Oh Tannenbaum! A Story of .

By Katharina Lapin

December 12th 2020

Their home is the temperate Northern Hemisphere, and their evergreen leafs are popular around the world, especially at Christmas time: Fir tree species, a genus of the family .

Since a long time ago the fir tree catched my attention, because like no other coniferous tree species, fir are of such and cultural importance economic value and simple beauty like the fir like the species of these genus. You may be familiar with the silver fir, which is native to the Alpine Space, or the Nordmann fir, which you might have decorated for Christmas, but there are so many more fir tree species to explore –56 different fir species, to be exact (see the list of fir trees below).

Although the different fir species are widely distributed across the Northern Hemisphere - from the dry of Spain to the frosty forests of Siberia, and across different mountain ranges, they share common features, in reproduction, habit and growth characteristics.

The trunks of many young fir trees, for example, often show large resin blisters. The are always evergreen needle leaves, which are spirally or often also parted. A particularly remarkable feature is the disc-shaped base, which is shed as a whole, which is an important distinguishing feature from the Norway . The cones of the fir species are always mainly located in the crown and point upwards. The cones can be 4 - 20 centimeters long and, depending on the species, are either cylindrical or conical or even elongated to ovoid. Another important feature of the fir species are the seed scales, or cap scales, which often fall apart easily after the first year of seed maturation. Therefore, when you walk through the , you will rarely see a fir cone lying on the ground that still has scales, as we might know it from spruce or pine.

In forests of the Alpine space, we can find the native quite frequently in higher elevations, where it is among the stand forming tree species. The latest studies have shown that the silver fir has the potential to replace spruce well in large areas of Central under climate change. However, selective browsing by cloven-hoofed game and inappropriate silvicultural treatment by disregarding its specific growth characteristics have led to a dramatic decline of this tree species. Further, the immigration history after the Ice

Age and the utilization history of the tree species needs to be considered: The fir has slowly established after the last Ice Age and has not yet exhausted its potential range! Since the late Middle Ages, large-scale clear-cutting took place in the Alpine region to cover the enormous demand for . The one-sided reforestation of these areas with spruce made the emergence of the fir considerably more difficult. Today, fir is less susceptible to drought and at the same time more storm-resistant than spruce and is becoming more and more popular as the "bearer of hope for silviculture in climate change".

But besides the native tree’s species the non-native (grand fir or giant fir) was planted in some forests in the Alpine space, which is native to the west part of USA. It can be considered an important and well-tested non-native tree for forestry in the Alpine Space and one of the fir species with the strongest growth. Grand fir, as the name predicts, reaches a maximum height of 85 m and a diameter at breast height of 1.6 m as well as a maximum age of 280 years.

While the number of non-native fir species used in forests in the Alpine region is very low, the number of fir tree species used in cities, parks and gardens is considerably higher. In the cities of the Alpine region alone, we have counted 13 different fir species within the framework of our ALPTREES project (see the list of fir trees below).

If you walk through an old park, you will probably come across the Greek fir or sometimes the Spanish fir, both of which have very remarkable appearances. But despite their beauty, fir threes like the Greek fir are tricky to grow: it´s optimal conditions are well drained and calcareous soils. In the northern part of its natural range, the dry habitats of Mediterranean Island Euboea in the Aegean sea and Cephalonia in the Ionian sea, it has adapted to relatively dry summers and wet winters, with annual precipitation from 700 to 1500 mm, with mean annual temperature ranges 7.5-16°C but does not tolerate temperature below - 15°C. Nevertheless, are important trees for landscaping and garden design, especially under climate change.

That was a very brief insight into the diversity of fir tree species. Fir species have a high forestry economic importance, they are remarkably interesting for timber use, but also for landscape design and their ecological function. Personally, I am happy every time I come across a fir in the forest or in the park, and this joy is probably influenced by many memories of happy Christmasses.

List of the 13 Fir tree species in the Alpine Space

Native to the Alpine space:

1. Abies alba

Non native to the Alpine Space:

2. Abies borisii-regis 3. 4. 5. Abies grandis 6. Abies homolepis 7. Abies homolepsis 8. 9. 10. 11. Abies spec. 12. 13. Abies vilmorinii

List of the 68 Fir tree species

1. Abies alba Mill. 2. (Douglas ex Loudon) J.Forbes 3. Abies balsamea (L.) Mill. a. Abies balsamea var. phanerolepis Fernald 4. Abies beshanzuensis M.H.Wu 5. Abies × borisii-regis Mattf. 6. Abies bracteata (D.Don) Poit. 7. Abies cephalonica Loudon 8. Abies chensiensis Tiegh. 9. Abies chensiensis subsp. salouenensis (Bordères & Gaussen) Rushforth 10. Abies chensiensis subsp. yulongxueshanensis Rushforth 11. Abies cilicica (Antoine & Kotschy) Carrière 12. Abies cilicica subsp. isaurica Coode & Cullen 13. Abies concolor (Gordon) Lindl. ex Hildebr. 14. Abies delavayi Franch. 15. Abies delavayi subsp. fansipanensis (Q.P.Xiang, L.K.Fu & Nan Li) Rushforth a. Abies delavayi var. motuoensis W.C.Cheng & L.K.Fu b. Abies delavayi var. nukiangensis (W.C.Cheng & L.K.Fu) Farjon & Silba

16. Griff. 17. Abies durangensis Martínez a. Abies durangensis var. coahuilensis (I.M.Johnst.) Martínez 18. (Mast.) Craib 19. Abies fabri subsp. minensis (Bordères & Gaussen) Rushforth 20. Abies fanjingshanensis W.L.Huang, Y.L.Tu & S.Z.Fang 21. Franch. a. Abies fargesii var. faxoniana (Rehder & E.H.Wilson) Tang S.Liu b. Abies fargesii var. sutchuensis Franch. 22. Abies firma Siebold & Zucc. 23. Coltm.-Rog. a. Abies forrestii var. ferreana (Bordères & Gaussen) Farjon & Silba b. Abies forrestii var. georgei (Orr) Farjon c. Abies forrestii var. smithii R.Vig. & Gaussen 24. Abies fraseri (Pursh) Poir. 25. Abies grandis (Douglas ex D.Don) Lindl. 26. Rehder a. Abies guatemalensis var. jaliscana Martínez 27. Abies hickelii Flous & Gaussen a. Abies hickelii var. macrocarpa Martínez 28. Abies hidalgensis Debreczy, I.Rácz & Guízar 29. Abies holophylla Maxim. 30. Abies homolepis Siebold & Zucc. a. Abies homolepis var. umbellata (Mayr) E.H.Wilson 31. (Hayata) Ito 32. Abies koreana E.H.Wilson 33. Abies lasiocarpa (Hook.) Nutt. a. Abies lasiocarpa var. arizonica (Merriam) Lemmon 34. A.Murray bis a. Abies magnifica var. shastensis Lemmon 35. Mast. 36. Abies nebrodensis (Lojac.) Mattei 37. (Trautv. ex Maxim.) Maxim. 38. Abies nordmanniana (Steven) Spach 39. Abies nordmanniana subsp. equi-trojani (Asch. & Sint. ex Boiss.) Coode & Cullen 40. Abies numidica de Lannoy ex Carrière 41. Abies pendula (Aiton) Lindl. & Gordon 42. (Royle ex D.Don) Royle a. Abies pindrow var. brevifolia Dallim. & A.B.Jacks. 43. Abies pinsapo Boiss.

a. Abies pinsapo subsp. marocana (Trab.) Emb. & Maire 44. Rehder 45. Abies recurvata Mast. a. Abies recurvata var. ernestii (Rehder) Rushforth 46. (Kunth) Schltdl. & Cham. 47. Abies religiosa subsp. mexicana (Martínez) Strandby, K.I.Chr. & M.Sørensen 48. (F.Schmidt) Mast. a. Abies sachalinensis var. gracilis (Kom.) Farjon b. Abies sachalinensis var. mayriana Miyabe & Kudô c. Abies sachalinensis var. nemorensis Mayr 49. Ledeb. 50. Abies sibirica subsp. semenovii (B.Fedtsch.) Farjon 51. (D.Don) Mirb. 52. Abies squamata Mast. 53. Abies veitchii Lindl. a. Abies veitchii var. sikokiana (Nakai) Kusaka 54. Abies vejarii Martínez a. Abies vejarii var. macrocarpa Martínez 55. Abies yuanbaoshanensis Y.J.Lu & L.K.Fu 56. Abies ziyuanensis L.K.Fu & S.L.Mo

Links

• The List (10.12.2020): http://www.theplantlist.org/tpl1.1/search?q=abies

• Muck, P.; Borchert, H.; Elling, W.; Hahn, J.; Immler, T.; Konnert, M.; Walentowski, H.; Walter, A. (2008): Die Weißtanne – ein Baum mit Zukunft. LWF aktuell 67, S. 56 – 58.

• https://www.die-forstpflanze.de/grosse-kuestentanne-abies-grandis/

Figure 1. Natural regeneration in Silver fir.

Figure 2 the Spanish fir and the green fir in urban parks.

Figure 3. Observing the potential and risk of non-native fir species.