Sierra Nevada forests, Ecoregions, WWF
Sierra Nevada forests
- 1 Sierra Nevada forests
- 2 Coniferous Forest
- 3 How Coniferous Forests Develop
- 4 Kinds of Coniferous Forests
- 5 Climate
- 6 Geography of Coniferous Forests
- 7 Plant Life
- 8 Animal Life
- 9 Human Life
- 10 The Food Web
- 11 Spotlight on Coniferous Forests
- 12 For More Information
The Sierra Nevada run NW to SW and are approximately 400 miles long and 50 mile wide. The range is highest towards the south with several peaks over 14,000 ft. Several large river vallies dissect the western slope with steep canyons. The eastern escarpment is much steeper than the western slope, in general. The range supports a diverse set of natural communities with many endemic species and extraordinary habitats.
The Sierra Nevada ecoregion harbors one of the most diverse temperate conifer forests on Earth displaying an extraordinary range of habitat types and supporting many unusual species. Fifty percent of California s estimated 7,000 species of vascular plants occur in the Sierra Nevada, with 400 Sierra endemics and 200 rare species (CWWR 1996). The southern region [section] has the highest concentration of species and rare and endemic species, but pockets of rare plants occur throughout the range. The eastern slope west of the Owens River valley is also noted for many unusual plant species. Geographic patterns of plant diversity are complex, with the species compositions of communities changing dramatically with altitude and between watersheds along a north-south gradient (i.e., high beta diversity).
Different communities are distributed in elevational belts on both sides of the range, with counterpart communities occurring at higher elevation on the eastern slope. Above the chaparral and foothill woodlands on the west slope of the Sierra Nevada, part of the Interior chaparral and woodland ecoregion, occurs a series of forests at montane and subalpine elevations. The montane elevation is itself sorted into several extensive forest types. First is the ponderosa pine forest which replaces chaparral and woodland, then the mixed conifer forest dominates. Here five conifers, ponderosa pine, sugar pine, Douglas-fir, and white fir mix on the most productive soils in the Sierra. Sugar pine is the world’s tallest and largest pine species of this forest type. Some seventy-five groves of giant sequoia (Sequoiadendron giganteum) exit within the mixed conifer forest. Giant sequoias are the most massive trees on Earth, with some trees 273 ft tall, over 36 ft in diameter, and over 3,200 years old. Sequoias and many other tree, shrub, and herbaceous plant species tolerate frequent fires and some require fire for their regeneration. Sequoias benefit from fire’s reduction of fungal pathogens and carpenter ants that weaken structural integrity in larger trees, clearing of understory trees and brush that compete with seedlings, and opening of cones through heat (Schoenner 1992). Fires in the past were often frequent and of low intensity because fuel loads were generally low. A diverse assemblage of herbaceous plants and shrubs is also found in this zone, including numerous local endemics and species specialized on particular soil types such as serpentine. Above the mixed conifer forest grows simple forests dominated first by white fir and then by red fir. They occur the zone of deepest snow.
From 7,000-9,000 ft , in the subalpine zone, lodgepole pine forms extensive forests mixed with meadows and montane chaparral. Jeffrey pine, western white pine, mountain juniper, pine, and aspen are locally common. Between 9,000-10,000 ft mountain hemlock, whitebark pine, foxtail pine, and limber pine are characteristic. Above timberline, alpine meadows, talus slopes, and rocky outcrops cover the land. On the eastern slope, the alpine zone extends down to around 11,800 ft, lodgepole pine or red fir-dominated forests occur down to 8,000 ft, and Jeffrey pine forests to 6,000 ft. Below this elevation the pinyon-juniper woodlands grade into sagebrush scrubs of the Great Basin. Extensive talus slopes, meadows, montane chaparral, lakes, and rock outcrops throughout the Sierra.
Approximately 400 terrestrial vertebrate species occur in the Sierra Nevada , although around 100 of these are largely distributed elsewhere. Around 60 percent of California’s vertebrate species are found here. Thirteen vertebrate species (e.g., salamanders, frogs, rodents, birds) are endemic to the range, this includes some of the highest levels of mammal endemism in the United States and Canada. Some endemics include the Yosemite toad, Mount Lyell salamander, Limestone salamander, Kern salamander, long-eared chipmunk, alpine chipmunk, western heather vole, Walker Pass pocket mouse, yellow-eared pocket-mouse, and the golden trout. A diverse vertebrate predator assemblage once occurred in the ecoregion including grizzly bear (Ursus arctos), black bear (Ursus americanus), coyote (Canis latrans), cougar (Puma concolor), ringtails (Bassariscus astutus), fishers (Martes pennanti), pine martens (Martes americana), wolverines (Gulo gulo, and several large owls, hawks, and eagles.
The Sierra’s support a diverse invertebrate fauna with a number of endemics, including Behr’s colias butterfly (Colias behrii), restricted to a small area around Tioga Pass. Many other invertebrate species have very local distributions. New plant and invertebrate species are being added to lists with further investigations in the region. Between 1968 and 1986 sixty-five new plant species were described for the Sierra’s (CWWR 1986).
A century of intensive logging, mining, railroad building, development, fire suppression, and grazing by sheep and cattle have left only around 25 percent «intact» natural habitat in the Sierra Nevada. Much of this intact habitat occurs at higher elevations, often in non-forested alpine or in less productive forests and woodlands. More than 60 percent of the ponderosa pine or mixed conifer forests have been altered with many remaining forests degraded through logging and fire suppression. Overall, around 19 percent of the entire mid-elevation conifer belt is still relatively intact (CWWR 1996). Between 7 percent and 30 percent of late-successional old growth forests of middle elevations remain, the percentage depending on the forest type. One third of the original extent of Giant Sequoia groves have been harvested, with the U.S. Forest Service allowing these rare and unique trees to be cut in some of the northern groves as recently as the 1980’s. The greatest percentage loss of habitat has occurred in late-successional forests, foothill woodlands, and riparian habitats.
Remaining Blocks of Intact Habitat
Four National Parks, Lassen,Yosemite, Sequoia, and Kings Canyon, and some National Forest Wilderness Areas, harbor the largest remaining blocks of relatively intact montane mixed conifer forests. Most of the rest of this zone has been cut over at least once. There is extensive high montane and subalpine forests and meadows, and alpine habitats in national park and forest service wilderness areas. Much of the higher elevations were once heavily grazed, and Forest Service wilderness areas are still subjected to grazing. Most remaining habitats, including late-successional forests suffer from significant alterations of historic fire regimes and consequent changes to processes (e.g., dense in growth of shade-tolerant species). A variety of changes resulting from intensive exploitation and current management of remaining forests contributes to the lower resiliency of forests to fire and epizootic disturbances. The SNEP analysis came to the conclusion that historic logging, creating simple forests, was more important in creating the fire problems in the Sierra, next comes fire suppression it self. These problems include forest simplification, removal of older trees with their structural and genetic resistance, loss of natural firebreaks such old growth patches with sparse understories and moist riparian vegetation, replanting schemes using genetically-similar seedlings of a single tree species, and intensive application of pesticides that also destroys natural predators on epizootics.
Degree of Fragmentation
Fragmentation varies inversely with altitude. The last remaining less distrubed habitats at lower elevation are severely fragmented.
Degree of Protection
The National Parks share a high degree of protection, including the few remnant lower elevation habitats they encompass. Recent changes in fire management policies within National Parks are helping to restore natural disturbance regimes and successional processes. Wilderness Areas, which usually are located at higher elevations, are protected from commercial logging, but they are still intensively grazed by domestic livestock causing significant damage to riparian habitats and other vegetation types.
Types and Severity of Threats
The vast majority of native forests have already been largely converted to tree plantations. Intensive forestry practices have simplified forest structure and composition in most remaining forests, causing reduced ecologic resilience, genetic variability, and impaired function. Forest simplification and fire suppression together contribute to greatly increased probabilities of catastrophic fires and increased frequencies and severity of widespread mortality from epizootics such as bark beetles and fungal pathogens (CWWR 1996, Dellasala et al. 1996). Most remaining fragments of unlogged forests outside National Parks are threatened by logging, fire suppression, and grazing. Meadows throughout the range outside the national parks continue to be significantly damaged by sheep and cattle grazing and pack animals. Soil compaction from logging and development activities is altering natural succession patterns.
Introduced pathogens from livestock harm native species, the entire herd of 65 bighorn sheep in the Warner Range, a small range northwest of the Sierra Nevada was extirpated by an introduced virus from a single sheep in 1988 (Jensen et al. 1993). Sugar pines in many areas are being killed by the introduced white pine blister rust (Cronartium ribicola) which is rapidly spreading. Continued cutting of larger and potentially resistant sugar pine trees may preclude any effective conservation programs. The creation of clear-cuts, a commonly used timber extraction practice, promotes the growth of gooseberry and currants, vectors of the rust (Johnston 1994). Tree mortality from Anosus root rot fungus (Heterobasidion annosum), a native pathogen, continues to increase from logging, which creates stumps that are a foci for the fungus, and from dense stands of young trees resulting from fire suppression (Johnston 1994).
In the middle-elevation conifer belt, oxidant-induced air pollution damage caused by ozone and other chemicals from air pollution from coastal and valley cities, is damaging many tree species, including Abies concolor, Pinus ponderosa, and P. jeffreyi. Lichens have also suffered significant damage and reduction due to air pollution.
Across the range, 218 endemic plant species are considered rare or threatened, and three plant species (Monardella leucocephala, Mimulus whipplei, Erigeron mariposanus) are believed to be extinct. Sixty-nine terrestrial vertebrate species (17% of the fauna) are considered at risk by government agencies. Many amphibian species at all elevations have severely declined and are disappearing in many areas throughout the range (Drost and Fellers 1996). Introduced fish appear to be a major cause of amphibian decline at higher elevations, although increased UV radiation, viruses, loss of habitat, acid rain been suggested as additional causes of this dramatic decline. Dams and impoundments, as well as grazing and logging in surrounding catchments, have degraded most aquatic habitats. Only 10 percent of the original habitat of anadromous fish in the Sierra are reachable for spawning.
Suite of Priority Activities to Enhance Biodiversity Conservation
A tree is a large woody plant with one main stem, or trunk, and many branches that lives year after year. A forest is a large number of trees covering at least 25 percent of an area where the tops of the trees, called crowns, interlock to form an enclosure or canopy at maturity. Coniferous (koh-NIH-fuhr-uhs) forests primarily contain conifer trees including spruces, pines, firs, larches, cedars, and junipers. Almost all coniferous trees, such as pines and firs, bear their seeds inside cones. Most also have stiff, flattened or needlelike leaves that usually remain green all winter.
Coniferous forests are found in Asia, primarily in Siberia, China, Korea, and Japan, and on the slopes of the Himalaya and Hindu Kush Mountains. In Europe, they cover much of Scandinavia and the coast of the Baltic Sea and are found on the primary mountain ranges—the Alps, the Vosges, and the Carpathians. In North America, coniferous forests stretch across the northern part of the continent from Alaska to Newfoundland; down into Washington, Oregon, and California; and along the Cascades, the Sierra Nevadas, and the Rocky Mountains. In the Southern Hemisphere, they are found in Mexico, along the western coast of South America, in parts of Argentina and Brazil, in parts of the Australasia region, and in portions of Africa.
How Coniferous Forests Develop
The first forests evolved during Earth’s prehistoric past. Since then, all forests have developed by means of a process called succession.
The first forests
The first forests evolved from clubmosses, ferns, and other prehistoric plants, which, over time, adapted to the surrounding environment, and grew more treelike. Trees that preferred a warm, humid, tropical climate developed first, followed by those that gradually adapted to drier, cooler weather. Coniferous forests flourished during the Jurassic Period, about 160 million years ago.
|WORDS TO KNOW|
|Boreal forest: A type of coniferous forest found in areas bordering the Arctic tundra. Also called taiga.|
|Clear-cutting: The cutting down of every tree in a selected area.|
|Deciduous: Term used to describe trees, such as oaks and elms, that lose their leaves during cold or very dry seasons.|
|Epiphytes: Plants that grow on other plants or hang on them for physical support.|
|Montane forest: The moist and cool sloped areas near mountains.|
|Muskeg: A type of wetland containing thick layers of decaying plant matter.|
|Pioneer trees: The first trees to appear during primary succession; they include birch, pine, poplar, and aspen.|
|Predator: An animal that kills and eat other animals.|
|Succession: The process by which one type of plant or tree is gradually replaced by another.|
|Taiga: Coniferous forest found in areas bordering the Arctic tundra; also called boreal forest.|
About one million years ago, during the Ice Ages, glaciers (slow-moving masses of ice) covered about one-third of the land surface of the Earth. Eventually, the glaciers retreated, but not before they had destroyed many of the world’s forests and scoured the land of plants. Roughly twelve thousand years ago, trees began to repopulate the land that had been covered by ice. Spruce, larch, ash and birch trees were among the first species to make a comeback, preparing the way for other trees.
Trees compete with one another for sunlight, water, and nutrients, thus a forest is constantly changing. The process by which one type of plant or tree is gradually replaced by others is called succession. During succession, different species of trees become dominant as time progresses and the environment changes. Succession began following the last Ice Age and continues today. It can occur naturally, when different species of trees become dominant as time progresses and the environment changes. It can also occur from natural disasters, such as forest fires.
Primary succession usually begins on bare soil or sand where no plants grew before. When the right amount of sunlight, moisture, and air temperatures are present, seeds begin to germinate (grow). These first plants are usually made up of the grasses and forbs (a non-woody broad-leaved plant) type. They continue to grow and eventually form meadows. Over time, and as conditions change, other plants
begin to grow such as shrubs and trees. These plants become dominant and replace or take over where the grasses and forbs originally grew.
As primary succession continues, “pioneer” trees begin to thrive. In North America, examples of pioneer trees include birch, pine, poplar, and aspen. They are all tall, sun-loving trees, and they quickly take over the meadow. However, they also change the environment by making shade. If conditions are right, a mixed forest of sun-loving and shade-loving trees may continue for many years. Eventually, more changes occur.
The climax forest
Seedlings from pioneer trees do not grow well in shade; therefore, new pioneer trees do not grow. As the mature trees begin to die from old age, disease, and other causes, the broad-leaf, shade-loving trees become dominant. The shade from these trees can be too dense for their own seedlings as well. As a result, seedlings from the trees that prefer heavy shade, such as beech and sugar maple, begin to thrive and dominate
the forest. These trees produce such deep shade that only trees or plants that can survive in complete shade succeed there. When this happens, the result is a climax forest characteristic of a certain region, for example an oak-hickory forest in the eastern United States.
Few true climax forests actually exist because forests are dynamic and changes take place that interfere with stability. Fires, floods, high winds,
Fire in the forest
About 12,000,000 acres (4,800,000 hectares) of forest in the United States are damaged or destroyed by fire every year. Forest fires can spread as fast as 10 miles (15 kilometers) per hour downwind. Most forest fires are caused by humans and occur in coniferous forests, where both the air and the wood tend to be dry. Also, pine needles contain resin (sap), which burns easily.
Fires not only burn trees, but they also destroy other plant and animal life. Ground fires burn up organic material beneath the vegetation on the forest floor. Although ground fires move slowly, they do much damage. Fires that burn small vegetation and loose material are called surface fires. A crown fire is one that moves quickly through the tops of trees or shrubs.
Forests can actually benefit from fire. The huge fire in Yellowstone National Park in 1988 is an example. In the beginning, it was a controlled fire. The park’s managers allowed it to burn naturally in order to restore the natural balance of the forest. The fire eventually got out of control and destroyed about 20 percent of the park. It left ashes rich in minerals such as calcium and phosphorous. These minerals promoted the growth of new plants, such as pine grass, that grows beneath Douglas firs and flowers only after a fire. The standing dead trees now attract certain types of birds, like the woodpecker and tree swallow. Smoke and heat killed harmful insects and parasitic fungi that endangered trees. The comparatively few animals that died provided food for other species. Many of the burned areas now support tree seedlings, as well as many other plants.
and people can all destroy a single tree or several acres of trees. Glaciers can mow them down; volcanoes can smother them with ash or molten rock or knock them over with explosive force. When this happens, the process of succession starts over.
When the land has been stripped of trees, it will eventually be covered with them again if left alone. This is called secondary succession and can take place more quickly than primary succession. Seeds from other forests in neighboring regions are blown by the wind or carried by animals to the site. The seeds take root and seedlings sprout restarting the process.
Kinds of Coniferous Forests
Forests can be classified in many ways. In general, coniferous forests are categorized as boreal/taiga, mountain, temperate evergreen, temperate pine, or Southern Hemisphere forests.
The word boreal (BOHR-ee-yuhl) means “northern,” and taiga (TAY-guh) is a Russian word for “little sticks.” Boreal forests, or
A conifer for St. Nick
The most popular tree used as a Christmas tree is the coniferous fir. Fir trees are cone-shaped and can grow between 30 and 150 feet (9 and 46 meters) tall. Their needles are very fragrant and remain on the tree for a long time after it has been cut. Most of the trees used for Christmas trees are not wild but are grown on tree plantations.
taiga, are found in regions bordering the Arctic tundra (a region so dry and cold that no trees can grow). These are the great northern forests of Canada, Alaska, Russia, and Scandinavia. They form some of the largest forest biomes in the world. About 11 percent of the Earth’s land surface is considered to be taiga.
Trees in the boreal forest grow at higher latitudes (a distance north or south of the equator measured in degrees), usually between 45° and 70° North, than trees in any other type of forest. The most common are spruce, pine, and fir.
The boreal forest may be divided into three zones. The northernmost zone is the forest-tundra, where trees meet treeless land. Few species are able to survive here. The second zone is the lichen (LY-ken; an algae and fungi combination) woodland, or sparse taiga. Here, trees grow far apart and a lichen mat covers the forest floor. The southernmost region is the closed-canopy forest where many species of conifers grow close together and the forest floor is covered with mosses that grow well in shade.
Mountain coniferous forest
Mountain coniferous forests are found on mountains below the permanent snowfields. They are located in the Rockies, Cascades, and Sierra Nevadas of North America; the Alps and Carpathians in Europe; and the Hindu Kush and Himalayas in Asia.
|COMMON SOFTWOOD TREES|
|Europe||North America||South America|
|Austrian pine||Balasam fir||Alerce|
|European larch||Douglas fir||Monkey-puzzle tree|
|Matime pine||Larch||(Chile pine)|
|Norway spruce||Norway spruce||Parana pine|
|Silberian yellow pine||Pine|
Forests on the upper slopes just below the snowfields are called subalpine forests. At these higher elevations, where the weather is harshest, trees such as the bristlecone pine are long-lived but often stunted in growth. Lodgepole pines grow erect, but alpine firs grow close to the ground, as if shrinking from the harsh climate. Forests on the lower and middle slopes are called montane forests. In this more moderate climate conifers grow taller.
Trees common in mountain forests vary from region to region. In North America, Douglas fir, sierra redwood, and ponderosa pine predominate. Silver fir and larch are found in Europe, and chir pines, Himalayan firs, and morinda spruces grow in Asian forests.
Temperate evergreen forest
Temperate evergreen forests grow in regions with moderate, humid climates. Summers are warm and winters may be cool, but temperatures are seldom extreme. In North America, these forests range along the Pacific coast from Alaska and British Columbia to west central California, where they are sometimes called temperate rain forests. Common tree species include western hemlock, western red cedar, Douglas fir, and coast redwood.
The giant redwoods of California and southern Oregon are the tallest trees in America, many exceeding 300 feet (91 meters) in height and measuring up to 22 feet (7 meters) in circumference. The tallest individual tree, Hyperion, measures 379.1 feet (115.5 meters). A species of redwoods found on the western slopes of the Sierra Nevada Mountains, giant Sequoias, are among the world’s oldest trees. One Sequoia, named
|COMMON SOFTWOOD TREES|
|Pencil cedar||Beuguet pine||Celery-top pine||Carlbbean pitch pine|
|Radiata pine||Hemlock||Radiata pine|
|Thuya||Himalayan Silver fir||Rimu|
“General Sherman”, stands 275 feet (84 meters) tall, has a diameter of 36.5 feet (11 meters), and may be as many as 2,000-2,300 years old. It is also the largest tree by volume in the world, measuring 52,500 cubic feet (1,515 cubic meters).
Where winters are mildest, temperate evergreen forests often contain broad-leaved evergreen trees. The humid conditions help the growth of moss and other moisture-loving plants on the forest floor.
Temperate pine forest
Temperate pinelands grow in hilly or upland regions with warm, dry climates. In the United States, they are found in southern California and in the region stretching from New Jersey to southern Florida and west to Texas. They also occur in Mexico, China, and throughout the regions bordering the Mediterranean Sea.
Southern hemisphere coniferous forest
Coniferous forests located primarily in the Southern Hemisphere, including those of Africa, Southeast Asia, Australia, and New Zealand, are not the same as forests in the Northern Hemisphere. In general, the native coniferous trees are smaller and their leaves have different forms. Members of the monkey-puzzle family are common. Most are found in the mountains or high plateaus.
In South America, native conifers include the Parana pine, monkey-puzzle, Patagonian cedar, and Chilean cedar. In Australia, bunya pine, white cypress pine, and hoop pine grow. Forests of kauri pine grow in New Zealand, and the South African yellowwood is found in southern Africa. The Norfolk Island pine, native to the island of that name, is a popular ornamental tree worldwide.
The climate of a coniferous forest depends upon where it is located. In general, the farther north the latitude, the cooler the climate. The presence of mountain ranges and oceans also affects the climate of
Different conifer genera have species called cedar. They are durable and fragrant woods that have been used by humans since at least 2000 BC. True cedars (Cedrus) are in the pine family. They do not easily rot and are resistant to fire and high winds. Great cedar forests were once found in Algeria, Morocco, the Himalayas, the Pacific Northwest in the United States, and Lebanon in the Middle East. The Phoenicians, who lived in Lebanon, were excellent carpenters and sold much of their wood.
Some of the Phoenicians’ best customers were ancient Egyptians who lived in the Nile Valley where few trees grow. Because cedar is so strong, the Egyptians used it to construct homes and other buildings and for wooden rollers that moved huge stones into place for the construction of the pyramids. Cedar sawdust was used in the process of mummifying the dead, and the resin was used for embalming and coating coffins.
Cedar was also used in the construction of King Solomon’s temple in Jerusalem between 965 to 926 BC. The Romans used it to build ships, and the Roman emperor Hadrian brought about legislation to conserve the cedars of Lebanon between 117 and 138 AD.
The North American western red cedar (Thuja plicata) is a member of the cypress family (Cupressaceae). Native Americans on the Pacific coast made clothing and baskets from the bark, rope from the branches, and canoes and lodges from the trunks. Various types of Cupressaceae have also long been valued in Japan, where conservation was first practiced during the sixteenth century. These trees form stands more than 1,000 years old.
Although most of the once mighty cedar forests are gone, the western red cedar and the Atlantic white cedar (Chamaecyparis thyoides, also a member of the cypress family) is still used for building boats and homes. The cedar used in clothes closets and chests, where the aroma of cedar is said to repel cloth-eating moths, comes from junipers (Juniperus) and eastern red cedar (J. virginiana).
an area. In Japan, for example, Siberian air masses bring severe winters to some forests, while other forests are influenced by warm ocean currents, and have a more tropical climate.
The most severe climate is found in the boreal forest, or taiga, where temperatures are below freezing for more than half of the year. Winter temperatures range from -65° to 30°F (-54° to -1°C), and summer temperatures from 20° to 70°F (-7° to 21°C). However, because the taiga is a land of extremes, temperatures can drop as low as -76°F (-60°C) in winter or climb as high as 104°F (40°C) in summer.
Record holding trees!
Not to be outdone by the redwoods with their reputation as the world’s tallest trees, the Mexican cypress has its own world record. An outstanding individual cypress in Tule, Mexico, known as “El Gigante,” is the world’s fattest tree. Although El Gigante is only 140 feet (43 meters) tall, the circumference of its trunk measures 115 feet (35 meters).
Most of the precipitation (rain, snow, or sleet) in the boreal forest comes from summer rain, which averages 12 to 33 inches (30 to 85 centimeters) per year.
Mountain coniferous forest
Mountain forests face cold, dry climates and high winds. The higher the elevation, the harsher the conditions. Scientists estimate that for every 300 feet (91 meters) in elevation, the temperature drops more than 1°F. On Alaskan mountains, temperatures in January average about 8°F (-13°C) and in July only 47°F (8°C).
In general, northern hemisphere forests found on the northern side of mountains are shaded from the sun and the air is cooler. The forests receive more rainfall and have denser stands (groups) of trees and other plants. Forests on the southern side of mountains are drier, warmer and have less vegetation.
Temperate evergreen forest
The redwood and Pacific Northwestern forests have a climate that is moderated by the Pacific Ocean and the coastal mountain ranges. In the Olympic Rain Forest in Washington, for example, the temperature is always above freezing in winter and is seldom higher than 85°F (29°C) in summer. Up to 145 inches (368 centimeters) of rain fall annually.
Temperate pine forest
In the Mediterranean and parts of California, winters are warm and wet, while summers are hot and dry. Droughts (extremely dry periods) may be common. In the Mediterranean region, for example, winter temperatures usually do not fall below freezing.
Southern hemisphere coniferous forest
The climate in Southern Hemisphere forests varies, depending upon where they are located. In the tropics (the regions around the equator), where the forests are at higher elevations, clouds of mist may blanket them creating cool and damp conditions. In more temperate regions, such as in the mountains of Chile, conditions are drier and colder.
Geography of Coniferous Forests
The geography of coniferous forests includes land-forms, elevation, soil, mineral resources, and water resources.
Coniferous forest landforms vary, depending upon the location, and may include mountains, valleys, rolling hills, or flat plateaus. The boreal forest landscape is dotted with wet-lands, lakes, and ponds. Unique to the Canadian and Alaskan forest is the muskeg, a type of bog or marsh with thick layers of decaying plant matter. The muskeg looks like moss-covered ground, but is actually so wet and spongy that hikers may sink while passing through. When the muskeg freezes in winter, irregularly shaped ridges, called hummocks, may form.
Treeless hollows are often found in coniferous forests in the Northern Hemisphere. These hollows are usually created when glaciers move over the area and destroy the trees. The glaciers also leave behind basins that eventually fill with water and become lakes. Streams and rivers are common in these forests as well.
Coniferous forests grow at different elevations throughout the world, from sea level (the average height of the surface of the sea) to more than 15,000 feet (4,600 meters) above sea level. Temperate rain forests along the northern Pacific coast are usually found below 2,700 feet (820 meters). The mountain forests in the Pacific Northwest range between 3,000 and 7,000 feet (910 and 2,100 meters), and those in the Rocky Mountains between 4,000 and 7,500 feet (1,200 and 2,300 meters). The giant Sequoias in the Sierra Nevada Mountains grow between 4,500 and 8,000 feet (1,400 and 2,400 meters). Subalpine forests in the Sierra Nevadas are found between 6,500 and 11,000 feet (2,000 and 3,400 meters) and in the Rockies between 7,500 and 11,500 feet (2,300 and 3,500 meters).
In Peru, mountain forests begin around 9,800 feet (3,000 meters) and subalpine forests grow to an altitude of 15,000 feet (4,500 meters). In central Japan, mountain forests are common above 6,560 feet (2,000 meters), however, on the island of Hokkaido, coniferous forests are
The oldest of all living things?
High in the Rocky Mountains of southwest California, Nevada, Utah, Arizona, New Mexico, and Colorado live the bristlecone pines, the oldest trees in the world. A tree cut down on Wheeler Ridge contained 4,900 rings of growth, and the oldest living specimen, the Methuselah Tree of California, is estimated at 4,800 years old. These twisted, ancient trees exist only at high altitudes—between 8,000 and 10,000 feet (2,432 and 3,040 meters)—and seldom grow more than 30 feet (9 meters) tall.
found at sea level. Himalayan conifers dominate below 10,000 feet (3,000 meters) and Himalayan firs above that point.
The presence of trees protect soil from erosion by holding it in place with their roots. Even fallen trees are important in conserving and cycling nutrients back into the soil and in reducing erosion. Trees also create windbreaks that help prevent topsoil from being blown away. A coniferous forest’s soil is acidic because the needles of coniferous trees have high acid content. The soil is also affected by both climate and location.
In the boreal forest, for example, soil is poorly developed because of the cold temperatures. In areas adjacent to tundra, a layer of permafrost (permanently frozen soil) prevents rain and melting snow from being absorbed deep into the ground. The topsoil is soggy because the moisture stays close to the surface. Cold temperatures are also responsible for the slow rate of decomposition of dead plants and animals, which means that soil forms slowly and there are not a lot of soil-mixing creatures.
Mountain soil is usually dry because the sloping terrain allows rain and melting snow to run off. This runoff washes away nutrients. The soil often makes up only a thin layer over a rocky foundation. As a result, tree roots do not penetrate deeply.
In the temperate evergreen forests of North America, the soil is often reddish in color and high in aluminum and iron. Decomposition takes place rapidly because of the high moisture content. This richer soil supports more plant growth on the forest floor.
Mineral resources found deep in the ground below coniferous forests began developing millions of years ago. As ancient trees died and soil gradually built up over them, their remains were compressed and evolved into coal, oil, and natural gas in a process that takes millions of years.
Broad-leaved evergreens—the trees-in-between
In northern climates, most broad-leaved trees lose their leaves in the autumn. However, some that live in climates where winters are mild but wet and summers are hot and dry remain green all year long. They are not conifers, because they are flowering plants that produce seeds enclosed in fruits, but they have learned to conserve moisture as conifers do by producing small leaves that they retain for several years. In effect, they are somewhere in-between conifers and deciduous trees, having characteristics of both. Common species include the olive tree of the Mediterranean region, the eucalyptus of Australia and South America, the cork oak of Spain and Portugal, and the canyon live oak of California.
Certain broad-leaved evergreens have other unusual characteristics. For example, the cork oak produces bark as thick as 1 foot (30 centimeters), which can be harvested and used for corks. Another example is the eucalyptus, the giant tree of the southern hemisphere. Called the “giant gum” in Australia, some trees attain heights of 300 feet (91 meters), rivaling the giant Sequoias of the Northern Hemisphere.
In northern Russian forests, coal, oil, and gas are found beneath the forest floor. In other parts of the taiga, aluminum is mined. In the province of Cita in far eastern Russia, mining and primary-ore processing dominate the economy. Gold, tin, tungsten, molybdenum, and lead are among the many minerals found there.
Gold was often mined from the rivers and streams that run through the forests of the Pacific northwest in the United States and Canada, and nickel was occasionally found in the northern forest of Manitoba, Canada.
A job in the woods
Forestry is the profession that deals with development and management of forests. The main objective is to ensure that there will always be trees and a supply of timber. Foresters are also involved with the conservation of soil, water, and wildlife resources, and with preserving land for recreation. By the mid-1990s, there were more than 20,000 foresters and conservation scientists in the United States, and about 50 colleges and universities offered degrees in the field.
Silviculture is a branch of forestry focused on forest growth. Foresters in this branch cultivate different types of forests and encourage them to grow as quickly as possible using such methods as fertilizers. Some forests are developed for lumber, paper, or pulp. Researchers use scientific breeding methods to raise the type of tree best fit for each purpose.
With a need for superior quality trees grown for specific uses, cloning may become a tool of the forester. A clone is the genetically identical copy of an organism. An entire forest could be cloned from one ideal parent tree.
In temperate regions, water resources include rivers, streams, springs, lakes, and ponds. Permafrost prevents water from sinking very deeply into the soil, so wetlands, lakes, and ponds form in the boreal forests. Mountain forests are often dotted with lakes and ponds that were carved out by glaciers. Mountains formed by volcanic action usually have craters that filled with water and became lakes. Crater Lake in Oregon is an example of such a lake.
Most forests contain a mixture of trees, and coniferous forests are no different. Stands of deciduous (dee-SID-joo-uhs) trees, such as larches (a type of conifer), birches, and poplars, may exist within their boundaries. (Deciduous trees lose their leaves at the end of each growing season.)
These mixed trees and smaller plants grow to different heights forming “layers” in the forest. The tallest trees create a canopy, or roof, over the rest. In the coniferous forest, these trees are often spruces and firs. Beneath the canopy grows the understory, a layer of shorter, shade-tolerant trees, such as the Pacific dogwoods of California. The next layer, only a few feet off the ground, is composed of small shrubs, such as junipers, blueberry, witch-hobble, and mountain laurel. Growing close to the ground are wild flowers, grasses, ferns, mosses, and mushrooms. In a coniferous forest, the canopy is so dense that little light is able to penetrate down to the forest floor. As a result of this limited light and high humidity, organisms such as algae, fungi, and lichens tend to flourish.
Algae, fungi, and lichens
It is generally recognized that algae (AL-jee), fungi (FUHN-ji), and lichens do not fit neatly into the plant category. In this chapter, however, they will be discussed as if they were plants.
Many algae are single-celled organisms, although quite a few are multicellular. Most algal species have the ability to make their own food by means of photosynthesis (foh-toh-SIHN-thuh-sihs), the process by which plants use the energy from sunlight to change water and carbon dioxide into the sugars and starches they use for food. Others absorb nutrients from their surroundings.
Algae may reproduce in one of three ways. Some algae split into two or more parts, each part becoming a new, separate plant. Other algae form spores (single cells that have the ability to grow into a new organism). A few algae can reproduce sexually, during which cells from two different plants unite to create a new plant.
Unlike algae, fungi cannot make their own food by means of photosynthesis. Some fungi, like mold and mushrooms, obtain nutrients from dead or decaying organic matter (derived from living organisms). They assist in the decomposition (breaking down) of this matter and in releasing into the soil the nutrients needed by other plants. Parasitic fungi attach themselves to other living things. Fungi reproduce by means of spores.
One type of fungi, called mycorrhizae, surround the roots of conifers, helping them absorb nutrients from the soil. Slippery jack, a toadstool fungus that grows in coniferous forests, gets its name from the slimy material on its cap.
Lichens are combinations of algae and fungi that live in cooperation. The fungi surround the algal cells, and the algae produce food for themselves and the fungi by means of photosynthesis. The fungi may help keep the algae moist. In harsher climates, such as that of the forest-tundra, lichens are often the only vegetation to survive. They have no root system and they can grow on bare rock. While their growth is slow, lichens often live for hundreds of years. Hemlock forests may contain as many as 150 species of lichens. Reindeer moss, a common type of lichen, is found in many coniferous forests.
Like algae, lichens can reproduce in several ways. If a spore from the fungus lands next to an algea, they can join together to form new lichen. Lichens can also reproduce by means of soredia. Soredia are algal cells with a few strands of fungus around them. When soredia break off, they may form new lichens wherever they land.
Green plants other than trees
Most green plants need several basic things to grow: light, air, water, warmth, and nutrients. In the coniferous woodland, light, water, and warmth are not always abundant. Nutrients, such as nitrogen, phosphorus, and potassium, are obtained from the soil,
which may not always have a large supply. For this reason, plants beneath many coniferous trees can be sparse and must often make special adaptations in order to survive. The pitcher plant, for example, catches insects for food, while others compete with trees for space and nutrients by emitting chemicals into the soil that prevent the germination of trees.
Coniferous woodlands are home to both annual and perennial plants. Annuals live only one year or one growing season. Perennials live at least two years or two growing seasons, often appearing to die when the climate becomes too cold or dry, but returning to life when conditions improve.
Common coniferous forest green plants other than trees
Typical green plants found in coniferous forests include mosses, forbs, and ferns.
Mosses Mosses are plentiful in forests; as many as 25,000 species exist. They grow on the ground, tree trunks, decaying logs, and rocks. Mosses range in size from a few millimeters to rare varieties that reach 6.5 feet (2 meters) long. Each moss plant is formed like a tiny tree, with a single straight trunk and leaflike structures growing from it. Mosses grow close together and can store large quantities of water.
Plume moss, also called feather moss or boreal forest moss, resembles an ostrich plume. It forms dense, light-green mats on rocks, rotten wood, or peaty (highly rich, organic) soil, especially in mountain forests of the Northern Hemisphere.
Some mosses are epiphytes, plants that grow on other plants for physical support. Epiphytes are found in warmer climates, such as that of the Pacific Northwest. They absorb water and nutrients from rain and debris that collects on the supporting plants rather than from their own roots.
Forbs Forbs are non-grass, non-woody, flowering plants. They have extensive root systems, and some can live as long as 50 years. Yellow trout lilies, large-flowered trilliums, and lupines are most common in non-conifer forests. Because little sunlight may reach the forest floor, some forbs store food in bulbs and rootstocks beneath the ground. Their small flowers grow low to the ground, and bloom before taller plants block all sunlight.
Ferns Many species of ferns grow in coniferous forests. Ferns are nonflowering perennial plants, which reproduce by means of spores. Sword ferns are long and wispy, with toothed leaflets. Licorice ferns grow on tree trunks and stumps and are often seen draped over branches. Deer ferns prefer the moist forest floor.
Location, soil, and moisture all help to determine the number and types of green plants that grow in the forest. Many different plants are found in the temperate evergreen forests, where the rich soil, warm climate, and moisture promote growth year-round. Fewer plants are found in the colder, drier, boreal forests where the growing season may last only about twelve weeks. In the hot, dry climate of the Mediterranean forests, plant growth prospers during the rainy, winter season.
Most green plants, such as wildflowers, reproduce by means of pollination (the process during which pollen is carried by visiting animals or the wind from the male reproductive flower part to the female reproductive part). As the growing season comes to an end, seeds are usually produced. The seed’s hard outer covering protects it during cold winters, or long dry seasons until it sprouts.
A few woodland plants, such as ferns, reproduce by means of spores. Perennial grasses produce rhizomes—long, rootlike stems that spread out below ground. These stems develop their own root systems and send up sprouts that grow into new plants.
Most coniferous trees have a single strong stem, or trunk, and live 100 to 250 years. Some of the oldest living things on Earth are the bristlecone pines of the western United States, which may be as old as 5,000 years. Most of the tree’s growth is directed upward. Redwoods can reach nearly 400 feet (122 meters) in height and their trunks may weigh over 1,000 tons (907 metric tons). While broad-leaved trees spread their limbs and branches out from the trunk to create a crown of leaves, conifers devote their energy to growing taller. Without interference from diseases, natural disasters, and human interference, these trees can attain huge proportions.
Each year a tree grows, its trunk is thickened with a new layer, or ring, of cells. When the tree is cut down, its age can be determined by how many of these rings are present, although those in conifers are not as pronounced. As the tree ages, the cells from the center outward become hardened to produce a sturdy core. Like all green plants, trees grow by means of photosynthesis, during which they release the oxygen essential to animals and humans back into the air.
In general, trees are divided into two groups according to how they bear their seeds. Angiosperms have flowers and produce their seeds inside fruits, and many shed their leaves during cold or very dry periods. Broad-leaved trees, such as oaks and elms, are often angiosperms. Conifers are gymnosperms that produce seeds on scales that are usually clustered to form a cone, which may be woody or berrylike. Gymnosperm seeds are “naked,” not enclosed in fruits.
Conifers are well adapted to cool or cold temperatures and long dry periods. Their stiff, narrow needles prevent loss of moisture and offer less resistance to strong winter winds, which results in less wind damage. They stay green all year and are often called “evergreens.” They remain ready for sudden warm weather and can take advantage of a short growing season. Coniferous trees do not shed their needles every autumn. However, evergreens do shed the inner growth of needles approximately every two to three years. Since these needles were formed during past growth, their loss does not hinder new growth of the tree.
Fir trees are cone-shaped and can grow between 30 and 150 feet (9 and 46 meters) tall. Their needles are very fragrant and remain on the tree long after it has been cut. These characteristics make them a popular choice as a Christmas tree.
Common coniferous trees
Common coniferous trees include parana pine, bunya pine, lodgepole pine, white pine, yew, Norway spruce, and yellowwood.
Parana pine In South America, the parana pine, or candelabra tree, is a conifer found in the hilly countries of Brazil and Argentina. It is a slow-growing tree with a very straight trunk that can reach a height of 150 feet (46 meters) with a diameter of 12-70 inches (30-180 centimeters). It is an important source of timber because its trunk has no branches up to 100 feet (30 meters)—it can produce up to six, 16 foot (5 meter) logs. The parana pine is being overharvested because it grows very slowly, so it is being replaced by other types of faster-growing pines. It is commonly found on high mountain ranges at elevations 1,800-3,500 feet (550-1,100 meters) above sea level.
Bunya pine The fast-growing bunya pine is a large Australian conifer native to the ranges and rain forests of Brisbane. Reaching 147 feet (45 meters) or more in height, it is known for its large leafy crown and symmetrical branches. The wood is used for boxes, plywood, and veneers. The bunya produces both male and female cones. The female cones contain edible seeds and can weigh as much as 22 pounds (10 kilograms). Even though the trees can only be harvested every three years, the food is plentiful enough to be useful.
Lodgepole pine The lodgepole pine is common in British Columbia, the Pacific Northwest, the Rocky Mountains, and along the Alaskan coast. Its needles are about 2 inches (5 centimeters) long and very sharp. Cones are yellowish brown, often grow in clusters of six or more, and are 0.8 to 1.6 inches (2 to 4 centimeters) long. Because the tree is so straight, Native Americans used the trunk as the main support in their lodges, giving the tree its name. Today it is also commonly used as plywood and paneling.
White pine The white pine is a valuable North American timber tree for its large trunk and soft, even wood. Capable of reaching 200 years of age, it ranges between 50 and 100 feet (15 and 30 meters) in height, has a trunk more than 3 feet (1 meter) in diameter, and needles 3 to 5 inches (8 to 13 centimeters) long. Eastern white pines once grew in large stands in Maine and Minnesota, as well as Manitoba, Canada. Western white pines once flourished in British Columbia and the northwestern United States. However, because of overharvesting, very few of either species remain.
Yews Once widespread in Europe, the Yew is now rare and protected. Native to Scandinavia and North Africa, it can also be found from Great Britain to the Asia minor, as well as in Syria, Iran and the Himalayas. This small tree, not usually taller than 82 feet (25 meters), is quite poisonous, though it has been historically used in medicinal remedies, and is currently used to treat some cancers. The Fortingall Yew tree in Glen Lyon, Perthshire, Scotland is estimated to be 3,000 to 5,000 years old. This tree does not form the rings traditionally used to calculate age, so its age can not be determined accurately.
Norway spruce Norway spruces have thick crowns and grow symmetrically, sometimes to heights of 150 feet (46 meters). Cones are long and tapered, and male cones produce so much pollen that the forest floor is often yellow from it. Norway spruces are common in Europe and Asia.
In general, forests need at least 10 to 15 inches (25 to 38 centimeters) of annual precipitation and at least 14 weeks of weather warm enough to promote growth. However, these conditions vary depending upon the location of the forest.
The growing season in the taiga, for example, is short, lasting only about 12 weeks. With little precipitation and cold temperatures, trees do not develop well. Even the oldest of trees is short and stunted. Sub-alpine forests also experience harsh climates, but their growing season is longer, enabling trees to grow taller.
Forests in more temperate climates have more moisture, warmer weather, and a longer growing season. Growing conditions are so favorable in the Pacific Northwest, trees like the redwoods grow to gigantic proportions. Warm pineland climates also produce rapid growth, as long as the rainy season is consistent.
Lodgepole pines and jack pines are among the first trees to grow after a fire. Their seeds are sealed in cones by resins (sap) and may remain inactive for a long time on the forest floor. Some lodgepole pine seeds, for example, have been known to survive this way for more than 80 years. Only the heat from a fire can melt the resin, thus releasing the seeds. The seeds quickly germinate in the ash-enriched soil, and a new forest begins to grow.
Coniferous plants have female and male cones, many of which grow on the same tree. Male cones are small and soft. They produce pollen that fertilizes the eggs in the female cone. These eggs become seeds, which eventually fall from the cones and produce new trees.
Conifers also reproduce by layering. Layering occurs when a branch that is low to the ground is covered by soil. Roots form from the buried portion of the branch and grow into a new tree.
Trees can be threatened by natural dangers, such as forest fires, animals, and diseases, as well as by humans. Fires are more of a threat in dry climates, while animals and diseases seem prevalent in all climates. For example, when deer populations get too large, they can destroy forests by eating wildflowers and tree seedlings. Also, if enough insects attack a stand of trees, all the leaves are eaten and the trees die. Pollution is a serious threat because it appears to weaken trees, allowing pests and diseases to overtake them more easily.
In New Zealand, the kauri pine, once threatened by overharvesting, is now protected. At 200 feet (61 meters) tall, it is one of the largest commercial trees in the world. Similarly, forests in the Himalayan Mountains in Asia are currently being overharvested. In the European Alps, people have interfered with forest growth to such an extent that the trees now grow 500 feet (152 meters) lower on the mountain slopes than they did 1,000 years ago. According to the World Conservation Union (IUCN), 25 percent of all conifers in the world are endangered.
Coniferous forests support a wide range of animals, and different regions are home to different species. These animals can be classified as micro-organisms, invertebrates, amphibians, reptiles, birds, and mammals.
A microorganism is an animal, such as a protozoan, that cannot be seen without the aid of a microscope. Every forest is host to millions of these tiny creatures. Microscopic roundworms, or nematodes, for example, live by the thousands in small areas of soil in coniferous forests and aid the process of decomposition.
Bacteria are microorganisms that are always present in woodland soil where they help decompose dead plant and animal matter. In temperate climates, bacteria help create nutrient-rich humus (broken down organic matter). Fewer bacteria are at work in dry climates or in moist climates with long dry seasons.
Animals without backbones are called invertebrates. They include simple animals such as worms, and more complex animals such as the wasp and the snail. Certain groups of invertebrates must spend part of their lives in water. These types are not usually found in the trees, but in ponds, lakes, and streams, or in pools of rainwater.
Insects are found in abundance in coniferous forests and they multiply very quickly when the weather warms up. Mosquitoes and midges swarm in clouds in boreal forests.
Common coniferous forest invertebrates
The pine panthea moth caterpillar and white pine weevil live on white pine trees. The caterpillar eats the needles and the weevil’s larva eats the new shoots at the tips of stems. Because the weevil kills the shoots at the top, new shoots grow out of the sides of the stem instead, and the tree grows crookedly.
Engelmann spruce bark beetles, which bore under tree bark, live in the high spruce forests in Colorado. At one time the beetle population became so numerous that millions of spruce trees were killed.
The caterpillar of the pine hawk moth does serious damage to European pine trees. However, the adult moth, which lives only long enough to mate and lay eggs, eats very little.
The green plants in the forest provide food for some insects, such as caterpillars and moths. Other insects, like wood ants and pine-bark beetles, eat dying or dead trees. Certain insects have very specific food requirements. Caterpillars of the Pandora moth feed on healthy pine trees, often killing them. White pine butterfly larvae feed only on the needles of the Douglas fir. Some insect larvae store fat in their bodies and do not have to look for food.
Snails prefer to eat plants, while bees, butterflies, and moths gather pollen and nectar (sweet liquid) from flowers. Arachnids (spiders), which are carnivores, prey on insects. If they are big enough, certain spiders can eat small lizards, mice, and birds.
The first part of an insect (the most common invertebrates) life cycle is spent as an egg. The second stage is the larva (such as a caterpillar), which may actually be divided into several stages between which the outer casing is shed as the animal increases in size. During the third, or pupal, stage, the animal’s casing offers as much protection as an egg. An example of this stage is seen when a caterpillar spins a cocoon to live in while it develops into a moth. Finally, the adult emerges, usually by chewing its way out of its casing.
In coniferous forests, insect eggs and pupae are found on twigs, under the snow, or in tree cracks. Caterpillars often emerge from eggs laid in the bark of trees. Some insects are picky about the trees they use. The white pine butterfly, for example, deposits its eggs only in Douglas firs. Pools of water on the damp forest floor provide a good location for the breeding of insects that require water, especially mosquitoes and midges.
Amphibians are vertebrates (animals with backbones) that usually spend part, if not most, of their lives in water. Most amphibians are found in warm, moist, freshwater environments and in temperate zones (areas where temperatures are seldom extreme). Amphibians found in coniferous forests include salamanders, newts, toads, and frogs. They generally live in moist areas like the underside of a log or beneath a mass of leaves. Only a few amphibians are found in the colder boreal forests.
Amphibians breathe through their skin, and only moist skin can absorb oxygen. Therefore, they usually remain close to a water source, although mature animals leave the pools for dry land where they feed on both plants and insects. In warm climates, amphibians must find shade during the day or risk dying in the heat of the sun.
Amphibians are cold-blooded animals, which means their bodies are about the same temperature as their environment. As temperatures get cooler, they slow down, seeking a warm environment in order to remain active. During the winter season in temperate climates, they hibernate (remain inactive). In hot, dry climates, amphibians go through estivation, an inactive period similar to hibernation. While the soil is still moist from the rain, they dig themselves a foot or more into the ground, where they remain until the rain returns. Only their nostrils remain exposed to the surface.
Common coniferous forest amphibians
The black salamander is commonly found in the high mountain forests in Europe, especially where Norway spruces grow. The black coat of the salamander absorbs heat and helps maintain a higher body temperature. The salamander is viviparous (vy-VIP-ah-ruhs), meaning that the young are kept inside the mother’s body until they are fully developed.
The Pacific tree frog, which lives in the Pacific coast coniferous forests, is small and slender with long legs and suction cups on the bottom of its toes that aid in climbing.
Amphibians often use their tongues to capture their prey. Even though some have teeth, they swallow their food whole without chewing. Their larvae are mostly herbivorous, feeding on vegetation. Adult frogs and toads feed not only on algae and other plants, but also on insects, such as mosquitoes.
Mating and egg-laying for most amphibians must take place in water. Usually, male sperm are deposited in the water and swim to and penetrate the jellylike eggs laid by the female. As the offspring develop into larvae and young adults, they often have gills for breathing that require a watery habitat. Once they mature, they develop lungs and can live on land. Male salamanders deposit sperm directly into the female for internal fertilization of the eggs.
Some amphibian females carry their eggs inside their bodies until they hatch. Certain species protect the eggs until the young are born, while others lay the eggs and abandon them.
Most amphibians reach maturity at three or four years. They breed for the first time about one year after they become adults.
Reptiles are cold-blooded vertebrates, such as lizards, turtles, and snakes, that depend on their environment for warmth. They are usually most active when the weather is warm. Reptiles do not do well in extreme temperatures, whether hot or cold. During hot, dry periods, they find shade or a hole in which to wait for cooler weather. During chilly nights, they become slow and sluggish. In temperate climates, snakes may hibernate in burrows during the long winter.
Common coniferous forest reptiles
Garter snakes, rattlesnakes, western pond turtles, and skinks are all found in the California redwood forests. Skinks are lizards, some of which climb trees. Some species are herbivorous, while others eat mostly insects.
The web of life: Predator and prey
Some people shudder at the thought of predators killing deer. After all, deer are so cute and those mountain lions and wolves so bloodthirsty! But a balance is needed between predators and prey or other problems arise. For example, in 1905, the Kaibab Forest in Arizona supported about 4,000 deer. Because the forest had the potential of supporting up to 30,000, people who wanted to enlarge the deer herd destroyed the predators that fed on the deer. They killed 7,000 coyotes, 716 mountain lions, and a number of wolves.
By 1918, the deer herds had increased to more than 40,000, and the plants the deer used for food began to diminish. By 1923, the herd had increased to 100,000, and many food plants had been completely wiped out. During the winter of 1924–25, 60,000 deer, many of which were fawns, died of starvation. The only solution was to restore the balance and return the predators to the forest.
African pine forests are home to the agama lizard. Other reptiles found in dry regions include many species of snakes such as the night, the puff, and the Gabonan adders.
Most reptiles are carnivorous. Snakes consume their prey whole—and often alive—without chewing. Their teeth can curve backward, which keeps their prey from escaping. It can take an hour or more to swallow a large prey.
A lizard’s diet varies, depending upon the species. Some have long tongues with sticky tips and specialize in insects. Many are carnivores that eat small mammals and birds. The water they need is usually obtained from the food they eat. Turtles, for example, feed on soft plant material, small animals, or both.
Most reptiles reproduce sexually, and their young come from eggs. The eggs are leathery and tough, and the offspring are seldom coddled. Some females remain with the eggs, but most reptiles bury the eggs in a hole and abandon them. The young are left to hatch by themselves. Once free of the eggs, the babies dig themselves out of the hole and begin life on their own.
Coniferous forests are home to hundreds of bird species. Some, such as insect-eating wood warblers, Canada geese, and northern goshawks, are migratory, which means they travel from one seasonal breeding place to another. Canada geese and northern goshawks return to northern forests by the thousands each spring and summer from areas with warmer winter climates.
During excessively cold or dry periods, birds can fly to more comfortable regions. Some birds, such as the blue jay, live in a particular forest year-round. If food is plentiful, the evening grosbeak, pine siskin, and red crossbill also choose to not migrate during the winter weather.
Feathers protect birds not only from cold winters but also from tropical heat. Air trapped between the layers of feathers acts as insulation.
Common coniferous forest birds
In temperate forests, common birds include screech owls, great horned owls, hummingbirds, woodpeckers, nuthatches, wood thrushes, American redstarts, hawks, blue jays, cardinals, scarlet tanagers, chickadees, and turkey vultures. Wrens, falcons, weaverbirds, thrushes, and chats are found in dry regions. Other common forest birds include the American dipper and the crossbill.
American Dipper The American dipper lives year-round in the mountain forests along the Pacific coast, from Alaska to Mexico. These birds stay near swift streams in which they wade and swim in search of insects, freshwater shrimp, snails, and fish. Since the dipper must dive into the water to catch its food, it maintains a waterproof covering. The dipper spreads oil over its feathers from oil glands and a special flap keeps water out of its nostrils. Its long toes help it grasp underwater surfaces. Dippers can stay submerged for about 30 seconds and dive as deep as 30 feet (9 meters).
Dippers breed in February or March and lay their eggs in nests made out of materials found along the streams in which they hunt for food. Baby birds hatch after about two weeks and learn to dive very quickly.
Crossbill The crossbill lives year-round in coniferous forests and has a beak specially designed for digging the seeds out of pine cones. Only 5.5 to 6 inches (14 to 15 centimeters) in length, crossbills eat about 1,000 seeds each day. Different species of crossbills vary in color, like red or yellow, and their beaks are shaped differently depending upon where they live and what kind of cones they must open. The birds summer in the more northern forests in Alaska and Canada and winter in the warmer mountain forests of North Carolina and Oregon.
Millions of insects attract summer birds, such as kinglets, woodpeckers, and flycatchers, to coniferous forests. Birds that stay in the forest all year must work hard for their food during the winter. For example, the nutcracker uses its powerful jaws to rip open cones for seeds. Blue grouse and the capercaillies, the largest species of European
Rare bird in a rare forest
Kirtland’s warblers are rare songbirds that breed only in young jack pine forests in north-central Michigan. They usually build their nests on the ground under the small, growing trees. After jack pines reach more than 20 feet (6 meters) in height and no longer provide enough shelter, the birds abandon them. However, new jack pines will sprout and grow only after a forest fire, many of which are put out by humans. As a result, few new trees grow and, therefore, few warblers can raise families.
grouse, have an easier time, preferring to eat the conifer needles. Small birds and rodents are food for predators like eagles, owls, and hawks.
All birds reproduce by laying eggs. One parent sits on the eggs to protect them from heat or cold until they hatch.
Mammals are warm-blooded verte-brates having some hair. They bear their live young and produce their own milk. A few large mammals, such as mountain lions, bears, and deer, live in northern coniferous forests. Most coniferous forests are home to many small mammals, including mice, squirrels, woodchucks, and foxes.
During cold winters, mammals may burrow underground or find shelter among thick evergreens or under the snow. Snow dens are used by shrews and voles that remain active all winter. Some mammals, such as black bears, hibernate. In a study completed by the University of Iowa, the bear’s heart rate dropped from 40–50 beats per minute to only 8 beats per minute while in hibernation. This is the bear’s method of conserving body energy. Chipmunks accumulate deposits of fat below their skin that help insulate them and provide nourishment while they hibernate. In dry, warm climates, small mammals may remain inactive during hot weather.
Common coniferous forest mammals
Common mammals found in the boreal forest are wolverines, grizzly bears, lynxes, pine martins, minks, ermines, and sables. These animals are all predators and feed on other common boreal mammals like voles, snowshoe hares, marmots, and tiny tree mice. Chamois, red deer, moose, and elks live in the European mountain forests, while the mountain forests in Canada are home to moose, beavers, Canadian lynxes, black bears, and wolves.
Tree Vole The tree vole spends most of its life at the top of fir trees in the Pacific Northwest and almost never walks on the ground. This small mammal is a type of rodent with a stout body and short tail. Voles construct treetop nests and tunnels from twigs and eat parts of pine needles.
Wolverine The wolverine is the largest member of the weasel family and grows to be about 4 feet (1.2 meters) long from the tip of its nose to the end of its tail. This stocky carnivore can weigh up between 24 and 40 pounds (10.9 and 18.1 kilograms). Thick fur protects them from the snow and cold. Wolverines live in North America and Eurasia and are famous as savage hunters and ravenous eaters, capable of killing and eating an entire deer. They may wander up to 15 miles (24 kilometers) at a time to locate food, and can live up to twelve years in the wild.
Female wolverines give birth in early spring to two to four pups. The nest is usually in a crevice or other protected spot.
Chamois The chamois (SHAM-ee) is a small goatlike, antelope found in European mountain forests in the Alps, Pyrenees, and Dolomites. The males range from 65-110 pounds (29-59 kilograms) in size, and measures from 3 to 4 feet (1 to 1.2 meters) in length. The females are typically slightly smaller. Both males and females grow straight horns with backward-bending tips. In the summer, the chamois is reddish-brown in color with a black stripe on the rump. In the winter, its coat turns black or brown to help absorb heat.
The chamois has adapted to the mountains by developing rubbery hoof pads that help the animal keep its footing on slippery rocks. It eats mountain vegetation, especially clover, and some fir needles. If winter is especially harsh, the chamois moves to deciduous forests at lower elevations to find food. The chamois can live up to seventeen years in captivity.
Grizzly Bear The grizzly bear is one of the fiercest animals in North America. They are strong enough to carry full-grown cattle. Most have broad heads, extended jaws, big paws, and powerful claws. Grizzlies eat insects, like ants and bees, as well as seeds, roots, nuts, and berries. They also eat salmon, and are famous for their fishing skills.
Mammals may be herbivores (plant eaters), carnivores (meat eaters), or omnivores (plant and meat eaters). Moss and lichens provide food for caribou, while downed trees and brush feed beaver and elk. Green plants, such as rushes, feed marmots and voles. Shrews eat insects that they dig out of the ground. Some carnivores, like the wolf, hunt in packs for deer and other animals. Bears are omnivores.
Mammals give birth to live young that have developed inside the mother’s body. Some mammals, like the hare, are helpless at birth, while others, such as deer, are able to walk and even run almost immediately.
In the United States, acid rain (a mixture of water vapor and polluting compounds in the atmosphere that falls to Earth as rain or snow) has endangered the peregrine falcon. The grizzly bear,
beaver, and timber wolf are threatened in the United States and Canada. In Australia some species of kangaroos are threatened.
Kirtland’s warblers are endangered song-birds that conceal their nests in shrubs below five- to twenty-year-old jack pines in north-central Michigan. New jack pines sprout and grow only after a forest fire, many of which are put out by humans. As a result, few new trees grow and few warblers can raise families, making it a rare bird.
Before the great expansion of the population westward, it is estimated that 100,000 grizzly bears lived in North America. By the 1990s, fewer than 1,000 existed, with most of them living in preserves such as Yellowstone National Park, though some can be found in British Columbia, Alberta, the Yukon, and the Northwest Territories. Even though grizzly bears are occasionally shot, the greatest threat to the bear’s survival is destruction of its habitat. Since bears are huge animals, weighing as much as 1,000 pounds (454 kilograms), they require large spaces to roam and huge quantities of food. In 2006, the World Conservation Union (IUCN) listed the grizzly bear as low risk and conservation dependent.
The beaver once ranged over North America from Mexico to the Arctic regions. It was widely hunted for its fur and for a liquid called castorium, produced in the beaver’s musk glands and used in perfume. The beaver is now confined largely to northern wooded regions. Beavers were also common throughout northern Europe, where they are now almost extinct, except in some parts of Scandinavia, Germany, and Siberia.
Many animals, including humans, are creatures of the forest. In early North America, native tribes, such as the Nootka and Haida, lived in the forests, hunting, trapping, and gathering for their survival.
Impact of the coniferous forest on human life
Forests have an important impact on the environment as a whole by contributing to the environmental cycles. From the earliest times, forests have offered food and shelter, a place to hide from predators, and many useful products. Forests are an integral part of life on Earth.
Trees, soil, animals, and other plants all interact to create a balance in the environment from which humans benefit. This balance is often maintained in cycles.
The oxygen cycle Plants and animals take in oxygen from the air and use it for their life processes. When animals and humans breathe, the oxygen they inhale is used and carbon dioxide is given off as a byproduct. This oxygen must be replaced, or life could not continue. Trees help replace oxygen during photosynthesis when they release oxygen into the atmosphere through their leaves.
The carbon cycle Carbon dioxide is also necessary to life, but too much is harmful. During photosynthesis, trees and other plants pull carbon dioxide from the air. This helps maintain the oxygen/carbon dioxide balance in the atmosphere.
When trees die, the carbon in their tissues is returned to the soil. Decaying trees become part of Earth’s crust, and after millions of years, this carbon is converted into oil and natural gas.
The water cycle Coniferous forests shade the snow, allowing it to remain in deep drifts. The trees’ root systems and fallen needles help build an absorbent covering on the forest floor, letting water from rain and melting snow trickle down into the Earth to feed underground streams and groundwater.
Not only do forests help preserve water in this way, but they also protect the land from erosion during heavy rain by acting as a wall or barrier. When forests are cut down, there are no trees to act as barriers, and no tree roots to hold the soil in place, so it washes away. As a result, flooding is more common. For example, by 2007, 19 million residents of India and Bangladesh had been evacuated from their homes due to severe flooding, caused in part by cutting of forests in the nearby Himalaya Mountains.
Trees take up water through their roots and use it for their own life processes. Extra moisture is then released through their leaves back into the atmosphere, helping to form clouds and continue the water cycle.
The nutrient cycle Trees get the mineral nutrients they need from the soil. Dissolved minerals are absorbed from the soil by the tree’s roots and are sent upward throughout the tree. These mineral nutrients are used by the tree much like humans take vitamins. When the tree dies, these nutrients, which are still contained within parts of the tree, decompose and are returned back into the soil making them available for other plants and animals to use.
Since the earliest times, forests have been home to game animals, such as rabbits, which have supplied meat for hunters and their families. Forests also supply fruits, seeds, berries, and nuts. Several species of pines, for example, produce edible seeds (pine nuts) that are still collected by hand.
During prehistoric times, humans lived in the forest because it offered protection from predators and the weather. Today, people who choose to live in forested areas usually do so because they enjoy their beauty.
Forests are important to the world economy, since many commercially used products, such as wood, medicine, resins and oils, are obtained from forests.
Trees produce one of two general types of wood, hardwood or softwood, based on the trees’ cell wall structure. Hardwoods are usually produced by deciduous trees, such as oaks and elms, while most coniferous trees produce softwoods. These names can be confusing because some softwood trees, such as the yew, produce woods that are harder than many hardwoods and some hardwoods, such as balsa, are softer than most softwoods.
Wood is used not only for fuel, but also for building structures and manufacturing other products, such as furniture and paper. Hardwood from deciduous trees is more expensive because the trees grow more slowly. As a result, it is used primarily for fine furniture and paneling. Wood used for general construction is usually softwood, such as white pine, Douglas fir, and spruce. Araucaria and kauri are commercially important conifers of the Southern Hemisphere. In order to conserve trees and reduce costs, some manufacturers have created engineered wood, which is composed of particles of several types of wood, combined with strong glues and preservatives. Engineered woods are very strong and can be used for many construction needs.
Since the earliest times, plants have been used for their healing properties. For example, the yew was once considered a worthless ‘‘weed’’ tree and was burned by loggers after clearing a section of forest. Then taxol, an anti-cancer drug, was discovered in the bark of the yew. It takes the bark of six trees to make enough medicine for one cancer patient. In 1994, a synthetic form of taxol was created in the laboratory (though difficult to make) reducing the need for yew trees.
Resins and oils
Tree resins (REH-zihns; sap) and oils are also valuable. Conifer resins are used to make turpentine, paints, and varnish, while their oils are used as the fragrance in air fresheners, disinfectants, and cosmetics.
More people live in cities today than ever before, and many feel the need to occasionally escape to more natural surroundings. The beauty and quiet of coniferous forests draw many visitors for hiking, horseback riding, skiing, fishing, hunting, bird watching, or just sitting and listening to the sounds of nature.
Forest rivers are often dammed to provide a source of water for hydroelectric power. Norway, Sweden, Canada, and Switzerland rely heavily on hydroelectricity. The United States, Russia, China, India, and Brazil also use hydroelectric power, but on a smaller scale.
Impact of human life on the coniferous forest
Forests originally covered 48 percent of the Earth’s surface. Half of this quantity is now gone, and about one-fifth of the remainder are, as of yet, undisturbed. In North America, more than 430,000 miles (692,000 kilometers) of road cut through U.S. National Forests. Although it was once thought that forests of the far north were so inhospitable they were safe from human interference, the building of railroads made the area accessible. As a result, each year more land is being cleared for logging and mining operations.
Use of plants and animals
As more and more forest land is being developed, native vegetation and wildlife habitats are destroyed. Trees are cut down and used for lumber and other products. In Canada, for example, much of the timber in the southern forests is gone, and northern forests are now being invaded by logging companies.
Trees are not the only forest plants in danger from overharvesting. In northern forests, mosses from the forest floor are used as fuel by construction workers and are being removed in large quantities. Without the insulation provided by the moss, permafrost is melting and causing floods.
Logging is the harvesting of trees, sawing them into logs, and transporting them to a sawmill. About one percent of the world’s timber is cut down each year. Half of it is used for fuel, and the rest for wood products, paper, and packaging materials. Most trees used for paper products are raised on tree farms and do not come from wild forests.
In the nineteenth century, logging was done by men using hand axes and saws. This method took a lot of people and time. In the 1950s, power chainsaws were used, and, by the 1970s, a variety of machines had revolutionized the logging industry.
Because logging machines can cut trees no bigger than about 2 feet (0.6 meter) in diameter, large trees are still cut by hand. A wedge is chopped from the trunk on one side of the tree and a cut is made with a saw on the other side. This causes the tree to fall in the direction of the wedge. After the tree is down, the limbs are removed and it is cut into lengths that can be easily moved.
In general, trees are removed either selectively or by clear-cutting. With selective methods, only certain trees are cut from a stand (group of trees). With clear-cutting, all the trees from several acres (hectares) of land are removed. Ideally, trees of the same species are then replanted, but many times this is not the case.
In India, some logging is done by “girdling.” In girdling, a circular cut made around the tree trunk prevents water or nutrients from being carried to the branches. Several years later, when the tree is dead, it is harvested.
As too much logging destroys mountain forests, villages are at risk from landslides and avalanches that were once held in check by the dense trees.
Clear-cutting disrupts wildlife habitats, and new roads give hunters better access to wildlife, which sometimes results in overhunting. In some Canadian areas, for example, grizzly bears and bighorn sheep are now easy targets. Despite conservation efforts, parks and other protected areas are not necessarily safe from development. In British Columbia, mining interests have gained access to once-protected areas in parks.
Quality of the environment
The quality of the forest environment is threatened not only by the direct effects of logging, mining, and hydroelectric development, but also by pollution and visitors. Roads, drilling rigs, and pipelines, all a necessary part of mining, destroy wilderness and disrupt habitats. Mercury, a poisonous liquid metal used in gold mining operations, and waste from chemical and petrochemical plants contaminate forest water sources. In Lake Baikal in the Siberian taiga, for example, mining activities have destroyed life on the lake bottom.
Millions of acres (hectares) of forests in industrialized Europe, North America, and China are dead or dying from pollution and acid rain. Acid rain is a type of air pollution that forms when pollutants such as sulfur or nitrogen combine with moisture in the atmosphere to produce sulfuric or nitric acids. These acids can be carried long distances by the wind before they fall, either as dry deposits, or in the form of rain or snow. When acid rain is absorbed into the soil, it can destroy nutrients and make the soil too acidic to support some species of trees. In coniferous forests, acid rain causes needles to drop and their color to fade and turn brown. Forests in northern Europe, southern Canada, and the eastern United States have been damaged by acid rain.
A large increase in the number of tourists all over the world has also put a tremendous stress on the forest environment. Many “wilderness” areas are being developed, and fragile forests are endangered as tourists hike, bike, ski, and snowmobile over the vegetation and disturb wild animals with their noise.
The National Forest Service was established in the United States in 1905 to protect forest resources. More than 193,000,000 acres (78,000,000 hectares) of land are now publicly owned. Most of this acreage is west of the Mississippi. Forests in the eastern half of the United States are usually managed by state programs.
Most of these forests consist of areas that can be used for logging and other commercial purposes. However, the rest of the land is kept for recreation and conservation.
Several other nations, including Great Britain, Japan, China, and India, have also established programs to conserve and replant forests.
By 1950, native people in industrialized parts of the world had abandoned most of their tribal lands and customs. Many went to live in cities. In remote regions, some people still live a traditional lifestyle. For example, some taiga peoples are found in small Siberian towns that are accessible via the Trans-Siberian Railway. Other people live in mountain forests, especially in the Alps and Himalayas.
In the northern Asian taiga of Siberia, Mongolia, and China live the Evenki (which means he who runs swifter than a tiger). Traditionally, the Evenki were nomads, surviving by means of hunting or reindeer herding. Although small groups still live this way, their traditional way of life is being threatened as oil, coal, and gas are mined and their homelands are taken over.
Many Evenki were removed from their lands by the government and settled onto collective farms after the Russian Revolution in 1917, and only 30,000 remain. In 1930, the Evenki national district was created, providing a permanent home for the people. This district contains some tundra vegetation and is covered by larch forest, but the climate is severe, with long, cold winters. The livelihood of the Evenki is supplemented by fur farming, farming, and jobs in industry or government.
Along with other native groups in Russia and China, like the Oroqen, the Evenki are working to preserve their culture.
The Ouje-Bougoumou Cree are a native people from the James and Hudson Bay area of Quebec in Canada. Some Cree tribes, collectively known as the Cree nation, lived on the plains and cultivated corn. Others lived in the forests and fished and hunted caribou, moose, bear, beaver, and hare.
The Cree believe they have a special relationship with nature—nature provides them with food and they take care of the land and hunt only what is necessary for life. Beginning in 1920 when the first non-native miners came onto their land searching for gold and copper, the Cree were forced to relocate their villages. About 14,500 Cree remain, primarily in the James and Hudson Bay regions. Clear-cutting of the boreal forests and hydroelectric development in the James Bay area continues to threaten their lifestyle. The Cree nation has been fighting since the 1970s to disband the James Bay hydroelectric project. They continue to negotiate treaties with the Canadian government involving the destruction in their homeland.
The Pehuenche live in the forests of southeastern Chile. To them, the coniferous monkey-puzzle tree is sacred, and they refuse to cut it down. Its seeds are ground and turned into flour. Even though the Chilean government outlawed cutting the trees, logging continues and endangers the existence of both the people and the tree.
The Food Web
The transfer of energy from organism to organism forms a series called a food chain or food web. All the possible feeding relationships that exist in a biome make up its food web. In the forest, as elsewhere, the food web
consists of producers, consumers, and decomposers. An analysis of the food web shows how energy is transferred within a biome.
Green plants are the primary producers in the forest. They produce organic materials from inorganic chemicals and outside sources of energy, primarily the sun. Trees and other plants turn energy into plant matter, such as pine cones, needles, and seeds.
Animals are consumers. Primary consumers are plant-eating animals like squirrels, voles, mice, and beetles. Secondary consumers eat the plant-eaters. Tertiary consumers are the predators, like owls, wolves, and humans that eat other animals. Bears and humans are also omnivores, eating both plants and animals.
Decomposers eat the decaying matter from dead plants and animals and help return nutrients to the environment. Small underground insects called springtails and mollusks, such as the banana slug, help the decomposition process by breaking down dead plants. This allows other organisms, like bacteria and fungi, to reach the decaying matter and decompose it further.
Spotlight on Coniferous Forests
Bonanza Creek Experimental Forest
Bonanza Creek Experimental Forest was established in 1963 with 8,300 acres (3,359 hectares) and increased to 12,487 acres (5,053 hectare) in 1969. This area is located south of Fairbanks, Alaska, in the Yukon-Tanana uplands in the Tanana Valley State Forest, south of the Brooks Mountain Range and north of the Alaska Range.
Bonanza Creek Experimental Forest
Area: 12,487 acres (5,053 hectares)
Classification: Boreal forest/taiga
Within the Yukon-Tanana uplands are forests, grasslands, wetlands, and alpine tundra (a cold, dry, windy region where no trees grow). The Tanana river crosses the region at 394 feet (120 meters) of elevation.
The climate in the Alaskan taiga is extreme, with temperatures ranging from -58° to 95°F (-50° to +35°C) in January and July, the coldest and warmest months. The average annual temperature is 26°F (-3.3°C). July is the warmest month with an average daily temperature of 61.5°F (16.4°C). For about 233 days each year, freezing temperatures are possible. About 70 percent of the area’s precipitation falls as rain in the summer; the other 30 percent is snow, which falls from October to April. The annual average precipitation over the last 50 years is about 11 inches (28 centimeters).
Taiga soils are often poorly developed. In some areas, a layer of permafrost (permanently frozen soil) is on the lowlands and northern slopes of mountains, and prevents rain and melting snow from being absorbed into the ground. Since the moisture stays close to the surface, the soil is soggy.
Predominant trees in the area are white spruce, black spruce, paper birch, and aspen.
Numerous insects found on the taiga include budworms, sawflies, midges, and beetles. The northern wood frog is one of the few amphibians that live there.
Woodpeckers, swallows, sparrows, peregrine falcons, great horned owls, snowy owls, and boreal owls are among the birds that make the Bonanza Creek Forest their home.
Mammals include a number of voles and lemmings, muskrats, red squirrels, and meadow jumping mice. Moose and caribou migrate here to breed. Carnivores include coyotes, gray wolves, and wolverines.
Olympic National Park
Olympic National Park is a 922,000 acre (373,120 hectare) area located on the Olympic Peninsula in northwestern Washington state. Forests in the park lie between sea level and 2,000 feet (609 meters) above sea level. Just 90 miles (145 kilometers) from the thriving city of Seattle, 95 percent of this park has been declared as wilderness.
Olympic National Park
Area: 908,447 acres (363,379 hectares)
Classification: Temperate evergreen forest
Among the coniferous forests in the park is a temperate rain forest found in its lower western and southern regions. Temperate rain forests grow at higher latitudes than tropical rain forests. Forests on the western side of the park experience heavy precipitation, 12-14 feet (3.6-4.3 meters) annually. Forests in the eastern portion of the park are the driest areas of the Pacific coast, north of Los Angeles. The nearness of the ocean keeps the temperatures somewhat moderate with very few days of below-freezing weather in winter. In summer, temperatures rarely exceed 85°F (29°C).
The forest floor supports toadstools, creepers, and ferns, such as sword, bracken, and licorice ferns. Club moss and algae hang from the trees. Shrubs found in the park include red huckleberry and salmonberry. The western thimbleberry can be recognized by its large, hairy, maplelike leaves. Wildflowers include western starflower, western trillium, and foamflower. The deerfoot vanillaleaf lives deep in the woods.
Douglas fir and Pacific silver fir are common trees. The species of the Sitka spruce found there rarely grows far from salt water. The grand fir also grows only in this region.
Invertebrates include the unusual banana slug, a scavenger and decomposer that helps to keep the forest floor and soil healthy. Springtails, golden buprested beetles, and questing spiders can also be found here.
The Pacific tree frog and the bullfrog live in the park, as do several species of snakes.
More than 200 species of birds are common to the Olympic Peninsula including flicker, crow, cliff swallow, winter wren, water ouzel, pileated woodpecker, northern spotted owl, winter wren, raven, and jay. Both golden and bald eagles also frequent the area. Ruffled grouse stay all winter and grow long, feathery “snowshoes” on their toes.
The park is home to one of the largest herds of Roosevelt elk, and was nearly named Elk National Park. An adult male can weigh an average of 875 pounds (397 kilograms), and the elk are a major hunting and tourist attraction. Other mammals found on the peninsula are the coyote, mountain beaver, Olympic marmot, raccoon, skunk, Columbian black-tailed deer, Rocky Mountain goat, black bear, mountain cottontail rabbit, and snowshoe hare. Cougars may be found in remote areas.
Yellowstone National Park
The first national park in the United States, Yellowstone is located primarily in the state of Wyoming, with small portions in southern Montana and eastern Idaho, and was established in 1872. It covers an area of 2,219,789 acres (898,317 hectares). Mountains, lakes, rivers, and waterfalls cross the terrain. Most of the park is coniferous forest, but Yellowstone is also famous for the geyser (GY-zuhr) called Old Faithful, and its hot springs, steam vents, and mud caldrons.
Yellowstone National Park
Area: 2,219,791 acres (898,318 hectares)
Classification: Mountain coniferous forest
Located on a high plateau, Yellowstone is 11,358 feet (3,462 meters) above sea level at its highest point, Eagle Peak. Its lowest elevation is 5,282 feet (1,610 meters), Reese Creek. Eighty percent of the park is forested, while the other 20 percent is grassland and water.
Annual precipitation varies from one end of the park to the other. In the north the average is 10 inches (26 centimeters). In the south, it is 80 inches (205 centimeters). Average annual snowfall is about 150 inches (380 centimeters). The average temperature is 10°F (-12°C) in January and 80°F (27°C) in July.
Eight species of conifers grow in the park, with lodgepole pine being the most common. Smaller stands of Douglas fir are found at both lower and higher elevations. Engelmann spruce and alpine fir abound. The park also has more than 170 species of colorful flowering plants, 80 percent of which are exotic.
The park supports about ten species of reptiles and amphibians. Its lakes are stocked with fish, including some non-native species.
Hundreds of species of birds live in the park, including the western tanager, goshawk, bald eagle, and dipper.
Large mammals include buffalo, elk, bighorn sheep, moose, and grizzly bear. Wolves, which had been eliminated by ranchers who feared they would prey on cattle, were reintroduced to the park in 1995. The park also supports a large herd of wapiti deer, or American elk. This once common animal is now found only in the Rocky Mountains and southern Canada. The wapiti is hunted for its hide, flesh, and head, which is usually displayed as a trophy. The park also protects five threatened and endangered species; the bald eagle, the grizzly bear, the lynx, the whooping crane and the gray wolf.
Coniferous forests of Japan
Japan is a 4,400 square mile (11,500 square kilometer) chain of four islands in the Pacific Ocean—Hokkaido, Honshu, Shikoku, and Kyushu. The coniferous forests in Japan are found primarily in northeastern Honshu and Hokkaido.
Coniferous forests of Japan
Classification: Mountain coniferous forest and temperate evergreen forest
Japan’s climate is influenced by the presence of mountain ranges, the Sea of Japan, and the range of latitudes it crosses. In general, Japan receives more than 40 inches (102 centimeters) of precipitation annually, mostly as rain during June and July. Typhoons (ocean storms) are not uncommon during this time. The southern islands are generally warmer. In Hokkaido, the average temperature in January, the coldest month, is 16°F (-9°C), and in August, the hottest month, it is 70°F (21°C).
Coniferous trees are found from sea level up to 5,900-9,800 feet (1,800-3,000 meters) in the mountains. Common conifers in the forests of Hokkaido are Hondo and Sakhalin spruce and Maries and Veitch firs. Mosses and lichens are found on the forest floor and hanging from tree branches.
Many native forests have been destroyed and replanted with coniferous forests that are managed as commercial plantations. Two of the most important timber trees are the hiba and the Japanese cedar. The cedars, often exceeding 150 feet (46 meters), have long trunks, reddish bark and spread 15-25 feet (4.6-7.6 meters).
Natural stands of Japanese cedars, with trees more than 2,000 years old, cover about 4,133 square miles (10,747 square kilometers) on Yaku Island south of Kyushu. These trees grow in rocky areas with little soil and light, and as a result, their growth is stunted. Because the grain of their wood is tightly compacted and contains large quantities of resin, they do not easily decay. Many cedars on the island exceed the average life span of 500 years. The Yaku sugi tree, which also grows here, is a decay-resistant conifer related to the redwood. Also on Yaku are mixed forests containing broad-leaved trees. In 1993, the Yaku forests were declared a World Heritage Property by the World Heritage Convention.
Japan’s forests are home to about 150 species of songbirds, as well as birds of prey such as eagles, hawks, and falcons. Bramblings and Eurasian nutcrackers are also common.
Brown bears, wild boars, Siberian chipmunks, Asiatic pika, and Hokkaido squirrels live in the forests. An unusual inhabitant is the raccoon dog, or tanuki, a native of eastern Asia that some scientists place in the dog family and others in the raccoon family. The tanuki looks like a raccoon, with dark face markings that stand out against a yellow-brown coat. Its long fur is sold commercially.
Lapland National Parks
Much of Scandinavia (Norway, Sweden, and Finland) is covered in coniferous forest. The Lapland National Parks are comprised of three parks, Sarek National Park, Padjelanta National Park, and Stora Sjofallet National Park. Both Sarek and Stora were established in 1909; Padjelanta was established in 1962. All three parks are boreal forests and are interspersed with wetlands, lakes, and mountains. Of the three, Padjelanta is the most accessible park.
Lapland National Parks
Area: 1,292,300 acres (523,200 hectares)
Classification: Boreal forest/taiga
Many people visit Padjelanta, which has marked trails and cross-country ski paths. Scientists visit to conduct research on plants, animals, geology, glaciers, and water resources. The flora and fauna are impressive, with over 400 species spread across 490,257 acres (198,400 hectares) of land. The wildlife is also unique, and visitors may catch a glimpse of snowy owls, arctic foxes, and wolverines. The open mountain landscape and the large lakes make it a very scenic location.
To the left of the Padjelanta park lies the Sarek National Park. Sarek, with the most wilderness, is mostly alpine landscape with glaciers, tall mountain peaks, and alpine tundra (a cold, treeless region). Its 486,798 acres (197,000 hectares) is home to over 200 mountains and 100 glaciers that are mostly unspoiled. Though plants are more scarce than at Padjalenta, the animal population is rich in bears, wolverines, lynxes and elk. Of the three parks, Sarek is the least accessible and not recommended for beginners.
North of Sarek Park lies the Stora Sjofallet National Park. At 315,800 acres (127,800 hectares), it is the smallest of the three parks. The forest is nearly bisected by a hydroelectric power facility, which destroyed much of the original landscape.
Coniferous forests of New Zealand
New Zealand is an island nation in the South Pacific, about 1,000 miles (1,600 kilometers) southeast of Australia. A temperate evergreen forest with mixed deciduous and coniferous trees grows in the north.
Coniferous forests of New Zealand
Location: New Zealand
Classification: Southern Hemisphere forest
New Zealand’s climate has no real extremes. In general, summer temperatures are above 70°F (21°C), and winter temperatures are rarely below 50°F (10°C). Annual rainfall ranges from 29 to 59 inches (64 to 150 centimeters).
Conifers make up most of the canopy in the forests and include the huge kauri tree, as well as trees in the plum pine family. The rimu, or New Zealand red pine, grows as tall as 150 feet (45 meters) and its wood is reddish-to-yellowish brown. Rimu is used in construction and furniture making, and its bark contains a tanning agent that colors leather red. The radiata pine, a native of California, was transplanted in New Zealand and has become a key species there. Only a few flowers, like yellow kowhai and pohutakawa (New Zealand’s Christmas tree), grow in the New Zealand forests. The pohutakawa reaches averages of 100 feet (30 meters) high, and 3 feet (1 meter) wide. It can live anywhere between 700 and 800 years. Approximately 80 percent of the flora in the park is native to New Zealand.
Very few animals are native to New Zealand. They include several species of frogs and bats, as well as the gecko lizard and the tuatara. Europeans introduced deer, opossums, and goats.
Coniferous forests of Russia and Siberia
At 2.5 billion acres (1 billion hectares), Russia and Siberia are home to 22 percent of the all the world’s forests combined. The most popular trees are larch, spruce and pine.
Coniferous forests of Russia and Siberia
Location: Russia and Siberia
Classification: Boreal forest/taiga
The climate in the forests varies. In the more northern section, the weather is harsh and summers are short. In the Yakut taiga, located in eastern Siberia, for example, winter temperatures may reach -85°F (-65°C). The average annual temperature is only around 10°F (-12°C). Temperatures in the middle taiga, such as that near Lake Baikal, are less severe, and conditions for tree growth are better. There, the average annual temperature is about 19°F (-7°C), and the growing season lasts from twelve to seventeen weeks. An even milder climate is characteristic in the southernmost region of the taiga where the growing season may last more than twenty weeks.
Conifers found here include pine, spruce, fir, larch, cedar, Japanese stone pine, Jeddo spruce, and dwarf mountain pine. Many trees are stunted by the cold wind; reaching only about 19 feet (6 meters) in height. Where trees are protected from the wind, they grow about 50 feet (15 meters) tall. Shrubs like crowberry and bilberry grow in the understory. Mosses and lichens grow on the forest floor.
Some areas of the taiga are richer in wildlife than others. The more southern regions support hundreds of species of birds and about 50 species of mammals. The hazel hen and Siberian jay are unique to the taiga. Mammals include the moose, lynx, brown bear, Siberian red deer, wolverine, Asiatic chipmunk, northern pika, and sable. The sable is hunted for its highly prized fur, known as “soft gold.” Once endangered, it is now being protected in nature reserves such as the Barguzin Nature Reserve near Lake Baikal.
Coniferous forests of the Southeastern United States
Temperate pine-lands in the United States are found primarily in New Jersey, Virginia, North Carolina, South Carolina, Georgia, Alabama, Mississippi, Louisiana, Arkansas, Florida, and Tennessee. The pines that grow here are called southern pines, and loblolly, slush, longleaf, and shortleaf pines predominate. Many of these trees took over farms and plantations abandoned after the Civil War (1861–65).
Coniferous forests of the Southeastern United States
Location: Southeastern states
Classification: Temperate pineland
The temperate climate with its mild winters favors tree growth. In Georgia, for example, average annual temperatures are about 40°F (4.4°C) in the mountains and 54°F (12°C) on the southern coast. Average annual rainfall is about 50 inches (127 centimeters).
The soil of these forests tends to be rich and supports much tree growth, including oak and hickory, in addition to the many pines.
Wildlife includes many species of snakes and birds, as well as rabbits, squirrels, opossums, badgers, moles, deer, and wildcats.
For More Information
Allaby, Michael. Biomes of the Earth: Temperate Forests. New York: Chelsea House, 2006.
Allaby, Michael. Biomes of the Earth: Tropical Forests. New York: Chelsea House, 2006.
Brockman, C. Frank. Trees of North America: A Guide to Field Identification, Revised and Updated. New York: St. Martin’s Press, 2001.
Burie, David, and Don E. Wilson, eds. Animal. New York: Smithsonian Institute, 2001.
Day, Trevor. Biomes of the Earth: Taiga. New York: Chelsea House, 2006.
Jacke, Dave. Edible Forest Gardens. White River Junction, VT: Chelsea Green Publishing Co., 2005.
Jose, Shibu, Eric J. Jokela, and Deborah L. Miller The Longleaf Pine Ecosystem: Ecology, Silviculture, and Restoration. New York: Springer, 2006.
Miller, James H., and Karl V. Miller. Forest Plants Of The Southeast And Their Wildlife Uses. Athens: University of Georgia Press, 2005.
O’Shea, Mark, and Tim Halliday. Smithsonian Handbooks: Reptiles and Amphibians. New York: Dorling Kindersley, 2001.
Zabel, Cynthia, and Robert G. Anthony. Mammal Community Dynamics: Management and Conservation in the Coniferous Forests of Western North America. New York: Cambridge University Press, 2003.
Morris, John. “Will the Forest Survive?” Wide World. 13. 1 September 2001: 15.
“Siberia Sees the Wood from the Trees.” Geographical. 73. 1 January 2001: 10.
Environmental Defense Fund, 257 Park Ave. South, New York, NY 10010; Telephone: 212-505-2100. Fax: 212-505-2375; Internet: http://www.edf.org
Environmental Protection Agency, 401 M Street, SW, Washington DC 20460; Telephone:202-260-2090; Internet: http://www.epa.gov
Friends of the Earth, 1717 Massachusetts Ave. NW 300, Washington, DC 20036; Telephone:877-843-8687; Fax:202-783-0444; Internet: http://www.foe.org
Global ReLeaf, American Forests, PO Box 2000, Washington, DC 20013; Telephone:202-737-1944; Internet: http://www.amfor.org
Greenpeace USA, 702 H Street NW, Washington, DC 20001; Telephone: 202-462-1177; Internet: http://www.greenpeace.org
Izaak Walton League of America, 707 Conservation Lane, Gaithersburg, MD 20878; Telephone:301-548-0150; Internet: http://www.iwla.org
Sierra Club, 85 Street, 2 nd fl., San Francisco, CA 94105; Telephone:415-977-5500; Fax:415-977-5799; Internet: http://www.sierraclub.org
The Wilderness Society, 1615 M St. NW, Washington, DC 20036; Telephone: 800-the-wild; Internet: http://www.wilderness.org
World Wildlife Fund, 1250 24th Street NW, Washington, DC 20090; Internet: http://www.wwf.org
National Geographic Magazine. http://www.nationalgeographic.com (accessed August 25, 2007).
National Park Service. http://www.nps.gov (accessed August 25, 2007).
Ouje-Bougoumou Cree Nation. http://www.ouje.ca (accessed August 25, 2007).
Scientific American Magazine. http://www.sciam.com (accessed August 25, 2007).
Swedish Environmental Protection Agency. http://www.internat.naturvardsverket.se (accessed August 25, 2007).
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