Greater Yellowstone Ecosystem
Encyclopedia
Ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....
in the northern temperate zone of the Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
and is partly located in Yellowstone National Park
Yellowstone National Park
Yellowstone National Park, established by the U.S. Congress and signed into law by President Ulysses S. Grant on March 1, 1872, is a national park located primarily in the U.S. state of Wyoming, although it also extends into Montana and Idaho...
. Conflict over management has been controversial, and the area is a flagship site among conservation groups that promote ecosystem management. The Greater Yellow Ecosystem (GYE) is one of the world's foremost natural laboratories in landscape ecology
Landscape ecology
Landscape ecology is the science of studying and improving relationships between urban development and ecological processes in the environment and particular ecosystems...
and geology
Geology
Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...
and is a world-renowned recreational site. It is also home to the animals of Yellowstone
Animals of Yellowstone
Yellowstone National Park in the northwest United States is home to a large variety of mammals, birds, fish, reptiles and amphibians, many of which migrate within the Greater Yellowstone Ecosystem. These Animals of Yellowstone, especially larger mammals, birds and fish are a major park...
.
History
Yellowstone National Park boundaries were arbitrarily drawn in 1872 in hopes of including all regional geothermal basins in the areaGeothermal areas of Yellowstone
The geothermal areas of Yellowstone include several geyser basins in Yellowstone National Park as well as other geothermal features such as hot springs, mud pots, and fumaroles...
. No other landscape considerations were incorporated. By the 1970s, however, the grizzly bear
Grizzly Bear
The grizzly bear , also known as the silvertip bear, the grizzly, or the North American brown bear, is a subspecies of brown bear that generally lives in the uplands of western North America...
's (Ursus arctos) range in and near the park became the first informal minimum boundary of a theoretical Greater Yellowstone Ecosystem that included at least 16000 square kilometres (3,953,682.6 acre). Since then, definitions of the greater ecosystem's size have steadily grown larger. A 1994 study listed the size as 76890 square kilometres (18,999,916 acre), while a 1994 speech by a Greater Yellowstone Coalition leader enlarged that to 80000 square kilometres (19,768,413 acre).
In 1985 the United States House of Representatives
United States House of Representatives
The United States House of Representatives is one of the two Houses of the United States Congress, the bicameral legislature which also includes the Senate.The composition and powers of the House are established in Article One of the Constitution...
Subcommittees on Public Lands and National Parks and Recreation held a joint subcommittee hearing on Greater Yellowstone, resulting in a 1986 report by the Congressional Research Service
Congressional Research Service
The Congressional Research Service , known as "Congress's think tank", is the public policy research arm of the United States Congress. As a legislative branch agency within the Library of Congress, CRS works exclusively and directly for Members of Congress, their Committees and staff on a...
outlining shortcomings in interagency coordination and concluding that the area's essential values were at risk.
Other federally managed areas within the GYE include Gallatin
Gallatin National Forest
Founded in 1899, Gallatin National Forest is located in south central Montana, United States. The forest comprises 2.1 million acres and has portions of both the Absaroka-Beartooth and Lee Metcalf Wilderness areas within its boundaries...
, Custer
Custer National Forest
Custer National Forest is located primarily in the southern part of the U.S. state of Montana but also has separate sections in northwestern South Dakota. With a total area of 1,278,279 acres , the forest comprises over 10 separate sections...
, Caribou-Targhee
Caribou-Targhee National Forest
Caribou-Targhee National Forest is located in the states of Idaho and Wyoming, with a small section in Utah in the United States. The forest is broken into several separate sections and extends over . To the east the forest borders Yellowstone National Park, Grand Teton National Park and...
, Bridger-Teton
Bridger-Teton National Forest
Bridger-Teton National Forest is located in western Wyoming, United States. The forest consists of , making it the second largest National Forest outside of Alaska. The forest stretches from Yellowstone National Park, along the eastern boundary of Grand Teton National Park and from there rides...
and Shoshone National Forest
Shoshone National Forest
Shoshone National Forest is the first federally protected National Forest in the United States and covers nearly 2.5 million acres in the state of Wyoming. Originally a part of the Yellowstone Timberland Reserve, the forest was created by an act of Congress and signed into law by U.S....
s, the John D. Rockefeller, Jr. Memorial Parkway
John D. Rockefeller, Jr. Memorial Parkway
John D. Rockefeller, Jr. Memorial Parkway is a scenic road that connects Grand Teton National Park and Yellowstone National Park in Wyoming, United States. It is federally owned and managed by the National Park Service. It is named in remembrance of John D...
, as well as the National Elk Refuge
National Elk Refuge
The National Elk Refuge is located in the U.S. state of Wyoming and was created in 1912 to protect habitat and provide sanctuary for the largest elk herd on Earth. The refuge borders the town of Jackson, Wyoming on the northeast while Bridger-Teton National Forest is to the east and Grand Teton...
and Grand Teton National Park
Grand Teton National Park
Grand Teton National Park is a United States National Park located in northwestern Wyoming, U.S. The Park consists of approximately and includes the major peaks of the long Teton Range as well as most of the northern sections of the valley known as Jackson Hole. Only south of Yellowstone...
. The GYE also encompasses some privately held lands surrounding those managed by the U.S. Government. Outside of Yellowstone National Park, ten distinct wilderness
Wilderness
Wilderness or wildland is a natural environment on Earth that has not been significantly modified by human activity. It may also be defined as: "The most intact, undisturbed wild natural areas left on our planet—those last truly wild places that humans do not control and have not developed with...
areas have been established in the National Forest
United States National Forest
National Forest is a classification of federal lands in the United States.National Forests are largely forest and woodland areas owned by the federal government and managed by the United States Forest Service, part of the United States Department of Agriculture. Land management of these areas...
s since 1966 to ensure a higher level of habitat protection than is normally mandated.
Ecosystem management by species
The great ecosystem concept has been most often advanced through concerns over individual speciesSpecies
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
rather than over broader ecological principles. Though 20 or 30 or even 50 years of information on a population may be considered long-term by some, one of the important lessons of Greater Yellowstone management is that even half a century is not long enough to give a full idea of how a species may vary in its occupation of a wild ecosystem.
For example, anecdotal information on grizzly bear abundance dates to the mid-19th century, and administrators have made informal population estimates for more than 70 years. From these sources, ecologists know the species was common in Greater Yellowstone when Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
ans arrived and that the population was not isolated before the 1930s, but is now. Researchers do not know if bears were more or less common than now.
A 1959-1970 bear
Bear
Bears are mammals of the family Ursidae. Bears are classified as caniforms, or doglike carnivorans, with the pinnipeds being their closest living relatives. Although there are only eight living species of bear, they are widespread, appearing in a wide variety of habitats throughout the Northern...
study suggested a grizzly bear population size of about 175, later revised to about 229. Later estimates have ranged as low as 136 and as high as 540; the most recent is a minimum estimate of 236. Although the Greater Yellowstone population is relatively close to recovery goals, the plan's definition of recovery is controversial. Thus, even though the population may be stable or possibly increasing in the short term, in the longer term, continued habitat
Habitat (ecology)
A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant or other type of organism...
loss and increasing human
Human
Humans are the only living species in the Homo genus...
activities may well reverse the trend.
Yellowstone cutthroat trout
Yellowstone cutthroat trout
The Yellowstone cutthroat trout is a subspecies of the cutthroat trout and is a freshwater fish in the salmon family of the order Salmoniformes. Native only to a few U.S...
(Oncorhynchus clarki bouvieri) have suffered considerable declines since European settlement, but recently began flourishing in some areas. Especially in Yellowstone Lake
Yellowstone Lake
Yellowstone Lake is the largest body of water in Yellowstone National Park, The lake is 7,732 feet above sea level and covers with 110 miles of shoreline. While the average depth of the lake is 139 feet its deepest spot is at least 390 feet...
itself, long-term records indicate an almost remarkable restoration of robust populations from only three decades ago when the numbers of this fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
were depleted because of excessive harvest. Its current recovery, though a significant management achievement, does not begin to restore the species' historical abundance.
Early accounts of pronghorn
Pronghorn
The pronghorn is a species of artiodactyl mammal endemic to interior western and central North America. Though not an antelope, it is often known colloquially in North America as the prong buck, pronghorn antelope, or simply antelope, as it closely resembles the true antelopes of the Old World and...
(Antilocapra americana) in Greater Yellowstone described herd
Herd
Herd refers to a social grouping of certain animals of the same species, either wild or domestic, and also to the form of collective animal behavior associated with this or as a verb, to herd, to its control by another species such as humans or dogs.The term herd is generally applied to mammals,...
s of hundreds seen ranging through most major river valley
Valley
In geology, a valley or dale is a depression with predominant extent in one direction. A very deep river valley may be called a canyon or gorge.The terms U-shaped and V-shaped are descriptive terms of geography to characterize the form of valleys...
s. These populations were decimated by 1900, and declines continued among remaining herds. On the park's northern range, pronghorn declined from 500-700 in the 1930s to about 122 in 1968. By 1992 the herd had increased to 536.
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
s, whitebark pine
Whitebark Pine
Pinus albicaulis, known commonly as Whitebark Pine, Pitch Pine, Scrub Pine, and Creeping Pine occurs in the mountains of the Western United States and Canada, specifically the subalpine areas of the Sierra Nevada, the Cascade Range, the Pacific Coast Ranges, and the northern Rocky Mountains –...
(Pinus albicaulis) is a species of special interest, in large part because of its seasonal importance to grizzly bears, but also because its distribution could be dramatically reduced by relatively minor global warming
Global warming
Global warming refers to the rising average temperature of Earth's atmosphere and oceans and its projected continuation. In the last 100 years, Earth's average surface temperature increased by about with about two thirds of the increase occurring over just the last three decades...
. In this case, researchers do not have a good long-term data set on the species, but they understand its ecology well enough to project declining future conservation status
Conservation status
The conservation status of a group of organisms indicates whether the group is still extant and how likely the group is to become extinct in the near future...
. A more immediate, and serious, threat to whitebark pine is an introduced fungal
Rust (fungus)
Rusts are plant diseases caused by pathogenic fungi of the order Pucciniales. About 7800 species are known. Rusts can affect a variety of plants; leaves, stems, fruits and seeds. Rust is most commonly seen as coloured powder, composed off tiny aeciospores which land on vegetation producing...
disease, white pine blister rust (Cronartium ribicola), which is causing heavy mortality in the species. Occasional resistant individuals occur, but in the short to medium term, a severe population decline is expected.
Estimates of the decline of quaking aspen
Aspen
Populus section Populus, of the Populus genus, includes the aspen trees and the white poplar Populus alba. The five typical aspens are all native to cold regions with cool summers, in the north of the Northern Hemisphere, extending south at high altitudes in the mountains. The White Poplar, by...
(Populus tremuloides) on the park's northern range since 1872 range from 50% to 95%, and perhaps no controversy underway in Greater Yellowstone more clearly reveals the need for comprehensive interdisciplinary research. Several factors are suspected in the aspen
Aspen
Populus section Populus, of the Populus genus, includes the aspen trees and the white poplar Populus alba. The five typical aspens are all native to cold regions with cool summers, in the north of the Northern Hemisphere, extending south at high altitudes in the mountains. The White Poplar, by...
's changing status, including Native American
Native Americans in the United States
Native Americans in the United States are the indigenous peoples in North America within the boundaries of the present-day continental United States, parts of Alaska, and the island state of Hawaii. They are composed of numerous, distinct tribes, states, and ethnic groups, many of which survive as...
influences on numerous mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
species and on fire
Fire
Fire is the rapid oxidation of a material in the chemical process of combustion, releasing heat, light, and various reaction products. Slower oxidative processes like rusting or digestion are not included by this definition....
-return intervals before the creation of the park in 1872; European influences on fire frequency since 1886; regional climate
Climate
Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and other meteorological elemental measurements in a given region over long periods...
warming; human harvests of beaver
American Beaver
The North American Beaver is the only species of beaver in the Americas, native to North America and introduced to South America. In the United States and Canada, where no other species of beaver occurs, it is usually simply referred to as "beaver"...
and ungulate
Ungulate
Ungulates are several groups of mammals, most of which use the tips of their toes, usually hoofed, to sustain their whole body weight while moving. They make up several orders of mammals, of which six to eight survive...
s in the first 15 years of the park's history and of wolves and other predators before 1930; human settlement of traditional ungulate migration routes north of the park since 1872; ungulate (especially elk
Elk
The Elk is the large deer, also called Cervus canadensis or wapiti, of North America and eastern Asia.Elk may also refer to:Other antlered mammals:...
) effects on all other parts of the ecosystem since 1900; and human influences on elk distribution in the park.
The Yellowstone hot springs are important for their diversity of thermophilic
Thermophile
A thermophile is an organism — a type of extremophile — that thrives at relatively high temperatures, between 45 and 122 °C . Many thermophiles are archaea...
bacteria. These bacteria have been useful in studies of the evolution of photosynthesis
Photosynthesis
Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...
and as sources of thermostable enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
s for molecular biology
Molecular biology
Molecular biology is the branch of biology that deals with the molecular basis of biological activity. This field overlaps with other areas of biology and chemistry, particularly genetics and biochemistry...
. Although the smell of sulfur
Sulfur
Sulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...
is common and there are some sulfur fixing cyanobacteria, it has been found that hydrogen
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
is being used as an energy source by extremophile
Extremophile
An extremophile is an organism that thrives in physically or geochemically extreme conditions that are detrimental to most life on Earth. In contrast, organisms that live in more moderate environments may be termed mesophiles or neutrophiles...
microbes.
Gray Wolf reintroduction
The park is a commonly cited example of apex predatorApex predator
Apex predators are predators that have no predators of their own, residing at the top of their food chain. Zoologists define predation as the killing and consumption of another organism...
s affecting an ecosystem. After the reintroduction of the gray wolf
Gray Wolf
The gray wolf , also known as the wolf, is the largest extant wild member of the Canidae family...
in 1995, researchers noticed drastic changes occurring. Elk, the primary prey of the gray wolf, became less abundant and changed their behavior, freeing riparian zones from constant grazing. The respite allowed willows and aspens to grow, creating habitat for beaver
Beaver
The beaver is a primarily nocturnal, large, semi-aquatic rodent. Castor includes two extant species, North American Beaver and Eurasian Beaver . Beavers are known for building dams, canals, and lodges . They are the second-largest rodent in the world...
, moose
Moose
The moose or Eurasian elk is the largest extant species in the deer family. Moose are distinguished by the palmate antlers of the males; other members of the family have antlers with a dendritic configuration...
, and scores of other species. In addition to the effects on prey species, the gray wolf's presence also affected the park's grizzly bear
Grizzly Bear
The grizzly bear , also known as the silvertip bear, the grizzly, or the North American brown bear, is a subspecies of brown bear that generally lives in the uplands of western North America...
population. The bears, emerging from hibernation, chose to scavenge off wolf kills to gain needed energy and fatten up after fasting for months. Dozens of other species have been documented scavenging from wolf kills.