Flora of Turkey
As of 2000[update] about 9300 species of vascular plant were known to grow in Turkey. By comparison, Europe as a whole contains only about 24% more species (about 11500), despite having thirteen times the area.
A third of Turkish plant species are endemic to Turkey. One reason for this relative importance of endemism in the Turkish flora is the mountainous and at the same time rather strongly fragmented surface of Anatolia. In fact the Anatolian mountains resemble archipelagos like the famous Galapagos Islands. Since Darwin we know that geographic isolation between islands or separated mountains is an important means of speciation, leading to high spatial diversity. For Anatolia this assumption is conformed by concentrations of endemism on highly isolated and relatively old massifs such as Uludağ and Ilgaz Dağ, whereas very young volcanic cones such as Ercyes Dağ and Hassan Dağ are surprisingly poor in endemics.
.As the evolution of local endemics is a rather lengthy process, we have to consider also the different histories of central and north European mountains and the Anatolian ones. During each of the glacial periods the former were covered by thick shields of permanent ice, which destroyed most pre-glacial endemism and hindered neo-endemics from forming. Only less glaciated, peripheral areas, the so-called “massifs de refuge”, offered suitable conditions for the survival of local endemics during glacial periods.
In Anatolia the Pleistocene glaciations only covered the highest peaks, so there are many species with small ranges. In other words: Anatolia as a whole is a big “massif de refuge”, showing all degrees of past and recent speciation.
For a visitor from Central Europe climatic diversity within Turkey is quite astonishing. All climatic zones present in Europe can be found in Turkey on a somewhat smaller scale. The Black Sea coast is humid all the year round, with the highest rainfall between Rize and Hopa. South of the Pontic Range rainfall drops abruptly and in Central Anatolia dry and winter-cold conditions prevail. Approaching the southern and western coasts, the climate turns more and more Mediterranean, with mild but very rainy winters and dry, hot summers. This simple scheme is complicated a lot by the mountainous surface of Anatolia. On the high mountains harsh climatic conditions persist all the year round and, as of 2020[update], there are glaciers in Turkey, for example on Mount Ararat.
Also Anatolia’s diversity of soils is astonishingly high. Saline soils are rather common in the driest parts of central Anatolia. But also the Aras valley between Kağızman and the Armenian border is full of impressive salt outlets, some pouring directly out of the mountains and thus resembling snow patches from a distance. In the regions south of Sivas and around Gürün large areas of Gypsum hills are to be found with a very special flora. A further lot of endemics have been described from the extensive serpentine areas in South-West Anatolia, especially from Sandras Dağ (Cicekbaba D.) near Köyceğiz.
The Anatolian diagonal is an ecological dividing line which runs slant-wise across central and eastern Turkey from the northeastern portion of the Mediterranean Sea to the southeastern part of the Black Sea. Many species of plant that exist west of the diagonal are not present to the east, while others found to the east are not present to the west. Of 550 species analysed, 135 were found to be "eastern" and 228 "western". Besides the Anatolian diagonal forming a barrier to floral biodiversity, about four hundred species of plant are endemic to the diagonal itself.
Main components of the Turkish flora
The genus Astragalus (milk-vetch, goat's-thorn; Fabaceae) has by far the most species of the Turkish flora; as historically humans have dramatically expanded its favored treeless, dry and heavily grazed habitats. Still more Astragalus species are reported from Central Asia. The flora of the former USSR contains about 800 species. The plasticity of this genus is astonishingly high. Depending on environmental conditions a big variety of life-forms evolved, ranging from tiny annuals to small woody and thorny bushes. Speciation seems to be in plain progress in Astragalus. Nearly all of its different sections consists of clusters of closely related species whose determination is one of the hardest tasks in a closer study of the Anatolian flora. One of the most successful growth forms of Turkish Astragali is the thorn cushion, which is very characteristic of the dry mountains of inner Anatolia. Such thorn cushions were not exclusively invented by many Astragali. Really striking examples of convergent evolution are the impressive thorn cushions of Onobrychis cornuta, also belonging to the Fabaceae. But there are a lot of thorn cushions also in Acantholimon (Plumbaginaceae). Even some Asteraceae (in Turkey e.g. Centaurea urvillei, C. iberica) and Caryophyllaceae (e.g. Minuartia juniperina) evolved in that direction. Second in importance comes Verbascum (Scrophulariaceae) and third is Centaurea (Asteraceae). For Verbascum Turkey evidently is the centre of distribution. Of approximately 360 species worldwide not less than 232 are to be found in Turkey, almost 80% of them being Anatolian endemics! Most Verbascum species are protected against water losses and hungry cattle by a dense cover of tree-shaped micro hairs. Centaurea species rarely have woolly hairs, but in defence against heavy grazing developed thorny phyllaries or evolved to acaulous forms.
Along the northern border of Anatolia the Pontic Range forms a more or less continuous barrier against humid air from the Black Sea, causing high precipitation on the northern slopes of the Pontus during the whole year. Climatic conditions on the northern coast therefore resemble those in central Europe and so does the vegetation. A limited Mediterranean influence is noticeable only on a very narrow coastal strip, but almost completely missing in the North-East. In the lower forest zone often Hornbeam (Carpinus betulus) prevails, frequently intermingled with Sweet Chestnut (Castanea sativa). Further up Oriental Beech (Fagus orientalis) and/or Nordmann Fir (Abies nordmanniana) form extensive forests. Humidity becomes extremely high in Lazistan, where the Pontic barrier culminates in the nearly 4000 m high Kackar Daği. East of Trabzon therefore vegetation becomes somewhat sub-tropic, with a lot of evergreens on the forest grounds and tea plantations everywhere on the slopes.
South of the Pontic watershed the climate immediately gets drier. In the mountains first Abies nordmanniana, but then soon Pinus becomes dominant. In the western parts of Anatolia this is often Black Pine (Pinus nigra), in the east nearly exclusively Scotts Pine (Pinus sylvestris). Penetrating further into the central parts of inner Anatolia leads to still dryer, wintercold conditions. Today the lower parts of central Anatolia are virtually treeless. Fields on deep alluvial soils alternate with steppe on the dryer hills. But it is still an open question where and to what degree this central Anatolian steppe is due to aridity or to human deforestation. Aridity is most pronounced around Tuz Gölü south of Ankara und and in the Aras-valley near the Armenian border. Between Kağizman and Tuzluca this valley is so dry, that here and there pure salt deposits glitter like white snowfields on the bare slopes.
The Taurus Range forms the southern limit of the central Anatolian Plateau. Mediterranean influence is already very pronounced there, with a lot of snow in winter, but dry and warm summers. Climax forests are formed by Black Pine, Cilician Fir (Abies cilicica) and Lebanon Cedar (Cedrus libani). Unfortunately there has been a lot of deforestation in the Taurus, most gravely affecting the stands of Cedrus. On the Aegean and Mediterranean coasts pronounced Mediterranean conditions prevail, with very hot and dry summers and very rainy winters. Antalya has considerably more total precipitation than London (1071 mm versus 759 mm), but its seasonal distribution is completely different and average temperature is of course much higher (18,3 °C versus 9,7°). Such conditions favour the growth of hard-leaved evergreen trees such as Kermes Oak (Quercus coccifera) and Turkish Pine (Pinus brutia). But due to massive forest destruction today hills and slopes in coastal West and South Anatolia are mostly covered with macchie. Where fertile alluvial soils prevail, e.g. in the Cilician Plain around Adana, there is intense agriculture.
Rest of the Anatolian steppe with Crambe tatarica (white), with fields in the background, Ahiboz, c.35 km south of Ankara, c.1000 m s.l.
Semidesertic vegetation in the Aras-valley near the Armenian border. Sparse plant cover consists mainly of drought- and salt-tolerant members of the Goosefoot Family (Chenopodiaceae), 35 km west of Tuzluca, 1110 m s.l.
Turkish women drying hazelnuts, Sacmalipinar (Düsce-Province).
- Climate change in Turkey
- Flora of Turkey, Apocynaceae
- Flora of Turkey, Betulaceae
- Flora of Turkey, Fagaceae
- "Turkey's flora and fauna". allaboutturkey.com. Retrieved 12 June 2014.
- Schneeweiss, Gerald M.; Asgarpour, Zahra; Moser, Dietmar; Mahmoodi, Mohammad; Sherafati, Mahbubeh; Zare, Golshan; Noroozi, Jalil (2019). "Patterns of Endemism in Turkey, the Meeting Point of Three Global Biodiversity Hotspots, Based on Three Diverse Families of Vascular Plants". Frontiers in Ecology and Evolution. 7. doi:10.3389/fevo.2019.00159. ISSN 2296-701X.
- Ekima, T.; Günera, A. (1989). "The Anatolian Diagonal: fact or fiction?". Proceedings of the Royal Society of Edinburgh. Section B. Biological Sciences. 86: 69–77. doi:10.1017/S0269727000008915.
- Münir Öztürk; Khalid Rehman Hakeem; I. Faridah-Hanum; Recep Efe (2015). Climate Change Impacts on High-Altitude Ecosystems. Springer. pp. 280–283. ISBN 978-3-319-12859-7.
AVCI. M. 2005. "Çeşitlilik Ve Endemizm Açısından Türkiye’nin Bitki Örtüsü-Diversity and endemism in Turkey's Vegetation", İstanbul Üniversitesi Edebiyat Fakültesi Coğrafya Bölümü Coğrafya Dergisi 13:27-55.
Further basic literature about Turkish Flora and Vegetation:
- DAVIS, P. H. ed. 1965-1988: Flora of Turkey and the East Aegean Islands, 10 vols.− Edinburgh: University Press.
- GÜNER, A. & al. 2000: Flora of Turkey Supplement 2 [= vol 11].− Edinburgh: University Press.
- KREUTZ, D.A.J. 1998: Die Orchideen der Türkei, 766 pp.− Landgraaf (NL): Selbstverlag.
- MAYER, H. & AKSOY, H. 1986: Wälder der Türkei.– Stuttgart & New York: G. Fischer Verlag. Contents as pdf
- KÜRSCHNER, H., RAUS, T. & VENTER, J. 1995: Pflanzen der Türkei. Ägäis - Taurus - Inneranatolien.− Wiesbaden: Quelle & Meyer. Contents as pdf
- PILS, G., 2013: Endemism in Mainland Regions – Case Studies: Turkey.- p. 240-255 in: HOBOHM, C. (Ed.): Endemism in Vascular Plants.- Springer Verlag 
- SORGER, F. 1994: Blumen der Türkei.− Stapfia (Linz) 34. [pdf, 21,54Mb]
- TURKISH JOURNAL OF BOTANY