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ŠUMARSKI LIST 11-12/2016 str. 48     <-- 48 -->        PDF

phytogeographic regions (Martinčič et al. 2010). It is common in the Mediterranean area (Kraški rob, Dragonja Valley), but more rare in the Karst area, where it appears in a valley between Brestovica and Gorjanski near Solkan and in the Vipavska Valley. In warmer Mediterranean and Sub-Mediterranean forests, C. australis grows as an individual tree or in groups with Quercus pubescens Willd., Fraxinus ornus L., Pistacia terebinthus L. and other thermophilic tree species. It grows on steep, rocky, dry karst areas, protecting the soil against erosion (Brus 2005).
In Croatia C. australis is indigenous in Istria and throughout the whole Mediterranean area (Potočić et al. 1983; Matić et al. 2011).
In Hungary there are some monumental introduced C. australis trees in the central part of the country (in Dég, at the Danube river shores in Adony, in Mezőhegyes, Kajdacs, Alsóhídvégpuszta (county of Tolna)), (Monumental trees at Alsóhídvégpuszta… http://www.monumentaltrees.com/en/hun/dunantul/tolna/3920_alsohidvegpuszta/).
C. australis is a long-lived, 15–20 m tall tree, reaching a diameter of 1–2 m and an age of 1,000 years, with quality wood (the genus name derives from the Greek word kello – driven, because of its hard wood used for whips). The wood is stiff, with gray colored hardwood and yellow sapwood and is suitable for carving, making musical instruments, sports equipment, paddles, etc. The young shoots are slender and wiry, suitable for whips and rods. The root system is strong and deep. The leaves alternate; they are 5–12 cm long, simple, with serrate edges; the leaf surface is asymmetrical and with three stronger vessels. The flowers are polygamous or hermaphroditic, small, apetalic, with 4–5 stamens, appearing on young shoots. The fruit is round, up to 1 cm thick, with a sweet and edible wrapper (Jovanović 1971; Brus 2005).
Interestingly, according to literature data, C. australis has only a few diseases. Some earlier authors, such as Kišpatić (1983) (Potočić et al. 1983), note that C. australis is rarely infected by fungi, such as Laetiporus sulphureus (Bull.) Murrill (1920) and Ganoderma applanatum (Pers.) Pat., which cause rot in old trees. In the monograph Insects and diseases damaging trees and shrubs of Europe (Zúbrik et al. 2013) only one species (Phyllonoricter millierella (Staudinger, 1877)) from C. australis is listed. Aside from these few observations, very little is known about the herbivore insect assemblages of C. australis, and, to our best knowledge, no reports on the health condition of C. australis in recent years exist from other countries within its range.
Afforestation of the Karst region in south-western Slovenia began in the 19th century, when the first successful black pine (Pinus nigra Arnold) plantations were established and over time, black pine plantations improved site conditions considerably (Škulj 1988). Black pine was also irreplaceable in the processes of degraded site re-cultivation in the Croatian Mediterranean area (Matić et al. 2011). Climatic extremes, especially drought, can be considered the basic adverse factor causing stress and physiological weakening of pine trees and simultaneously improving the conditions for attacks of various types of pests.
The conversion of old black pine plantations into ecologically more stable broadleaf forests is an important goal in many Mediterranean countries. Some native deciduous species as C. australis, Quercus petraea (Matt.) Liebl., Prunus avium L., Juglans regia L. and other were used experimentally to achieve this gool. Based on their high survival rates after the first growing season, all tested species showed promising potential for future conversion of old pine stands in the Slovenian and Croatia (Topić 1997, Gajšek et al. 2015).
This paper aims to summarize the literature data and the results of our own pilot studies on herbivorous entomofauna on C. australis in Slovenia and Croatia, where this tree species is native in Mediterranean area, and in Hungary, where the C. australis has been introduced and planted. The results are intended to give some deciding whether this tree species could be introduced on a wider scale in plantations of P. nigra in Slovenian and Croation Mediterranean.
MATERIALS AND METHODS
Materijal i metode
Observations of health status on C. australis in the studied area – Opažanja zdravstvenog stanja C. australis u području istraživanja
On September 8, 2011 on the Dekani location near Koper (Slovenia), we collected 15 branches of C. australis with visibly damaged leaves (mines), and on the basis of the symptoms of the damage, the pest species was identified. In 2013 we screened a wider area of the Sub-Mediterranean zone in Slovenia and assessed various symptoms of biotic damage on C. australis. On May 5, 2014, in the Brseč location near Opatija (Croatia) (Figure 1), a similar screening procedure was conducted in an urban environment during a strong outbreak and total defoliation of European nettle tree crowns. We collected 18 branches of C. australis with heavily consumed leaves with different species of lepidopteran larvae. The diameter of twigs averaged 0.8 cm, and total length was 3.9 m. They were grown in entomological rearing containers at room temperature until October 1, 2014. All insects present on the twigs (number / diameter / length of twigs, dead larvae, left pupal exuviae, dead pupae, adult moths) were analyzed and species identified. Some lepidopteran species were identified in larval stages according to their specific caterpillar features (Csóka 2003) and on the basis of photos taken at the Brseč location.