The boreal owl is a small owl. In Europe, it is known as Tengmalm's owl after Swedish naturalist Peter Gustaf Tengmalm or, more Richardson's owl after Sir John Richardson; the scientific name is from Latin. The genus name Aegolius is a type of screech owl thought to be a bird of ill omen, funereus means "funereal"; this species is a part of the larger grouping of owls known as typical owls, which contains most species of owl. The other grouping is Tytonidae. Due to its shyness and evasive reaction to human activities, nocturnal habits and preferred inaccessible taiga forest habitat, it ranks as one of the, if not the, least known owls in both North America and Europe; the boreal owl is 22–27 cm long with a 50–62 cm wingspan. It is brown above, with white flecking on the shoulders. Underparts whitish streaked with rust; the head is large, with yellow eyes and a white facial disc, a "surprised" appearance. The beak is light yellow colored rather than dark like its relative the northern saw-whet owl.
The flight is direct. Young birds are chocolate brown; the boreal owl is an unsociable nocturnal owl. Its call is similar in sound to the "winnowing" of the North American Wilson's snipe; this species is not migratory, but in some autumns significant numbers move further south. It is any great distance south of its breeding range, although this is due to the problems of detecting this nocturnal owl outside the breeding season when it is not calling; the boreal owl breeds in dense coniferous forests across northern North America and Eurasia, in mountain ranges such as the Alps and the Rockies. It lays 3–6 eggs in a tree hole. Across much of Europe, to a lesser extent in Asia and North America and biologists put up nest boxes for these and other small owls; this small owl eats voles and other mammals but birds as well as insects and other invertebrates. It is nocturnal, though in the northernmost parts of its range, it is forced to hunt during daylight because of the short nights in summer. Banded boreal owls have been known to live up to 16 years.
Due to the owl's small stature it is preyed upon by other owls and large raptors thus decreasing its average life span. Boreal owls have seven subspecies: A.f funereus: nominate subspecies, from Scandinavia down south to the Pyrenees and east to the Urals, but not the Caucasus Mountains A.f. richardsoni: the North American subspecies, from Alaska down the Rocky Mountains and as far east as Southeastern Canada and the American Northeast A.f. pallens: from southeastern Siberia to Tien Shan in China A.f. caucasicus: Caucasus Mountains A.f. magnus: from Eastern Siberia from Kolyma to the Kamchatka peninsula A.f. sibiricus: widespread over Siberia A.f. beickianus Stresemann, 1928: from Northwest India to western China "Boreal Owl media". Internet Bird Collection. "Aegolius funereus". Integrated Taxonomic Information System. Retrieved 24 February 2009. Aegolius funereus in the Flickr: Field Guide Birds of the World "Aegolius funereus". Avibase. Boreal Owl photo gallery at VIREO
American black bear
The American black bear is a medium-sized bear native to North America. It is the continent's smallest and most distributed bear species. American black bears are omnivores, with their diets varying depending on season and location, they live in forested areas, but do leave forests in search of food. Sometimes they become attracted to human communities because of the immediate availability of food; the American black bear is the world's most common bear species. It is listed by the International Union for Conservation of Nature as a least-concern species, due to its widespread distribution and a large population estimated to be twice that of all other bear species combined. Along with the brown bear, it is one of only two of the eight modern bear species not considered by the IUCN to be globally threatened with extinction. American black bears mark trees using their teeth and claws as a form of communication with other bears, a behavior common to many species of bears. Despite living in North America, American black bears are not related to brown bears and polar bears.
American and Asian black bears are considered sister taxa and are more related to each other than to the other modern species of bears. According to recent studies, the sun bear is a recent split from this lineage. A small primitive bear called Ursus abstrusus is the oldest known North American fossil member of the genus Ursus, dated to 4.95 mya. This suggests that U. abstrusus may be the direct ancestor of the American black bear, which evolved in North America. Although Wolverton and Lyman still consider U. vitabilis an "apparent precursor to modern black bears", it has been placed within U. americanus. The ancestors of American black bears and Asian black bears diverged from sun bears 4.58 mya. The American black bear split from the Asian black bear 4.08 mya. The earliest American black bear fossils, which were located in Port Kennedy, Pennsylvania resemble the Asian species, though specimens grew to sizes comparable to grizzly bears. From the Holocene to the present, American black bears seem to have shrunk in size, but this has been disputed because of problems with dating these fossil specimens.
The American black bear lived during the same period as the giant and lesser short-faced bears and the Florida spectacled bear. These tremarctine bears evolved from bears -- 8 ma; the giant and lesser short-faced bears are thought to have been carnivorous and the Florida spectacled bear more herbivorous, while the American black bears remained arboreal omnivores, like their Asian ancestors. The American black bear's generalist behavior allowed it to exploit a wider variety of foods and has been given as a reason why, of these three genera, it alone survived climate and vegetative changes through the last Ice Age while the other, more specialized North American predators became extinct. However, both Arctodus and Tremarctos had survived several previous ice ages. After these prehistoric ursids became extinct during the last glacial period 10,000 years ago, American black bears were the only bear present in much of North America until the migration of brown bears to the rest of the continent.
American black bears are reproductively compatible with several other bear species and have produced hybrid offspring. According to Jack Hanna's Monkeys on the Interstate, a bear captured in Sanford, was thought to have been the offspring of an escaped female Asian black bear and a male American black bear. In 1859, an American black bear and a Eurasian brown bear were bred together in the London Zoological Gardens, but the three cubs that were born died before they reached maturity. In The Variation of Animals and Plants under Domestication, Charles Darwin noted: In the nine-year Report it is stated that the bears had been seen in the zoological gardens to couple but to 1848 most had conceived. In the reports published since this date three species have produced young... An American black bear shot in autumn 1986 in Michigan was thought by some to be an American black bear/grizzly bear hybrid, due to its unusually large size and its proportionately larger braincase and skull. DNA testing was unable to determine whether it was a grizzly bear.
Listed alphabetically. American black bears occupied the majority of North America's forested regions. Today, they are limited to sparsely settled, forested areas. American black bears inhabit much of their original Canadian range, though they occur in the southern farmlands of Alberta and Manitoba; the total Canadian black bear population is between 396,000 and 476,000, based on surveys taken in the mid-1990s in seven Canadian provinces, though this estimate excludes American black bear populations in New Brunswick, the Northwest Territories, Nova Scotia and Saskatchewan. All provinces indicated stable populations of American black bears over the last decade; the current range of American black bears in the United States is constant throughout most of the northeast and within the Appalachian Mountains continuously from Maine to northern Georgia, the northern Midwest, the Rocky Mountain region, the West Coast and Alaska. However, it becomes fragmented or absent in other regions. Despite this, American black bears in those areas seem to have expanded their range during the last decade, such as with recent sightings in Ohio an
The City of Delta is the Home Rule Municipality, the county seat and the most populous municipality of Delta County, United States. The population was 8,915 at the 2010 census, up from 6,400 at the 2000 census; the United States Forest Service headquarters of the Grand Mesa and Uncompahgre National Forests are located in Delta. Delta was built as a trading post for early settlers. Fort Uncompahgre was built in 1828; the town was named because of its location on the delta where the Uncompahgre River flows into the Gunnison River. The town was incorporated in 1882. Delta is located in southwestern Delta County at 38°44′27″N 108°3′48″W; the downtown area is situated east of the Uncompaghre River. The city limits extend north across the Gunnison into the area now known as "North Delta" west 6 miles along U. S. Route 50 as far as Westwinds Airport. According to the United States Census Bureau, the city has a total area of 14.0 square miles, of which 13.7 square miles is land and 0.3 square miles, or 2.02%, is water.
Delta is part of the Colorado Western Slope region. Parks: Pow Wow Arbor Mountain View Pavilion Riley Pavilion / Cleland Park Shade Pavilion Island Cottonwood Park Emerald Hills Park As of the census of 2010, there were 8,915 people, 3,530 households, 2,337 families residing in the city; the population density was 1,682.1 people per square mile. There were 3,825 housing units at an average density of 721.7 per square mile. The racial makeup of the city was 82.2% White, 0.2% African American, 1.1% Native American, 0.7% Asian, 12.5% from other races, 3.1% from two or more races. Hispanic or Latino of any race were 26.1% of the population. There were 3,530 households out of which 30.3% had children under the age of 18 living with them, 49.3% were married couples living together, 11.6% had a female householder with no husband present, 33.8% were non-families. 30.0% of all households were made up of individuals and 14.8% had someone living alone, 65 years of age or older. The average household size was 2.49, the average family size was 3.08.
In the city, the population was spread out with 26.7% under the age of 18, 8.2% from 18 to 24, 23.2% from 25 to 44, 24.5% from 45 to 64, 17.5% who were 65 years of age or older. The median age was 38.0 years. For every 100 females, there were 93.8 males. For every 100 females age 18 and over, there were 91.0 males. Fort Uncompahgre was built in 1828, established as a fur trading post by Antoine Robidoux. Tour guides dress in period attire and trap beavers, make buckskins, knap arrowheads, work the forge; the principal newspaper is the Delta County Independent, published weekly on Wednesdays. Local readers enjoy The High Country Shopper, a free paper that distributes over 15,000 copies throughout the county. Montrose Regional Airport, located 21 miles south of Delta, is the closest airport served by scheduled airlines. In Grand Junction, 39 miles to the north, there are scheduled airline services, as well as an Amtrak train station with a daily California Zephyr departure in each direction. U. S. Highway 50 runs east-west, crossing 12 states and linking Sacramento, with Ocean City, Maryland.
In Colorado, it passes through Delta as Main Street and connects the city to Montrose, Grand Junction and Pueblo. State Highway 65 is a 61-mile stretch that runs north from State Highway 92 east of Delta, over the Grand Mesa, to Interstate 70 near Palisade. State Highway 92 begins at the intersection of Main Street and First Street, it runs 73 miles to the east, re-encountering US 50 near Blue Mesa Reservoir and Curecanti National Recreation Area. Chuck Cottier, baseball player and manager Dale Ishimoto, American actor Frank H. Ono, Medal of Honor recipient Felix L. Sparks, American army general Egyptian Theatre Borowsky and Cleary, Brooke, "Delta's King of Kings: The Egyptian Theatre and the Bank Night Craze". Colorado Heritage Summer 2002: pp. 2–15 Ferguson, Olivia Spalding, "A Sketch of Delta County History". The Colorado Magazine 5: pp. 161–164 City of Delta official website CDOT map of the City of Delta Delta Area Chamber of Commerce Delta County Independent
The Grand Mesa is a large mesa in western Colorado in the United States. It is the largest flat-topped mountain in the world, it has an area of about 500 square miles and stretches for about 40 miles east of Grand Junction between the Colorado River and the Gunnison River, its tributary to the south. The north side of the mesa is drained by Plateau Creek, a smaller tributary of the Colorado; the west side is drained by Kannah Creek, received to the west by the lower Gunnison River. The mesa rises about 6,000 feet above the surrounding river valleys, including the Grand Valley to the west, reaching an elevation of about 11,000 feet. Much of the mesa is within Grand Mesa National Forest. Over 300 lakes, including many reservoirs created and used for drinking and irrigation water, are scattered along the top of the formation; the Grand Mesa is quite rugged in others. The mesa is topped by a hard volcanic basalt; this layer, formed 10 million years ago by basalt flows, suppressed erosion compared to the surrounding sedimentary rock layers, which suffered rapid downcutting from the action of the Colorado and the Gunnison rivers.
The top layer rests on a thick sequence of Eocene shale and sandstone known as the Green River and Wasatch Formations. These layers in turn rest on a Cretaceous layer known as the Mesaverde Group that forms a cliff about halfway up the side of the mesa; the lowest layers are gray Mancos Shale of late Cretaceous age. The shale continues outward into the surrounding valleys in the vicinity of the mesa, providing a soil base, fertile for various kinds of agriculture in the Gunnison Valley to the south. Climate on Grand Mesa varies by elevation. Higher elevations tend to receive more precipitation; the top of the mesa is more than two miles above sea level, experiences an alpine climate with substantial amounts of precipitation throughout the year. Because of the high altitude, summer days are mild, temperatures drop after sunset. Winter temperatures rise above freezing, can be cold falling far below zero at night; the top of the mesa is snow-free from late June through early October. Accumulations of 20 or 30 inches of snow in the winter are typical.
Surrounding areas with lower elevation are more arid throughout the year. The following climate data is for Mesa Lakes Resort, located on the north slopes of the mesa at 9,800 feet above sea level, which experiences a subalpine climate; the mesa is traversed by the Grand Mesa Scenic and Historic Byway, which includes SH 65, between the town of Mesa on the north and the town of Cedaredge on the south. The route over the mesa provides a dramatic contrast in landscape and vegetation. On the north side, the road climbs the steep terrain near the Powderhorn Resort ski area; the forested top of the mesa remains snowbound much in the spring than the surrounding valleys, is a popular location for cross-country skiing and snowmobiling. Mountain ranges of Colorado Table 2014 West Salt Creek landslide Halka Chronic. Roadside Geology of Colorado. Missoula Montana: Mountain Press Publishing Co. ISBN 0-87842-105-X. "Grand Mesa". Peakbagger.com. Summer Nightfall on Grand Mesa
The common raven known as the northern raven, is a large all-black passerine bird. Found across the Northern Hemisphere, it is the most distributed of all corvids. There are at least eight subspecies with little variation in appearance, although recent research has demonstrated significant genetic differences among populations from various regions, it is one of the two largest corvids, alongside the thick-billed raven, is the heaviest passerine bird. Common ravens can live up to 21 years in the wild, a lifespan surpassed among passerines by only a few Australasian species such as the satin bowerbird and the lyrebirds. Young birds may travel in flocks but mate for life, with each mated pair defending a territory. Common ravens have coexisted with humans for thousands of years and in some areas have been so numerous that people have regarded them as pests. Part of their success as a species is due to their omnivorous diet; some notable feats of problem-solving provide evidence that the common raven is unusually intelligent.
Over the centuries, it has been the subject of mythology, folklore and literature. In many cultures, including the indigenous cultures of Scandinavia, ancient Ireland and Wales, the northwest coast of North America, Siberia and northeast Asia, the common raven has been revered as a spiritual figure or godlike creature; the common raven was one of the many species described by Linnaeus in his 18th century work, Systema Naturae, it still bears its original name of Corvus corax. It is the type species of the genus Corvus, derived from the Latin word for "raven"; the specific epithet, corax/κοραξ, is the Ancient Greek word for "raven" or "crow". The modern English word raven has cognates in all other Germanic languages, including Old Norse hrafn and Old High German raban, all which descend from Proto-Germanic *khrabanas. An old Scottish word corby or corbie, akin to the French corbeau, has been used for both this bird and the carrion crow. Obsolete collective nouns for a group of ravens include "unkindness" and "conspiracy".
In practice, most English-speakers use the more generic "flock". The closest relatives of the common raven are the brown-necked raven, the pied crow of Africa, the Chihuahuan raven of the North American southwest. While some authorities have recognized as many as 11 subspecies, others recognize only eight: The common raven evolved in the Old World and crossed the Bering land bridge into North America. Recent genetic studies, which examined the DNA of common ravens from across the world, have determined that the birds fall into at least two clades: a California clade, found only in the southwestern United States, a Holarctic clade, found across the rest of the Northern Hemisphere. Birds from both clades look alike, but the groups are genetically distinct and began to diverge about two million years ago; the findings indicate that based on mitochondrial DNA, common ravens from the rest of the United States are more related to those in Europe and Asia than to those in the California clade, that common ravens in the California clade are more related to the Chihuahuan raven than to those in the Holarctic clade.
Ravens in the Holarctic clade are more related to the pied crow than they are to the California clade. Thus, the common raven species as traditionally delimited is considered to be paraphyletic. One explanation for these genetic findings is that common ravens settled in California at least two million years ago and became separated from their relatives in Europe and Asia during an ice age. One million years ago, a group from the California clade evolved into a new species, the Chihuahuan raven. Other members of the Holarctic clade arrived in a separate migration from Asia at the same time as humans. A 2011 study suggested that there are no restrictions on gene flow between the Californian and Holarctic common raven groups, that the lineages can remerge reversing a potential speciation. A recent study of raven mitochondrial DNA showed that the isolated population from the Canary Islands is distinct from other populations; the study did not include any individuals from the North African population, its position is therefore unclear, though its morphology is close to the population of the Canaries.
A mature common raven ranges between 67 cm long, with a wingspan of 115 to 150 cm. Recorded weights range from 0.69 to 2 kg, thus making the common raven one of the heaviest passerines. Birds from colder regions such as the Himalayas and Greenland are larger with larger bills, while those from warmer regions are smaller with proportionally smaller bills. Representative of the size variation in the species, ravens from California weighed an average of 784 g, those from Alaska weighed an average of 1,135 g and those from Nova Scotia weighed an average of 1,230 g; the bill is large and curved, with a culmen length of 5.7 to 8.5 cm one of the largest bills amongst passerines. It has a longish graduated tail, at 20 to 26.3 cm, black iridescent plumage, a dark brown iris. Th
The Canada lynx is a lynx species native to North America. It ranges across Alaska extending into the Rocky Mountains and New Mexico, it has been listed as Least Concern on the IUCN Red List since 2002. With a dense silvery-brown coat, ruffed face and tufted ears, the Canada lynx resembles the other species of the mid-sized feline genus Lynx, it is larger than the bobcat, with which it shares parts of its range, over twice the size of the domestic cat. In his 1792 work The Animal Kingdom, Scottish scientific writer Robert Kerr described a lynx from Canada, giving it the name Felis lynx canadensis; the taxonomy of the Canada lynx remained disputed through the early 21st centuries. In 1912, American zoologist Gerrit Miller placed the Canada lynx under the genus Lynx, with the name L. canadensis. Till as late as the early 2000s, scientists were divided on whether Lynx should be considered a subgenus of Felis, or a subfamily itself. American zoologist W. C. Wozencraft revised the classification of Carnivora in 2005, recognized the Canada lynx as a species under Lynx, along with the bobcat, the Eurasian lynx and the Iberian lynx.
In 2017, the Cat Classification Task Force of the IUCN Cat Specialist Group revised felid taxonomy, considering the Canada lynx a monotypic species. Wozencraft recognized three subspecies of the Canada lynx in Mammal Species of the World: L. c. canadensis Kerr, 1792 - Found in the North American mainland. L. c. mollipilosus Stone, 1900 – Described by American mammalogist Witmer Stone from a skin and skull of a male lynx killed near Wainwright, Alaska. L. c. subsolanus Bangs, 1897 – Described by American zoologist Outram Bangs from a lynx skin and skull collected near Codroy in Newfoundland. A study of the differences between L. c. canadensis and L. c. subsolanus showed that apart from a few variations, the standard measurements are not distinct. The researchers noted that, given that only a few differences exist between the two forms, L. c. subsolanus appears to have diverged only from the mainland form. The lack of appreciable subspecific distinctions led them to doubt the identity of the Newfoundland lynx as a separate subspecies.
According to a 2006 study based on genetic analysis, the ancestor of five felid lineages – Lynx, Puma and Prionailurus plus Otocolobus – arrived in North America after crossing the Bering Strait 8.5–8 mya. Lynx diverged from the Puma and Prionailurus plus Otocolobus lineages around 3.24 mya. The Issoire lynx, that originated in Africa 4 mya and occurred in Europe and northern Asia until it became extinct around 1 mya, is believed to be the ancestor of the four modern species of Lynx. A 1987 study suggested that the populations of the Eurasian lynx that reached North America 20,000 years ago moved toward the southern half of the continent, as the northern part was covered by glaciers; the southern populations evolved into the modern bobcat. When the continent was invaded by the Eurasian lynx for a second time, the populations that settled in the northern part of the continent, now devoid of glaciers, evolved into the Canada lynx; the 2006 study gave the phylogenetic relationships of the Canada lynx as follows: The Canada lynx is a medium-sized cat, similar in many ways to the bobcat.
This lynx is between 80 and 100 centimetres in head-and-body length, stands 48–56 centimetres tall at the shoulder and weighs 5–18 kilograms. At half the size of the Eurasian lynx, physical proportions do not vary across its range and are naturally selected to allow the animal to survive on smaller prey; the Canada lynx is sexually dimorphic, with males heavier than females. Like the bobcat, the Canada lynx has forelimbs shorter than the hindlimbs, so that the back appears to be sloping downward toward the front; the stubby tail, typical of lynxes, measures 5–15 centimetres. The coat is yellowish brown, can change colour seasonally; the dense, long fur insulates it in its frosty habitat. Although no melanistic or albinistic forms of the Canada lynx are known, "blue" lynxes have been reported from Alaska. Black hair tufts, a feature common to all lynxes, emerge from the tips of the ears, which are lined with black. In winter, the hair on the lower cheeks grow so long that it appears to form a ruffle covering the throat.
Some dark spots can be seen on the underbelly, where the fur is white. There are four nipples; the coat is short and reddish brown to greyish in summer, but becomes notably longer and greyer in winter, with a mix of greyish brown and buff hairs. The tail is marked with dark rings and, unlike the tail of the bobcat, terminates in a black tip; the paws, covered in long and thick fur, can support nearly double the weight the paws of a bobcat can bear. The Canada lynx has 28 teeth, same as in other lynxes but unlike other felids, with four long canines for puncturing and gripping; the lynx can feel where it is biting the prey with its canines because they are laced with nerves. It has four carnassial teeth that cut the meat into small pieces. In order for the lynx to use its carnassials, it must chew the meat with its head to its side. There are large spaces between the four canines and the rest of the teeth
United States Forest Service
The United States Forest Service is an agency of the U. S. Department of Agriculture that administers the nation's 154 national forests and 20 national grasslands, which encompass 193 million acres. Major divisions of the agency include the National Forest System and Private Forestry, Business Operations, the Research and Development branch. Managing 25% of federal lands, it is the only major national land agency, outside the U. S. Department of the Interior; the concept of the National Forests was born from Theodore Roosevelt’s conservation group and Crockett Club, due to concerns regarding Yellowstone National Park beginning as early as 1875. In 1876, Congress formed the office of Special Agent in the Department of Agriculture to assess the quality and conditions of forests in the United States. Franklin B. Hough was appointed the head of the office. In 1881, the office was expanded into the newly formed Division of Forestry; the Forest Reserve Act of 1891 authorized withdrawing land from the public domain as "forest reserves," managed by the Department of the Interior.
In 1901, the Division of Forestry was renamed the Bureau of Forestry. The Transfer Act of 1905 transferred the management of forest reserves from the General Land Office of the Interior Department to the Bureau of Forestry, henceforth known as the United States Forest Service. Gifford Pinchot was the first United States Chief Forester in the Presidency of Theodore Roosevelt. Significant federal legislation affecting the Forest Service includes the Weeks Act of 1911, the Multiple Use – Sustained Yield Act of 1960, P. L. 86-517. L. 88-577. L. 94-588. L. 91-190. L. 95-313. L. 95-307. In February 2009, the Government Accountability Office evaluated whether the Forest Service should be moved from the Department of Agriculture to the Department of the Interior, which includes the National Park Service, the Fish and Wildlife Service, the Bureau of Land Management, managing some 438,000,000 acres of public land; as of 2009, the Forest Service has a total budget authority of $5.5 billion, of which 42% is spent fighting fires.
The Forest Service employs 34,250 employees in 750 locations, including 10,050 firefighters, 737 law enforcement personnel, 500 scientists. The mission of the Forest Service is "To sustain the health and productivity of the Nation's forests and grasslands to meet the needs of present and future generations." Its motto is "Caring for the land and serving people." As the lead federal agency in natural resource conservation, the US Forest Service provides leadership in the protection and use of the nation's forest and aquatic ecosystems. The agency's ecosystem approach to management integrates ecological and social factors to maintain and enhance the quality of the environment to meet current and future needs. Through implementation of land and resource management plans, the agency ensures sustainable ecosystems by restoring and maintaining species diversity and ecological productivity that helps provide recreation, timber, fish, wildlife and aesthetic values for current and future generations of people.
The everyday work of the Forest Service balances resource extraction, resource protection, providing recreation. The work includes managing 193,000,000 acres of national forest and grasslands, including 59,000,000 acres of roadless areas. Further, the Forest Service fought fires on 2,996,000 acres of land in 2007; the Forest Service organization includes ranger districts, national forests, research stations and research work units and the Northeastern Area Office for State and Private Forestry. Each level has responsibility for a variety of functions; the Chief of the Forest Service is a career federal employee. The Chief reports to the Under Secretary for Natural Resources and Environment in the U. S. Department of Agriculture, an appointee of the President confirmed by the Senate; the Chief's staff provides broad policy and direction for the agency, works with the Administration to develop a budget to submit to Congress, provides information to Congress on accomplishments, monitors activities of the agency.
There are five deputy chiefs for the following areas: National Forest System and Private Forestry and Development, Business Operations, Finance. The Forest Service Research and Development deputy area includes five research stations, the Forest Products Laboratory, the International Institute of Tropical Forestry, in Puerto Rico. Station directors, like regional foresters, report to the Chief. Research stations include Northern, Pacific Northwest, Pacific Southwest, Rocky Mountain, Southern. There are 92 research work units located at 67 sites throughout the United States. There are 80 Experimental Forests and Ranges that have been established progressively since 1908; the system provides places for long-term science and management studies in major vegetation types of the 195 million acres of public land administered by the Forest Service. Individual sites range from 47 to 22,500 ha in size. Operations of Experimental Forests and Ranges are directed by local research teams for the individual sites, by Research Stations for the regions in which they are located, at the level of the Forest Service.
Major themes in