Quercus ilex
Holm oak

Holm oak, evergreen, or holly oak (Quercus ilex) is a medium-sized, long-living evergreen tree. The tree is native to and widespread across the central-western Mediterranean region (Ortego, Bonal, and Muñoz, 2010). Holm oak is shade-tolerant and able to germinate and resprout in the understorey of woodlands. It is often found in mixed vegetation together with other broadleaved evergreen plants and is characterized by its resilience to dry climates and ability to thrive in various soils and at a range of altitudes.

Holm oak is economically important and has been extensively used by humans for centuries (Ortego, Bonal, and Muñoz, 2010). The tree produces hard wood that is used for smaller woodcrafts, but it is also coppiced to produce firewood and planted in pastures, providing acorns for grazing livestock. Additionally, its aesthetic qualities make it a preferred choice for ornamental purposes in landscapes and preventing soil erosion. Despite its slow growth, its longevity and utility in creating robust ecosystems make it a keystone species in Mediterranean forests, where its dense, rounded canopy provides crucial habitat and food for numerous wildlife species and helps maintain ecological balance (Ortego, Bonal, and Muñoz, 2010).

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EUFORGEN’s publications on Abies alba

Technical guidelines for genetic conservation and use

Quercus ilex - Technical guidelines for genetic conservation of Holm oak

Publication Year: 2019

Seed propagation for high forests is the most suitable management method to main­tain and increase genetic diver­sity and, therefore, the conser­vation of the genetic resourc­es of the species. It is the most adequate regime for landscape protection, or­namental and recreational functionalities. High forest merits are also on the use of water, which is a special feature for Mediterranean regions where increasing hu­man demands for water are expected together with cli­mate change induced drought (Gracia, 2009).

Coppices for firewood pro­duction (coppicing every 30–40 years) usually host a large amount of the biodiversity of Mediterranean ecosystems, but reduce the genetic diversity of the coppiced species, in par­ticular where up growing single stems per stump are not left. Therefore, the chance to con­vert coppices into high forests, through a gradual increase of the number of single stems per stump, should be considered. For instance, a coppice stand with a single stem per stump system, with long cycles (not less than 40 to 50 years) and a large number of seed-bearing trees (even >200), contributes to the regeneration of the popu­lation and the maintenance of the understory and favours the natural evolution of Q. ilex to­wards its climax situation (which is pure high forest).

Holm oak hybridizes with other oak species and hybridi­zation may result in a loss or an increase of genetic diver­sity according to the concrete situation of the population or species evolution (Soltis & Solt­is, 2009). Where populations for conservation of genetic resources are established in mixed oak- stands, hybridiza­tion monitoring is recommend­ed, whenever possible through genomics, transcriptomics and progeny testing.

Since limited genetic infor­mation about Q. ilex is available, it is recommended that genetic conservation programmes start with the following objectives: conservation of endangered, marginal populations and habi­tats of Q. ilex; sampling the genetic diversity; establishment of Dynamic Conservation Units based on long term autochtho­ny, high biodiversity value and location in ecologically diverse regions of large populations (> 1000 individuals).

Seed propagation for high forests is the most suitable management method to main­tain and increase genetic diver­sity and, therefore, the conser­vation of the genetic resourc­es of the species. It is the most adequate regime for landscape protection, or­namental and recreational functionalities. High forest merits are also on the use of water, which is a special feature for Mediterranean...

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Acknowledgements

This distribution map has been developed by the European Commission Joint Research Centre (partly based on the EUFORGEN map) and released under Creative Commons Attribution 4.0 International (CC-BY 4.0)


Caudullo, G., Welk, E., San-Miguel-Ayanz, J., 2017. Chorological maps for the main European woody species. Data in Brief 12, 662-666. DOI: https://doi.org/10.1016/j.dib.2017.05.007

The following experts have contributed to the development of the EUFORGEN distribution maps:

Fazia Krouchi (Algeria), Hasmik Ghalachyan (Armenia), Thomas Geburek (Austria), Berthold Heinze (Austria), Rudi Litschauer (Austria), Rudolf Litschauer (Austria), Michael Mengl (Austria), Ferdinand Müller (Austria), Franz Starlinger (Austria), Valida Ali-zade (Azerbaijan), Vahid Djalal Hajiyev (Azerbaijan), Karen Cox (Belgium), Bart De Cuyper (Belgium), Olivier Desteucq (Belgium), Patrick Mertens (Belgium), Jos Van Slycken (Belgium), An Vanden Broeck (Belgium), Kristine Vander Mijnsbrugge (Belgium), Dalibor Ballian (Bosnia and Herzegovina), Alexander H. Alexandrov (Bulgaria), Alexander Delkov (Bulgaria), Ivanova Denitsa Pandeva (Bulgaria), Peter Zhelev Stoyanov (Bulgaria), Joso Gracan (Croatia), Marilena Idzojtic (Croatia), Mladen Ivankovic (Croatia), Željka Ivanović (Croatia), Davorin Kajba (Croatia), Hrvoje Marjanovic (Croatia), Sanja Peric (Croatia), Andreas Christou (Cyprus), Xenophon Hadjikyriacou (Cyprus), Václav Buriánek (Czech Republic), Jan Chládek (Czech Republic), Josef Frýdl (Czech Republic), Petr Novotný (Czech Republic), Martin Slovacek (Czech Republic), Zdenek Špišek (Czech Republic), Karel Vancura (Czech Republic), Ulrik Bräuner (Denmark), Bjerne Ditlevsen (Denmark), Jon Kehlet Hansen (Denmark), Jan Svejgaard Jensen (Denmark), Kalev Jðgiste (Estonia), Tiit Maaten (Estonia), Raul Pihu (Estonia), Ülo Tamm (Estonia), Arvo Tullus (Estonia), Aivo Vares (Estonia), Teijo Nikkanen (Finland), Sanna Paanukoski (Finland), Mari Rusanen (Finland), Pekka Vakkari (Finland), Leena Yrjänä (Finland), Daniel Cambon (France), Eric Collin (France), Alexis Ducousso (France), Bruno Fady (France), François Lefèvre (France), Brigitte Musch (France), Sylvie Oddou-Muratorio (France), Luc E. Pâques (France), Julien Saudubray (France), Marc Villar (France), Vlatko Andonovski (FYR Macedonia), Dragi Pop-Stojanov (FYR Macedonia), Merab Machavariani (Georgia), Irina Tvauri (Georgia), Alexander Urushadze (Georgia), Bernd Degen (Germany), Jochen Kleinschmit (Germany), Armin König (Germany), Armin König (Germany), Volker Schneck (Germany), Richard Stephan (Germany), H. H. Kausch-Blecken Von Schmeling (Germany), Georg von Wühlisch (Germany), Iris Wagner (Germany), Heino Wolf (Germany), Paraskevi Alizoti (Greece), Filippos Aravanopoulos (Greece), Andreas Drouzas (Greece), Despina Paitaridou (Greece), Aristotelis C. Papageorgiou (Greece), Kostas Thanos (Greece), Sándor Bordács (Hungary), Csaba Mátyás (Hungary), László Nagy (Hungary), Thröstur Eysteinsson (Iceland), Adalsteinn Sigurgeirsson (Iceland), Halldór Sverrisson (Iceland), John Fennessy (Ireland), Ellen O'Connor (Ireland), Fulvio Ducci (Italy), Silvia Fineschi (Italy), Bartolomeo Schirone (Italy), Marco Cosimo Simeone (Italy), Giovanni Giuseppe Vendramin (Italy), Lorenzo Vietto (Italy), Janis Birgelis (Latvia), Virgilijus Baliuckas (Lithuania), Kestutis Cesnavicius (Lithuania), Darius Danusevicius (Lithuania), Valmantas Kundrotas (Lithuania), Alfas Pliûra (Lithuania), Darius Raudonius (Lithuania), Robert du Fays (Luxembourg), Myriam Heuertz (Luxembourg), Claude Parini (Luxembourg), Fred Trossen (Luxembourg), Frank Wolter (Luxembourg), Joseph Buhagiar (Malta), Eman Calleja (Malta), Ion Palancean (Moldova), Dragos Postolache (Moldova), Gheorghe Postolache (Moldova), Hassan Sbay (Morocco), Tor Myking (Norway), Tore Skrøppa (Norway), Anna Gugala (Poland), Jan Kowalczyk (Poland), Czeslaw Koziol (Poland), Jan Matras (Poland), Zbigniew Sobierajski (Poland), Maria Helena Almeida (Portugal), Filipe Costa e Silva (Portugal), Luís Reis (Portugal), Maria Carolina Varela (Portugal), Ioan Blada (Romania), Alexandru-Lucian Curtu (Romania), Lucian Dinca (Romania), Georgeta Mihai (Romania), Mihai Olaru (Romania), Gheorghe Parnuta (Romania), Natalia Demidova (Russian Federation), Mikhail V. Pridnya (Russian Federation), Andrey Prokazin (Russian Federation), Srdjan Bojovic (Serbia) , Vasilije Isajev (Serbia), Saša Orlovic (Serbia), Rudolf Bruchánik (Slovakia), Roman Longauer (Slovakia), Ladislav Paule (Slovakia), Gregor Bozič (Slovenia), Robert Brus (Slovenia), Katarina Celič (Slovenia), Hojka Kraigher (Slovenia), Andrej Verlič (Slovenia), Marjana Westergren (Slovenia), Ricardo Alía (Spain), Josefa Fernández-López (Spain), Luis Gil Sanchez (Spain), Pablo Gonzalez Goicoechea (Spain), Santiago C. González-Martínez (Spain), Sonia Martin Albertos (Spain), Eduardo Notivol Paino (Spain), María Arantxa Prada (Spain), Alvaro Soto de Viana (Spain), Lennart Ackzell (Sweden), Jonas Bergquist (Sweden), Sanna Black-Samuelsson (Sweden), Jonas Cedergren (Sweden), Gösta Eriksson (Sweden), Markus Bolliger (Switzerland), Felix Gugerli (Switzerland), Rolf Holderegger (Switzerland), Peter Rotach (Switzerland), Marcus Ulber (Switzerland), Sven M.G. de Vries (The Netherlands), Khouja Mohamed Larbi (Tunisia), Murat Alan (Turkey), Gaye Kandemir (Turkey), Gursel Karagöz (Turkey), Zeki Kaya (Turkey), Hasan Özer (Turkey), Hacer Semerci (Turkey), Ferit Toplu (Turkey), Mykola M. Vedmid (Ukraine), Roman T. Volosyanchuk (Ukraine), Stuart A'Hara (United Kingdom), Joan Cottrell (United Kingdom), Colin Edwards (United Kingdom), Michael Frankis (United Kingdom), Jason Hubert (United Kingdom), Karen Russell (United Kingdom), C.J.A. Samuel (United Kingdom).
 

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