By Rhett Butler
Mar 22, 2016
Today is International Forest Day, which was launched by the United Nations March 21, 2012 to promote the importance of forests and trees. In recognition of the designation, below are ten facts about forests.
Forests cover around 4 billion hectares or 30 percent of Earth’s land surface
Forests cover about four billion four billion hectares (16 million square miles). That represents about 30 percent of Earth’s land surface or eight percent of its total surface area. Ten countries hold about two-thirds the world’s forest cover, led by Russia (7.8 million square kilometers), Brazil (4.8m sq km), Canada (3.1m sq km), the United States (3m sq km), China (1.8m sq km) and Democratic Republic of the Congo (1.8m sq km).
Forests are storehouses of biodiversity
The world’s forests are thought to house more than 50 percent of the world’s plant and animal species. The highest biodiversity ever recorded on land is in the Amazon rainforest, specifically the area where the Amazon meets the Andes mountains in Peru and Ecuador. Forests in Borneo, New Guinea, northwestern South America and Central America, and the Congo Basin are other hotbeds of species richness. Some of these forests may house more than 300 species of tree per hectare.
Forests have hundreds of billions of trees
While the exact number is still being hostly debated, scientists agree that the world’s forests have hundreds of billions of trees. At the high end is a 2015 estimate of three trillion trees, including 1.4 trillion in the topics and subtropics, 700 billion in boreal areas, and 600 billion in temperate regions. That research estimated 15.3 billion trees are chopped down every year and 46 percent of the world’s trees have been cleared over the past 12,000 years.
Forests store massive amounts of carbon and afford other important ecosystem services upon which life on Earth depends
When plants grow they sequester atmospheric carbon in their tissues via the process of photosynthesis. Because forests are full of large trees and other plants, they store massive amounts of carbon. But when they are burned or chopped down, much of that carbon is released into the atmosphere as carbon dioxide and other greenhouse gases (nitrous oxide, methane, and other nitrogen oxides). The clearing and burning of tropical forests and peatlands accounts for about ten percent of greenhouse gases from human activities. Therefore forest protection and restoration are critical to slowing climate change. By one estimate, published in 2015 in the scientific journal Nature, tropical forests alone could meet half the 2050 target for reducing carbon emissions. But forests do much more than lock up carbon: they moderate local temperatures, play an important role in maintaining rainfall and weather patterns through transpiration, reduce erosion and run-off into rivers, stem drought and flood cycles, and provide critical habitat for millions of species.
The world still loses vast areas of forest every year
Estimates of global forest loss vary depending on how forests are defined, the methodology for measuring loss, and timeframes, but there is no question that large areas of forest continue to be chopped down. According to the U.N.’s survey of national forestry agencies, net loss of natural forests averaged 6.6 million hectares per year between 2010-2015. The bulk of that loss over the past five years occurred in the tropics, led by Brazil, Indonesia, and Myanmar. Howeversatellite data that looked only at change in tree cover, showed far higher levels of gross forest loss: 19 million hectares in 2014 alone.
Most forest loss is the result of human activities
Mankind is responsible for most forest loss worldwide. The biggest drivers of deforestation are agriculture and livestock production, logging, and forest fires. Humans are worsening outbreaks of fire via forest degradation, intentional fire-setting, and contributing to climate change, which exacerbates climate change in places where forests don’t typically burn, like the Amazon. The biggest causes of deforestation in the tropics are commercial and subsistence agriculture, including cattle ranching and palm oil production; road construction, which opens up remote forest areas to conversion; and logging. Russia, Canada, and Brazil had the highest gross forest cover loss between 2012 and 2014.
Forests are recovering in some countries
While most of the world’s attention is on forest loss, forests are recovering in some countries. For example, vast areas of forest have regrown in North America and Europe following centuries of destruction. More recently, countries like Costa Rica and New Zealand have reversed deforestation trends. And several nations, like China and Rwanda, are aggressively replanting forests to restore ecosystem function.
Forests are better monitored than every before
The past decade has produced a revolution in forest monitoring, primarily a result of greater availability of satellite imagery and improved computing power. For example, Global Forest Watch, a platform that maps forest data, now enable scientists, policymakers, companies, and environmental groups to see deforestation in near-real time. That sort of capability was instrumental in the sharp reduction in deforestation observed in Brazil since 2004: monitoring enabled better environmental law enforcement. Tools like Google Earth have also helped users better visualize — and therefore understand — threats to forests.
Some of the best protected forests are those occupied by indigenous peoples
Research has shown that some of the world’s best protected forests are those inhabited by indigenous peoples. Intuitively this makes sense, given that people who have lived forests for generations recognize the value of the ecosystem on which they depend for food, shelter, and water. Studies have also found that tree cover is better maintained in areas where communities have legal rights to forest lands.
One-eighth of global forests are managed for biodiversity conservation.
According to the U.N., about 13 percent of the world’s forests, or 5.24 million sq km, are managed primarily for biodiversity conservation. The United States (65 million ha), Brazil (47 million ha), and Mexico (28 million ha) lead the world in terms of forest area designated for biological diversity conservation. Brazil, with 206 million ha, has the largest forest area within designated protected areas.