Environment, SYM-WRA
Biological diversity is key to a healthy ecosystem, whether it’s a small biological community or the global biosphere. Ecology, which studies the relationships between organisms and their environment, is an invaluable science that helps us understand what allows an ecological community to thrive.
Environment Encyclopedia Articles By Title
symbiosis, any of several living arrangements between members of two different species, including mutualism, commensalism,......
syntrophism, mutual dependence of different types of organisms for the satisfaction of their respective nutritional......
systems ecology, Branch of ecosystem ecology (the study of energy budgets, biogeochemical cycles, and feeding and......
Tablas de Daimiel National Park, nature reserve and wetland ecosystem, located about 19 miles (30 km) northeast......
Tadoba National Park, national park in eastern Maharashtra state, western India. It was established as a wildlife......
taiga, biome (major life zone) of vegetation composed primarily of cone-bearing needle-leaved or scale-leaved evergreen......
An earlier version of this article was published on the Britannica blog Advocacy for Animals. In July 2015 a piece......
Tatshenshini-Alsek Wilderness Provincial Park, wilderness park, extreme northwestern British Columbia, Canada,......
Parc National de Taï, national park, southwestern Côte d’Ivoire (Ivory Coast), situated between the Liberian border......
temperate forest, vegetation type with a more or less continuous canopy of broad-leaved trees. Such forests occur......
temperate rainforest, in ecology, a biome dominated by a mix of broad-leaved or coniferous trees that occurs in......
territory, in ecology, any area defended by an organism or a group of similar organisms for such purposes as mating,......
Beyond the Arctic Circle lies the Svalbard Global Seed Vault, the world’s largest secure seed storage. Opened by......
Abraham Lincoln and Charles Darwin, two of the 19th century’s most enduring thinkers and figures, share more than......
Outside of the tropics, the spring season is a time of renewal as buds and leaves begin to sprout on trees and......
Empowered by the Clean Air Act of 1970, the U.S. Environmental Protection Agency (EPA) quickly established air......
thermal-heat recovery, use of heat energy that is released from some industrial processes and that would otherwise......
Thomas Robert Malthus (1766–1834) demonstrated perfectly the propensity of each generation to overthrow the fondest......
thorn forest, dense scrublike vegetation characteristic of dry subtropical and warm temperate areas with a seasonal......
Thousand Islands National Park, national park covering an area of mainland, islands, and islets in southeastern......
Greta Thunberg is a Swedish environmental activist who addresses the problem of climate change. In 2018 she founded......
timberline, upper limit of tree growth in mountainous regions or in high latitudes, as in the Arctic. Its location......
This infographic presents a timeline of climate change. A detailed description of this infographic appears below.......
Timpanogos Cave National Monument, limestone cave system in American Fork Canyon, north-central Utah, U.S. The......
Tongass National Forest, forest region and wilderness area in southeastern Alaska, U.S. It was established in 1907......
toxic waste, chemical waste material capable of causing death or injury to life. Waste is considered toxic if it......
tragedy of the commons, concept highlighting the conflict between individual and collective rationality. The idea......
trophic cascade, an ecological phenomenon triggered by the addition or removal of top predators and involving reciprocal......
trophic level, step in a nutritive series, or food chain, of an ecosystem. The organisms of a chain are classified......
trophic pyramid, the basic structure of interaction in all biological communities characterized by the manner in......
tropical dry forest, biome of any open woodland in tropical areas that have a long dry season followed by a season......
tropical rainforest, luxuriant forest found in wet tropical uplands and lowlands around the Equator. Tropical rainforests,......
Tsavo National Park, national park, southeastern Kenya, east of Mount Kilimanjaro. The largest (8,036 square miles......
tundra, a major zone of treeless level or rolling ground found in cold regions, mostly north of the Arctic Circle......
Type I survivorship curve, in ecology, a curve displayed on a semilogarithmic scale that tracks organisms that......
Type II survivorship curve, in ecology, a curve displayed on a semilogarithmic scale that tracks organisms whose......
This infographic shows the death toll caused by major events during the history of the United States, including......
U.S. Forest Service (USFS), federal agency within the U.S. Department of Agriculture (USDA) charged with oversight,......
Ujung Kulon National Park, national park on the island of Java, in the province of Banten, Indonesia. It is best......
Umfolozi Game Reserve, wild animal sanctuary in northern KwaZulu/Natal province, South Africa. The reserve lies......
uMkhuze Game Reserve, park in northern KwaZulu-Natal province, South Africa. The park, established in 1912, lies......
UNESCO, specialized agency of the United Nations (UN) that was outlined in a constitution signed November 16, 1945.......
What’s slimy and spineless and looking to parasitize you? (They’re not running for office, if that narrows it down.)......
United Nations Conference on Environment and Development (UNCED), conference held at Rio de Janeiro, Brazil (June......
United Nations Environment Programme (UNEP), organization established in 1972 to guide and coordinate environmental......
United Nations Population Fund (UNFPA), trust fund under the jurisdiction of the United Nations Development Programme......
Upemba National Park, park in southeastern Congo (Kinshasa). It was created in 1939 and has an area of 4,529 square......
urban ecosystem, any ecological system located within a city or other densely settled area or, in a broader sense,......
Vanoise National Park, nature reserve in Savoie département, Rhône-Alpes région, southeastern France. It is contiguous......
Nikolai Vavilov was a Soviet plant geneticist whose research into the origins of cultivated plants incurred the......
veld, name given to various types of open country in Southern Africa that is used for pasturage and farmland. To......
Virgin Islands Coral Reef National Monument, natural marine area lying off the island of St. John in the United......
Virunga National Park, park in northeastern Democratic Republic of the Congo (Kinshasa). Created in 1925, it has......
vital rates, relative frequencies of vital occurrences that affect changes in the size and composition of a population.......
volcanic winter, cooling at Earth’s surface resulting from the deposition of massive amounts of volcanic ash and......
Voyageurs National Park, region of lakes and wilderness in northern Minnesota, U.S. The park lies along the Canadian......
Wallace Line, boundary between the Oriental and Australian faunal regions, proposed by the 19th-century British......
Barbara Ward, Baroness Jackson was a British economist and writer. After studying economics at the University of......
Johannes Eugenius Bülow Warming was a Danish botanist whose work on the relations between living plants and their......
water bloom, dense aquatic population of microscopic photosynthetic organisms produced by an abundance of nutrient......
water cycle, cycle that involves the continuous circulation of water in the Earth-atmosphere system. Of the many......
water pollution, the release of substances into subsurface groundwater or into lakes, streams, rivers, estuaries,......
water purification, process by which undesired chemical compounds, organic and inorganic materials, and biological......
water resource, any of the entire range of natural waters that occur on the Earth, regardless of their state (i.e.,......
water scarcity, insufficient freshwater resources to meet the human and environmental demands of a given area.......
Water scarcity results from insufficient available freshwater resources to meet the human and environmental demands......
water supply, available water provided to fulfill a particular need. If the need is domestic, industrial, or agricultural,......
Paul Watson is a Canadian American environmental activist who founded (1977) the Sea Shepherd Conservation Society,......
Pollution can be described as a nutrient or substance that is out of place. More specifically, however, it is the......
The main contributors to acid rain are sulfur dioxide (SO2) and nitrogen oxides (NOx; the combination of NO and......
There are approximately 10,000 species of ants on Earth, with a wide range of diets and behaviors among them. Many......
Although snakes are predators, they are also themselves eaten by other creatures, making them secondary consumers......
During the 1970s and ’80s the phenomenon called acid rain was one of the most well-known environmental problems......
Metaphorically speaking, the vast tropical rainforest in South America’s Amazon River basin is often called the......
Rumors, conjecture, and conspiracy theories swirl around the explosion that happened near the Podkamennaya Tunguska......
Wildfires erupt from a deadly confluence of extreme weather conditions and primed fuel sources. Drought, heat,......
Ecosystems are not static things. Wetlands and grasslands, patches of forests, and even whole landscapes (which......
All of us have experienced this: It’s nighttime, and we’re drifting off to sleep when we think we hear something......
When most people think of ice ages, or “glacial ages,” they often envision cavemen, woolly mammoths, and vast plains......
People often confuse the concepts of global warming and climate change, and it doesn’t help that media companies......
The primary difference between areas defined as urban (Latin: urbanus, “related to the city”) and rural (Latin:......
Many climate scientists define the start of summer in terms of meteorological phenomena and the calendar year.......
Between August 23 and 29, 2005, a tropical depression called “Katrina” grew into one of the most destructive storms......
White Sands National Park, an expanse of dazzling white gypsum sands in south-central New Mexico, U.S., covering......
The Earth’s magnificent tropical rainforests represent a treasure trove of biological heritage. They not only retain......
Seasons occur due to the tilt of Earth’s axis, which is approximately 23.5°. Because of this tilt, each hemisphere......
Antarctica can be classified as a desert because it receives very little precipitation. The average amount—which......
Touching a manatee is illegal in the United States. The ban’s aim is to protect these vulnerable marine mammals......
The temperature people feel outside is largely based on the absorption of radiant energy from the Sun. Differing......
The Gobi Desert, spanning parts of northern China and southern Mongolia, is famously known as a “cold desert” due......
The Huang He, also known as the Yellow River, is often referred to as “China’s Sorrow” due to its long history......
Wilderness Act, U.S. environmental protection legislation (1964) that created the National Wilderness Preservation......
wildfire, uncontrolled fire in a forest, grassland, brushland, or land sown to crops. The terms forest fire, brush......
The Wildfowl and Wetlands Trust, centre of the world’s largest collection of waterfowl. It was established in 1946......
Willem Pretorius Game Reserve, game sanctuary in Free State province, South Africa, adjoining Allemanskraal Dam......
Wind Cave National Park, scenic area in southwestern South Dakota, U.S., about 35 miles (56 km) south-southwest......
winter, coldest season of the year, between autumn and spring; the name comes from an old Germanic word that means......
This infographic shows graphs that compare aspects of the lives of women in the United States over a century. Spotlight,......
World Resources Institute (WRI), research institute established in 1982 to promote environmentally sound and socially......
Wrangell–Saint Elias National Park and Preserve, vast natural area in southeastern Alaska, U.S., on the Canadian......