Plant stem
A stem is one of two main structural axes of a vascular plant, the other being the root. The stem is divided into nodes and internodes: The nodes hold one or more leaves, as well as buds which can grow into branches. Adventitious roots may be produced from the nodes; the internodes distance one node from another. The term "shoots" is confused with "stems". In most plants stems are located above the soil surface but some plants have underground stems. Stems have four main functions which are: Support for and the elevation of leaves and fruits; the stems keep the leaves in the light and provide a place for the plant to keep its flowers and fruits. Transport of fluids between the roots and the shoots in the xylem and phloem Storage of nutrients Production of new living tissue; the normal lifespan of plant cells is one to three years. Stems have cells called meristems. Stems are specialized for storage, asexual reproduction, protection or photosynthesis, including the following: Acaulescent – used to describe stems in plants that appear to be stemless.
These stems are just short, the leaves appearing to rise directly out of the ground, e.g. some Viola species. Arborescent – tree like with woody stems with a single trunk. Axillary bud – a bud which grows at the point of attachment of an older leaf with the stem, it gives rise to a shoot. Branched – aerial stems are described as being branched or unbranched Bud – an embryonic shoot with immature stem tip. Bulb – a short vertical underground stem with fleshy storage leaves attached, e.g. onion, tulip. Bulbs function in reproduction by splitting to form new bulbs or producing small new bulbs termed bulblets. Bulbs are a combination of stem and leaves so may better be considered as leaves because the leaves make up the greater part. Caespitose – when stems grow in a tangled mass or clump or in low growing mats. Cladode – a flattened stem that appears more-or-less leaf like and is specialized for photosynthesis, e.g. cactus pads. Climbing -- stems that wrap around other plants or structures. Corm – a short enlarged underground, storage stem, e.g. taro, gladiolus.
Decumbent -- stems that lie flat on the turn upwards at the ends. Fruticose -- stems. Herbaceous – non woody, they die at the end of the growing season. Internode – an interval between two successive nodes, it possesses the ability to elongate, either from its base or from its extremity depending on the species. Node – a point of attachment of a leaf or a twig on the stem in seed plants. A node is a small growth zone. Pedicel – stems that serve as the stalk of an individual flower in an inflorescence or infrutescence. Peduncle – a stem that supports an inflorescence Prickle – a sharpened extension of the stem's outer layers, e.g. roses. Pseudostem – a false stem made of the rolled bases of leaves, which may be 2 or 3 m tall as in banana Rhizome – a horizontal underground stem that functions in reproduction but in storage, e.g. most ferns, iris Runner – a type of stolon, horizontally growing on top of the ground and rooting at the nodes, aids in reproduction. E.g. garden strawberry, Chlorophytum comosum.
Scape – a stem that holds flowers that comes out of the ground and has no normal leaves. Hosta, Iris, Garlic. Stolon – a horizontal stem that produces rooted plantlets at its nodes and ends, forming near the surface of the ground. Thorn – a modified stem with a sharpened point. Tuber – a swollen, underground storage stem adapted for storage and reproduction, e.g. potato. Woody – hard textured stems with secondary xylem. Stem consist of three tissues, dermal tissue, ground tissue and vascular tissue; the dermal tissue covers the outer surface of the stem and functions to waterproof and control gas exchange. The ground tissue consists of parenchyma cells and fills in around the vascular tissue, it sometimes functions in photosynthesis. Vascular tissue provides structural support. Most or all ground tissue may be lost in woody stems; the dermal tissue of aquatic plants stems. The arrangement of the vascular tissues varies among plant species. Dicot stems with primary growth have pith in the center, with vascular bundles forming a distinct ring visible when the stem is viewed in cross section.
The outside of the stem is covered with an epidermis, covered by a waterproof cuticle. The epidermis may contain stomata for gas exchange and multicellular stem hairs called trichomes. A cortex consisting of hypodermis and endodermis is present above the pericycle and vascular bundles. Woody dicots and many nonwoody dicots have secondary growth originating from their lateral or secondary meristems: the vascular cambium and the cork cambium or phellogen; the vascular cambium forms between the xylem and phloem in the vascular bundles and connects to form a continuous cylinder. The vascular cambium cells divide to produce secondary xylem to the inside and secondary phloem to the outside; as the stem increases in diameter due to production of secondary xylem and secondary phloem, the cortex and epidermis are destroyed. Before the cortex is destroyed, a cork cambium develops there; the cork cambium divides to produce waterproof cork cells externally and sometimes phelloderm cells internally. Those three tissues form the periderm.
Areas of loosely pack
Habitat
In ecology, a habitat is the type of natural environment in which a particular species of organism lives. It is characterized by both biological features. A species' habitat is those places where it can find food, shelter and mates for reproduction; the physical factors are for example soil, range of temperature, light intensity as well as biotic factors such as the availability of food and the presence or absence of predators. Every organism has certain habitat needs for the conditions in which it will thrive, but some are tolerant of wide variations while others are specific in their requirements. A habitat is not a geographical area, it can be the interior of a stem, a rotten log, a rock or a clump of moss, for a parasitic organism it is the body of its host, part of the host's body such as the digestive tract, or a single cell within the host's body. Habitat types include polar, temperate and tropical; the terrestrial vegetation type may be forest, grassland, semi-arid or desert. Fresh water habitats include marshes, rivers and ponds, marine habitats include salt marshes, the coast, the intertidal zone, reefs, the open sea, the sea bed, deep water and submarine vents.
Habitats change over time. This may be due to a violent event such as the eruption of a volcano, an earthquake, a tsunami, a wildfire or a change in oceanic currents. Other changes come as a direct result of human activities; the introduction of alien species can have a devastating effect on native wildlife, through increased predation, through competition for resources or through the introduction of pests and diseases to which the native species have no immunity. The word "habitat" has been in use since about 1755 and derives from the Latin habitāre, to inhabit, from habēre, to have or to hold. Habitat can be defined as the natural environment of an organism, the type of place in which it is natural for it to live and grow, it is similar in meaning to a biotope. The chief environmental factors affecting the distribution of living organisms are temperature, climate, soil type and light intensity, the presence or absence of all the requirements that the organism needs to sustain it. Speaking, animal communities are reliant on specific types of plant communities.
Some plants and animals are generalists, their habitat requirements are met in a wide range of locations. The small white butterfly for example is found on all the continents of the world apart from Antarctica, its larvae feed on a wide range of Brassicas and various other plant species, it thrives in any open location with diverse plant associations. The large blue butterfly is much more specific in its requirements. Disturbance is important in the creation of biodiverse habitats. In the absence of disturbance, a climax vegetation cover develops that prevents the establishment of other species. Wildflower meadows are sometimes created by conservationists but most of the flowering plants used are either annuals or biennials and disappear after a few years in the absence of patches of bare ground on which their seedlings can grow. Lightning strikes and toppled trees in tropical forests allow species richness to be maintained as pioneering species move in to fill the gaps created. Coastal habitats can become dominated by kelp until the seabed is disturbed by a storm and the algae swept away, or shifting sediment exposes new areas for colonisation.
Another cause of disturbance is when an area may be overwhelmed by an invasive introduced species, not kept under control by natural enemies in its new habitat. Terrestrial habitat types include forests, grasslands and deserts. Within these broad biomes are more specific habitats with varying climate types, temperature regimes, soils and vegetation types. Many of these habitats grade into each other and each one has its own typical communities of plants and animals. A habitat may suit a particular species well, but its presence or absence at any particular location depends to some extent on chance, on its dispersal abilities and its efficiency as a coloniser. Freshwater habitats include rivers, lakes, ponds and bogs. Although some organisms are found across most of these habitats, the majority have more specific requirements; the water velocity, its temperature and oxygen saturation are important factors, but in river systems, there are fast and slow sections, pools and backwaters which provide a range of habitats.
Aquatic plants can be floating, semi-submerged, submerged or grow in permanently or temporarily saturated soils besides bodies of water. Marginal plants provide important habitat for both invertebrates and vertebrates, submerged plants provide oxygenation of the water, absorb nutrients and play a part in the reduction of pollution. Marine habitats include brackish water, bays, the open sea, the intertidal zone, the sea bed and deep / shallow water zones. Further variations include rock pools, sand banks, brackish lagoons and pebbly beaches, seagrass beds, all supporting their own flora and fauna; the benth
Rocky Mountain elk
The Rocky Mountain elk is a subspecies of elk found in the Rocky Mountains and adjacent ranges of Western North America. The winter ranges are most common in open forests and floodplain marshes in the lower elevations. In the summer it migrates to alpine basins. Elk have a diverse habitat range that they can reside in but are most found in forest and forest edge habitat and in mountain regions they stay in higher elevations during warmer months and migrate down lower in the winter, they may come down the mountain and leave the forest into some grassland for part of the day but head back into the timber in the evening. The total wild population is about one million individuals; the Rocky Mountain elk was reintroduced in 1913 to Colorado from Wyoming after the near-extinction of the regional herds. While overhunting is a significant contributing factor, the elk’s near-extinction is attributed to human encroachment and destruction of their natural habitats and migratory corridors. A year twenty-one elk from Jackson Hole, Wyoming were reintroduced to South Dakota's Wind Cave National Park for population increase.
Conservation efforts brought the elk populations in New Mexico from near zero numbers in the late 1800s and early 1900s, to healthy populations in the 1930s in Northern New Mexico. Population numbers of elk in Nebraska continued to increase through the 1970s and 1980s, to a level in which complaints from landowners in the Pine Ridge region led to the implementation of liberal hunting seasons in the late 1980s. Elk numbers continued to increase through the 1990s to the present. All Rocky Mountain elk in Washington are the result of reintroductions conducted in the early 1900s from Yellowstone elk herds; these initial reintroductions have expanded their range and have been translocated within the State. Not all of these elk have all the habitat to be successful in large numbers. In 1990, feasibility studies were conducted to determine if wild, free-ranging elk still had a place in some of their former eastern haunts. Once this was complete, healthy source herds of Rocky Mountain elk from Arizona, New Mexico, North Dakota and Utah were used to introduce this elk subspecies to the former eastern elk range.
In recent years, elk from Utah have been used to reestablish a population in Kentucky. As of 2010, the Rocky Mountain elk herd has been diagnosed with a serious disorder called Chronic Wasting Disease. CWD affects the brain tissue of infected elk and is similar in symptoms to bovine spongiform encephalopathy known as mad-cow disease. There is no evidence to conclude that elk CWD is transmittable to humans, research concerning CWD and its effect on the eco-system continues. Environmental and CWD problems in Estes Park, Colorado and, on a greater scale, throughout the Western U. S. and North America have local and federal policy makers searching for solutions. The Rocky Mountain National Park and the Estes Park environments are physically disrupted by the migration of the elk, ranging in size from calves to full-grown 700-pound adults. Several indigenous butterfly and plant species are harmed the aspen groves that the elk herd of 3,000 animals decimates in its search for food; the elk population, while taxing the common food resources adversely affects native species that share the same food supply, such as the indigenous beavers.
Fish and Wildlife Habitat Management Leaflet. 1999. American Elk: Cervus elaphus. United States Department of Agriculture. Habitat Management Institute. Tule elk Manitoban elk Roosevelt elk Chronic Wasting Disease Alliance Rocky Mountain Elk Foundation
Medicine Bow Mountains
The Medicine Bow Mountains are a mountain range in the Rocky Mountains that extend for 100-mile from northern Colorado into southern Wyoming. The northern extent of this range is the sub-range the Snowy Range. From the northern end of Colorado's Never Summer Mountains, the Medicine Bow mountains extend north from Cameron Pass along the border between Larimer and Jackson counties in Colorado and northward into south central Wyoming. In Wyoming, the range sits west of Laramie, in Albany and Carbon counties to the route of the Union Pacific Railroad and U. S. Interstate 80; the mountains serve as a symbol for the city of Laramie. The range is home to Snowy Range Ski Area; the highest peak in the range is Clark Peak, located in Rawah Wilderness and is along the southern end of the range in Northern Colorado. Much of the range is located within the Medicine Bow National Forest in Wyoming; the highest peak on the Wyoming side is Medicine Bow Peak. The range is drained along the western flank by the Michigan and Canadian rivers, tributaries of the North Platte in North Park.
On its eastern flank it is drained by another tributary of the North Platte. The Medicine Bow Mountains resulted from continental compression during the Laramide Orogeny. Beginning about 70 million years ago, the Rockies began uplifting along thrust faults that broke up the Precambrian granite of Earth's crust. By 50 million years ago, all of Wyoming's major mountain ranges were elevated and the major basins defined. Rocks exposed along the flanks and peaks of the Medicine Bow Mountains span the Precambrian to modern, with the peaks composed of 2.4-2.0 billion year old Medicine Peak Quartzite. This rock was once a shallow marine sand deposit that has since been compressed and heated during burial, forming the metamorphic rock, quartzite. What may be traces of multicellular animals are preserved in this rock, making it of particular interest to paleontologists; the Cheyenne belt, the 1.78–1.74 billion year old suture between the Wyoming craton and the Yavapai province that formed as North America was assembled, is exposed in the Medicine Bow Mountains.
Wildlife abounds in these mountains, with mule deer, moose, black bear, mountain lions, marmots, Richardson's ground squirrels and lynx as well as a tremendous variety of birds. Brook and rainbow trout as well as grayling and golden trout are found in the streams. A disjunct population of arctic fairy shrimp has been documented in a few lakes in the northern part of the range. Since 1987, the Glacier Lakes area of the Snowy Range has been home to the Glacier Lakes Ecosystem Experiments Site, a field unit of the Rocky Mountain Research Station, United States Forest Service. Areas of scientific inquiry at the site include atmospheric pollutant deposition, forest carbon and water vapor cycling, effect of insect outbreaks, alpine lake and stream hydrology; the site is 642 ha in extent and hosts facilities for the National Atmospheric Deposition Program, the National Dry Deposition Network and AmeriFlux. This mountain range is home to some of the remains of a Douglas DC-4 aircraft, operated as United Airlines Flight 409.
The aircraft crashed into Medicine Bow Peak on October 1955, killing all 66 people on board. Mountain ranges of Colorado Mountain ranges of Wyoming Local Backcountry Advocacy Medicine Bow Mountains @ Peakbagger Medicine Bow Mountains on summitpost.org Snowy Range info page on summitpost.org Snowy Range photo album on summitpost.org Roadless Area Descriptions from Biodiversity Conservation Alliance
Fungus
A fungus is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separate from the other eukaryotic life kingdoms of plants and animals. A characteristic that places fungi in a different kingdom from plants and some protists is chitin in their cell walls. Similar to animals, fungi are heterotrophs. Fungi do not photosynthesize. Growth is their means of mobility, except for spores, which may travel through the water. Fungi are the principal decomposers in ecological systems; these and other differences place fungi in a single group of related organisms, named the Eumycota, which share a common ancestor, an interpretation, strongly supported by molecular phylogenetics. This fungal group oomycetes; the discipline of biology devoted to the study of fungi is known as mycology. In the past, mycology was regarded as a branch of botany, although it is now known fungi are genetically more related to animals than to plants.
Abundant worldwide, most fungi are inconspicuous because of the small size of their structures, their cryptic lifestyles in soil or on dead matter. Fungi include symbionts of plants, animals, or other fungi and parasites, they may become noticeable when fruiting, either as molds. Fungi perform an essential role in the decomposition of organic matter and have fundamental roles in nutrient cycling and exchange in the environment, they have long been used in the form of mushrooms and truffles. Since the 1940s, fungi have been used for the production of antibiotics, more various enzymes produced by fungi are used industrially and in detergents. Fungi are used as biological pesticides to control weeds, plant diseases and insect pests. Many species produce bioactive compounds called mycotoxins, such as alkaloids and polyketides, that are toxic to animals including humans; the fruiting structures of a few species contain psychotropic compounds and are consumed recreationally or in traditional spiritual ceremonies.
Fungi can break down manufactured materials and buildings, become significant pathogens of humans and other animals. Losses of crops due to fungal diseases or food spoilage can have a large impact on human food supplies and local economies; the fungus kingdom encompasses an enormous diversity of taxa with varied ecologies, life cycle strategies, morphologies ranging from unicellular aquatic chytrids to large mushrooms. However, little is known of the true biodiversity of Kingdom Fungi, estimated at 2.2 million to 3.8 million species. Of these, only about 120,000 have been described, with over 8,000 species known to be detrimental to plants and at least 300 that can be pathogenic to humans. Since the pioneering 18th and 19th century taxonomical works of Carl Linnaeus, Christian Hendrik Persoon, Elias Magnus Fries, fungi have been classified according to their morphology or physiology. Advances in molecular genetics have opened the way for DNA analysis to be incorporated into taxonomy, which has sometimes challenged the historical groupings based on morphology and other traits.
Phylogenetic studies published in the last decade have helped reshape the classification within Kingdom Fungi, divided into one subkingdom, seven phyla, ten subphyla. The English word fungus is directly adopted from the Latin fungus, used in the writings of Horace and Pliny; this in turn is derived from the Greek word sphongos, which refers to the macroscopic structures and morphology of mushrooms and molds. The word mycology is derived from the Greek logos, it denotes the scientific study of fungi. The Latin adjectival form of "mycology" appeared as early as 1796 in a book on the subject by Christiaan Hendrik Persoon; the word appeared in English as early as 1824 in a book by Robert Kaye Greville. In 1836 the English naturalist Miles Joseph Berkeley's publication The English Flora of Sir James Edward Smith, Vol. 5. Refers to mycology as the study of fungi. A group of all the fungi present in a particular area or geographic region is known as mycobiota, e.g. "the mycobiota of Ireland". Before the introduction of molecular methods for phylogenetic analysis, taxonomists considered fungi to be members of the plant kingdom because of similarities in lifestyle: both fungi and plants are immobile, have similarities in general morphology and growth habitat.
Like plants, fungi grow in soil and, in the case of mushrooms, form conspicuous fruit bodies, which sometimes resemble plants such as mosses. The fungi are now considered a separate kingdom, distinct from both plants and animals, from which they appear to have diverged around one billion years ago; some morphological and genetic features are shared with other organisms, while others are unique to the fungi separating them from the other kingdoms: Shared features: With other euka
Brook trout
The brook trout is a species of freshwater fish in the char genus Salvelinus of the salmon family Salmonidae. It is native to Eastern North America in the United States and Canada, but has been introduced elsewhere in North America, as well as to Iceland and Asia. In parts of its range, it is known as the eastern brook trout, speckled trout, brook charr, squaretail, or mud trout, among others. A potamodromous population in Lake Superior, as well as an anadromous population in Maine, is known as coaster trout or as coasters; the brook trout is the state fish of nine U. S. states: Michigan, New Hampshire, New Jersey, New York, North Carolina, Vermont and West Virginia, the Provincial Fish of Nova Scotia in Canada. The brook trout was first scientifically described as Salmo fontinalis by the naturalist Samuel Latham Mitchill in 1814; the specific epithet "fontinalis" comes from the Latin for "of a spring or fountain", in reference to the clear, cold streams and ponds in its native habitat. The species was moved to the char genus Salvelinus.
Though called a trout, the brook trout is thus one of the chars, which in North America include the lake trout, bull trout, Dolly Varden, the Arctic char. There is little recognized systematic substructure in the brook trout, but two subspecies have been proposed. On the other hand, three ecological forms are distinguished; the aurora trout, S. f. timagamiensis, is a subspecies native to two lakes in the Temagami District of Ontario, Canada. The silver trout, is an extinct trout species or subspecies last seen in Dublin Pond, New Hampshire, in 1930, it is considered by fisheries biologist Robert J. Behnke as a specialized form of brook trout. Robert J. Behnke describes three ecological forms of the brook trout. A large lake form evolved in the larger lakes in the northern reaches of its range and are piscivorous as adults. A sea-run form that migrates into saltwater for short periods of time to feed evolved along the Atlantic coastline. A smaller generalist form that evolved in the small lakes, ponds and streams throughout most of the original native range.
This generalist form attains sizes larger than 12 in or lives for more than three years. All three forms have the same general appearance; the brook trout produces hybrids both with its congeners Salvelinus namaycush and Salvelinus alpinus, intergeneric hybrids with Salmo trutta. The splake is an intrageneric hybrid between the brook trout and lake trout. Although uncommon in nature, they are artificially propagated in substantial numbers for stocking into brook trout or lake trout habitats. Although they are fertile, back-crossing in nature is behaviorally problematic and little natural reproduction occurs. Splake grow more than brook trout and become piscivorous sooner and are more tolerant of competitors than brook trout; the tiger trout is an intergeneric hybrid between the Eurasian brown trout. Tiger trout occur rarely but are sometimes artificially propagated; such crosses are always reproductively sterile. They are popular with many fish-stocking programs because they can grow and may help keep rough fish populations in check due to their piscivorous nature.
The sparctic char is an intrageneric hybrid between the Arctic char. The brook trout has a dark green to brown color, with a distinctive marbled pattern of lighter shades across the flanks and back and extending at least to the dorsal fin, to the tail. A distinctive sprinkling of red dots, surrounded by blue halos, occurs along the flanks; the belly and lower fins are reddish in the latter with white leading edges. The belly of the males, becomes red or orange when the fish are spawning. Typical lengths of the brook trout vary from 25 to 65 cm, weights from 0.3 to 3 kg. The maximum recorded length is maximum weight 6.6 kg. Brook trout can reach at least seven years of age, with reports of 15-year-old specimens observed in California habitats to which the species has been introduced. Growth rates are dependent on season, age and ambient air temperatures, flow rates. In general, flow rates affect the rate of change in the relationship between temperature and growth rate. For example, in spring, growth increased with temperature at a faster rate with high flow rates than with low flow rates.
Brook trout are native to a wide area of Eastern North America, but are confined to higher elevations southward in the Appalachian Mountains to northern Georgia and northwest South Carolina, Canada from the Hudson Bay basin east, the Great Lakes–Saint Lawrence system, the Canadian maritime provinces, the upper Mississippi River drainage as far west as eastern Iowa. Their southern historic native range has been drastically reduced, with fish being restricted to higher-elevation, remote streams due to habitat loss and introductions of brown and rainbow trout; as early as 1850, the brook trout's range started to extend west from its native range through introductions. The brook trout was introduced into suitable habitats throughout the western U. S. during the late 19th and early 20th centuries at the behest of the American Acclimatization Society and by private and federal fisheries authorities. Acclimatization movements in Europe, South America, Oceania resulted in brook trout introductions throughout Europe, in Argentina and New Zealand.
Although not all introductions were successful, a great many established wild, self-susta
Continental Divide of the Americas
The Continental Divide is the principal, mountainous, hydrological divide of the Americas. The Continental Divide extends from the Bering Strait to the Strait of Magellan, separates the watersheds that drain into the Pacific Ocean from those river systems that drain into the Atlantic Ocean and, along the northernmost reaches of the Divide, those river systems that drain into the Arctic Ocean. Though there are a few other hydrological divides in the Americas, the Continental Divide is by far the most prominent of these because it tends to follow a line of high peaks along the main ranges of the Rocky Mountains and Andes, at a much higher elevation than the other hydrological divisions; the Continental Divide begins at Cape Prince of Wales, the westernmost point on the mainland of the Americas. The Divide crosses northern Alaska into the Yukon zig-zags south into British Columbia via the Cassiar Mountains and Omineca Mountains and northern Nechako Plateau to Summit Lake, north of the city of Prince George and just south of the community of McLeod Lake.
From there the Divide traverses the McGregor Plateau to the spine of the Rockies, following the crest of the Canadian Rockies southeast to the 120th meridian west, from there forming the boundary between southern British Columbia and southern Alberta. The Divide crosses into the United States in northwestern Montana, at the boundary between Waterton Lakes National Park and Glacier National Park. In Canada, it forms the western boundary of Waterton Lakes National Park, in the US bisects Glacier National Park. Further south, the Divide forms the backbone of the Rocky Mountain Front in the Bob Marshall Wilderness, heads south towards Helena and Butte west past the namesake community of Divide, through the Anaconda-Pintler Wilderness to the Bitterroot Range, where it forms the eastern third of the state boundary between Idaho and Montana; the Divide crosses into Wyoming within Yellowstone National Park and continues southeast into Colorado where it reaches its highest point in North America at the summit of Grays Peak at 4,352 m.
It crosses US Hwy 160 in southwestern Colorado at Wolf Creek Pass, where a line symbolizes the division. The Divide proceeds south into western New Mexico, passing along the western boundary of the endorheic Plains of San Agustin. Although the Divide represents the height of land between watersheds, it does not always follow the highest ranges/peaks within each state or province. In Mexico, it passes through Chihuahua, Zacatecas, Jalisco, Querétaro, México, the Federal District, Puebla and Chiapas. In Central America, it continues through southern Guatemala, southwestern Honduras, western Nicaragua, western/southwestern Costa Rica, southern Panama; the divide reaches its lowest natural point in Central America at the Isthmus of Rivas at 47 m in Nicaragua. In Panama, the Canal cuts through it at 85 ft; the Divide continues into South America, where it follows the peaks of the Andes Mountains, traversing western Colombia, central Ecuador and southwestern Peru, eastern Chile, southward to the southern end of Patagonia and Tierra del Fuego.
In North America, another non-mountainous divide, the Laurentian Divide, further separates the Hudson Bay-Arctic Ocean drainage region from the Atlantic watershed region. Secondary divides separate the watersheds that flow into the Great Lakes and Saint Lawrence River from watersheds that flow to the Atlantic via the Missouri-Mississippi complex. Another secondary divide follows the Appalachian chain, which separates those streams and rivers that flow directly into the Atlantic Ocean from those that exit via the Mississippi River. Triple Divide Peak in Glacier National Park, Montana, is the point where two of the principal continental divides in North America converge, the primary Continental Divide and the Northern or Laurentian Divide. From this point, waters flow to the Pacific Ocean, the Atlantic Ocean via the Gulf of Mexico, the Arctic Ocean via Hudson Bay. Most geographers, geologists and oceanographers consider this point the hydrological apex of North America, as Hudson Bay is considered part of the Arctic.
For example, the International Hydrographic Organization defines the Hudson Bay, with its outlet extending from 62.5 to 66.5 degrees north as being part of the Arctic Ocean "Arctic Ocean Subdivision 9.11." This hydrological apex of North America status of Triple Divide Peak is the main reason behind the designation of Waterton-Glacier International Peace Park as the "Crown of the Continent" of North America. The summit of the peak is the world's only oceanic triple divide point. Discounting Antarctica and its ice sheets, only one other continent borders three oceans, but the inward-draining Endorheic basin area of Central Asia from western China to the Aral and Caspian Seas is so vast that any Arctic and Indian Ocean tributaries are never within proximity of each other. Thus, North America's status of having a single location draining into three oceans is unique in the world. Sources differ, however, on whether Hudson Bay south of the Arctic Circle, is part of the Atlantic or Arctic Ocean. Hudson Bay's water budget connects to the Atlantic more than to the Arctic Ocean.
The
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