« Back to Glossary Index

**1. Definitions and Etymology of Forests:**
– Forest has over 800 definitions globally, falling into administrative, land use, and land cover categories.
– The term ‘forest’ originates from Old French, denoting a vast land covered by trees.
– Initially, ‘forest’ referred to uncultivated hunting land, evolving to include woodland regardless of tree density.
– Other related English terms include ‘firth,’ ‘holt,’ ‘weald,’ ‘wold,’ ‘wood,’ and ‘woodland.’

**2. Global Forest Coverage and Biomes:**
– Forests cover approximately 31% of the world’s land area, making them the largest terrestrial ecosystem.
– 45% of forests are located in tropical latitudes, contributing to 75% of the Earth’s gross primary production.
– Forests form various biomes based on factors like latitude, elevation, and precipitation levels.

**3. Threats to Forests and Conservation Importance:**
– Deforestation driven by timber, beef, soy, and palm oil production is a major threat.
– European forest cover has decreased significantly over the last 2,000 years.
– Forests play a crucial role in providing habitat for wildlife, producing oxygen, regulating climate, supporting biodiversity, and contributing to the water cycle.
– Forest conservation offers benefits like carbon sequestration, ecotourism opportunities, protection of watersheds, sustainable timber resources, and medicinal plant discovery.

**4. Forest Ecosystem Services and Human Interactions:**
– Forests provide ecosystem services like serving as tourist attractions and impacting human health.
– Unsustainable use of forest resources can harm forest ecosystems.
Human society and forests have complex interactions, both positive and negative.

**5. Types of Forest Ecosystems and Global Forest Cover:**
– Forest ecosystems consist of canopy layer, understory layer, forest floor, emergent layer, and riverine ecosystems.
– Global forest cover includes the Amazon Rainforest, Boreal forests, Tropical forests, Temperate forests, and Mangrove forests.

Forest (Wikipedia)

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 (FRA 2020) found that forests covered 4.06 billion hectares (10.0 billion acres; 40.6 million square kilometres; 15.7 million square miles), or approximately 31 percent of the world's land area in 2020.

The Amazon rainforest alongside the Solimões River, a tropical rainforest. These forests are the most biodiverse and productive ecosystems in the world.

Forests are the largest terrestrial ecosystems of Earth by area, and are found around the globe. 45 percent of forest land is in the tropical latitudes. The next largest share of forests are found in subarctic climates, followed by temperate, and subtropical zones.

Forests account for 75% of the gross primary production of the Earth's biosphere, and contain 80% of the Earth's plant biomass. Net primary production is estimated at 21.9 gigatonnes of biomass per year for tropical forests, 8.1 for temperate forests, and 2.6 for boreal forests.

Forests form distinctly different biomes at different latitudes and elevations, and with different precipitation and evapotranspiration rates. These biomes include boreal forests in subarctic climates, tropical moist forests and tropical dry forests around the Equator, and temperate forests at the middle latitudes. Forests form in areas of the Earth with high rainfall, while drier conditions produce a transition to savanna. However, in areas with intermediate rainfall levels, forest transitions to savanna rapidly when the percentage of land that is covered by trees drops below 40 to 45 percent. Research conducted in the Amazon rainforest shows that trees can alter rainfall rates across a region, releasing water from their leaves in anticipation of seasonal rains to trigger the wet season early. Because of this, seasonal rainfall in the Amazon begins two to three months earlier than the climate would otherwise allow. Deforestation in the Amazon and anthropogenic climate change hold the potential to interfere with this process, causing the forest to pass a threshold where it transitions into savanna.

Deforestation threatens many forest ecosystems. Deforestation occurs when humans remove trees from a forested area by cutting or burning, either to harvest timber or to make way for farming. Most deforestation today occurs in tropical forests. The vast majority of this deforestation is because of the production of four commodities: wood, beef, soy, and palm oil. Over the past 2,000 years, the area of land covered by forest in Europe has been reduced from 80% to 34%. Large areas of forest have also been cleared in China and in the eastern United States, in which only 0.1% of land was left undisturbed. Almost half of Earth's forest area (49 percent) is relatively intact, while 9 percent is found in fragments with little or no connectivity. Tropical rainforests and boreal coniferous forests are the least fragmented, whereas subtropical dry forests and temperate oceanic forests are among the most fragmented. Roughly 80 percent of the world's forest area is found in patches larger than 1 million hectares (2.5 million acres). The remaining 20 percent is located in more than 34 million patches around the world – the vast majority less than 1,000 hectares (2,500 acres) in size.

Human society and forests can affect one another positively or negatively. Forests provide ecosystem services to humans and serve as tourist attractions. Forests can also affect people's health. Human activities, including unsustainable use of forest resources, can negatively affect forest ecosystems.

« Back to Glossary Index