Technical guidelines for genetic conservation and use Turkey oak Quercus cerris Quercus cerris Quercus cerris Q Marco Cosimo Simeone1, Peter Zhelev Stojanov2 and Gaye Kandemir3 1 University of Tuscia, Viterbo, Italy 2 University of Forestry, Sofia, Bulgaria 3 Forest Tree Seeds and Tree Breeding Research Institute Directorate, Ankara, Turkey

These Technical Guidelines are intended to assist those who cherish the valuable Turkey oak gene pool and its inheritance, through conserving valuable seed sources or use in practical forestry. The focus is on conserving the genetic diversity of the species at the European scale. The recommendations provided in this module should be regarded as a commonly agreed basis to be complemented and further developed in local, national or regional conditions. The Guidelines are based on the available knowledge of the species and on widely accepted methods for the conservation of forest genetic resources.

Biology and ecology

Turkey oak (Quercus cer- ris L.) is native to Europe and Asia Minor and exhibits strong morphological variability and ecological adaptability. It has deciduous leaves and ovoid acorns with big curly cups, which ripen in the second year (Sep- tember–October). It may reach 30–35 m in height, with a straight trunk up to 2 m in diameter and 5–5.5 m in circumference. The crown is oval, broad and open. The bark is thick, rough and deeply furrowed into irregular horizontal and vertical ridges. The inner part is characteristically red. Leaves are yellow-green, with 6–12 triangular narrow lobes and deep incisions on each side. The regularity of the lobbing varies greatly, with some trees having very regular, moderately to deeply incised lobes TurkeyQuercus oakQuercus cerrisTurkey oakQuercus cerris Turkeycerris oakQuercus cerrisTurkey QuercusoakQuercus cerrisTurkey oakQuercus cerrisTurkey cerris oakQuercus cerrisTurkey oak QuercusQuercus cerrisTurkey oakQuercus cerrisTurkey oakcerrisQuercus cerrisTurkey oakQuercus Quer cerrisTurkey oakQuercus cerri

(var. Haliphleos and Cerris), Distribution Importance and use while others are just toothed (var. austriaca). Leaves are shed in October. Turkey oak is a very impor- Due to its relatively fast growth, Turkey oak is characterized tant forest species in south- Turkey oak is widely planted and it by mesophilous-subcontinental central and eastern Europe and is naturalized in much of Europe. behaviour. It is wa- Anatolia; it occurs as far south It is used as ornamental in parks ter-demanding and as the mountains of south and gardens, and as windbreak. moderately resist- Lebanon/northern Israel. Its The timber has no valuable tech- ant to low and high distribution is centred round nological properties; it is prone to thermal extremes. Un- the lower parts of the Danube cracking and splitting and hence der xeric conditions, its Basin, in Croatia, Hunga- commonly used for fencing, fuel competitive ability de- ry and around the Black wood and charcoal, owing to the creases perceptibly. Sea. The western limits strong re-sprouting ability of its The species is he- of its range are in France, coppiced stands. In the past, it liophilous; in full light, while the northern limits run was widely used for railway sleep- the growth rate is par- across southeast Switzer- ers, now these remains only for a ticularly fast, especially land, eastern Austria, northern small proportion of the logs final that of the sprouts. Par- Czech Republic and Slovakia. destination. Indeed, the current tial shade is tolerated, It is widely distributed in Slove- importance of Q. cerris relies in its however. Turkey oak nia, especialy in the sub-Med- major ecological role. Turkey oak prefers basic, deep, iterranean and pre-Pannonian has diverse types of interactions fresh soils, but it regions, in predominantly pure with ectomycorrhizal fungi, gall- is highly tolerant stands and as single trees in forming insects and seed-eating to almost any soil mixed broadleaf stands. vertebrates. Its forests contrib- (except very wet It is common in the ute to biodiversity safeguard soil). Turkey oak Italian peninsula and in the temperate regions also tolerates strong winds, in the Balkan area, providing habitats for but not maritime exposure. It from Croatia and numerous plant and forms both pure and mixed southern Austria animal communi- stands, mainly with other oaks. to Hungary, up to ties, including verte- Pure populations with an an- northern Greece brates, arthropods, thropic origin are common. It and the Bulgar- greens and epi- may show a sporadic occur- ian and Romanian phytes. rence in Mediterranean ever- Black Sea coasts. It is possible to see green forests, where summer In Turkey there are pure managed stands drought is not a limiting factor. two different subspecies. and mixed forests with Q. cerris is found from the low- It also occurs in south and east different Quercus species (Q. lands up to about 1500 m above Anatolia (reaching Erzincan), up frainetto, Q pubescens, Q. infec- sea level, in Anatolia mostly be- to Samsun in Northern Ana- toria, Q. petrea, Q libani), other tween 500-2000 m, in Lebanon tolia and the Aegean coast of broad leaved species (Fagus, between 1300 and 2200 m. Turkey. Castanea, Carpinus) and conifers TurkeyQuercus oakQuercus cerrisTurkey oakQuercus cerris Turkeycerris oakQuercus cerrisTurkey QuercusoakQuercus cerrisTurkey oakQuercus cerrisTurkey cerris oakQuercus cerrisTurkey oak QuercusQuercus cerrisTurkey oakQuercus cerrisTurkey oakcerrisQuercus cerrisTurkey oakQuercus Quer cerrisTurkey oakQuercus cerri

(Pinus nigra, Pinus brutia, Pinus Genetic knowledge and Balkan populations was pinea). There are also monumen- probably caused by a marked tal individuals with symbolic value population contraction during widely occurring in many old vil- It is commonly agreed that, a glacial phase of the Middle lages across Europe as part of the during the last ice age, the natu- Pleistocene. In Italy, Q. cerris local heritage. ral range of oak species was shares the two most common In past times, the seeds were mainly restricted to the Iberian, haplotypes with Q. suber, thus cooked, dried, ground into pow- Italian and Balkan peninsulas. indicating the possible retention der and used as a thickening During the postglacial period of ancestral variation or unidi- agent in stews or mixed with ce- (approximately the last 7000 rectional introgression between reals for bread-making. The seed years), oaks recolonized their Turkey oak (as seed parent) contains bitter tannins, which can present range from the different and cork oak (pollen parent). In be leached out by washing the refuge areas. These movements Anatolia, an extensive investi- seed thoroughly in running water. have basically impacted the ge- gation with nuclear microsatel- The roasted seeds were also used netic diversity distribution. Ac- lites revealed the occurrence of as a coffee substitute. Other uses cordingly, recent data based on two different gene pools, with concern the seed cups, leaves, plastid microsatellites across low and high genetic diversity bark and wood, commercially the whole species’ range show (the northern and south-cen- used as a source of tannins. Fi- an important level of popula- tral region, respectively). The nally, Quercus cerris can be ef- tion divergence, with the high- false cork oak (Quercus crenata ficiently used in the establishment est genetic diversity within the Lam.), scattered in Italy, south- of truffle orchards, or trufferies. Balkan area and the presence ern France, Slovenia and Croa- Truffles (Tuber melanosporum of unique lineages in the far tia is considered the resulting Vitt., T. magnatum Pico, T. aesti- eastern range (Bagnoli et al. hybrid between Q. cerris and vum L.) grow in an ectomychor- 2016). Three genetically and the cork oak (Quercus suber rizal association with the tree's geographically distinct L.). Based on morphological roots. clusters were identified: intermediacy and some pre- a Western (Italian penin- liminary genetic studies, other sula and Northwestern less frequent hybrids are those Balkan region), a Cen- suggested with other eastern tral (Central and south- Mediterranean oaks such as ern Balkans), and an Q. libani Oliv. (Q. x libanerris Eastern group (Anatolia Boom.), Q. trojana Webb. (Q. and Middle East). Fossil x schneideri Viehr.), Q. pube- data and approximate Bayes- scens (Q. x baenitzii A.Camus), ian computation analysis in- Q. brantii Lindl., Q. infectoria dicate a possible bottleneck Oliv. and Q. ithaburensis Dec- leading to the divergence ne. (Özer, 2014). However, a of the Eastern and Cen- clear assessment of the hybrid- tral populations in the ization ability of the Turkey oak Early Pleistocene. The and validation of its presumed split between the Italian hybrids are still missing. TurkeyQuercus oakQuercus cerrisTurkey oakQuercus cerris Turkeycerris oakQuercus cerrisTurkey QuercusoakQuercus cerrisTurkey oakQuercus cerrisTurkey cerris oakQuercus cerrisTurkey oak QuercusQuercus cerrisTurkey oakQuercus cerrisTurkey oakcerrisQuercus cerrisTurkey oakQuercus Quer cerrisTurkey oakQuercus cerri

Threats to Guidelines for genetic In high forests for production, even-aged populations are pre- genetic diversity conservation and use ferred, in order to reduce com- Humans have greatly reduced Concerning Q. cerris wild petition among individuals of dif- the natural distribution of oaks in populations, special care should ferent sizes. Since Turkey oak the past, and most oak forests be taken regarding habitat con- wood is not valuable, high forest have been managed for millen- servation, soil protection and management, with shelter wood nia. Due to the good resprouting water regime management. As felling on small areas and short ability, Q. cerris, was commonly for managed stands, Q. cerris periods dedicated to regenera- managed as coppice. Indis- grows well within a high forest tion, is the management system criminate cuttings, inappropriate system, which would in itself generally adopted. Where regen- silvicultural management, fires, be a good measure for the spe- eration is naturally poor, working overgrazing (especially during re- cies protection. To preserve soil the soil (superficially), removing generation), mining activities and fertility and increase stand biodi- the understorey and plantation of climatic changes also constitute versity, traditional coppice sys- new seedlings are good options. a threat. In order to allow the tems, performed with short rota- Grazing should in any case be species to adapt, fragmentation tion regimes (20 years), should avoided. For natural regenera- of stands and low numbers of vi- be replaced by longer rotation tion, 70–80 seed bearing trees/ able and reproducing individuals time periods of about 25–30 ha (80–150 with diameter < 50 should be avoided, whereas nat- years, with 1000–2000 stumps/ cm), should be preserved at eve- ural gene flow via pol- ha and preserving at least 80 ry felling. Thinning should be len and acorns seeding trees/ha. This practice performed between 80 and 100 should is suggested especially to small years. After 150 years, the only be fa- private farms, and where the care suggested is to remove voured. ecological conditions are not damaged and unhealthy indi- completely favourable. Cop- viduals. Mixed forests with 150- pice conversion to high 200 individuals/ha and forests requires a fell- natural co-occurrence ing after 50–80 years’ of native tree spe- delay, leaving 80–130 cies should be seed bearing trees/ pursued. ha, if there are optimal For Q. conditions for natural cerris, in situ regeneration (good soil conservation fertility, low density methods based of healthy stand- on natural re- ards), or 30-50 generation are years and 170–200 generally pre- seed bearing trees/ ferred. If natural ha in over-exploited regeneration is stands or where natural re- not sufficient, the generation is poor. use of non-native QuercusTurkey oakQuercus cerrisTurkey oakQuercus cerriscerrisTurkey oakQuercus cerrisTurkey Quercus oakQuercus cerrisTurkey oakQuercus cerris Turkeycerris oakQuercus cerrisTurkey oakQQuercu

Distribution range of Turkey oak

reproductive material can be on- economic, political and social context of climate change. Given ly exceptionally accepted, and it situations, etc. the genetic information available, should be transferred only at a In the case of intensive use it is recommended that conser- local scale, based on the detect- of forest reproductive material vation programmes start with ed species’ genetic structure. (FRM)—acorns, seedlings raised the following objectives: conser- Transfers among provenance re- or lifted—the rules and require- vation of endangered, marginal gions must be strictly avoided. ments of EC legislation for FRM populations and habitats of Q. If in situ methods are not and/or OECD Forestry Scheme cerris; protection of the identified sufficient, an ex situ conserva- shall be primarily applied or genetic variants; establishment tion programme should also be adapted. of Dynamic Conservation Units applied to preserve the endan- Due to its adaptive poten- based on long term autochtho- gered gene pool. Ex situ pro- tial, Turkey oak might have an ny, high biodiversity value and grammes should be adapted to increasing role in present and fu- location in ecologically diverse local conditions, such as popula- ture sub-Mediterranean regions, regions of large populations tion structure; forestry practices; which may be important in the (> 1000 individuals). QuercusTurkey oakQuercus cerrisTurkey oakQuercus cerriscerrisTurkey oakQuercus cerrisTurkey Quercus oakQuercus cerrisTurkey oakQuercus cerris Turkeycerris oakQuercus cerrisTurkey oakQQuercu

These Technical Guidelines and Selected bibliography distribution maps were produced by members of the EUFORGEN Networks. The objective is to Bagnoli F., Tsuda Y., Fineschi S., Bruschi P., Magri D., Zhelev P., Paule L., Simeone M.C., González-Martínez S.C., Vendramin G.G., 2016. Combining identify minimum genetic con- molecular and fossil data to infer demographic history of Quercus cerris: servation requirements in the insights on European eastern glacial refugia. Journal of Biogeography, long term in Europe to reduce 43(4): 679-690. the overall conservation cost and Petit, R.J., S. Brewer, S. Bordács, K. Burg, R. Cheddadi, E. Coart, J. Cottrell, U.M. Csaikl, J.D. Deans, S. Fineschi, R. Finkeldey, I. Glaz, P.G. Goicoe- improve the quality of standards chea, J.S. Jensen, A.O. König, A.J. Lowe, S.F. Madsen, G. Mátyás, R.C. in each country. Munro, F. Popescu, D. Slade, H. Tabbener, B. van Dam, S.G.M. [S.M.G.] de Vries, B. Ziegenhagen J-L. de Beaulieu and A. Kremer. 2002. Identifica- tion of refugia and postglacial colonisation routes of European white oaks based on chloroplast DNA and fossil pollen evidence. Forest Ecology and Citation: Simeone M.C., P. Zhelev Management. Vol. 156 (1-3):49-74. and G. Kandemir. 2019. EUFOR- Özer, T. Y., 2014. Pattern of genetic diversity in Turkey oak (Quercus cerris L.) populations. Ph D. Thesis Middle East Technical University, Department of GEN Technical Guidelines for Biology, 119 pages. genetic conservation and use of The distribution map is based on: Caudullo, G., Welk, E., San-Miguel-Ayanz, Turkey oak (Quercus cerris), Euro- J., 2017. Chorological maps for the main European woody species. Data in pean Forest Genetic Resources Brief 12, 662-666. https://doi.org/10.1016/j.dib.2017.05.007 Programme (EUFORGEN), Euro- pean Forest Institute. 6 pages.

Drawings: Quercus cerris, Giovanna Bernetti.

ISBN 978-952-5980-43-1

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