Environment, PET-SUL
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
Peterson, Roger Tory
Roger Tory Peterson was an American ornithologist, author, conservationist, and wildlife artist whose field books......
Petrified Forest National Park
Petrified Forest National Park, desert area containing plant and animal fossils and archaeological sites in eastern......
Phenology
Phenology, the study of phenomena or happenings. It is applied to the recording and study of the dates of recurrent......
Phosphorus cycle
Phosphorus cycle, circulation of phosphorus in various forms through nature. Of all the elements recycled in the......
photic zone
photic zone, surface layer of the ocean that receives sunlight. The uppermost 80 m (260 feet) or more of the ocean,......
Pictured Rocks National Lakeshore
Pictured Rocks National Lakeshore, colourful sandstone cliffs lining the southern shore of Lake Superior in the......
Pinchot, Gifford
Gifford Pinchot was a pioneer of U.S. forestry and conservation and a public official. Pinchot graduated from Yale......
pioneer species
pioneer species, species that are the first to colonize newly created environments or recently disturbed environments......
Plastic Disaster: How Your Bags, Bottles, and Body Wash Pollute the Oceans
Plastic is cheap and durable and has revolutionized human activity. Modern life is addicted to and dependent on......
plastic pollution
plastic pollution, accumulation in the environment of synthetic plastic products to the point that they create......
poaching
poaching, in law, the illegal shooting, trapping, or taking of game, fish, or plants from private property or from......
Pohl, Frederik
Frederik Pohl was an American science-fiction writer whose best work uses the genre as a mode of social criticism......
Point Pelee National Park
Point Pelee National Park, park in southeastern Ontario, Canada, lying southeast of Leamington, at the western......
Polar Bear Provincial Park
Polar Bear Provincial Park, wilderness park, northern Ontario, Canada, on Hudson and James bays. A huge undeveloped......
Polar ecosystem
Polar ecosystem, complex of living organisms in polar regions such as polar barrens and tundra. Polar barrens and......
polder
polder, tract of lowland reclaimed from a body of water, often the sea, by the construction of dikes roughly parallel......
pollution
pollution, the addition of any substance (solid, liquid, or gas) or any form of energy (such as heat, sound, or......
pollution in India
pollution in India, environmental contamination in India caused by the addition of volumes of substances at a rate......
population
population, in human biology, the whole number of inhabitants occupying an area (such as a country or the world)......
- Introduction
- Fertility, Reproduction, Demography
- Mortality, Age Structure, Demography
- Migration, Demography, Ecology
- Natural Increase, Growth, Demography
- Age Structure, Demographics, Mortality
- Geography, Urbanization, Distribution
- Malthusian, Demography, Dynamics
- Developing Countries, 1950s, Demographics
- Projections, Dynamics, Growth
Population Council
Population Council, international nonprofit nongovernmental organization (NGO) founded in 1952 to contribute to......
Population density
Population density, the number of individuals of a certain species per unit area. It can be expressed by the formula......
population ecology
population ecology, study of the processes that affect the distribution and abundance of animal and plant populations.......
Population growth
Population growth, in population ecology, a change in the number of members of a certain plant or animal species......
population pyramid
population pyramid, graphical representation of the age and sex composition of a specific population. The age and......
Prairie
Prairie, level or rolling grassland, especially that found in central North America. Decreasing amounts of rainfall,......
Precipitation
Precipitation, all liquid and solid water particles that fall from clouds and reach the ground. These particles......
primary productivity
primary productivity, in ecology, the rate at which energy is converted to organic substances by photosynthetic......
primary succession
primary succession, type of ecological succession (the evolution of a biological community’s ecological structure)......
Prince Albert National Park
Prince Albert National Park, park in central Saskatchewan, Canada. Its main entrance is 25 miles (40 km) northwest......
Prince Edward Island National Park
Prince Edward Island National Park, park in Canada, comprising a coastal strip along Prince Edward Island’s north......
Pukaskwa National Park
Pukaskwa National Park, national park, central Ontario, Canada, on the northeastern shore of Lake Superior. Established......
Quetico Provincial Park
Quetico Provincial Park, wilderness park, southwestern Ontario, Canada, west of Lake Superior and adjoining the......
Rainbow Bridge National Monument
Rainbow Bridge National Monument, rainbow-shaped natural bridge of pink sandstone spanning a canyon 290 feet (88......
Rainforest
Rainforest, luxuriant forest, generally composed of tall, broad-leaved trees and usually found in wet tropical......
Rainforest Alliance
Rainforest Alliance, international organization dedicated to conserving biodiversity and promoting environmentally......
Ramsar Convention
Ramsar Convention, agreement adopted in the eponymous city of Ramsar, Iran, on February 2, 1971, with the goal......
Rangeland
Rangeland, any extensive area of land that is occupied by native herbaceous or shrubby vegetation which is grazed......
Ranthambore National Park
Ranthambore National Park, wildlife preserve in the Sawai Madhopur district of Rajasthan state in northwestern......
recycling
recycling, recovery and reprocessing of waste materials for use in new products. The basic phases in recycling......
Red tide
Red tide, discoloration of sea water usually caused by dinoflagellates, during periodic blooms (or population increases).......
Redwood National Park
Redwood National Park, national park in the northwestern corner of California, U.S. It was established in 1968,......
reforestation
reforestation, the conversion of previously forested land back to forest. Reforestation is an essential part of......
refuse
refuse, nonhazardous solid waste that requires collection and transport to a processing or disposal site. Refuse......
riverine ecosystem
riverine ecosystem, any spring, stream, or river viewed as an ecosystem. The waters are flowing (lotic) and exhibit......
Rockefeller, Laurance S.
Laurance S. Rockefeller was an American venture capitalist and philanthropist and a member of the famed Rockefeller......
Rocky Mountain National Park
Rocky Mountain National Park, spectacular mountainous region of north-central Colorado, U.S. It lies just west......
Rolston, Holmes, III
Holmes Rolston III was an American utilitarian philosopher and theologian who pioneered the fields of environmental......
Roosevelt, Theodore
Theodore Roosevelt was the 26th president of the United States (1901–09) and a writer, naturalist, and soldier.......
Ruaha National Park
Ruaha National Park, national park, west of Iringa town in south-central Tanzania. The park is located at an elevation......
runoff
runoff, in hydrology, quantity of water discharged in surface streams. Runoff includes not only the waters that......
Saguaro National Park
Saguaro National Park, mountain and desert region in southern Arizona, U.S. The park—consisting of two districts,......
Saint Lucia Game Reserve
Saint Lucia Game Reserve, sanctuary on the northeastern coast of KwaZulu/Natal province, South Africa. It encompasses......
Salonga National Park
Salonga National Park, largest reserve in Congo (Kinshasa), Africa, covering more than 14,000 square miles (36,000......
Salt nucleus
Salt nucleus, tiny particle in the atmosphere that is composed of a salt, either solid or in an aqueous solution;......
saprotroph
saprotroph, organism that feeds on nonliving organic matter known as detritus at a microscopic level. The etymology......
Sarek National Park
Sarek National Park, park in Norrbotten län (county), northwestern Sweden, encompassing most of the Sarek mountain......
Sariska National Park
Sariska National Park, national park and wildlife preserve in Alwar district of the state of Rajasthan in northwestern......
Savanna
Savanna, vegetation type that grows under hot, seasonally dry climatic conditions and is characterized by an open......
Saving Sharks in the 2020s
Shark finning is the harvesting of a shark’s lateral, dorsal, and lower tail fins, which is often followed by releasing......
scavenger
scavenger, animal that feeds partly or wholly on the bodies of dead animals. Many invertebrates, such as carrion......
Schaller, George B.
George B. Schaller is an American environmental conservationist and author who is considered one of the world’s......
Schmidt, Karl P.
Karl P. Schmidt was a U.S. zoologist whose international reputation derived from the principles of animal ecology......
Schumacher, E.F.
E.F. Schumacher was a German-born British economist who developed the concepts of “intermediate technology” and......
Scott, Sir Peter Markham
Sir Peter Markham Scott was a British conservationist and artist. He founded the Severn Wildfowl Trust (1946; renamed......
scrap metal
scrap metal, used metals that are an important source of industrial metals and alloys, particularly in the production......
Scrubland
Scrubland, diverse assortment of vegetation types sharing the common physical characteristic of dominance by shrubs.......
Season
Season, any of four divisions of the year according to consistent annual changes in the weather. The seasons—winter,......
secondary succession
secondary succession, type of ecological succession (the evolution of a biological community’s ecological structure)......
sedimentary facies
sedimentary facies, physical, chemical, and biological aspects of a sedimentary bed and the lateral change within......
Selous Game Reserve
Selous Game Reserve, huge game reserve, southeastern Tanzania. It is named after Frederick Selous, a naturalist,......
Sequoia National Park
Sequoia National Park, forested area of 629 square miles (1,629 square km) in the Sierra Nevada, east-central California,......
Serengeti National Park
Serengeti National Park, national park and wildlife refuge on the Serengeti Plain in north-central Tanzania. It......
sertão
sertão, (Portuguese: “backwoods,” or “bush”), dry interior region of northeastern Brazil that is largely covered......
Shadow biosphere
Shadow biosphere, hypothetical life-supporting system on Earth, consisting of microorganisms of unique or unusual......
Shelford, Victor Ernest
Victor Ernest Shelford was an American zoologist and animal ecologist whose pioneering studies of animal communities......
Shenandoah National Park
Shenandoah National Park, preserve of 311 square miles (805 square km) in the Blue Ridge section of the Appalachian......
Shiva, Vandana
Vandana Shiva is an Indian physicist and social activist. Shiva founded the Research Foundation for Science, Technology,......
Sibley Provincial Park
Sibley Provincial Park, park, southwestern Ontario, Canada, on Sibley Peninsula on the northern shore of Lake Superior,......
Sierra Club
Sierra Club, American organization that promotes environmental conservation. Its headquarters are in Oakland, California.......
Simwinga, Hammerskjoeld
Hammerskjoeld Simwinga is a Zambian environmentalist who helped fight wildlife poaching in Zambia by creating new......
Singer, Peter
Peter Singer is an Australian ethical and political philosopher best known for his work in bioethics and his role......
slick
slick, glassy patch or streak on a relatively undisturbed ocean or lake surface, formed where surface tension is......
Slushball Earth hypothesis
Slushball Earth hypothesis, in geology and climatology, a counter-premise to the “Snowball Earth” hypothesis. The......
Smithsonian Tropical Research Institute
Smithsonian Tropical Research Institute (STRI), a collection of scientific facilities in Panama that is primarily......
smog
smog, community-wide polluted air. Its composition is variable. The term is derived from the words smoke and fog,......
Snow line
Snow line, the lower topographic limit of permanent snow cover. The snow line is an irregular line located along......
Snowball Earth hypothesis
Snowball Earth hypothesis, in geology and climatology, an explanation first proposed by American geobiologist J.L.......
soil megafauna
soil megafauna, in soil science, animals such as earthworms and small vertebrates (including moles, prairie dogs,......
soil organism
soil organism, any organism inhabiting the soil during part or all of its life. Soil organisms, which range in......
soil seed bank
soil seed bank, natural storage of seeds in the leaf litter, on the soil surface, or in the soil of many ecosystems,......
South Spitsbergen National Park
South Spitsbergen National Park, national park and bird sanctuary established by Norway in 1973 in the southern......
Southeast Svalbard Nature Reservation
Southeast Svalbard Nature Reservation, nature reserve established in 1973 by Norway. One of several protected areas......
species abundance
species abundance, typically, the sum total of individuals from a given species within a given area. A species......
species richness
species richness, the count, or total number, of unique species within a given biological community, ecosystem,......
Spring
Spring, in climatology, season of the year between winter and summer during which temperatures gradually rise.......
Stein, Jill
Jill Stein is a former practicing physician and an environmental activist who has run as the candidate of the Green......
Steppe
Steppe, vast grassland, devoid of trees and with little diversity in vegetation, receiving around 25 to 30 cm (10......
Stora Sjöfallet National Park
Stora Sjöfallet National Park, national park in northwestern Sweden. The park was established in 1909 and is located......
Sukumar, Raman
Raman Sukumar is an Indian ecologist best known for his work on the behaviour of Asian elephants and how their......
Sulfur cycle
Sulfur cycle, circulation of sulfur in various forms through nature. Sulfur occurs in all living matter as a component......