Downy oak

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Downy oak
Downy oak (Quercus pubescens)

Downy oak ( Quercus pubescens )

Systematics
Rosids
Eurosiden I
Order : Beech-like (Fagales)
Family : Beech family (Fagaceae)
Genre : Oak trees ( Quercus )
Type : Downy oak
Scientific name
Quercus pubescens
Willd.

The downy oak , botanical name Quercus pubescens Willd. , Botanists often prefer the hyphen notation as downy oak , is a plant of the genus of oak ( Quercus ) in the family of the beech plants (Fagaceae). It is widespread from western to southern central , southern and southeastern Europe to Asia Minor and the Caucasus .

description

Young branch with downy hairs
Branch with inflorescences
Ripe acorns with cupula

Vegetative characteristics

The downy oak is a small to medium-sized tree or shrub . It reaches a height of 15 to 20, exceptionally up to 25 meters. It is usually broad-crowned with sparsely protruding branches. The often crooked trunks reach broad breast diameters of 40 to 50 centimeters; a few older specimens even a maximum of 2 to 2.5 meters. A maximum age of up to 500 years is given, but this is based more on extrapolation than on actual measurement. The gray-brown bark is thick (interpreted as a special adaptation to fire) and regularly roughly rough fielded, cracked on branches. The winter buds are egg-shaped and pointed, their scales brown and hairy. Young shoots are densely downy to tomentose, older shoots glabrous.

The deciduous, rarely semi-evergreen leaves reach 4 to 12 centimeters in length, rarely a little more. They are oval or obovate to elliptical in outline, often broadest in the middle, but of very variable shape. The leaf margin is bulged with about 4 to 8 round, irregular lobes on each side. The leaf base is broadly wedge-shaped to slightly heart-shaped, the petiole 0.6 to 1.9, usually about 1.5 centimeters long. The leaves are hairy on both sides when young. The upper side later becomes bald and is then colored dark green, the underside is densely covered with tufted hair and mostly four to six-pointed star hairs and is therefore gray-green tomentose.

Generative characteristics

The downy oak is single sexed ( monoecious ). The flowering time is from March to May, depending on the altitude, and their acorns ripen in September to November. The male flowers have an inconspicuous five- to six-lobed inflorescence and 6 to 10 (12) stamens, they sit in hanging, 5 to 10 centimeters long hairy catkins that sprout from previous year's branches in spring together with the young leaves. The sessile to short-stalked female flowers with three to four greenish stigmas are located (in single-flowered dichasias ) individually or in few clusters in the leaf axils of the distal leaves of the young (this year's) shoots. The female flowers only become ripe when the male ones on the same tree have dried up to prevent self-pollination. The acorns are elliptical, rounded on both sides, they are about 22 to 28 millimeters long and 11 to 14 millimeters wide. Their surface is smooth and shiny, somewhat indistinctly ribbed lengthways, they are brown in color. A quarter of them, up to a maximum of about half, are enclosed in the hemispherical cupula (the cup-shaped covering around the fruit), the adjoining, roof-tiled scales of which are lanceolate and hairy. They sit singly or in small groups of three to four.

The number of chromosomes is 2n = 24.

Similar species

The species is similar to the sessile oak , which is widespread in Central Europe , with which it is connected via numerous hybrids , so that many trees with intermediate characteristics occur. The Central European downy oaks are more similar to the sessile oak than those growing in the Mediterranean area, this is interpreted as an introgression of their characteristics, which is widespread in the wind-flowering oak species. The leaves of the sessile oak always have star hairs on the underside, those of the downy oak in Central Europe. The hairiness of the young shoots is important for a reliable differentiation. Quercus pubescens has multicellular trichomes formed as tufted hairs on all parts of the young shoots; in Quercus petraea these only occur on the veins of the underside of the leaf. Star hairs on the underside of the leaves are interpreted in the downy oak as a genetic influence from crossed sessile oaks.

In the Mediterranean area, there are numerous other similar clans, the taxonomic status of which is partly controversial.

The downy oaks of southern Europe

Distribution area of Quercus pubescens s. l., the downy oak in the broader sense

Within its extensive range in the Mediterranean and Black Sea regions, a number of clans are distributed, collectively known as Quercus pubescens s. l. ( sensu lato , Latin “in the broader sense”). Some of them are regarded by some plant classifiers as separate species ("small species") within this collective species, while others see them as subspecies , or even see them only as local forms without taxonomic value. In addition to a precise morphological analysis according to cladistic methods, genetic methods are also increasingly being used ( phylogenomics , isozyme analysis). The closed distribution area of ​​the species is also surrounded by a swarm of isolated ( disjoint ) outposts, which points to recent changes in the area (expansions or regressions) that may still be ongoing. The picture is also complicated by a number of questionable species names that are not published according to the rules, this even applies to the name Quercus pubescens itself. Therefore, within the collective species (corresponds roughly to the Lanuginosae series) there are dozens of species names that many taxonomists use as synonyms while others consider them valid species.

Quercus virgiliana

Quercus virgiliana ( Ten. ) Ten. is a clan of Southeast Europe, which is indicated from Corsica and Sardinia to the east to western Anatolia, sometimes it is called "Italian oak". For large parts of its distribution area it is said to occur sympatric with Quercus pubescens , in a few also separately from it. Quercus virgiliana is said to build closed forests more frequently in the Balkans than Quercus pubescens sensu stricto and less often to grow shrub-like in open stands. The main morphological distinguishing features given are: length of the cupula and their stalk, shape of their scales, length of the leaf blade and petiole, number of leaf lobes. All features overlap with those of the nominate form , so that complicated morphometric calculations are given to distinguish them. According to more recent analyzes, the morphological and genetic characteristics of both clans overlap so much that their position as a separate species hardly seems justified.

Quercus subpyrenaica

This clan is supposed to replace the typical Quercus pubescens in the Pyrenees and in the northeast of the Iberian Peninsula (on which Quercus pubescens is otherwise missing). In addition to the name Quercus subpyrenaica Villar in Cavanillesia, the name Quercus pubescens subsp. palensis (Palassou) O.Black ( probably mistakenly) used for it. The smaller leaves and the irregular scales of the cupula are given as morphological distinguishing features. As has long been suspected, Quercus subpyrenaica is a hybrid between the oak species Quercus pubescens and the more south-westerly widespread Quercus faginea , in whose contact zone the clan occurs. Other species such as Quercus robur and Quercus petraea may also be involved.

Quercus crispata

This clan was descended from Schwarz, in the Flora Europaea, under the name Quercus pubescens subsp. anatolica and is listed by most authors under the name Quercus pubescens subsp. crispata ( Steven ) Greuter & Burdet accepted as a subspecies of the downy oak. The main distinguishing feature is the shape of the cupula. It is widespread in western and central Anatolia, on the Crimean peninsula and in a few isolated outposts in the Caucasus; old data are also available from the eastern Balkans. Although the subspecies is accepted by most taxonomists, it has hardly been studied.

Quercus brachyphylla

As Quercus brachyphylla Kotschy a deciduous or semi-evergreen shrub or small tree is described, which is to occur in southern Greece, on the Aegean islands, including Crete and in western Anatolia, old data for southern Italy and Sicily are considered untrustworthy. In genetic and morphological investigations, the clan was usually not differentiable from the typical Quercus pubescens and is usually regarded as its synonym . However, it is remarkable in that it is intended to characterize a protected habitat type within the scope of the EU Habitats Directive : Type 9310, Aegean forests with Quercus brachyphylla . There are currently eight Natura 2000 protected areas of this type, all of which are located in Greece.

Quercus dalechampii

The species described by the Italian botanist Michele Tenore is taxonomically extremely problematic. The name has been used in different senses by different botanists. Some consider them, following Otto Schwarz, as a clan from the Quercus petraea species group, which grows mainly in the Balkans and prefers relatively acidic soils there. Others, following the French botanist Aimée Antoinette Camus , regard it as a species from the Quercus pubescens aggregate that is largely restricted to southern Italy. A more recent examination of the descriptions and the herbarium material from Tenore now shows that these difficulties can be traced back to him himself. In the material he collected under this name, both types are included. By selecting a lectotype from the material on which the description could have been based, the editors narrow down the name to a clan from the collective species Quercus pubescens . The " Quercus dalechampii " by the Czech, Slovak and other Central and Eastern European authors who related to Quercus robur s. l. is a different species according to their research.

The Italian Quercus dalechampii Ten. is considered by some botanists to be one of Quercus pubescens s. st. various species described, some accept it as a distinct subspecies of the downy oak. Many others cannot tell the difference. They refer to the extreme variability that can already be seen when comparing the trees in a forest, and which would make a genetic separation unlikely for a wind-blooming oak species. According to this view, there is only one extremely variable species of downy oak in southern Italy.

Downy oak site in Poland

Occurrence

The distribution area of the downy oak (in the broader sense) extends from southern Europe through southern central and western Europe to western and central Asia Minor , where it avoids the forest-hostile innermost areas with steppe climate. With a few isolated outposts, it grows in the Crimea and in the Caucasus . It occurs in the northeast of the Iberian Peninsula , in the Pyrenees and their foothills, in France , Italy , on the Balkans , on Sardinia , Corsica , Sicily and Crete . Due to the uncertainties of the species allocation (see above), some authors do not count some of the marginal or outpost occurrences as species.

In the north of its range, in Central Europe, the downy oak is a rare species with only a few and small, isolated occurrences in particularly heat-favored locations. In the west, in France, it occurs not only in the Mediterranean region, but far in the center and north of the country, but avoids the coastal regions here, it is a type of the Mediterranean and oceanic (Atlantic) climatic zones. It is (including the Mediterranean parts of the country) the third most common type of oak, with a forest area of ​​around 8,555 square kilometers. Your spread is u. a. limited by the frost hardiness, which at −20 ° C is lower than that of the sessile and English oak. In Provence it reaches 1,000 meters above sea level.

The occurrences north of the Alps connect to the French to the east. Here are scattered deposits in areas with a dry, warm, sub-Mediterranean climate: in the Swiss Jura , in Upper Alsace , in the Rhine plain and on the Middle Rhine, in the Kaiserstuhl , on the Heilsberg near Gottmadingen , in the Saale Valley near Jena and in the Lower Oder Valley National Park . These Brandenburg deposits, which contain only a few trees, are near Gartz and Angermünde - Gellmersdorf . The only Polish occurrence is next to it, on the steep slopes of the Oder Valley near Bielinek . Many northern outposts, such as the occurrences in Brandenburg, turned out to be hybrids with the sessile oak on inspection. 15,000 individuals of the true downy oak were recorded in only 26 occurrences in Germany , all of which, with the exception of one occurrence in the Thuringian Saale Valley with only approx. 120 trees, are located in the southwest of Baden-Württemberg. The forest area in Germany only covers about 182 hectares. The main area of ​​distribution of the downy oak in Germany is in the Kaiserstuhl and the southern Upper Rhine Plain, with by far the largest population in the Büchsenberg nature reserve in the Kaiserstuhl. Smaller deposits can be found in the central Swabian Alb.

In Austria, the downy oak can be found in the south and east of the country, in the Weinviertel, Vienna Basin, Marchfeld, in the foothills of the Alps east of the Ödenburg Mountains, as well as in the Styrian hill country and the Mur plain, in heat-favored locations below 400 meters above sea level. Occurrences are found in the Grazer Bergland and the Wachau , among others .

Ecology and location

The downy oak grows in the center of its distribution, in the Mediterranean region, on basic and acidic soils. Towards the north it is more and more restricted to basic soils, mostly limestone. The species loves warmth (thermophilic), but also tolerates moderate night frosts. It does not tolerate shading (heliophile). It is moderately drought-resistant and prefers fresh to dry-ground habitats (mesophilic to xerophilic). In Italy it occurs in regions with annual rainfall between about 600 and over 1000 millimeters per year. It has low demands on nutrient supply and also colonizes nutrient-poor soils, but prefers deeper soils. Due to its high genetic variability with numerous morpho- and ecotypes or small species, it was able to adapt to very different climates. The populations of the northern Balkans are protected against late frosts by an extended dormant period without foliage. In contrast, clans in the southern Mediterranean and on the islands are semi-evergreen and keep their old foliage until the new leaves emerge.

The oak species grows in the northern part of its distribution area only in the plain or in the low hill country (planar and colline height level). Towards the south it increasingly withdraws from the very warm, lower elevations (without being completely absent here) and forms a belt in the middle elevations of the mountains, above the actual Mediterranean level, which is formed by the evergreen holm oak ( Quercus ilex ) and other evergreen Oak species is marked. It can reach the upper mountain forest level in locations with favorable climatic conditions. It rises to altitudes of 1,500 meters in Valais and 1,600 meters in southern Italy. It is the most common and characteristic forest tree species of the so-called sub-Mediterranean zone, which climatically mediates between the Mediterranean zone (with actual Mediterranean climate ) and the cooler temperate or temperate climate zone.

The downy oak tapers both generatively (via acorns) and vegetatively, via stick rashes.

Downy oak forests

Within the sub-Mediterranean climate zone, which connects to the actual Mediterranean zone to the north and at higher mountain heights, the downy oak is the most important forest-forming tree species in Europe. However, as a result of centuries of overexploitation , these forests have been pushed back in many places and the remaining stocks have been degraded. For Italy, for example, it is estimated that downy oak forests form the potential natural vegetation in over 20 percent of the country's area. Their actual share is only 0.8 percent. Today it usually forms very light, open forests or scrub forests. At these locations, however, if there were no disturbances, it could mostly form higher and more closed forests. As is typical for oak forests, however, the downy oak forests with a closed canopy are also relatively light and usually form a rich layer of shrubs and herbs.

In the plant sociological system, the downy oak forests form the order Quercetalia pubescentis, which is named after the downy oak as a character species . However, it is often accompanied by a variety of other tree species. Typical companion tree species are for example manna ash ( Fraxinus ornus ), hop beech ( Ostrya carpinifolia ), wild pear ( Pyrus pyraster ). In the Balkans in particular, it is accompanied by numerous other oak species, including Turkey oak ( Quercus cerris ), Hungarian oak ( Quercus frainetto ) and Macedonian oak ( Quercus trojana ), which they gradually displace from the forests further to the northeast. A typical companion in the east of the area is also the oriental hornbeam ( Carpinus orientalis ).

In the warm inner alpine dry valleys, downy oaks occur as a mixed tree species or in contact with pine forests (called pine forests in Switzerland). These are particularly typical for the Valais, but also occur in South Tyrol. For some time now, pine forests have been dying in Valais, which are being replaced by downy oak forests. In a research project, the Federal Research Institute for Forests, Snow and Landscape WSL found out that this is probably a consequence of climate change.

use

Downy oak stocks in France and Italy cover more than 8,500 square kilometers, the less well known stocks of the Balkans are also of great extent. The species is thus an important European forest tree species.

The downy oak forests were traditionally mainly cultivated as coppice for firewood. Next to it was forest pasture, d. H. Widespread use as a hut forest . The acorn fattening served as pig feed. The bark was used to extract tannin . Downy oaks are among the most important host species of the economically most important truffle species (genus Tuber ). The ring-pored wood, which is not differentiated in color into heartwood and sapwood, has numerous curved wood fibers, and the trunks are also often strongly curved or twisted. It is therefore not very suitable as building or construction timber.

Systematics and taxonomy

The scientific name Quercus pubescens for the species goes back to the publications of the German botanist Carl Ludwig Willdenow in 1796 and 1805. However, in 1796, as he recognized in 1805, he actually described another species, the American Quercus alba . The name Quercus pubescens was thus a later (heterotypical) homonym of the same author and, according to the nomenclature rules, invalid. Willdenow created a centuries-long confusion about the name, which was only resolved by a resolution of the ICBN through the establishment of the established name. Numerous authors previously used the (equally problematic) name Quercus lanuginosa Lam for this species . and Quercus humilis Mill. There are also dozens of other names, many of which are considered synonymous by some botanists and valid species by others (see above).

Quercus pubescens belongs to the group of so-called “white” or “roburoid” oaks, in the traditional system the sub-genus Quercus (considered by some systematics as section Quercus ), a species-rich group common in Eurasia and North America. The obviously closely related species can hardly be differentiated on the basis of genetic data. nor by DNA barcoding against each distinguishable Quercus pubescens is classified differently according to morphological criteria by different authors, mostly in the subsection Galliferae . Among the numerous hybrids, Quercus × calvescens Vuk are particularly noteworthy . ( Quercus petraea × Quercus pubescens ) and Quercus × kerneri Simk. ( Quercus robur × Quercus pubescens ).

literature

Individual evidence

  1. ↑ a b M. Nebel: Fagaceae, beech family. In: Oskar Sebald, Siegmund Seybold, Georg Philippi (eds.): The fern and flowering plants of Baden-Württemberg. Volume 1: General Part, Special Part: Lycopodiaceae to Plumbaginaceae. Eugen Ulmer Verlag, Stuttgart 1993, ISBN 3-8001-3322-9 .
  2. ↑ Andreas Roloff , Andreas Bärtels: Flora of the woods, purpose, properties and use. Fourth edition. Eugen Ulmer Verlag, Stuttgart 2014, ISBN 978-3-8001-8246-6 .
  3. ↑ a b c d Otto Schwarz: Quercus L. In: TG Tutin, NA Burges, AO Chater, JR Edmonson, VH Heywood, DM Moore, DH Valentine, SM Walters, DA Webb (eds.): Flora europaea. 2nd Edition. Volume I, Cambridge University Press, 1993, ISBN 0-521-41007-X , pp. 72-76.
  4. ↑ a b c d e f g Filippo Bussotti: Quercus pubescens. In: Encyclopedia of Woody Plants. Handbook and Atlas of Dendrology 12. Supplement 6/98. doi: 10.1002 / 9783527678518.ehg1998016
  5. ↑ Vít Bojnanský, Agáta Fargašová: Atlas of Seeds and Fruits of Central and East-European Flora: The Carpathian Mountains Region. Springer Verlag, Berlin / Heidelberg 2007, ISBN 978-1-4020-5361-0 , pp. 29-30.
  6. ↑ a b c d e f S. Pasta, D. de Rigo, G. Caudullo: Quercus pubescens in Europe: distribution, habitat, usage and threats. In: J. San-Miguel-Ayanz, D. de Rigo, G. Caudullo, T. Houston Durrant, A. Mauri (Eds.): European Atlas of Forest Tree Species. Publication Office of the EU, Luxembourg 2016, ISBN 978-92-79-52833-0 .
  7. ^ Erich Oberdorfer : Plant-sociological excursion flora for Germany and neighboring areas. 8th edition. Verlag Eugen Ulmer, Stuttgart 2001, ISBN 3-8001-3131-5 , p. 318.
  8. ^ Beat Müller: Variation and hybridization of Quercus pubescens. Dissertation . Swiss Federal Institute of Technology Zurich, 1999.
  9. ^ C. Wellstein, F. Spada: The Status of Quercus pubescens Willd in Europe. In: Elgene O. Box, Kazue Fujiwara (Ed.): Warm-Temperate Deciduous Forests around the Northern Hemisphere. Springer Verlag, Berlin / Heidelberg 2014, ISBN 978-3-319-01261-2 .
  10. ^ A b c Salvatore Brullo, Riccardo Guarino, Giuseppe Siracusa: Revisione tassonomica delle querce caducifoglie della Sicilia. In: Webbia. 54 (1), 1999, pp. 1-72. doi: 10.1080 / 00837792.1999.10670670
  11. ↑ Denes Bartha: Quercus virgiliana. In: Encyclopedia of Woody Plants. Handbook and Atlas of Dendrology - 25th Supplement 9/01. 6 pages. doi: 10.1002 / 9783527678518.ehg2001040
  12. ↑ Cristian Mihai Enescu, Alexandru Lucian Curtu, Neculae Șofletea: Is Quercus virgiliana a distinct morphological and genetic entity among European white oaks? In: Turkish Journal of Agriculture and Forestry. 37, 2013, pp. 632-641. doi: 10.3906 / tar-1210-28
  13. ^ A b Romeo Di Pietro, Piera Di Marzio, Piero Medagli, Giuseppe Misano, Giuseppe N. Silletti, Robert P. Wagensommer, Paola Fortini: Evidence from multivariate morphometric study of the Quercus pubescens complex in southeast Italy. In: Botanica Serbica. 40 (1), 2016, pp. 83-100. doi: 10.5281 / zenodo.48865
  14. ↑ a b Rafaël Govaerts (1995): Proposals to Conserve or Reject Three Species Names in Quercus L. (Fagaceae). Taxon 44 (4): 631-633. JSTOR 1223509
  15. ↑ Hocine Himrane, Jesús Julio Camarero, Eustaquio Gil-Pelegrín: Morphological and ecophysiological variation of the hybrid oak Quercus subpyrenaica (Q. faginea × Q. pubescens). In: Trees. 18, 2004, pp. 566-575. doi: 10.1007 / s00468-004-0340-0
  16. ↑ Werner Greuter, Thomas Raus: Med-Checklist Notulae. 5. In: Willdenowia. 12 (1), 1982, pp. 33-46. JSTOR 3996066
  17. ↑ Otto Schwarz: Draft for a natural system of the Cupulifera and the genus Quercus L. In: Notblatt des Königl. botanical garden and museum in Berlin. 13 (116), 1936, pp. 1-22. JSTOR 3994908
  18. ↑ Josip Franjić, Zlatko Liber, Željko Škvorc, Marilena Idžojtić, Renata Šoštarić, Zvjezdana Stančić: Morphological and molecular differentiation of the croatian populations of Ouercus pubescens Willd. (Fagaceae). In: Acta Societatis Botanicorum Poloniae. 75 (2), 2006, pp. 123-130. doi: 10.5586 / asbp.2006.015
  19. ↑ RGH Bunce, MBB Bogers, D. Evans, RHG Jongman: Rule based system for in situ identification of Annex I habitats. In: Alterra Report. 2276. Wageningen 2012.
  20. ↑ European Nature Information System EUNIS: Aegean Quercus brachyphylla woods. Factsheet
  21. ^ A b Romeo Di Pietro, Vincenzo Viscosi, Lorenzo Peruzzi, Paola Fortini: A review of the application of the name Quercus dalechampii. In: Taxon. 61 (6), 2012, pp. 1311-1316. JSTOR 24389116
  22. ^ R. Matula: Comparison of general tree characteristics of less known oak species Quercus dalechampii Ten. and Quercus polycarpa Schur. In: Journal of Forest Science. 54 (8), 2008, pp. 333-339.
  23. ^ Ignazio Camarda: Some considerations about diversity, distribution and problems of Quercus L. in Sardinia. In: Bocconea. 16 (1), 2003, pp. 65-72.
  24. ↑ Jaakko Jalas, Juha Suominen: Atlas Florae Europaeae. II. 3: Salicaceae to Balanophoraceae. 4: Polygonaceae. 5: Chenopodiaceae to Basellaceae. Cambridge University Press, 1988, ISBN 0-521-34271-6 , p. 78 (card 307)
  25. ↑ J. Timbal, G. Aussenac: An overview of ecology and silviculture of indigenous oaks in France. In: Annales des sciences forestieres. 53 (2-3), 1996, pp. 649-661.
  26. ↑ a b Collection and documentation of the genetic resources of the downy oak (Quercus pubescens), the service tree (Sorbus torminalis) and the service tree (Sorbus domestica) in Germany. AZ 114-02.05-20.0074 / 09-E - Lot 1. Final report, March 8, 2013. Prepared by the Forest Office East Bavaria, on behalf of the Federal Office for Agriculture and Food.
  27. ↑ a b Ralf Kätzel, Thomas Kamp, Aki Michael Höltken, Frank Becker, Helmut Josef Riederer, Jens Schröder: The occurrence of the downy oak and its hybrids north of the Alps. In: Landbauforschung. 2 2014 (64), 2014, pp. 73–84.
  28. ↑ Ralf Kärtel, Frank Becker, Jens Schröder, Jonas Glatthorn, Aki Höltken, Sonja Löffler: Downy Oak and Zerr Oak in Brandenburg - Alternative Tree Species in Climate Change? In: Eberswalder Forstliche Schriftenreihe. 49, 2012, pp. 23-36.
  29. ↑ K. Milecka K., M. Kupryjanowicz, M. Makohonienko, I. Okuniewska-Nowaczyk, D. Nalepka: Quercus L. Oak. In: M. Ralska-Jasiewiczowa, M. Latałowa, K. Wasylikowa, K. Tobolski, E. Madeyska, HE Wright Jr., C. Turner (eds.): Late Glacial and Holocene history of vegetation in Poland based on isopollen maps . W. Szafer Institute of Botany, Polish Academy of Sciences, Kraków 2004, pp. 189–198.
  30. ↑ Ladislav Mucina, Georg Grabherr, Susanne Wallnöfer: The plant communities of Austria. Part III: Forests and bushes. Gustav Fischer Verlag, Jena 1993, ISBN 3-334-60452-7 .
  31. ↑ Homepage of the Jauerling-Wachau Nature Park. Retrieved September 29, 2014 .
  32. ↑ a b Riccardo Guarino, Giuseppe Bazan, Bruno Paura: Downy-Oak Woods of Italy: Phytogeographical Remarks on a Controversial Taxonomic and Ecologic Issue. In: EO Box, K. Fujiwara (Ed.): Warm-temperate Deciduous Forests around the Northern Hemisphere. (= Geobotany Studies). Springer Verlag, 2014, ISBN 978-3-319-01260-5 . doi : 10.1007 / 978-3-319-01261-2_7
  33. ↑ Pannonian downy oak forests. Descriptions of the Natura 2000 habitats found in South Tyrol download
  34. ↑ Andreas Rigling, Matthias Dobbertin et al .: Do downy oaks displace the Walliser forest pines? Article on www.waldwissen.net, originally posted on April 25, 2006
  35. ↑ Do downy oaks displace the forest pines in Valais? Project report, WSL Federal Research Institute for Forests, Snow and Landscape, as of June 17, 2010 ( Memento of the original from September 26, 2016 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.wsl.ch
  36. ↑ Erwin Bergmeier, Jörg Petermann, Eckhard Schröder (2010): Geobotanical survey of wood-pasture habitats in Europe: diversity, threats and conservation. Biodiversity and Conservation 19: 2995-3014. doi : 10.1007 / s10531-010-9872-3
  37. ↑ Thomas Denk & Guido W. Grimm (2010): The oaks of western Eurasia: Traditional classifications and evidence from two nuclear markers. Taxon 59 (2): 351-366.
  38. ↑ Aki M. Höltken, Jutta Buschbom, Ralf Kätzel (2012): The species integrity of our native oaks Quercus robur L., Q. petraea (Matt.) Liebl. and Q. pubescens Willd. from a genetic point of view. Allgemeine Forst- und Jagdzeitung 183 (5/6): 100-110.
  39. ↑ Marco C. Simeone, Roberta Piredda, Alessio Papini, Federico Vessella, Bartolomeo Schirone (2013): Application of plastid and nuclear markers to DNA barcoding of Euro-Mediterranean oaks (Quercus, Fagaceae): problems, prospects and phylogenetic implications. Botanical Journal of the Linnean Society 172 (4): 478-499. doi : 10.1111 / boj.12059

Web links

Commons : Downy Oak ( Quercus pubescens )  - Album with pictures, videos and audio files
Wiktionary: Downy oak  - explanations of meanings, word origins, synonyms, translations