Forest cover is the amount of forest that covers a particular area of land. It may be measured as relative (in percent) or absolute (in square kilometres/square miles). Nearly a third of the world's land surface is covered with forest, with closed-canopy forest accounting for 4 - 5 billion hectares of land. [1] Forests provide many ecosystem services that humans and animals cannot survive without, but anthropogenic actions and climate change are threatening global forest cover in potentially irreversible ways.
According to the FAO's Global Forest Resources Assessment 2020, the world has a total forest area of 4.06 billion hectares (10.0 billion acres), which is 31% of the total land area. More than one-third of the world's forest cover is primary forest: naturally regenerated forests with native species and no visible indication of human activity. [2]
More than half (54%) of the world's forests are found in only five countries (Brazil, Canada, China, Russia and the United States). Russia has the largest forest area in the world, at 815 million hectares (a fifth of global forest cover). The other four countries all house more than 100 million hectares of forest each. The small African nation of Gabon, while only containing 0.58% of the world's forest cover, has the largest forest-to-land ratio of any country (91.3%). [3]
Forests are found throughout the world on a spatial scale determined by temperature and precipitation. There are four types of forest biomes: tropical, temperate, subtropical, and boreal. Most of the world's forest cover (45%) is found in the tropics, which is defined by high temperature and humidity. The boreal zone, which includes Russia and the Arctic, contains the second largest amount of forest (33%). The temperate/subtropical zone, located between the tropical and the boreal, contains 25%. Almost half of global forest cover (49%) is relatively continuous, while 9% is found in fragments with little to no connectivity. Roughly 80% of the world's forest area is found in patches larger than 1 million hectares (2.5 million acres). The remaining 20% is located in more than 34 million patches across the world [4] with the vast majority being less than 1,000 hectares (2,500 acres) in size. Tropical rainforests and boreal coniferous forests are the least fragmented, whereas subtropical dry forest and temperate oceanic forests are among the most fragmented.
The World Health Organization has compiled a list of ecological goods and services that depend on forests and without which humans could not survive, including: flood and drought mitigation, water purification, erosion control, and disease reduction. [5] Tropical forests especially act as one of the world's largest carbon sinks, accumulating atmospheric carbon dioxide during photosynthesis and thus mitigating climate change. Maintaining the size, continuity, and biodiversity of the world's forests is crucial for human health and prosperity. However, forest cover is severely threatened by deforestation, as a direct consequence of agriculture, grazing, [6] and mining. [7] Since the onset of agriculture (about 12,000 years ago), the number of trees worldwide has dropped by 46%. [8] Since 1990, the world has lost 178 million ha of forest (an area roughly the size of Libya).
Although global forest area is decreasing, the rate at which we are losing trees has slowed. In the 1990s the world was losing 7.8 million ha of area per year, but in the 2000s this rate slowed to 5.2 million ha, and in the 2010s it shrank even further (down to 4.7 million). This pattern is due to the regeneration abilities of forests, as well as a conscious global effort to reduce deforestation. Plantation forests are one method of reforestation/afforestation that has become increasingly popular since the 1990s. Intensively planned to be biodiverse and well-managed, these forests exist for the purpose of regenerating our global forest cover. [9] Although it is impossible to gain back the ecosystem services lost when a plot of forest is destroyed for industrial purposes, these new regenerative methods carry hope for the future of our global forest biome.[ citation needed ]
This article incorporates text from a free content work. Licensed under CC BY-SA 3.0( license statement/permission ). Text taken from Global Forest Resources Assessment 2020 Key findings , FAO, FAO.
This article incorporates text from a free content work. Licensed under CC BY-SA 3.0( license statement/permission ). Text taken from The State of the World's Forests 2020. In brief – Forests, biodiversity and people , FAO & UNEP, FAO & UNEP.
Deforestation or forest clearance is the removal and destruction of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated deforestation occurs in tropical rainforests. About 31% of Earth's land surface is covered by forests at present. This is one-third less than the forest cover before the expansion of agriculture, with half of that loss occurring in the last century. Between 15 million to 18 million hectares of forest, an area the size of Bangladesh, are destroyed every year. On average 2,400 trees are cut down each minute.
A forest is an ecosystem characterized by a dense community of trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' Food and Agriculture Organization (FAO) defines a forest as, "Land spanning more than 0.5 hectares with trees higher than 5 meters and a canopy cover of more than 10 percent, or trees able to reach these thresholds in situ. It does not include land that is predominantly under agricultural or urban use." Using this definition, Global Forest Resources Assessment 2020 found that forests covered 4.06 billion hectares, or approximately 31 percent of the world's land area in 2020.
Forestry is the science and craft of creating, managing, planting, using, conserving and repairing forests and woodlands for associated resources for human and environmental benefits. Forestry is practiced in plantations and natural stands. The science of forestry has elements that belong to the biological, physical, social, political and managerial sciences. Forest management plays an essential role in the creation and modification of habitats and affects ecosystem services provisioning.
Reforestation is the natural or intentional restocking of existing forests and woodlands (forestation) that have been depleted, usually through deforestation but also after clearcutting. Two important purposes of reforestation programs are for harvesting of wood or for climate change mitigation purposes.
Tropical forests are forested landscapes in tropical regions: i.e. land areas approximately bounded by the tropic of Cancer and Capricorn, but possibly affected by other factors such as prevailing winds.
An old-growth forest is a forest that has developed over a long period of time without disturbance. Due to this, old-growth forests exhibit unique ecological features. The Food and Agriculture Organization of the United Nations defines primary forests as naturally regenerated forests of native tree species where there are no clearly visible indications of human activity and the ecological processes are not significantly disturbed. One-third of the world's forests are primary forests. Old-growth features include diverse tree-related structures that provide diverse wildlife habitats that increases the biodiversity of the forested ecosystem. Virgin or first-growth forests are old-growth forests that have never been logged. The concept of diverse tree structure includes multi-layered canopies and canopy gaps, greatly varying tree heights and diameters, and diverse tree species and classes and sizes of woody debris.
A secondary forest is a forest or woodland area which has regenerated through largely natural processes after human-caused disturbances, such as timber harvest or agriculture clearing, or equivalently disruptive natural phenomena. It is distinguished from an old-growth forest, which has not recently undergone such disruption, and complex early seral forest, as well as third-growth forests that result from harvest in second growth forests. Secondary forest regrowing after timber harvest differs from forest regrowing after natural disturbances such as fire, insect infestation, or windthrow because the dead trees remain to provide nutrients, structure, and water retention after natural disturbances. Secondary forests are notably different from primary forests in their composition and biodiversity; however, they may still be helpful in providing habitat for native species, preserving watersheds, and restoring connectivity between ecosystems.
Forest ecology is the scientific study of the interrelated patterns, processes, flora, fauna and ecosystems in forests. The management of forests is known as forestry, silviculture, and forest management. A forest ecosystem is a natural woodland unit consisting of all plants, animals, and micro-organisms in that area functioning together with all of the non-living physical (abiotic) factors of the environment.
Sustainable forest management (SFM) is the management of forests according to the principles of sustainable development. Sustainable forest management must keep a balance between the three main pillars: ecological, economic and socio-cultural. The goal of sustainable forestry is to allow for a balance to be found between making use of trees while maintaining natural patterns of disturbance and regeneration. The forestry industry mitigates climate change by boosting carbon storage in growing trees and soils and improving the sustainable supply of renewable raw materials via sustainable forest management.
Forest management is a branch of forestry concerned with overall administrative, legal, economic, and social aspects, as well as scientific and technical aspects, such as silviculture, protection, and forest regulation. This includes management for timber, aesthetics, recreation, urban values, water, wildlife, inland and nearshore fisheries, wood products, plant genetic resources, and other forest resource values. Management objectives can be for conservation, utilisation, or a mixture of the two. Techniques include timber extraction, planting and replanting of different species, building and maintenance of roads and pathways through forests, and preventing fire.
Forestry in India is a significant rural industry and a major environmental resource. India is one of the ten most forest-rich countries of the world. Together, India and 9 other countries account for 67 percent of the total forest area of the world. India's forest cover grew at 0.20% annually over 1990–2000, and has grown at the rate of 0.7% per year over 2000–2010, after decades where forest degradation was a matter of serious concern.
Deforestation in Nigeria refers to the extensive and rapid clearing of forests within the borders of Nigeria. This environmental issue has significant impacts on both local and global scales.
Rates and causes of deforestation vary from region to region around the world. In 2009, two-thirds of the world's forests were located in just 10 countries: Russia, Brazil, Canada, the United States, China, Australia, the Democratic Republic of the Congo, Indonesia, India, and Peru.
Conservation in India can be traced to the time of Ashoka, tracing to the Ashoka Pillar Edicts as one of the earliest conservation efforts in the world. Conservation generally refers to the act of carefully and efficiently using natural resources. Conservation efforts begun in India before 5 AD, as efforts are made to have a forest administration. The Ministry of Environment, Forest and Climate Change is the ministry responsible for implementation of environmental and forestry program in India, which include the management of national parks, conservation of flora and fauna of India, and pollution controls.
Forest degradation is a process in which the biological wealth of a forest area is permanently diminished by some factor or by a combination of factors. "This does not involve a reduction of the forest area, but rather a quality decrease in its condition." The forest is still there, but with fewer trees, or less species of trees, plants or animals, or some of them affected by plagues. This degradation makes the forest less valuable and may lead to deforestation. Forest degradation is a type of the more general issue of land degradation. Deforestation and forest degradation continue to take place at alarming rates, which contributes significantly to the ongoing loss of biodiversity.
Forest restoration is defined as “actions to re-instate ecological processes, which accelerate recovery of forest structure, ecological functioning and biodiversity levels towards those typical of climax forest” i.e. the end-stage of natural forest succession. Climax forests are relatively stable ecosystems that have developed the maximum biomass, structural complexity and species diversity that are possible within the limits imposed by climate and soil and without continued disturbance from humans. Climax forest is therefore the target ecosystem, which defines the ultimate aim of forest restoration. Since climate is a major factor that determines climax forest composition, global climate change may result in changing restoration aims. Additionally, the potential impacts of climate change on restoration goals must be taken into account, as changes in temperature and precipitation patterns may alter the composition and distribution of climax forests.
Deforestation is a primary contributor to climate change, and climate change affects forests. Land use changes, especially in the form of deforestation, are the second largest anthropogenic source of atmospheric carbon dioxide emissions, after fossil fuel combustion. Greenhouse gases are emitted during combustion of forest biomass and decomposition of remaining plant material and soil carbon. Global models and national greenhouse gas inventories give similar results for deforestation emissions. As of 2019, deforestation is responsible for about 11% of global greenhouse gas emissions. Carbon emissions from tropical deforestation are accelerating. Growing forests are a carbon sink with additional potential to mitigate the effects of climate change. Some of the effects of climate change, such as more wildfires, insect outbreaks, invasive species, and storms are factors that increase deforestation.
The Global Forest Resources Assessment (FRA) reports on the status and trends of the world's forest resources. It is led by the Food and Agriculture Organization of the United Nations (FAO).
Agricultural expansion describes the growth of agricultural land especially in the 20th and 21st centuries.
