Forest Ecology and Forest Management Group Tree factsheet images at pages 3, 4, 5, 6 Alnus glutinosa (L.) Gaertn. taxonomy author, year Gärtner, 1792 synonym Alnus vulgaris Hill. Family Betulaceae Eng. Name European Black alder, Common alder Dutch name Zwarte els subspecies varieties A. glutinosa var. barbata hybrids A. x pubescens Tausch ( A. glutinosa x A. incana ) cultivars, frequently used: ‘Laciniata’ as a street tree ‘Pyramidalis’ as a street tree references Weeda, 2003, vol.1 (Dutch) Wiegers, J. 1989. Alnus (in Dutch). in: Schmidt, P. 1989. Nederlandse boomsoorten II, Syllabus Vakgroep Bosbouw Landbouwuniversiteit Wageningen morphology crown habit tree, oval max. height (m) 15-30 max. dbh (cm) >200 actual size Great Britain year 1800, d(120) 240, Geltsdale, Cumbria, England actual size The Netherlands year 1830-1840, d(130) 88, h 14 year 1900-1910, d(130) 92, h 18 year 1900-1910, d(130) 68, h 22 leaf length (cm) 5-9 leaf petiole (cm) 2 leaf colour upper surface green leaf colour under surface green leaves arrangement alternate flowering March flowering plant monoecious flower monosexual flower diameter (cm) <0,1 pollination wind fruit; length winged nut; 0,2 cm fruit petiole (cm) 1 seed; length nut; approx. 0,1 cm seed-wing length (cm) approx. 0,1 weight 1000 seeds (g) 1,2-1,4 seeds ripen October seed dispersal wind, water habitat natural distribution Europe, West Asia, N. Africa in N.W. Europe since 7.000 B.C. natural areas The Netherlands brook forests geological landscape types The Netherlands coversand area, river valleys (Hoek 1997) forested areas The Netherlands loamy, clay and peat soils area Netherlands Alnus spp. 967 (2002, Probos) % of forest trees in the Netherlands 0,4 (2002, Probos) soil type indifferent pH-KCl neutral to alkaline soil fertility nutrient poor to rich light half shade tolerant shade tolerance 2.7 (0=no tolerance to 5=max. tolerance) drought tolerance 2.2 (0=no tolerance to 5=max. tolerance) waterlogging tolerance 3.9 (0=no tolerance to 5=max. tolerance) plant communities in the Netherlands Alnetea glutinosae (klasse der Elzenbroekbossen): -Thelipterido-Alnetum (Moerasvaren-Elzenbroek) -Carici elongatae-Alnetum (Elzenzegge-Elzenbroek) Querco-Fagetea (klasse der Eiken-Beukenbossen op voedselrijke grond): -Carici remotae-Fraxinetum (Goudveil-Essenbos) -Pruno-Fraxinetum (Vogelkers-Essenbos) -Violo odoratae-Ulmetum (Abelen-Iepenbos) management status Europe frequent species in forests, landscape status The Netherlands frequent indigenous species in forests, landscape; infrequent in urban environment application nature tree, timber tree, coppice tree propagation seed; named cultivars by grafting or cuttings regeneration planting; natural regeneration from seed; new stems optimal gap size for regeneration 2-3x tree length first plantation Netherlands resprouting after cutting good growth rate (M.A.I. in m 3ha -1j-1) 4-8 diseases Phytophthora cambivora , fungus insects aphids (bladluizen) Eriophyes laevis , gallmite (galmijt ) Agelastica alni , alder leaf beetle (elzenhaantje) wood wood Alder, Black alder (Europees elzen) wood structures key characteristics of pores diffuse porous; radial pore groups vol. mass heartwood (kg/m3) (490-)530(-640) (12% moisture content) elastic modulus (N/mm 2) 9400 durability heartwood fungus 5 heartwood color red-brown sapwood color red-brown contents products tools, cutlery, turnery, triplex, boxes; construction wood (old) non-timber products bark medicinal purposes Ülo Niinemets and Fernando Valladares. 2006. Tolerance to shade, drought, and waterlogging of temperate Northern Hemisphere trees and shrubs. Ecological Monographs 76:521–547 Black alder leaves and buds in summer seedling, one year old winter buds Young tree, Wageningen Mature tree, multi-stemmed, Wageningen photography 5x © Leo Goudzwaard, Wageningen University Black alder female flowers in detail, photography ©Plantengids KU Leuven flower buds in winter unripe fruits ripe fruits © Plantengids KU Leuven photos 2x © Leo Goudzwaard cone bract seed (here without wings) © 2006 GIA: het Groninger Instituut voor Archeologie heeft de rechten van alle afbeeldingen in de Digitale Zadenatlas van Nederland. Alle rechten voorbehouden. Mature alder bark Alder wood, photo © Chris Sonnemans Alder woodland, Vallei van de Zwarte Beek, Vlaanderen Alder woodland, Beaulieu River, New Forest Photo © Koen Jellema Photo © Leo Goudzwaard, Wageningen University Thomé, 1885 .