Red Alder
Encyclopedia
Alnus rubra, the Red alder, is a deciduous
broadleaf tree
native to western North America
.
It is the largest species of alder
in North America and one of the largest in the world, reaching heights of 20–35 m. The official tallest red alder (1979) stands 32 meters tall in Clatsop County, Oregon
(USA). The name derives from the bright rusty red color that develops in bruised or scraped bark. The bark is mottled, ashy-gray and smooth, often draped with moss
. The leaves
are ovate, 7–15 cm long, with bluntly serrated edges and a distinct point at the end; the leaf margin is revolute, the very edge being curled under, a diagnostic character which distinguishes it from all other alders. The leaves turn yellow in the autumn before falling. The male flower
s are dangling reddish catkin
s 10–15 cm long in early spring, and female flowers are erect catkins which develop into small, woody, superficially cone
-like oval dry fruit
2–3 cm long. The seed
s develop between the woody bracts of the 'cones' and are shed in the autumn and winter.
south to central coastal California
, nearly always within about 200 km of the Pacific coast, except for an extension 600 km inland across northern Washington into northernmost Idaho
.
In southern Alaska
, western British Columbia
and the northwestern Coast Ranges of the USA, red alder grows on cool and moist slopes; inland and at the southern end of its range (California) it grows mostly along the margins of watercourses and wetlands.
Pseudotsuga menziesii subsp. menziesii, western hemlock
Tsuga heterophylla, grand fir Abies grandis, western redcedar
Thuja plicata, and Sitka spruce
Picea sitchensis forests.
Along streambanks it is commonly associated with willow
s Salix spp., red osier dogwood
Cornus stolonifera, Oregon ash
Fraxinus latifolia and bigleaf maple
Acer macrophyllum.
(Alnus rhombifolia), which is closely related but differs in the leaf margins not being rolled under. In the high mountains it is replaced by the smaller Sitka alder
(Alnus viridis subsp. sinuata), and east of the Cascade Mountains by thinleaf alder
(Alnus incana subsp. tenuifolia).
to germinate
, and so skid trails and other areas disturbed by logging or fire are ideal seedbeds. Such areas may host several hundred thousand to several million seedlings per hectare in the first year after landscape disturbance (Zavitkovski & Stevens 1972).
and elk
do browse the twigs in fall and twigs and buds in the winter and spring. Beaver
s eat the bark. Several finch
es eat alder seeds, notably Common Redpoll
and Pine Siskin
, and as do deer mice.
. It is this ability which allows alder to grow in nitrate
-poor soils.
to dye fishing nets so as to make them less visible underwater.
and lupeol
, compounds shown to be effective against a variety of tumor
s.
tree. Its rapid growth makes it useful in covering disturbed land, such as mine
spoils. Alder leaves, shed in the fall, decay readily to form a nitrogen
-enriched humus. It is being considered as a rotation crop
to discourage the conifer root pathogen
Phellinus weirii
(Laminated root rot).
Alnus rubra are planted as ornamental trees and will do well in wet swale
s, riparian areas, or on stream banks.
If used domestically they should be planted well away from drainpipes, sewage
pipes, and water lines, as the roots may invade and clog the lines. Alnus rubra are known for growing easily in burned or destroyed land, and are used as "pioneering" or "reclamation" trees.
, Walnut
and Ash, historically Alder has not been considered of high value for timber
. However it is now becoming one of the more popular hardwood alternatives as it is more economically priced when compared to other hardwoods. In the world of musical instrument construction, Red Alder is valued by some electric guitar / electric bass builders for its balanced tonality; and Alder is frequently used by Native Americans
for making masks, bowls, tool handles, and other small goods.
The appearance of Alder lumber ranges from white through pinkish to light brown, has a relatively soft hardwood texture, and has medium luster. It is easily worked, glues well, and takes a good finish.
organism to locate areas prone to ozone
pollution, as the leaves will react to the presence of high ozone levels by developing red to brown or purple discolourations.
spraying of red alder over large areas of coastal Oregon
and Washington has resulted in a number of lawsuits, with the claim this spraying has caused health problems, including birth defects and other side effects.
Increasing value of the wood, combined with a better understanding of the species' benefits to other trees, has largely led to a cessation of this practice.
Deciduous
Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...
broadleaf tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
native to western North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
.
Description
Alder
Alder is the common name of a genus of flowering plants belonging to the birch family . The genus comprises about 30 species of monoecious trees and shrubs, few reaching large size, distributed throughout the North Temperate Zone and in the Americas along the Andes southwards to...
in North America and one of the largest in the world, reaching heights of 20–35 m. The official tallest red alder (1979) stands 32 meters tall in Clatsop County, Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
(USA). The name derives from the bright rusty red color that develops in bruised or scraped bark. The bark is mottled, ashy-gray and smooth, often draped with moss
Moss
Mosses are small, soft plants that are typically 1–10 cm tall, though some species are much larger. They commonly grow close together in clumps or mats in damp or shady locations. They do not have flowers or seeds, and their simple leaves cover the thin wiry stems...
. The leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
are ovate, 7–15 cm long, with bluntly serrated edges and a distinct point at the end; the leaf margin is revolute, the very edge being curled under, a diagnostic character which distinguishes it from all other alders. The leaves turn yellow in the autumn before falling. The male flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s are dangling reddish catkin
Catkin
A catkin or ament is a slim, cylindrical flower cluster, with inconspicuous or no petals, usually wind-pollinated but sometimes insect pollinated . They contain many, usually unisexual flowers, arranged closely along a central stem which is often drooping...
s 10–15 cm long in early spring, and female flowers are erect catkins which develop into small, woody, superficially cone
Conifer cone
A cone is an organ on plants in the division Pinophyta that contains the reproductive structures. The familiar woody cone is the female cone, which produces seeds. The male cones, which produce pollen, are usually herbaceous and much less conspicuous even at full maturity...
-like oval dry fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
2–3 cm long. The seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
s develop between the woody bracts of the 'cones' and are shed in the autumn and winter.
Distribution
Alnus rubra grows from southeast AlaskaAlaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
south to central coastal California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, nearly always within about 200 km of the Pacific coast, except for an extension 600 km inland across northern Washington into northernmost Idaho
Idaho
Idaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....
.
Ecology
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
, western British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
and the northwestern Coast Ranges of the USA, red alder grows on cool and moist slopes; inland and at the southern end of its range (California) it grows mostly along the margins of watercourses and wetlands.
Commonly associated trees
Red alder is associated with coast Douglas-firCoast Douglas-fir
Pseudotsuga menziesii, known as Douglas-fir, Oregon Pine, or Douglas spruce, is an evergreen conifer species native to western North America. Its variety Pseudotsuga menziesii var. menziesii, also known as coast Douglas-fir grows in the coastal regions, from west-central British Columbia, Canada...
Pseudotsuga menziesii subsp. menziesii, western hemlock
Western Hemlock
Tsuga heterophylla. the Western Hemlock, is a species of hemlock native to the west coast of North America, with its northwestern limit on the Kenai Peninsula, Alaska, and its southeastern limit in northern Sonoma County, California.-Habitat:...
Tsuga heterophylla, grand fir Abies grandis, western redcedar
Thuja plicata
Thuja plicata, commonly called Western or pacific red cedar, giant or western arborvitae, giant cedar, or shinglewood, is a species of Thuja, an evergreen coniferous tree in the cypress family Cupressaceae native to western North America...
Thuja plicata, and Sitka spruce
Sitka Spruce
Picea sitchensis, the Sitka Spruce, is a large coniferous evergreen tree growing to 50–70 m tall, exceptionally to 95 m tall, and with a trunk diameter of up to 5 m, exceptionally to 6–7 m diameter...
Picea sitchensis forests.
Along streambanks it is commonly associated with willow
Willow
Willows, sallows, and osiers form the genus Salix, around 400 species of deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions of the Northern Hemisphere...
s Salix spp., red osier dogwood
Red Osier Dogwood
The Red Osier Dogwood is a species of dogwood native throughout northern and western North America from Alaska east to Newfoundland, south to Durango and Nuevo León in the west, and Illinois and Virginia in the east...
Cornus stolonifera, Oregon ash
Oregon Ash
Fraxinus latifolia is a member of the ash genus Fraxinus, native to western North America.-Distribution:Fraxinus latifolia is found: on the west side of the Cascade Range from southwestern British Columbia south through western Washington, western Oregon, and northwestern California; and in...
Fraxinus latifolia and bigleaf maple
Bigleaf Maple
Acer macrophyllum is a large deciduous tree in the genus Acer.It can grow to be up to 35 m tall, but more commonly grows 15 m to 20 m tall. It is native to western North America, mostly near the Pacific coast, from southernmost Alaska to southern California...
Acer macrophyllum.
In marginal habitat
To the southeast of its range it is replaced by white alderAlnus rhombifolia
Alnus rhombifolia, the White Alder, is an alder tree native to western North America, from Washington east to western Montana, southeast to the Sierra Nevada, and south through the Peninsular Ranges and Colorado Desert oases in Southern California. It occurs in riparian zone habitats at an...
(Alnus rhombifolia), which is closely related but differs in the leaf margins not being rolled under. In the high mountains it is replaced by the smaller Sitka alder
Green Alder
Alnus viridis is an alder with a wide range across the cooler parts of the Northern Hemisphere.-Description:It is a large shrub or small tree 3–12 m tall with smooth grey bark even in old age. The leaves are shiny green, ovoid, 3–8 cm long and 2–6 cm broad...
(Alnus viridis subsp. sinuata), and east of the Cascade Mountains by thinleaf alder
Grey Alder
Alnus incana is a species of alder with a wide range across the cooler parts of the Northern Hemisphere....
(Alnus incana subsp. tenuifolia).
As pioneer species
In moist forest areas Alnus rubra will rapidly cover a former burn or clearcut, temporarily preventing the growth of conifers but also improving soil fertility for future growth of conifers. It is a prolific seed producer, but the seeds require an open area of mineral soilSoil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
to germinate
Germination
Germination is the process in which a plant or fungus emerges from a seed or spore, respectively, and begins growth. The most common example of germination is the sprouting of a seedling from a seed of an angiosperm or gymnosperm. However the growth of a sporeling from a spore, for example the...
, and so skid trails and other areas disturbed by logging or fire are ideal seedbeds. Such areas may host several hundred thousand to several million seedlings per hectare in the first year after landscape disturbance (Zavitkovski & Stevens 1972).
Role as wildlife fodder
Twigs and buds of alder are only fair browse for wildlife, though deerDeer
Deer are the ruminant mammals forming the family Cervidae. Species in the Cervidae family include white-tailed deer, elk, moose, red deer, reindeer, fallow deer, roe deer and chital. Male deer of all species and female reindeer grow and shed new antlers each year...
and elk
Red Deer
The red deer is one of the largest deer species. Depending on taxonomy, the red deer inhabits most of Europe, the Caucasus Mountains region, Asia Minor, parts of western Asia, and central Asia. It also inhabits the Atlas Mountains region between Morocco and Tunisia in northwestern Africa, being...
do browse the twigs in fall and twigs and buds in the winter and spring. Beaver
Beaver
The beaver is a primarily nocturnal, large, semi-aquatic rodent. Castor includes two extant species, North American Beaver and Eurasian Beaver . Beavers are known for building dams, canals, and lodges . They are the second-largest rodent in the world...
s eat the bark. Several finch
Finch
The true finches are passerine birds in the family Fringillidae. They are predominantly seed-eating songbirds. Most are native to the Northern Hemisphere, but one subfamily is endemic to the Neotropics, one to the Hawaiian Islands, and one subfamily – monotypic at genus level – is found...
es eat alder seeds, notably Common Redpoll
Common Redpoll
The Common Redpoll is a species in the finch family. It breeds somewhat further south than the Arctic Redpoll, also in habitats with thickets or shrubs. Nominate C. f. flammea breeds across the northern parts of North America and Eurasia. There is also an Icelandic subspecies, Icelandic Redpoll...
and Pine Siskin
Pine Siskin
The Pine Siskin is a North American bird in the finch family. It is a migratory bird with an extremely sporadic winter range.-Description:...
, and as do deer mice.
As soil enricher
Alnus rubra is also very valuable for playing host to the nitrogen fixing actinomycete FrankiaFrankia
Frankia is a genus of nitrogen fixing, filamentous bacteria that live in symbiosis with actinorhizal plants, similar to the Rhizobia bacteria that are found in the root nodules of legumes in the Fabaceae family. Bacteria of this genus also form root nodules.The genus Frankia was originally named by...
. It is this ability which allows alder to grow in nitrate
Nitrate
The nitrate ion is a polyatomic ion with the molecular formula NO and a molecular mass of 62.0049 g/mol. It is the conjugate base of nitric acid, consisting of one central nitrogen atom surrounded by three identically-bonded oxygen atoms in a trigonal planar arrangement. The nitrate ion carries a...
-poor soils.
Uses
As dye
A russet dye can be made from a decoction of the bark and was used by Native AmericansIndigenous peoples of the Americas
The indigenous peoples of the Americas are the pre-Columbian inhabitants of North and South America, their descendants and other ethnic groups who are identified with those peoples. Indigenous peoples are known in Canada as Aboriginal peoples, and in the United States as Native Americans...
to dye fishing nets so as to make them less visible underwater.
Tradition medicine usage
Native Americans used red alder bark (Alnus rubra) to treat poison oak, insect bites, and skin irritations. Blackfeet Indians used an infusion made from the bark of red alder to treat lymphatic disorders and tuberculosis. Recent clinical studies have verified that red alder contains betulinBetulin
Betulin is an abundant naturally occurring triterpene. It is commonly isolated from the bark of birch trees and forms up to 30% of the dry weight of the extractive . The purpose of the compound in the bark is not known...
and lupeol
Lupeol
Lupeol is a pharmacologically active triterpenoid found in a variety of plants, including mango and acacia visco. It has several medicinal properties, one being anti-inflammatory...
, compounds shown to be effective against a variety of tumor
Tumor
A tumor or tumour is commonly used as a synonym for a neoplasm that appears enlarged in size. Tumor is not synonymous with cancer...
s.
In restoration
Alnus rubra is an important forestryForestry
Forestry is the interdisciplinary profession embracing the science, art, and craft of creating, managing, using, and conserving forests and associated resources in a sustainable manner to meet desired goals, needs, and values for human benefit. Forestry is practiced in plantations and natural stands...
tree. Its rapid growth makes it useful in covering disturbed land, such as mine
Mining
Mining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...
spoils. Alder leaves, shed in the fall, decay readily to form a nitrogen
Nitrogen
Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
-enriched humus. It is being considered as a rotation crop
Crop rotation
Crop rotation is the practice of growing a series of dissimilar types of crops in the same area in sequential seasons.Crop rotation confers various benefits to the soil. A traditional element of crop rotation is the replenishment of nitrogen through the use of green manure in sequence with cereals...
to discourage the conifer root pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
Phellinus weirii
Phellinus weirii
Phellinus weirii is a plant pathogen causing laminated root rot in certain conifers, typically Douglas-fir and western redcedar. It is widespread in the Douglas Fir Growing regions of British Columbia, Washington and Oregon.-Overview:...
(Laminated root rot).
Alnus rubra are planted as ornamental trees and will do well in wet swale
Swale
Swale is a local government district with borough status in Kent, England. Its council is based in Sittingbourne. The borough is named after the narrow channel called The Swale, a channel that separates the mainland of Kent from the Isle of Sheppey, and which occupies the central part of the...
s, riparian areas, or on stream banks.
If used domestically they should be planted well away from drainpipes, sewage
Sewage
Sewage is water-carried waste, in solution or suspension, that is intended to be removed from a community. Also known as wastewater, it is more than 99% water and is characterized by volume or rate of flow, physical condition, chemical constituents and the bacteriological organisms that it contains...
pipes, and water lines, as the roots may invade and clog the lines. Alnus rubra are known for growing easily in burned or destroyed land, and are used as "pioneering" or "reclamation" trees.
In woodworking
Alder lumber is not considered to be a durable option for outdoor applications, but due to its workability and ease of finishing it is increasingly used for furniture and cabinetry. Because it is softer than other popular hardwoods such as MapleMaple
Acer is a genus of trees or shrubs commonly known as maple.Maples are variously classified in a family of their own, the Aceraceae, or together with the Hippocastanaceae included in the family Sapindaceae. Modern classifications, including the Angiosperm Phylogeny Group system, favour inclusion in...
, Walnut
Walnut
Juglans is a plant genus of the family Juglandaceae, the seeds of which are known as walnuts. They are deciduous trees, 10–40 meters tall , with pinnate leaves 200–900 millimetres long , with 5–25 leaflets; the shoots have chambered pith, a character shared with the wingnuts , but not the hickories...
and Ash, historically Alder has not been considered of high value for timber
Timber
Timber may refer to:* Timber, a term common in the United Kingdom and Australia for wood materials * Timber, Oregon, an unincorporated community in the U.S...
. However it is now becoming one of the more popular hardwood alternatives as it is more economically priced when compared to other hardwoods. In the world of musical instrument construction, Red Alder is valued by some electric guitar / electric bass builders for its balanced tonality; and Alder is frequently used by Native Americans
Indigenous peoples of the Americas
The indigenous peoples of the Americas are the pre-Columbian inhabitants of North and South America, their descendants and other ethnic groups who are identified with those peoples. Indigenous peoples are known in Canada as Aboriginal peoples, and in the United States as Native Americans...
for making masks, bowls, tool handles, and other small goods.
The appearance of Alder lumber ranges from white through pinkish to light brown, has a relatively soft hardwood texture, and has medium luster. It is easily worked, glues well, and takes a good finish.
In fish smoking
Because of its oily smoke, A. rubra is the wood of choice for smoking salmon.As an environmental indicator
Additionally, red alder is often used by scientists as a biomonitoringBiomonitoring
Aquatic biomonitoring is the science of inferring the ecological condition of rivers, lakes, streams, and wetlands by examining the organisms that live there...
organism to locate areas prone to ozone
Ozone
Ozone , or trioxygen, is a triatomic molecule, consisting of three oxygen atoms. It is an allotrope of oxygen that is much less stable than the diatomic allotrope...
pollution, as the leaves will react to the presence of high ozone levels by developing red to brown or purple discolourations.
Forestry
The vigorous growth has in the past earned it the designation of a "trash tree" by the timber industry. HerbicideHerbicide
Herbicides, also commonly known as weedkillers, are pesticides used to kill unwanted plants. Selective herbicides kill specific targets while leaving the desired crop relatively unharmed. Some of these act by interfering with the growth of the weed and are often synthetic "imitations" of plant...
spraying of red alder over large areas of coastal Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
and Washington has resulted in a number of lawsuits, with the claim this spraying has caused health problems, including birth defects and other side effects.
Increasing value of the wood, combined with a better understanding of the species' benefits to other trees, has largely led to a cessation of this practice.