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Alnus glutinosa (L.) Gaertn.

Betulaceae
European alder, Black alder

Source: James A. Duke. 1983. Handbook of Energy Crops. unpublished.

  1. Uses
  2. Folk Medicine
  3. Chemistry
  4. Description
  5. Germplasm
  6. Distribution
  7. Ecology
  8. Cultivation
  9. Harvesting
  10. Yields and Economics
  11. Energy
  12. Biotic Factors
  13. References

Uses

The wood, elastic and soft, fairly light and easily worked, is used for cigarboxes, pumps, and wooden carvings, shoes and slippers. The bark, used for tanning, imparts a hard red appearance to leather. The wood is also used in making the molds for glass manufacture. The tree provides habitat and food for wildlife, watershed protection, and is used in environmental forestry (Ag. Handbook 450). With little ornamental value, it is recommended only for wet sites.

Folk Medicine

According to Hartwell (1967–1971), the leaves are decocted in folk remedies for cancer of the breast, duodenum, esophagus, face, pylorus, pancreas, rectum, throat, tongue, and uterus. The bark and/or roots are used for cancers and inflammatory tumors of the throat. Reported to be alterative, astringent, detersive, diuretic, sudorific, tonic, and vermifuge, black alder is a folk remedy for cancer, fever, foot ailments, tumors, and worms (Duke and Wain, 1981). The bark decoction is taken as a gargle for angina and pharyngitis, as an enema in hematachezia.

Chemistry

The bark contains up to 20% tannin, a flavone glycoside of the hyperoside type, a reddish dye, emodin (?), alnulin (C30H50O), protoalnulin (C30H48O) phlobaphene, taraxerol, taraxerone, lupeol, b-sitosterol, glutinone (C30H48O), and citrullin. The leaves contain alnusfoliendiolone, 3-b-hydroxyglutin-5-en, D-amyrenone, taraxerol, b-sitosterol, wax, and sugars (List and Horhammer, 1969–1979). Gibbs (1974) reports l-ornithine in the roots of this species, l-serine in the genus.

Description

Shrub or small tree to 20 m, the bark initially gray-brown, smooth, lustrous, later dark gray and rougher. Leaves rotund or broadly ovate to ellipsoid or ovate, 4–9 cm long, 3–7 cm wide, basally rounded the petiole 1–2 cm long; stipules obtuse, soon deciduous. Male cones purplish brown in autumn and winter, brown in the spring, 6–12 cm long, in clusters of 3–5. Fruits rounded, the seeds winged. Seeds ca 700,000–750,000/kg, but yielding only ca 20–25,000 plantable seedlings.

Germplasm

Reported from the Eurosiberian Center of Diversity, black alder, or cvs thereof, is reported to tolerate frost, poor soil, and waterlogging. Hortus III lists var. barbata, denticulata, and glutinosa, as well as several cvs 'Aurea', 'Imperialis', 'Incisa', 'Oxycanthifolial, 'Pyramidatis', 'Quercifolia', 'Rubrinervia', and 'Sorbifolia'. Wyman (1974) mentions 'Laciniata'. Alnus glutinosa serves as a rootstock for grafting of other alder species.

Distribution

Throughout the Caucasus, Europe, Siberia, into Asia Minor, Iran, and North Africa. Naturalized locally in eastern Canada and Northeastern U.S.

Ecology

Estimated to range from Warm Temperate Dry to Moist through Cool Temperate Steppe to Wet Forest Life Zones, black alder is estimated to tolerate annual precipitation of 4 to 20 dm, annual temperature of 8 to 14°C, and pH of 6 to 8. Ranging north to Wyman's Zone 3.

Cultivation

Seeds which have remained viable after floating for 12 months, are sown at depths of 3–6 mm, in spring or fall. For blanket bogs in England, spot sowings have been recommended ca 15 seeds per spot fertilized with ca 60 g phosphate. Seeds germinate as well under continuous darkness as with normal day lengths. Air-dried seeds stored at 1–2°C retained their viability for two years. Seeds can however be sown immediately as soon as ripe.

Harvesting

Timber and/or firewood harvested as needed, the shrub apparently coppices readily. In the U.S., it flowers from March to May, the fruits ripening in fall, natural dispersal occurring from late fall to early spring.

Yields and Economics

A 13–18-year-old stand with ca 30,000 trees ha (ca 20% Alnus glutinosa, the dominant, with Carpinus and Crataegus et al) in an infertile gley at elevation 265 m had a basal area of 24–40 m2/ha. The standing biomass was about 59.3 MT/ha wood, bark, and branches, 2.8 MT leaves, and 4.3 MT estimated roots. Leaf litterfall was ca 2.5 MT/ha/yr. A British stand dominated by A. glutinosa (ca 1600 trees/ha, 55% Alnus, 44% Betula pendula and Acer pseudoplatanus) had a basal area of ca 25 m2/ha, a leaf area index of 3.6, and a standing biomass of 109 MT/ha.

Energy

According to the phytomass files, annual productivity is estimated at 6 to 9 MT/ha. The tree has yielded 11.8 MT/ha/yr on pulverized fuel ash (Dennington, et al, 1983). Kestemont (1975) estimated annual productivity at 8.66 MT/ha, with 5.87 MT in wood, bark, and branches, 2.79 MT in foliage. According to Cannell, (1982), Hughes (1971) estimated the aerial productivity at ca 6.7 MT/ha/yr with wood, bark, and branches accounting for 4.26 MT + 0.34 MT litter, 1.78 MT leaf and leaf litter, 0.34 MT fruit and fruit litter. NAS (1980a) recommends the black alder for consideration for firewood plantations in Tropical highlands where unseasonal cold might destroy the red alder. Nitrogen-fixation by trees up to 8 years old has been put at 125 kg/ha/yr, for 20 years at 56–130 kg/ha/yr (NAS, 1979). Related red alder has been estimated to fix as much as 300 kg/ha.

Biotic Factors

Agriculture Handbook 165 lists the following diseases for Alnus glutinosa: Phymatotrichum omnivorum (root rot), Polyporus versicolor (sapwood rot), Septoria alni (leaf spot), and Sphaeropsis alnicola (on twigs). Like other alders, the cv 'Laciniata' is susceptible to a canker which can kill large parts of the plant quickly (Wyman, 1974). Nematodes include Longidorus maximus, and Pratylenchus penetrans (Golden, pers. commun. 1984).

References

Complete list of references for Duke, Handbook of Energy Crops
Last update December 19, 1997