Original scientific paper
Yellow Mistletoe (Loranthus europaeus Jacq.) and White-berried Mistletoe (Viscum album L.) on the Area of the Forest Administration Bjelovar
Marilena Idžojtić
; Šumarski fakultet Sveučilišta u Zagrebu
Milan Glavaš
; Šumarski fakultet Sveučilišta u Zagrebu
Marko Zebec
; Šumarski fakultet Sveučilišta u Zagrebu
Renata Pernar
; Šumarski fakultet Sveučilišta u Zagrebu
Branko Bradić
; Hrvatske šume, UŠP Bjelovar
Dražen Husak
; Hrvatske šume, UŠP Bjelovar
Abstract
In the area managed by Croatian Forests Co. Ltd., Forest Administration Bjelovar, the infestation of sessile oak (Quercus petraea /Matt./ Liebl.) and pedunculate oak (Q. robur L.) with yellow mistletoe (Loranthus europaeus Jacq.)was investigated, as well as the infestation of the white poplar (Populus alba L.), common locust (Robinia pseudoacacia L.) and sessile oak with white mistletoe (Viscum album L.). The research was carried out in selected subcompartments of more than 30 years of age, in which the number of infected and non-infected trees, as well as the number of mistletoe shrubs on infected trees, was recorded through a diagonal survey.
On the sessile oak yellow mistletoe was found in the area of 7 forest offices: Bjelovar, Garešnica, Sirač, Virovitica, Pakrac, Suhopolje and Vrbovec. In total 9 management units, 144 compartments and 13,971 trees, of which 3 % were infected with mistletoe, were surveyed. On the average there were 2 mistletoe shrubs on the infected trees, and the highest number of shrubs on one tree was 17.
In the area of the forest office Daruvar and Lipik no mistletoe was observed, whereas in the area of the forest office Đulovac only white mistletoe was observed on common fir trees. The least infestation was noted in two management units (MU) of the Forest Office Garešnica: MU Garjevica 0.3 % and MU Dišnica-Zobikovac-Petkovača 0.5 %.
An infestation of less than 2 % was also found in the MU Pakračka gora-Zapadni Papuk, Forest Office Pakrac (1.7 %). Then the MU Javornik, Forest Office Sirač with 4.3 %, follows, and the MU Vrbovečke prigorske šume, Forest Office Vrbovec with 4.8 % and the MU Krnjača-Gradina-Sječa, Forest Office Garešnica with 6.0 % of infestation. In the area of Bilogora the infestation was higher and it amounted to 7.4 % for the MU Virovitička Bilogora of the Forest Office Virovitica, 10.0 % for the MU Suhopoljska Bilogora of the Forest Office Suhopolje, and 14.0 % for the MU Bjelovarska Bilogora of the Forest Office Bjelovar, which is at the same time the highest infestation on the sessile oak in a given management unit.
Yellow mistletoe was found on the pedunculate oak in the area of 8 forest offices: Bjelovar, Čazma, Garešnica, Grubišno Polje, Suhopolje, Velika Pisanica, Veliki Grđevac and Vrbovec. The research was carried out in 19 management units and 173 compartments on a specimen of 12.711 trees. Out of the total number of investigated trees, 7 % were infested with mistletoe. On the infested trees there were 3 mistletoe shrubs on the average, and the highest number of shrubs on one tree was 22. In the MU Česma of the Forest Office Vrbovec no mistletoe was observed.
Up to 5 % of the infested were found in the MU Dišnica-Zobikovac-Petkovača (0.5 %) and the MU Međuvode-Ilovski lug (1.8 %) of the Forest Office Garešnica, then the MU Česma of the Forest Office Bjelovar (3.0 %), the MU Zdenački gaj-Prespinjača of the Forest Office Grubišno Polje (4.2 %), the MU Krnjača-Gradina-Sječa of the Forest Office Veliki Grđevac (4.7 %) and two management units of the Forest Office Vrbovec, MU Bolčansko-žabljački lug (3.0 %) and MU Novakuša-Šikava (2.2 %). Between 5 and 10 % of the infested trees were found in the MU Bolčansko-žabljački lug of the Forest Office Bjelovar (5.6 %), MU Krnjača-Gradina-Sječa of the Forest Office Garešnica (7.0 %), MU Dugački gaj-Jasenova-Drljež of the Forest Office Velika Pisanica (9.6 %), MU Čazmanske nizinske šume of the Forest Office Čazma (8 %) and MU Suhopoljske virovitičke nizinske šume of the Forest Office Suhopolje (9.7 %). Between 10 and 20 % of the investigated trees were infested with mistletoe in the MU Bjelovarska Bilogora of the Forest Office Bjelovar (15.1 %) and the MU Trupinski-Pašijanski gaj of the Forest Office Veliki Grđevac (12.3 %). On more than 20 % of the investigated trees mistletoe was found in the MU Trupinski-Pašijanski gaj of the Forest Office Garešnica (21.5 %), MU Bedenik of the Forest Office Bjelovar (24.6 %) and the MU Pisanička Bilogora of the Forest Office Velika Pisanica (24.6 %). The highest infestation was noted in the MU Varoški lug of the Forest Office Vrbovec (30.5 % of the investigated trees).
White mistletoe was found on 36 % of investigated white poplar trees (Forest Office Virovitica), on 12 % of investigated common locust trees (Forest Office Bjelovar), as well as on 2.4 % of investigated sessile oak trees (Forest Office Garešnica). The occurrence of white mistletoe on autochthonous European oaks is very rare, and the MU Garjevica of the Forest Office Garešnica is the only locality in Croatia in which it has been found so far.
For the sessile and pedunculate oak the correlation between the occurence of yellow mistletoe and the site and stand parameters: site quality, expositionure, soil type, age, crown closure and elevation was analyzed. A positive correlation between the tree age and mistletoe infestation could be established, as well as a negative correlation between the elevation and the infestation with yellow mistletoe. The infestation is also influenced by the crown closure, and subcompartments with a very dense and dense crown closure are considerably less infested than subcompartments with an incomplete or discontinued crown closure.
The spacial arrangement of the infestation intensity of the sessile and pedunculate oak with yellow mistletoe in particular management units is shown.
Keywords
Croatian Forests Co. Ltd.; Forest Administration Bjelovar.; infestation; Loranthus europaeus Jacq.; mistletoe; Populus alba L.; Q. robur L.; Quercus petraea (Matt.) Liebl.; Robinia pseudoacacia L.; Viscum album L
Hrčak ID:
42704
URI
Publication date:
30.4.2006.
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