Environment, HOW-MIX

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.
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Environment Encyclopedia Articles By Title

How Long Was the Ice Age?
The most recent major ice age, known as the Great Ice Age or Pleistocene Epoch, spanned approximately 2.6 million......
How the 1815 Eruption of Mount Tambora Produced the “Year Without a Summer”
Mount Tambora is a stratovolcano and forms the entire 37.3-mile- (60-km-) wide Sanggar peninsula on Sumbawa island,......
How the Nitrogen Cycle Works
Nitrogen is the most plentiful element in Earth’s atmosphere and is a constituent of all living matter. It is essential......
human ecology
human ecology, man’s collective interaction with his environment. Influenced by the work of biologists on the interaction......
human microbiome
human microbiome, the full array of microorganisms (the microbiota) that live on and in humans and, more specifically,......
Humboldt, Alexander von
Alexander von Humboldt was a German naturalist and explorer who was a major figure in the classical period of physical......
Humility—How to Save the Planet
Human civilization faces, for the first time, questions about whether it can and will continue. Those were raised......
Hutchinson, G Evelyn
G. Evelyn Hutchinson was an English-born American zoologist known for his ecological studies of freshwater lakes.......
Hwange National Park
Hwange National Park, park in northwestern Zimbabwe, on the Botswana frontier. It was established in 1928 as a......
ice age
ice age, any geologic period during which thick ice sheets cover vast areas of land. Such periods of large-scale......
IJsselmeer Polders
IJsselmeer Polders, group of four polders, central Netherlands, that were reclaimed from the IJsselmeer, a lake......
Inconvenient Truth, An
An Inconvenient Truth, American documentary film, released in 2006, featuring the multimedia presentation of former......
Indian summer
Indian summer, period of dry, unseasonably warm weather in late October or November in the central and eastern......
Indiana Dunes
Indiana Dunes, area of sand dunes, woodlands, wetlands, and other environments located on the southern shore of......
indicator species
indicator species, organism—often a microorganism or a plant—that serves as a measure of the environmental conditions......
infant mortality rate
infant mortality rate, measure of human infant deaths in a group younger than one year of age. It is an important......
Intergovernmental Panel on Climate Change
Intergovernmental Panel on Climate Change (IPCC), United Nations panel established by the United Nations Environment......
International Union for Conservation of Nature
International Union for Conservation of Nature (IUCN), network of environmental organizations founded as the International......
invasive species
invasive species, any nonnative species that significantly modifies or disrupts the ecosystems it colonizes. Such......
Ironwood Forest National Monument
Ironwood Forest National Monument, ecologically rich region of the Sonoran Desert, southern Arizona, U.S., about......
Irwin, Steve
Steve Irwin was an Australian wildlife conservationist, television personality, and educator who achieved worldwide......
Is Climate Change Real?
By definition, climate change is the periodic modification of Earth’s climate due to changes in the atmosphere......
Ishihara Shintarō
Ishihara Shintarō was a Japanese writer and politician, who served as governor of Tokyo from 1999 to 2012. Ishihara......
Isle Royale National Park
Isle Royale National Park, island national park located in northwestern Lake Superior, northwestern Michigan, U.S.......
IUCN Red List of Threatened Species
IUCN Red List of Threatened Species, one of the most well-known objective assessment systems for classifying the......
Jackson Hole National Monument
Jackson Hole National Monument, fertile mountain valley and wildlife reserve mostly in Grand Teton National Park......
Jackson, Robert H.
Robert H. Jackson was an associate justice of the United States Supreme Court (1941–54). An adept scholar, Jackson......
Jaldapara Wildlife Sanctuary
Jaldapara Wildlife Sanctuary, wildlife preserve in West Bengal state, northeastern India. The preserve was established......
Jasper National Park
Jasper National Park, national park in western Alberta, Canada, located on the eastern flank of the Rocky Mountains,......
Jewel Cave National Monument
Jewel Cave National Monument, limestone caverns in southwestern South Dakota, U.S., 15 miles (24 km) west of Custer.......
Johnson, Lady Bird
Lady Bird Johnson was an American first lady (1963–69), the wife of Lyndon B. Johnson, 36th president of the United......
Joshua Tree National Park
Joshua Tree National Park, desert and wilderness area in southern California, U.S. It is situated just east of......
jungle
jungle, tropical forest with luxuriant, tangled, impenetrable vegetation, generally teeming with wildlife; popularly......
Kafue National Park
Kafue National Park, park, south-central Zambia. Established in 1950 and located about 200 miles (322 km) west......
Kakadu National Park
Kakadu National Park, extensive natural and cultural region in the Northern Territory, Australia. The park, which......
Kanha National Park
Kanha National Park, national park in Madhya Pradesh state, central India. The park extends over 122 square miles......
Katmai National Park and Preserve
Katmai National Park and Preserve, large area of wilderness and unique geologic features in southwestern Alaska,......
Kaziranga National Park
Kaziranga National Park, scenic natural area in north-central Assam state, northeastern India. It is situated on......
Kenai Fjords National Park
Kenai Fjords National Park, rugged wilderness area in southern Alaska, U.S., on the southern coast of Kenai Peninsula......
keystone species
keystone species, in ecology, a species that has a disproportionately large effect on the communities in which......
Kgalagadi Transfrontier Park
Kgalagadi Transfrontier Park, nature conservation area in the Kalahari. It lies within South Africa and Botswana......
Kidepo Valley National Park
Kidepo Valley National Park, national park located in northeastern Uganda. The park, which was established in 1962,......
Killarney Provincial Park
Killarney Provincial Park, wilderness park, southeastern Ontario, Canada, on the northern shore of Georgian Bay......
Kimmerer, Robin Wall
Robin Wall Kimmerer is a mother, writer, and plant ecologist perhaps best known for her book of essays Braiding......
Kings Canyon National Park
Kings Canyon National Park, scenic area in the Sierra Nevada, east-central California, U.S. It lies adjacent to......
Kobuk Valley National Park
Kobuk Valley National Park, large wilderness area in northwestern Alaska, U.S. It is part of a vast region of national......
Komoé National Park
Komoé National Park, national park, northeastern Côte d’Ivoire (Ivory Coast). Originally founded in 1953 as the......
Kootenay National Park
Kootenay National Park, national park in southeastern British Columbia, Canada. Centred around the Kootenay River,......
Kruger National Park
Kruger National Park, the largest national park in South Africa. It is located in Limpopo and Mpumalanga provinces,......
Kyoto Protocol
Kyoto Protocol, international treaty, named for the Japanese city in which it was adopted in December 1997, that......
K–T extinction
K–T extinction, a global mass extinction event responsible for eliminating approximately 80 percent of all species......
lacustrine ecosystem
lacustrine ecosystem, any pond or lake viewed as an ecosystem. A riverine, or lotic, ecosystem, by contrast, has......
Lake Clark National Park and Preserve
Lake Clark National Park and Preserve, rugged wilderness area in southern Alaska, U.S., on the western shore of......
Lake Superior Provincial Park
Lake Superior Provincial Park, park, central Ontario, Canada, on the eastern shore of Lake Superior. Established......
land pollution
land pollution, the deposition of solid or liquid waste materials on land or underground in a manner that can contaminate......
land reclamation
land reclamation, the process of improving lands to make them suitable for a more intensive use. Reclamation efforts......
Landless Workers Movement
Landless Workers Movement (MST), Brazilian social movement seeking agrarian reform through land expropriation.......
Lane, Franklin K
Franklin K. Lane was a U.S. lawyer and politician who, as secretary of the interior (1913–20) made important contributions......
last glacial maximum
last glacial maximum (LGM), the most recent geologic interval, which spanned 29,000 to 19,000 years ago, in which......
Lava Beds National Monument
Lava Beds National Monument, region of lava flows and related volcanic formations in far northern California, U.S.,......
Leopold, Aldo
Aldo Leopold was an American environmentalist whose book A Sand County Almanac (1949) was read by millions and......
lichen
lichen, any of about 15,000 species of plantlike organisms that consist of a symbiotic association of algae (usually......
life expectancy
life expectancy, estimate of the average number of additional years that a person of a given age can expect to......
light pollution
light pollution, unwanted or excessive artificial light. Like noise pollution, light pollution is a form of waste......
list of the populations of the world’s countries, dependencies, and territories
This list provides the populations for all the countries of the world and for all but the smallest political dependencies......
Little Ice Age
Little Ice Age (LIA), climate interval that occurred from the early 14th century through the mid-19th century,......
Little Missouri National Grassland
Little Missouri National Grassland, prairie grassland region of western North Dakota, U.S. Created in 1960, it......
littoral zone
littoral zone, marine ecological realm that experiences the effects of tidal and longshore currents and breaking......
Lomborg, Bjørn
Bjørn Lomborg is a Danish political scientist and statistician who gained world renown in the early 21st century......
Loskop Dam Nature Reserve
Loskop Dam Nature Reserve, nature preserve in Mpumalanga province, South Africa, on the Olifants River, north of......
Love Canal
Love Canal, neighbourhood in Niagara Falls, New York, U.S., that was the site of the worst environmental disaster......
Luangwa National Park
Luangwa National Park, park located in northeastern Zambia, southern Africa. Divided into two separate parks, one......
Maathai, Wangari
Wangari Maathai was a Kenyan politician and environmental activist who was awarded the 2004 Nobel Prize for Peace,......
macrofauna
macrofauna, in soil science, animals that are one centimetre or more long but smaller than an earthworm. Potworms,......
Madhav National Park
Madhav National Park, natural area in northern Madhya Pradesh state, central India. It is located about 70 miles......
Maiko National Park
Maiko National Park, reserve in eastern Democratic Republic of the Congo, about equidistant from Bukavu, in the......
Major Mass Extinctions
During the billions of years of its history, life on Earth has weathered some bumps in the road. As species evolved......
mallee
mallee, scrubland plant community found in southern Australia, composed primarily of woody shrubs and small trees......
Mammoth Cave National Park
Mammoth Cave National Park, national park containing an extensive system of limestone caverns in west-central Kentucky,......
Manas Wildlife Sanctuary
Manas Wildlife Sanctuary, wildlife sanctuary in western Assam state, eastern India. It is situated at the foot......
maquis
maquis, scrubland plant community of the Mediterranean region, composed primarily of leathery broad-leaved evergreen......
marine protected area
marine protected area (MPA), discrete parcel of ocean or estuarine ecosystems that is managed according to special......
Marsh, George Perkins
George Perkins Marsh was a U.S. diplomat, scholar, and conservationist whose greatest work, Man and Nature (1864),......
mass extinction event
mass extinction event, any circumstance that results in the loss of a significant portion of Earth’s living species......
Matthiessen, Peter
Peter Matthiessen was an American novelist, naturalist, and wilderness writer whose work dealt with the destructive......
McMurdo Station
McMurdo Station, research and logistics installation located on the Hut Point Peninsula, on Ross Island, Antarctica.......
Mendes, Chico
Chico Mendes was a Brazilian labour leader and conservationist who defended the interests of the seringueiros,......
mesofauna
mesofauna, in soil science, intermediate-sized animals (those greater than 40 microns in length, which is about......
mesopredator release
mesopredator release, in ecology, a phenomenon in which populations of medium-sized predators rapidly increase......
metapopulation
metapopulation, in ecology, a regional group of connected populations of a species. For a given species, each metapopulation......
methane burp hypothesis
methane burp hypothesis, in oceanography and climatology, an explanation of the sudden onset of the Paleocene-Eocene......
microplastics
microplastics, small pieces of plastic, less than 5 mm (0.2 inch) in length, that occur in the environment as a......
Milankovitch, Milutin
Milutin Milankovitch was a Serbian mathematician and geophysicist, best known for his work that linked long-term......
Miner, Jack
Jack Miner was a Canadian naturalist, author, and lecturer who won a reputation as a leading bird conservationist......
minimum viable population
minimum viable population (MVP), ecological threshold that specifies the smallest number of individuals in a species......
mixed forest
mixed forest, a vegetational transition between coniferous forest and broad-leaved deciduous forest, especially......

Environment Encyclopedia Articles By Title