You are holding in your hands the anniversary edition of the Yearbook of Arboriculture: 25 years of this reference book with a total of around 750 papers on the inspection, maintenance and protection of trees in cities and along roads.

      Unfortunately, the German Tree Care Conference had tobe cancelled this year and was postponed until 2022. However, we have decided to publish a yearbook even without the conference in Augsburg, namely on tree protection on construction sites.

      Tree protection is much more than just a protective fence on the construction site or a few boards attached to a trunk. What is needed is a comprehensive knowledge of the root zone and its importance for tree health. In addition, one must consider the possibilities and limitations of tree protection in regard to the various construction measures. Different requirements are necessary for pipeline laying than for the construction of sidewalks and bike paths or for building construction, for example.

       The current standards and guidelines for tree protection on construction sites in Germany

      • DIN 18920, 2014: Vegetationstechnik im Landschaftsbau – Schutz von Bäumen, Pflanzenbeständen und Vegetationsflächen bei Baumaßnahmen (Vegetation technology in landscaping – Protection of trees, plantations and vegetation areas during construction work), Beuth Verlag, Berlin, 8 S.

      • ESAB, 2006: Empfehlungen zum Schutz vor Unfällen mit Aufprall auf Bäume (Recommendations for protection against accidents with collisions with trees). Forschungsgesellschaft für Straßen- und Verkehrswesen (FGSV), Köln, 12 S.

      • H ArtB, 2017: Hinweise zum Artenschutz beim Bau von Straßen (Information on species protection during road construction). Forschungsgesellschaft für Straßen- und Verkehrswesen (FGSV), Köln, 56 S.

      • MA-StB 92, 1992: Merkblatt Alleen (Factsheet Alleys). Verkehrsblatt-Verlag Borgmann GmbH & Co. KG, Dortmund, 26 S.

      • Merkblatt DWA-M 162, 2013: Bäume, unterirdische Leitungen und Kanäle (Trees, underground pipes and ducts). Deutsche Vereinigung für Wasserwirtschaft, Abwasser und Abfall e. V. (DWA), Hennef, 24 S.

      • RAS-LP 4, 1999: Richtlinien für die Anlage von Straßen, Teil: Landschaftspflege, Abschnitt 4: Schutz von Bäumen, Vegetationsbeständen und Tieren bei Baumaßnahmen (Guidelines for the Construction of Roads, Part: Landscape Management, Section 4: Protection of Trees, Vegetation and Animals during Construction Work). Forschungsgesellschaft für Straßen- und Verkehrswesen (FGSV), Köln, 32 S.

      • ZTV-Baumpflege, 2017: Zusätzliche Technische Vertragsbedingungen und Richtlinien für Baumpflege (Additional Technical Terms of Contract and Guidelines for Tree Care). 6. Ausgabe, Forschungsgesellschaft Landschaftsentwicklung Landschaftsbau (FLL), Bonn, 82 S.

      Since 1997, the Yearbook of Arboriculture has included various articles on the subject of „tree protection on construction sites“. Unfortunately, many issues are now out of print. However, the contents of the articles are still highly relevant. In some instances the standards and regulations mentioned in earlier articles may now have changed. An overview of the current standards and regulations on tree protection on construction sites can be found on page 5.

      This anniversary edition is the first comprehensive book on tree protection on construction sites. Many of the out-of-print articles are once again available through this reprint. The year of first publication is mentioned at the beginning of each article and mail addresses at the end of the articles have been updated.

      This Yearbook has been organized into the following main chapters:

      - Soil, Root, Line Construction

      - Trees and road construction

      - Organization of tree protection measures.

      Each main chapter begins with an article of current news on the main topic of interest. Furthermore, this book continues the tradition of an article on the „Tree of the Year“, written for the last 25 years by Prof. Dr. Andreas Roloff. The tree of the year 2021 is the holly. There is also the updated chapter on „Associations and Research Institutions“, an „Address Register for Tree Care“ and the „Overall Index 1997–2021“.

      I hope that this yearbook will be widely distributed and that many trees will be protected so that they can be kept vital and safe for a long time! Well planned and executed tree protection contributes significantly to tree retention. In times of climate change, tree protection takes on a very special importance.

      I would like to thank the publisher Haymarket Media for making this book possible. I would especially like to thank Martina Borowski, Silke Burkert and Anja Pieper for their careful work on the various texts, image files and information, resulting in a highquality book to mark the 25th anniversary.

      Hamburg, May 2021 DIRK DUJESIEFKEN

       For your calendar:

      The next German Tree Care Conference will be held May 10th–12th, 2022.

      Contact address: Forum Baumpflege GmbH & Co. KG, Office: Brookkehre 60, 21029 Hamburg

      Tel.: +49 (0)40 55 26 07 07, Fax: +49 (0)40 55 26 07 28, www.Deutsche-Baumpflegetage.de or www.wetree.de

      The editorial deadline for the Yearbook of Arboriculture 2022 is December 1st, 2021.

      Inhaltsverzeichnis

       Cover

       Titel

       Impressum

       Baum des Jahres 2021: die Stechpalme (Ilex aquifolium) – Ihre Eigenschaften und Besonderheiten

      A.