain forests of Europe and North America, greatly intensified in tropical areas during the latter half of the twentieth century. Rain forests are believed to have covered more than 14 percent of the earth’s surface at one time, but in the twenty-first century, they began vanishing at an alarming rate in Thailand, Nigeria, Indonesia, Côte d’Ivoire, and Malaysia, devastating more than half of their original forestland. Between August 2006 and July 2007—during a period of declining deforestation rates—Brazil lost 1.1 million hectares (2.7 million acres) of rain forest in the Amazon, a number that only increased in 2020 to 3 million acres, and in 2022, 10,573 square kilometers were destroyed. In the Congo basin, rain forest losses have threatened the very existence of several indigenous peoples. In Indonesia, which is second only to Brazil in the amount of tropical rain forest land it contains, the deforestation rate in the period 2000-2005 was 1.8 million hectares (4.4 million acres) each year. Though 115,459 hectares of forest were destroyed in 2020, this number was a 75 percent improvement from the previous year, and in 2022, Indonesia reached an all-time low in deforestation records according to the UN-Redd program.

Factors Contributing to Destruction

Many factors are responsible for the loss of tropical rain forests. These include population growth and associated development, fuelwood collection, industrialization, and mineral exploitation. Agriculture has also taken its toll, particularly large-scale cattle ranching and the production of cash crops such as soybeans and palm oil.

Human population growth—and the accompanying demand for habitable and agricultural land and other resources—has had a major impact on rain forests. Migration of large human populations has also taken its toll. For example, following the Sahelian drought of the early 1980s, Côte d’Ivoire received an estimated 1.5 million refugees, thereby putting significant pressure on its resources. The situation in Nigeria, with one of the highest population densities in Africa, was similar. By 2010, only 10 percent of Nigeria’s forest cover remained, the rest having fallen to logging, agriculture, and petroleum exploration. It was estimated that at the rate of destruction seen in the first decade of the twenty-first century, Nigeria could have been without rain forests by 2020. As cities expanded and new megalopolises were created in industrialized countries, temperate rain forests also continued to lose ground. In 2022, high deforestation rates continued due to the construction of a super highway, agricultural practices, and the high poverty rate, and 44 percent of the forest cover, which could be seen in 2000, was destroyed.

Related to population growth is the growing need for energy. Many countries that have abundant rain forests use wood as their main source of energy. Therefore, along with intensive logging for export, cutting wood as biomass for fuel has accelerated the destruction of the rain forests and led to severe erosional problems.

Another important factor contributing to rain forest destruction is slash-and-burn agriculture, in which land is cleared, burned, and subjected to crop and livestock production for a few years, followed by new slashing and burning of previously undisturbed forestlands. While crop yields are initially high, they rapidly decline after the second and third years. Subsistence agriculture, upon which slash-and-burn agriculture is based, was originally associated with small populations. Land could be allowed to go fallow for many years, leading to full regeneration of secondary forests under natural conditions. Increased population, along with other factors, has greatly reduced the length of time land can be allowed to go fallow, and more forests have been destroyed to keep up with demand.

Halting Destruction

Reforestation efforts have been under way for many years in Europe and North America to restore lost temperate rain forests. However, such reforestation activities have often been approached from an industrial perspective. Plantations of only one or two species are grown, giving rise to monocultures. This is different from a natural regeneration approach that aims eventually to restore an area’s original plant and animal biodiversity and watershed functions. One 2010 study in Australia, which was further confirmed in 2020 by a study published in the Environmental Research Letters, found that rain forest restoration projects involving a diverse mix of trees were more efficient at capturing carbon than were plantations with monocultures or mixed tree species. Restoration projects that strive to mimic natural ecosystems are also more likely to withstand diseases and insect infestations than are monoculture plantations.

One way in which the destruction of tropical rain forests is being halted or slowed is through the use of agroforestry systems—sustainable integrations of agriculture and forestry—to complement and reduce slash-and-burn agriculture. The collection of fuelwood can be decreased during sunny months through the use of inexpensive solar cookers, which are nonpolluting and cost nothing to operate. Another approach is the establishment of nature preserves, national parks, and large botanical gardens, as has been done successfully in Costa Rica. Promoting rain forests as destinations for sustainable tourism creates an economic incentive against deforestation. Nature preserves have also been established for a number of temperate rain forests in the United States and elsewhere. Yet another strategy is the debt-for-nature swap, in which a national debt is forgiven in exchange for environmental preservation efforts. The United States has forgiven billions of dollars in loans to a number of Central and South American countries, with the condition that these countries set aside large tracts of forestland as nature preserves.

The research organization Bioversity International, which began in 1974 as an agricultural agency of the United Nations Food and Agriculture Organization, works to preserve the genetic resources of forest plants in addition to those of traditional crop resources. Facilities such as the Kew Royal Botanic Gardens in Great Britain participate in the Millennium Seed Bank, a partnership that conserves seeds for plants outside their native habitats. This program has successfully banked some 10 percent of the planet’s wild plant species by 2010, focusing its efforts on plants and regions, such as rain forests, that are most at risk of being obliterated by human activity and climate change. In 2019, Bioversity International partnered with International Center for Tropical Agriculture (CIAT) to form the Alliance of Bioversity International and the International Center for Tropical Agriculture, a global organization with goals to combat climate change challenges, the loss of biodiversity, environmental degradation, and malnutrition. In 2023, their work extended across a vast variety of research, genebanking, conservation planning, and more, all accomplished through partnerships with local, national, and multinational partners in Latin America, the Caribbean, Asia, and Africa.

Participants in the 1992 Earth Summit in Rio de Janeiro, Brazil, adopted a set of principles regarding sustainable forestry, and in 2007, the United Nations General Assembly adopted the Non-legally Binding Instrument on All Types of Forests to bring all stakeholders together in sustainable forest management efforts. The first international instrument devoted to sustainable forest management, its purpose is to strengthen and provide a framework for political commitment, action, and cooperation. In 2008, the United Nations launched the United Nations Collaborative Initiative on Reducing Emissions from Deforestation and Forest Degradation, or UN-REDD. This program provides developing forested countries with financial incentives to protect and better manage their forests, thereby contributing to the fight against global climate change. The UN-REDD program's 2023 plans included forest tenure, carbon rights, forest landscape restoration, forest monitoring, agriculture and food practices which are forest positive, social inclusion, and REDD+ financing needs. REDD+ was developed by members of the United Nations Framework Convention on Climate Change (UNFCCC) to include conservation, management tactics of forests and to enhance forest carbon stocks. Its framework was put into place at the COP 19 Warsaw in 2013 and is recognized as the Paris Agreement's Article 5.

Bibliography

Bush, Mark B., and John Flenley. Tropical Rainforest Responses to Climatic Change. Berlin: Springer, 2007.

Forsyth, Adrian, Michael Fogden, and Patricia Fogden. Nature of the Rainforest: Costa Rica and Beyond. Ithaca, N.Y.: Comstock, 2008.

Kirk, Ruth, Jerry F. Franklin, and Louis Kirk. The Olympic Rain Forest: An Ecological Web. Updated ed. Seattle: University of Washington Press, 2001.

London, Mark, and Brian Kelly. The Last Forest: The Amazon in the Age of Globalization. New York: Random House, 2007.

Marent, Thomas, with Trent Morgan. Rainforest. London: Dorling Kindersley, 2006.

Primack, Richard B., and Richard Corlett. Tropical Rain Forests: An Ecological and Biogeographical Comparison. Malden, Mass.: Blackwell, 2005.

“Rain Forest Threats Information and Facts.” Environment, National Geographic, 4 May 2021, www.nationalgeographic.com/environment/article/rainforest-threats. Accessed 12 Feb. 2023.

Weber, William, et al., eds. African Rain Forest Ecology and Conservation: An Interdisciplinary Perspective. New Haven, Conn.: Yale University Press, 2001.