Alnus rubra

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Alnus rubra
Red alder leaves.jpg
Red alder leaves
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Fagales
Family: Betulaceae
Genus: Alnus
Subgenus: Alnus subg. Alnus
Species:
A. rubra
Binomial name
Alnus rubra
Alnus rubra range map.jpg
Natural range of Alnus rubra
Synonyms [2]
  • Alnus incana var. rubra(Bong.) Regel
  • Alnus oreganaNutt.
  • Alnus rubra var. pinnatisectaStarker
  • Alnus rubra f. pinnatisecta(Starker) Rehder

Alnus rubra, the red alder, [3] [4] is a deciduous broadleaf tree native to western North America (Alaska, Yukon, British Columbia, Washington, Oregon, California, Idaho and Montana). [2] [5] [6]

Contents

Description

Alnus rubra is the largest species of alder in North America and one of the largest in the world, reaching heights of 20 to 30 metres (66 to 98 ft). The official tallest red alder (as of 1979) stands 32 m (105 ft) tall in Clatsop County, Oregon (US). [7] The trunks range from 25 to 50 centimetres (10 to 19+1⁄2 in) in diameter. [8] The bark is mottled, ashy-gray and smooth, often colonized by white lichen and moss. [8] The leaves are ovate, 7 to 15 centimetres (2+3⁄4 to 6 in) 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. Rather than turning yellow in autumn, its leaves darken in colour and wither before they are shed. The male flowers are dangling reddish catkins 10 to 15 cm (4 to 6 in) long in early spring. Female flowers occur in clusters of (3) 4–6 (8). Female catkins are erect during anthesis, but otherwise pendant. They develop into small, woody, superficially cone-like oval dry fruit 2 to 3 cm (3⁄4 to 1+1⁄4 in) long. The seeds develop between the woody bracts of the 'cones' and are shed in late autumn and winter. Red alder seeds have a membranous winged margin that allows long-distance dispersal. [7]

Specimens can live to about 60 years of age before being seriously afflicted by heart rot. [8]

Taxonomy

The name derives from the bright rusty red color that develops in bruised or scraped bark. [7]

Distribution

Alnus rubra grows from Southeast Alaska to central coastal California, nearly always within about 200 kilometres (120 mi) of the Pacific coast, except for an extension 600 km (370 mi) inland across Washington and Oregon into northernmost Montana. [5] [9] It can be found from sea level to elevations of 900 m (3,000 ft). [8]

Ecology

In southern Alaska, western British Columbia and the northwestern Pacific Coast Ranges of the United States, 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. [10] It is shade intolerant. [8]

In moist forest areas, Alnus rubra will rapidly cover a former burn or clearcut, often preventing the establishment of conifers. It is a prolific seed producer, [8] but the small, wind-dispersed seeds require an open area of mineral soil 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. [11]

Twigs and buds of alder are only fair browse for wildlife, but deer and elk browse the twigs in fall and twigs and buds in the winter and spring. Beaver occasionally eat the bark, though it is not a preferred species. Several finches eat alder seeds, notably common redpoll and pine siskin, and as do deer mice. Tent caterpillars often feed on the leaves, but the trees usually recover within a year. [8]

The tree hosts the nitrogen-fixing actinomycete Frankia in nodules on roots. This association allows alder to grow in nitrogen-poor soils, and makes the species an important early colonizer of disturbed forests and riparian areas. This self-fertilizing trait allows red alder to grow rapidly, and makes it effective in covering disturbed and/or degraded land, such as mine spoils. Imported Red Alder has been found to be able to make successful associations with Frankia strains present in the UK. [12] Alder leaves, shed in the fall, decay readily to form a nitrogen-enriched humus making the nitrogen available to other species.

Common associates

Red alder is associated with coast Douglas-fir (Pseudotsuga menziesii subsp. menziesii), western hemlock (Tsuga heterophylla), grand fir (Abies grandis), western redcedar (Thuja plicata), and Sitka spruce (Picea sitchensis) forests.

Along stream banks, it is commonly associated with willows (Salix spp.), red osier dogwood (Cornus stolonifera), Oregon ash (Fraxinus latifolia), and bigleaf maple (Acer macrophyllum).

To the southeast of its range it is replaced by white alder (Alnus rhombifolia), which is a tree of similar stature, but which differs in the leaf margins not being rolled under, lack of distinct lobes, and lack of membranous wings on seed margins. In the high mountains it is replaced by the smaller and more shrub-like Sitka alder (Alnus viridis subsp. sinuata), and east of the Cascade Mountains by thinleaf alder (Alnus incana subsp. tenuifolia).

Uses

Broken branch showing red weathered bark Alnus rubra 28199.JPG
Broken branch showing red weathered bark
Typical leaf discoloration caused by ozone pollution Alder showing ozone discolouration.jpg
Typical leaf discoloration caused by ozone pollution

As dye

A russet dye can be made from a decoction of the bark, apparently due to the tannin it contains, [8] and was used by Native Americans to dye fishing nets so as to make them less visible underwater. [8]

Medicine

Native Americans used red alder bark to treat poison oak reactions, 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 betulin and lupeol, compounds shown to be effective against a variety of tumors. [13]

Restoration

In addition to its use as a nitrogen fixer, red alder is occasionally used as a rotation crop to discourage the conifer root pathogen Phellinus weirii (causing laminated root rot).

Alnus rubra are occasionally planted as ornamental trees and will do well in Swales, riparian areas, or on stream banks, in light-textured soils that drain well. Red alder does not thrive in heavy, wet clay soils. If planted domestically, alders should be planted well away from drainpipes, sewage pipes, and water lines, as the roots may invade and clog the lines.[ citation needed ]

Woodworking

Alder lumber is not considered to be a durable option for outdoor applications,[ who? ] 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 maple, walnut and ash, alder has historically been considered of low value for timber. However it is now becoming one of the more popular hardwood alternatives as it is economically priced compared to many other hardwoods. In the world of musical instrument construction, red alder is valued by some electric guitar / electric bass builders for its balanced tonality. 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 texture, minimal grain, and has medium luster. It is easily worked, glues well, and takes a good finish.

Fish smoking

Because of its oily smoke, A. rubra is the wood of choice for smoking salmon. [14]

As an environmental indicator

Red alder is often used by scientists as a biomonitoring organism to locate areas prone to ozone pollution, as the leaves react to the presence of high ozone levels by developing red to brown or purple discolorations. [15]

Forestry

Red alder, western hemlock, and bigleaf maple forest RedAlder 7504.jpg
Red alder, western hemlock, and bigleaf maple forest

With a current inventory of about 7.4 billion cubic feet (210 million cubic metres), red alder comprises 60% of the total hardwood volume in the Pacific Northwest, and is by far the most valuable hardwood in term of diversity of products, commercial value, and manufacturing employment. [16] Increasing value of alder logs, combined with a better understanding of the species' ecological role, has led some land managers to tolerate and, in some cases, manage for alder.

As an 'aggressive pioneer' that was freely able to rapidly colonise areas to the detriment of the more valuable conifer species, it was regarded for a long time as a weed [17] and was neglected for its timber potential, however breeding programmes to improve stem form and timber quality [18] are now underway.

Since most forest land in the Northwest is managed for conifer production, over 200,000 acres (80,000 hectares) of timberland are sprayed with herbicides annually in Oregon alone to control red alder and other competing hardwood species. [19] Red alder's rapid early growth can interfere with establishment of conifer plantations. [20] Herbicide spraying of red alder over large areas of coastal Oregon and Washington has resulted in a number of lawsuits claiming it has caused health problems, including birth defects and other human health effects. [21] [22]

In addition to adding soil nitrogen, rotations of red alder are used to reduce laminated root rot in Douglas-fir forests. Nurse stands of red alder may also reduce spruce weevil damage in Sitka spruce stands on the Olympic Peninsula. [23] Alder continues to attract interest as log values approach and often exceed those of Douglas-fir. [24] This interest is limited by red alder's total stand productivity, which is significantly lower than that of Douglas-fir and western hemlock.

Related Research Articles

<span class="mw-page-title-main">Alder</span> Genus of flowering plants in the birch family Betulaceae

Alders are trees that compose the genus Alnus in the birch family Betulaceae. The genus includes about 35 species of monoecious trees and shrubs, a few reaching a large size, distributed throughout the north temperate zone with a few species extending into Central America, as well as the northern and southern Andes.

<i>Alnus glutinosa</i> Species of flowering plant in the birch family Betulaceae

Alnus glutinosa, the common alder, black alder, European alder, European black alder, or just alder, is a species of tree in the family Betulaceae, native to most of Europe, southwest Asia and northern Africa. It thrives in wet locations where its association with the bacterium Frankia alni enables it to grow in poor quality soils. It is a medium-sized, short-lived tree growing to a height of up to 30 metres (98 feet). It has short-stalked rounded leaves and separate male and female flowers in the form of catkins. The small, rounded fruits are cone-like and the seeds are dispersed by wind and water.

<span class="mw-page-title-main">Pacific temperate rainforests</span> Temperate rainforest in the Pacific Northwest

The Pacific temperate rainforests of western North America is the largest temperate rain forest region on the planet as defined by the World Wildlife Fund. The Pacific temperate rainforests lie along the western side of the Pacific Coast Ranges along the Pacific Northwest Coast of North America from the Prince William Sound in Alaska through the British Columbia Coast to Northern California, and are part of the Nearctic realm, as also defined by the World Wildlife Fund. The Pacific temperate rain forests are characterized by a high amount of rainfall, in some areas more than 300 cm (10 ft) per year and moderate temperatures in both the summer and winter months.

<i>Picea sitchensis</i> Species of large coniferous tree

Picea sitchensis, the Sitka spruce, is a large, coniferous, evergreen tree growing to almost 100 meters (330 ft) tall, with a trunk diameter at breast height that can exceed 5 m (16 ft). It is by far the largest species of spruce and the fifth-largest conifer in the world, and the third-tallest conifer species. The Sitka spruce is one of the few species documented to exceed 90 m (300 ft) in height. Its name is derived from the community of Sitka in southeast Alaska, where it is prevalent. Its range hugs the western coast of Canada and the US, continuing south into northernmost California.

<i>Alnus incana</i> Species of tree

Alnus incana, the grey alder, tag alder or speckled alder, is a species of multi-stemmed, shrubby tree in the birch family, with a wide range across the cooler parts of the Northern Hemisphere. Tolerant of wetter soils, it can slowly spread with runners and is a common sight in swamps and wetlands. It is easily distinguished by its small cones, speckled bark and broad leaves.

<i>Acer macrophyllum</i> Species of maple

Acer macrophyllum, the bigleaf maple or Oregon maple, is a large deciduous tree in the genus Acer. It is native to western North America. In addition to uses by animals, it is of some culinary and woodworking interest.

<i>Tsuga heterophylla</i> Species of conifer

Tsuga heterophylla, the western hemlock or western hemlock-spruce, 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. The Latin species name means 'variable leaves'.

<i>Picea glauca</i> Species of conifer

Picea glauca, the white spruce, is a species of spruce native to the northern temperate and boreal forests in North America. Picea glauca is native from central Alaska all through the east, across western and southern/central Canada to the Avalon Peninsula in Newfoundland, and south to Montana, North Dakota, Minnesota, Wisconsin, Michigan, Upstate New York and Vermont, along with the mountainous and immediate coastal portions of New Hampshire and Maine, where temperatures are just barely cool and moist enough to support it. There is also an isolated population in the Black Hills of South Dakota and Wyoming. It is also known as Canadian spruce, skunk spruce, cat spruce, Black Hills spruce, western white spruce, Alberta white spruce, and Porsild spruce.

<i>Betula papyrifera</i> Species of tree

Betula papyrifera is a short-lived species of birch native to northern North America. Paper birch is named after the tree's thin white bark, which often peels in paper-like layers from the trunk. Paper birch is often one of the first species to colonize a burned area within the northern latitudes, and is an important species for moose browsing. Primary commercial uses for paper birch wood are as boltwood and sawlogs, while secondary products include firewood and pulpwood. It is the provincial tree of Saskatchewan and the state tree of New Hampshire.

<i>Alnus cordata</i> Species of plant

Alnus cordata, the Italian alder, is a tree or shrub species belonging to the family Betulaceae, and native to the southern Apennine Mountains and the north-eastern mountains of Corsica. It has been introduced in Sicily, Sardinia, and more recently in Central-Northern Italy, other European countries and extra-European countries, where it has become naturalised.

<i>Alnus nepalensis</i> Species of plant

Alnus nepalensis is a large alder tree found in the subtropical highlands of the Himalayas. The tree is called Utis in Nepali and Nepalese alder in English. It is used in land reclamation, as firewood and for making charcoal.

<span class="mw-page-title-main">Northern California coastal forests</span> Temperate coniferous forests ecoregion in northern California and southwestern Oregon

The Northern California coastal forests are a temperate coniferous forests ecoregion of coastal Northern California and southwestern Oregon.

<i>Fraxinus latifolia</i> Species of ash

Fraxinus latifolia, the Oregon ash, is a member of the ash genus Fraxinus, native to western North America.

<i>Alnus rhombifolia</i> Species of tree

Alnus rhombifolia, the white alder, is an alder tree native to western North America, from British Columbia and 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 altitudes range of 100–2,400 metres (330–7,870 ft). While not reported in northern Baja California, it has been predicted on the basis of its climatic adaptation to occur there also. Alnus rhombifolia is primarily found in the chaparral and woodlands, montane, and temperate forests ecoregions.

The Northwoods are the boreal forest of North America, covering about half of Canada and parts of Minnesota, Wisconsin, Michigan, New York, Vermont, New Hampshire and Maine.

<span class="mw-page-title-main">Coniferous swamp</span> Forested wetlands dominated by conifers

Coniferous swamps are forested wetlands in which the dominant trees are lowland conifers such as northern white cedar. The soil in these swamp areas is typically saturated for most of the growing season and is occasionally inundated by seasonal storms or by winter snow melt.

<span class="mw-page-title-main">Eastern forest–boreal transition</span> Temperate broadleaf and mixed forest ecoregion in Canada and the United States

The eastern forest–boreal transition is a temperate broadleaf and mixed forests ecoregion of North America, mostly in eastern Canada. It is a transitional zone or region between the predominantly coniferous Boreal Forest and the mostly deciduous broadleaf forest region further south.

<i>Alnus serrulata</i> Species of tree

Alnus serrulata, the hazel alder or smooth alder, is a thicket-forming shrub in the family Betulaceae. It is native to eastern North America and can be found from western Nova Scotia and southern New Brunswick south to Florida and Texas.

<i>Pseudotsuga menziesii <span style="font-style:normal;">var.</span> menziesii</i> Variety of conifer

Pseudotsuga menziesii var. menziesii, commonly known as Coast Douglas-fir, Pacific Douglas-fir, Oregon pine, or Douglas spruce, is an evergreen conifer native to western North America from west-central British Columbia, Canada southward to central California, United States. In Oregon and Washington its range is continuous from the Cascades crest west to the Pacific Coast Ranges and Pacific Ocean. In California, it is found in the Klamath and California Coast Ranges as far south as the Santa Lucia Mountains with a small stand as far south as the Purisima Hills, Santa Barbara County. In the Sierra Nevada it ranges as far south as the Yosemite region. It occurs from near sea level along the coast to 1,800 metres (5,900 ft) in the California Mountains. Further inland, coast Douglas-fir is replaced by Rocky Mountain or interior Douglas-fir. Interior Douglas-fir intergrades with coast Douglas-fir in the Cascades of northern Washington and southern British Columbia.

<i>Alnus alnobetula</i> Species of tree

Alnus alnobetula is a common tree widespread across much of Europe, Asia, and North America. Many sources refer to it as Alnus viridis, the green alder, but botanically this is considered an illegitimate name synonymous with Alnus alnobetula subsp. fruticosa.

References

  1. ↑ Stritch, L. (2014). "Alnus rubra". The IUCN Red List of Threatened Species . 208. IUCN. e.T194598A2351803. doi: 10.2305/IUCN.UK.2014-3.RLTS.T194598A2351803.en .
  2. 1 2 Kew World Checklist of Selected Plant Families
  3. ↑ USDA Plants Profile: Alnus rubra
  4. ↑ BSBI List 2007 (xls). Botanical Society of Britain and Ireland. Archived from the original (xls) on 2015-06-26. Retrieved 2014-10-17.
  5. 1 2 Biota of North America Program, 2013 county distribution map
  6. ↑ "Alnus rubra". Plants of British Columbia. Vancouver, BC: University of British Columbia. Archived from the original on 2008-02-11. Retrieved 2007-11-25.
  7. 1 2 3 Furlow, J. (1979). The systematics of the American species of Alnus. Rhodora, v81-825: 1-248.
  8. 1 2 3 4 5 6 7 8 9 Arno, Stephen F.; Hammerly, Ramona P. (2020) [1977]. Northwest Trees: Identifying & Understanding the Region's Native Trees (field guide ed.). Seattle: Mountaineers Books. pp. 208–215. ISBN   978-1-68051-329-5. OCLC   1141235469.
  9. ↑ "Alnus rubra". efloras.org. Flora of North America.
  10. ↑ "Alnus rubra". Jepson Flora. Berkeley, CA: University of California.
  11. ↑ Zavitkovski, J.; Stevens, R.D. (1972). "Primary productivity of red alder ecosystems". Ecology. 53 (2): 235–242. Bibcode:1972Ecol...53..235Z. doi:10.2307/1934076. JSTOR   1934076.
  12. ↑ Malcolm, D. C.; Hooker, J. E.; Wheeler, C. T. (January 1985). "Frankia symbiosis as a source of nitrogen in forestry: a case study of symbiotic nitrogen-fixation in a mixed Alnus-Picea plantation in Scotland". Proceedings of the Royal Society of Edinburgh, Section B: Biological Sciences. 85 (3–4): 263–282. doi:10.1017/S0269727000004061. ISSN   2053-5910.
  13. ↑ Tilford, Gregory L. (15 June 1997). Edible and Medicinal Plants of the West (1st ed.). Mountain Press. ISBN   0-87842-359-1.
  14. ↑ Ewing, Susan (1996). The Great Alaska Nature Factbook. Portland, OR: Alaska Northwest Books.
  15. ↑ Jeannie Allen (2003-08-22). "Watching Our Ozone Weather". NASA Earth Observatory. Archived from the original on 2008-10-20. Retrieved 2008-10-11.
  16. ↑ Hibbs, D.E.; DeBell, D.S.; Tarrant, R.F. (1995). The Biology and Management of Red Alder. Corvallis, OR: Oregon State University Press.
  17. ↑ Burns, Russell M.; Honkala, Barbara H.; Coordinators, Technical (1990). "Silvics of North America: Volume 2. Hardwoods". United States Department of Agriculture (USDA), Forest Service, Agriculture Handbook 654.
  18. ↑ Xie, C. Y. (2008). "Ten-year results from red alder ( Alnus rubra Bong.) provenance-progeny testing and their implications for genetic improvement". New Forests. 36 (3): 273–284. doi:10.1007/s11056-008-9098-3.
  19. ↑ Oregon Dept of Forestry 2014[ full citation needed ]
  20. ↑ Haeussler, S.T.J. (1995). "Germination, survival and early growth of red alder seedlings in the central Coast Range of Oregon". Canadian Journal of Forest Research. 25 (10): 1639–1651. doi:10.1139/x95-178.
  21. ↑ Lobet, Ingrid (14 August 2012). "In Oregon, Residents Struggle to Solve a Pesticide Mystery". The Atlantic. Retrieved 2 February 2021.
  22. ↑ "Basal Spraying of Red Alder" (PDF). Retrieved 2 February 2021.
  23. ↑ Almond, Lyle (2006). "The value of red alder as an integrated pest management tool for controlling weevil damage to sitka spruce" (PDF). In Deal, R.L.; Harrington, C.A. (eds.). Red Alder: A State of Knowledge. Pacific Northwest Research Station (Technical report). Portland, OR: U.S. Department of Agriculture. General Technical Report PNW-GTR-669 – via Department of Forestry, Province of British Columbia, Canada.
  24. ↑ Bluhm, Andrew A. (25 March 2017) [31 July 2010]. Red alder management: Silviculture to marketing (PDF) (Report). Tree School. Oregon City, OR. Archived from the original (PDF) on 2017-12-07. Retrieved 2017-12-07– via Oregon State University Agricultural Extension Service.
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