
The Greater Yellowstone Ecosystem (GYE) is one of the last remaining large, nearly intact
ecosystem
An ecosystem (or ecological system) is a system formed by Organism, organisms in interaction with their Biophysical environment, environment. The Biotic material, biotic and abiotic components are linked together through nutrient cycles and en ...
s in the northern
temperate zone
In geography, the temperate climates of Earth occur in the middle latitudes (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ra ...
of
Earth
Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...
. It is located within the northern
Rocky Mountains
The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in great-circle distance, straight-line distance from the northernmost part of Western Can ...
, in areas of northwestern
Wyoming
Wyoming ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States, Western United States. It borders Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho t ...
, southwestern
Montana
Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an ...
, and eastern
Idaho
Idaho ( ) is a landlocked U.S. state, state in the Pacific Northwest and Mountain states, Mountain West subregions of the Western United States. It borders Montana and Wyoming to the east, Nevada and Utah to the south, and Washington (state), ...
, and is about .
Yellowstone National Park
Yellowstone National Park is a List of national parks of the United States, national park of the United States located in the northwest corner of Wyoming, with small portions extending into Montana and Idaho. It was established by the 42nd U ...
and the
Yellowstone Caldera
The Yellowstone Caldera, also known as the Yellowstone Plateau Volcanic Field, is a Quaternary caldera complex and volcanic plateau spanning parts of Wyoming, Idaho, and Montana. It is driven by the Yellowstone hotspot and is largely within Yel ...
'hotspot' are within it.
The area is a flagship site among conservation groups that promote
ecosystem management
Ecosystem management is an approach to natural resource management that aims to ensure the long-term sustainability and persistence of an ecosystem's function and services while meeting socioeconomic, political, and cultural needs. Although indi ...
. It is one of the world's foremost natural laboratories in
landscape ecology
Landscape ecology is the science of studying and improving relationships between ecological processes in the environment and particular ecosystems. This is done within a variety of landscape scales, development spatial patterns, and organizatio ...
and
Holocene
The Holocene () is the current geologic time scale, geological epoch, beginning approximately 11,700 years ago. It follows the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene to ...
geology
Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth ...
, and is a world-renowned recreational destination. It is also home to the diverse
native plant
In biogeography, a native species is indigenous to a given region or ecosystem if its presence in that region is the result of only local natural evolution (though often popularised as "with no human intervention") during history. The term is equi ...
s and
animals of Yellowstone.
History
Yellowstone National Park boundaries were drawn in 1872 with the intent to include all the known
geothermal basins in the region. As landscape ecology considerations were not incorporated into original boundary, revisions were suggested to conform more closely to natural topographic features, such as the ridgeline of the Absaroka Range along the east boundary. In 1929, President Hoover signed the first bill changing the park's boundaries: The northwest corner now included a significant area of petrified trees; the northeast corner was defined by the watershed of Pebble Creek; the eastern boundary included the headwaters of the Lamar River and part of the watershed of the Yellowstone River. In 1932, President Hoover issued an executive order that added more than between the north boundary and the Yellowstone River, west of Gardiner. These lands provided winter range for elk and other ungulates. By the 1970s, the
grizzly bear
The grizzly bear (''Ursus arctos horribilis''), also known as the North American brown bear or simply grizzly, is a population or subspecies of the brown bear inhabiting North America.
In addition to the mainland grizzly (''Ursus arctos horr ...
'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 . Since then, definitions of the greater ecosystem's size have steadily grown larger. A 1994 study listed the size as , while a 1994 speech by a Greater Yellowstone Coalition leader enlarged that to .
In 1985 the
United States House of Representatives
The United States House of Representatives is a chamber of the Bicameralism, bicameral United States Congress; it is the lower house, with the U.S. Senate being the upper house. Together, the House and Senate have the authority under Artic ...
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
The Congressional Research Service (CRS) is a public policy research institute of the United States Congress. Operating within the Library of Congress, it works primarily and directly for members of Congress and their committees and staff on a ...
outlining shortcomings in inter-agency coordination and concluding that the area's essential values were at risk.
Protected areas
Federally managed areas within the GYE include:
*
United States National Park Service (NPS) —
Yellowstone National Park
Yellowstone National Park is a List of national parks of the United States, national park of the United States located in the northwest corner of Wyoming, with small portions extending into Montana and Idaho. It was established by the 42nd U ...
,
Grand Teton National Park
Grand Teton National Park is a national park of the United States in northwestern Wyoming. At approximately , the park includes the major peaks of the Teton Range as well as most of the northern sections of the valley known as Jackson Hole. G ...
, and
John D. Rockefeller, Jr. Memorial Parkway.
*
United States National Forest Service (USFS) —
Gallatin,
Custer,
Beaverhead-Deerlodge,
Caribou-Targhee,
Bridger-Teton, and
Shoshone National Forests
*
United States Fish and Wildlife Service
The United States Fish and Wildlife Service (USFWS or FWS) is a List of federal agencies in the United States, U.S. federal government agency within the United States Department of the Interior which oversees the management of fish, wildlife, ...
(USFWS) —
National Elk Refuge,
Red Rock Lakes and
Grays Lake National Wildlife Refuges
Ten distinct
National Wilderness Areas have been established within the GYE's
National Forests since 1966, mandating a higher level of
habitat
In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...
protection than the USFS otherwise uses.
The GYE also encompasses some privately held and state lands surrounding those managed by the U.S. Government.
The Trust for Public Land
The Trust for Public Land is a U.S. nonprofit organization with a mission to "create parks and protect land for people, ensuring healthy, livable communities for generations to come". Since its founding in 1972, the Trust for Public Land has compl ...
has protected over about 40 projects in the Greater Yellowstone Ecosystem.
Animals and plant diversity
Large mammals
The GYE is home to some of North America's most iconic wildlife. The ecosystem supports the largest free-roaming herds of
American bison (Bison bison) on public land, a species central to the region's ecological balance.
Grizzly bears (Ursus arctos horribilis) and
gray wolves (Canis lupus) are
apex predators
An apex predator, also known as a top predator or superpredator, is a predator at the top of a food chain, without natural predators of its own.
Apex predators are usually defined in terms of trophic dynamics, meaning that they occupy the hi ...
that play crucial roles in regulating prey populations.
Elk (Cervus canadensis) are abundant and form a key component of the ecosystem, providing sustenance for predators. Other significant
ungulate
Ungulates ( ) are members of the diverse clade Euungulata ("true ungulates"), which primarily consists of large mammals with Hoof, hooves. Once part of the clade "Ungulata" along with the clade Paenungulata, "Ungulata" has since been determined ...
species include
moose
The moose (: 'moose'; used in North America) or elk (: 'elk' or 'elks'; used in Eurasia) (''Alces alces'') is the world's tallest, largest and heaviest extant species of deer and the only species in the genus ''Alces''. It is also the tal ...
(Alces alces),
pronghorn
The pronghorn (, ) (''Antilocapra americana'') is a species of artiodactyl (even-toed, hoofed) mammal indigenous to interior western and central North America. Though not an antelope, it is known colloquially in North America as the American ante ...
(Antilocapra americana),
bighorn sheep
The bighorn sheep (''Ovis canadensis'') is a species of Ovis, sheep native to North America. It is named for its large Horn (anatomy), horns. A pair of horns may weigh up to ; the sheep typically weigh up to . Recent genetic testing indicates th ...
(Ovis canadensis), and
mountain goats
The mountain goat (''Oreamnos americanus''), also known as the Rocky Mountain goat, is a cloven-footed mammal that is endemic to the remote and rugged mountainous areas of western North America. A subalpine to truly alpine species, it is a ...
(Oreamnos americanus).
Birds
The GYE is home to a variety of birds, including iconic species like
Bald Eagles
The bald eagle (''Haliaeetus leucocephalus'') is a bird of prey found in North America. A sea eagle, it has two known subspecies and forms a Species complex, species pair with the white-tailed eagle (''Haliaeetus albicilla''), which occupies ...
,
Golden Eagles
The golden eagle (''Aquila chrysaetos'') is a bird of prey living in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. They are one of the best-known birds of p ...
and
Peregrine Falcons
The peregrine falcon (''Falco peregrinus''), also known simply as the peregrine, is a cosmopolitan bird of prey (raptor) in the family Falconidae renowned for its speed. A large, crow-sized falcon, it has a blue-grey back, barred white underpa ...
.
Osprey
The osprey (; ''Pandion haliaetus''), historically known as sea hawk, river hawk, and fish hawk, is a diurnal, fish-eating bird of prey with a cosmopolitan range. It is a large raptor, reaching more than in length and a wingspan of . It ...
populations around
Yellowstone Lake, have experienced declines, linked to the decrease in Cutthroat Trout. Several bird species act as
keystone species
A keystone species is a species that has a disproportionately large effect on its natural environment relative to its abundance. The concept was introduced in 1969 by the zoologist Robert T. Paine. Keystone species play a critical role in main ...
within the GYE. For example, the
Clark's Nutcracker
Clark's nutcracker (''Nucifraga columbiana''), sometimes referred to as Clark's crow or woodpecker crow, is a passerine bird in the family Corvidae, native to the mountains of western North America. The nutcracker is an omnivore, but subsists mai ...
plays a crucial role in the dispersal of the all-important
Whitebark Pine
''Pinus albicaulis'', known by the common names whitebark pine, white bark pine, white pine, pitch pine, scrub pine, and creeping pine, is a conifer tree native to the mountains of the western United States and Canada, specifically subalpine ...
seeds.
Management by species
Ecological management has been most often advanced through concerns over individual
species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
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.
The Yellowstone hot springs are important for their diversity of
thermophilic
A thermophile is a type of extremophile that thrives at relatively high temperatures, between . Many thermophiles are archaea, though some of them are bacteria and fungi. Thermophilic eubacteria are suggested to have been among the earliest bact ...
bacteria. These bacteria have been useful in studies of the evolution of
photosynthesis
Photosynthesis ( ) is a system of biological processes by which photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical energy necessary to fuel their metabo ...
and as sources of thermostable
enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...
s for
molecular biology
Molecular biology is a branch of biology that seeks to understand the molecule, molecular basis of biological activity in and between Cell (biology), cells, including biomolecule, biomolecular synthesis, modification, mechanisms, and interactio ...
. Although the smell of
sulfur
Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms ...
is common and there are some sulfur fixing
cyanobacteria
Cyanobacteria ( ) are a group of autotrophic gram-negative bacteria that can obtain biological energy via oxygenic photosynthesis. The name "cyanobacteria" () refers to their bluish green (cyan) color, which forms the basis of cyanobacteri ...
, it has been found that
hydrogen
Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...
is being used as an energy source by
extremophile
An extremophile () is an organism that is able to live (or in some cases thrive) in extreme environments, i.e., environments with conditions approaching or stretching the limits of what known life can adapt to, such as extreme temperature, press ...
microbe
A microorganism, or microbe, is an organism of microscopic size, which may exist in its single-celled form or as a colony of cells. The possible existence of unseen microbial life was suspected from antiquity, with an early attestation in ...
s.
Flora
Among
native plant
In biogeography, a native species is indigenous to a given region or ecosystem if its presence in that region is the result of only local natural evolution (though often popularised as "with no human intervention") during history. The term is equi ...
s of the GYE,
whitebark pine (''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
Present-day climate change includes both global warming—the ongoing increase in global average temperature—and its wider effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes ...
. 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
The conservation status of a group of organisms (for instance, a species) indicates whether the group still exists and how likely the group is to become extinct in the near future. Many factors are taken into account when assessing conservation ...
. A more immediate and serious threat to whitebark pines is an introduced
fungal rust disease,
White Pine Blister Rust
''Cronartium ribicola'' is a species of rust (fungus), rust fungus in the family Cronartiaceae that causes the disease white pine blister rust. Other names include: (French), (German), (Spanish).
Origin
''Cronartium ribicola'' is native to C ...
(''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 (''Populus tremuloides'') on the park's northern range since 1872 range from 50% to 95%. The decline has been linked to multiple stressors, such as defoliation by the
forest tent caterpillar (''Malacosoma disstria''), aspen bark beetles (''
Trypophloeus populi'' and ''Procryphalus mucronatus''), wood-boring beetles such as the
poplar borer (''Saperda calcarata'') and the bronze poplar borer (''Agrilus liragus''), fungal disturbances such as those by the
Cytospora canker (''Valsa sordida''), and Climate change related stressors.
Fauna
Anecdotal information on
grizzly bear
The grizzly bear (''Ursus arctos horribilis''), also known as the North American brown bear or simply grizzly, is a population or subspecies of the brown bear inhabiting North America.
In addition to the mainland grizzly (''Ursus arctos horr ...
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 is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...
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 study suggested a grizzly bear population size of about 176, 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, but biologists think there may be as many as 1,000 bears in the ecosystem.
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 loss
Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...
, climate change, and increasing
human
Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are Hominidae, great apes characterized by their Prehistory of nakedness and clothing ...
activities may well reverse the trend.
Yellowstone cutthroat trout (''Oncorhynchus clarki bouvieri'') have suffered considerable declines since European settlement, but recently began flourishing in some areas. Especially in
Yellowstone Lake itself, long-term records indicate an almost remarkable restoration of robust populations from only three decades ago when the numbers of this
fish
A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...
were depleted because of excessive harvest. Its current recovery, though a significant management achievement, does not begin to restore the species' historical abundance. Also, they declined because of invasive lake trout. An aggressive lake trout removal program has caused the cutthroats to rebound.
Early accounts of
pronghorn
The pronghorn (, ) (''Antilocapra americana'') is a species of artiodactyl (even-toed, hoofed) mammal indigenous to interior western and central North America. Though not an antelope, it is known colloquially in North America as the American ante ...
(''Antilocapra americana'') in Greater Yellowstone described
herd
A herd is a social group of certain animals of the same species, either wild or domestic. The form of collective animal behavior associated with this is called '' herding''. These animals are known as gregarious animals.
The term ''herd'' ...
s of hundreds seen ranging through most major
river valley
A valley is an elongated low area often running between hills or mountains and typically containing a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams over a ...
s. These populations were decimated by 1900, and declines continued among remaining herds. On the park's northern range, pronghorn declined from 500 to 700 in the 1930s to about 122 in 1968. By 1992 the herd had increased to 536.
Gray Wolf reintroduction
The park is a commonly cited example of
apex predator
An apex predator, also known as a top predator or superpredator, is a predator at the top of a food chain, without natural predators of its own.
Apex predators are usually defined in terms of trophic dynamics, meaning that they occupy the hig ...
s affecting an ecosystem through a
trophic cascade
Trophic cascades are powerful indirect interactions that can control entire ecosystems, occurring when a trophic level in a food web is suppressed. For example, a top-down cascade will occur if predators are effective enough in predation to redu ...
. After the reintroduction of the
gray wolf
The wolf (''Canis lupus''; : wolves), also known as the grey wolf or gray wolf, is a canine native to Eurasia and North America. More than thirty subspecies of ''Canis lupus'' have been recognized, including the dog and dingo, though gr ...
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
Beavers (genus ''Castor'') are large, semiaquatic rodents of the Northern Hemisphere. There are two existing species: the North American beaver (''Castor canadensis'') and the Eurasian beaver (''C. fiber''). Beavers are the second-large ...
,
moose
The moose (: 'moose'; used in North America) or elk (: 'elk' or 'elks'; used in Eurasia) (''Alces alces'') is the world's tallest, largest and heaviest extant species of deer and the only species in the genus ''Alces''. It is also the tal ...
, 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
The grizzly bear (''Ursus arctos horribilis''), also known as the North American brown bear or simply grizzly, is a population or subspecies of the brown bear inhabiting North America.
In addition to the mainland grizzly (''Ursus arctos horr ...
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.
See also
*
Ecology of the Rocky Mountains
*
References
Further reading
*{{cite book , last=Turner , first=Jack , title=Travels in Greater Yellowstone , location=New York , publisher=St. Martin's Press , isbn=978-0-312-26672-1 , year=2008 , url-access=registration , url=https://archive.org/details/travelsingreater00turn
External links
Greater Yellowstone Coalition: The Greater Yellowstone Ecosystem websiteUSGS Rocky Mountain Mapping Center: Greater Yellowstone EcosystemYellowstone-Teton Clean Energy CoalitionThe Trust for Public Land - Greater Yellowstone Ecosystem Program
Ecology of the Rocky Mountains
Environment of Idaho
Environment of Montana
Environment of Wyoming
Northwestern United States
Yellowstone National Park
Fauna of the Rocky Mountains
Flora of the Rocky Mountains
Systems ecology