Original scientific paper

Distribution and Management of Black Walnut (Juglans nigra L.) in Croatia

DARIO KREMER ; Pharmaceutical Botanical Garden 'Fran Kušan’, Faculty of Pharmacy and Biochemistry, Zagreb, Schrotova 37, HR-10000 Zagreb, Croatia
JURO ČAVLOVIĆ ; Department of Forest Management, Faculty of Forestry Zagreb, P.O. Box 178, HR-10000 Zagreb, Croatia
MARIO BOŽIĆ ; Department of Forest Management, Faculty of Forestry Zagreb, P.O. Box 178, HR-10000 Zagreb, Croatia
TOMISLAV DUBRAVAC ; Department of Ecology and Silviculture, Forest Research Institute, Jastrebarsko, Trnjanska 35, HR-10000 Zageb, Croatia

Abstract

Background and Purpose: Black walnut (Juglans nigra L.) was introduced in forest management around 1890 in the lowland regions of eastern Croatia to establish plantations on the sites too dry for themost valuable native species, pedunculate oak (Quercus robur L.). Aim of the article was to perform a preliminary research of the distribution and representation of black walnut in Croatian lowland forests, and their significance in the management of lowland forests.
Materials and Methods: A database of plantationswas established from
the management plans (age, area, standing volume of black walnut, total standing volume, coordinates). Gauss-Krüger coordinates were used for mapping the distribution of black walnut (ArcView 3.3 software, UTM grid). Fifty subcompartments were randomly selected for ground surveying (assessment of stand structure, collecting of samples of fertile twigs with leaves and fruit).

Results and Discussion: A total number of 416 subcompartments (3,162 ha) with black walnut as pure stands (143 subcompartments, 827 ha) and with black walnut as partial stands, groups of trees, or individual trees was established. The total standing volume of black walnut was estimated to be 239,678 m3 (in pure plantations 112,198 m3). No hybrid between black walnut and Persianwalnut was found. The age structure of plantationswas disrupted during the war in Croatia when the most valuable plantations of around 80 year old trees were felled on the occupied territory.

Conclusions: Black walnut became a valuable exotic species in forest
management on the sites too dry for the most valuable indigenous species, pedunculate oak, in eastern Croatia.

Keywords

Hrčak ID:

35931

URI

https://hrcak.srce.hr/35931

Publication date:

31.12.2008.

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