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ŠUMARSKI LIST 1-2/2017 str. 50     <-- 50 -->        PDF

al., 2012). Ips species may attack live trees but they usually prefer broken, overturned (Birch, 1984), where they don’t face host resistance, trees that are dead or about to die (Fettig et al., 2007) and cause woody materials to decomposition, playing a role beneficial to forest ecosystems (Allen, 1994). In most species, while causing damage in low degree or below economic damage threshold in forests, large outbreaks of natural species are important in terms of development and sustainability of forests (Black et al., 2010). Besides that, huge losses happening in conifer forests due to bark beetle outbreaks are expected (Franceschi et al., 2005) and since their invasions cover large forest areas, it is not possible to fully evaluate the development of these invasions (Samalens et al., 2007). The relations between functional ecosystem and these outbreaks are not yet fully explained (Samman and Logan 2000). However, the determination of population dynamics of these beetles is very important to develop control strategies and increase success (Jactel and Lieutier, 1987).
Some beetles in the Coleoptera order are considered as the most destructive forest insects. Especially Dendroctonus, Ips, Scolytus species can cause large number of tree deaths (Drooz 1985; Furniss and Carolin 1977). Wood and Bright (1992) reported that there were 5812 species of bark beetles in the world. Bark beetles have a wide host range, including conifer species (Birch, 1984). These species, considered especially the important pests of conifer forests (Reeve, 1997), have caused important losses in the forests of the world until today (Bakke, 1989). These pests are the most dangerous beetles, especially the forests of northern hemisphere (Allen 1994; Lee et al., 2007). Six-toothed pine bark beetle, Ips sexdentatus (Boerner) (Coleoptera, Curculionidae, Scolytinae), one of the bark beetle pests, is one of the most destructive beetles of European pine forests and has an extremely high distribution potential (Jactel and Gaillard, 1991). This beetle, having the potential to create many offsprings from a female, depending on the number of generations, is also one of the most dangerous beetles of the forests of Turkey (Beºceli and Ekici, 1969). I. sexdentatus is a natural species of Turkey (Öymen, 1992) and is a principal beetle species (Özkaya et al., 2010) of pine and spruce trees (Akkuzu and Guzel, 2015). This species was found in the areas of Pinus nigra, Pinus silvestris, Pinus brutia, Picea orientalis, Abies nordmanniana and Abies bornmülleriana in our nation (Defne, 1954; Beºceli and Ekici, 1969; Yüksel, 1996; Öymen, 1992; Selmi 1998). One of the natural species of Turkey, Pinus nigra Arnold, constitutes 21,6% of nations existence of forest (Anonymous, 2014). It also has large forestation potential (Topacoglu, 2013). Taking an important place in Turkey in terms of forest areas, forestry activities and forestry economy, 64% of Kastamonu is covered with forests. This ratio is considerably above the ratio of Turkey’s existence of forest to total surface area of the nation. When the pure coniferous stands are evaluated in terms of tree species, stands constituted by black pines form about 28% of provincial forest area and about 67% in the pure coniferous stands (Anonymous, 2013; 2014; URL-1). Most of these forests are threatened by I. sexdentatus, which causes tree deaths in large areas in case of a large outbreak and plays a critical role in forest dynamics. In this study, the capture rates of I. sexdentatus to pheromone traps, capture times, flight periods and the effects of these to daily maximum and average temperatures, changes of capture ratios according to shaded and sunny aspects in the black pine stand were determined (êrcan et al., 2011). Also, the damage status evaluated that caused in the stand by the beetle species after the end of flight period in the same year. The findings that will be obtained as a result of this study will make important contributions for creating a projection against this beetle which carries risks that may cause disruption of a health ecosystem by causing large damage to wide areas, monitoring, taking measures, ensure success in control management and sustainable forestry management.
Materials and Methods
MATERIJALI I METODE
Study area – Promatrano podruèje
This study, carried out in the pure stands of Pinus nigra Arnold in 2014, was conducted in Kastamonu, located in the western Blacksea region of Turkey (Figure 1). No damage and death trees record caused by I. sexdentatus in the area within the borders of Gölköy Forest Sub-District Directorate. Average altitude of the area was 1015.6+36.4 m, average slope was 14.6+8.6%. According to increment items taken from a total of 61 trees, tree age was 15.6+2.0 year and mean tree diameter was 16+3.5 cm in terms of total tree in sample plot.
Data Collection – Prikupljanje podataka
30 pheromone traps (Figure 2) placed in black pine stands, captured total of Ips sexdentatus and Thanasimus formicarius (L.) (Coleoptera: Cleridae) adult in the traps are materials used to determine the rate of capture, capture times and flight periods of adult I. sexdentatus. Jactel (1991) has suggested that effect time of pheromone dispenser is short and the attraction radius of these preparations for Ips sexdentatus adults cannot exceed 100 m. Besides that, the traps being placed close to each other can affect the capture rates due to causing competition between the traps (Serez, 1987; Bacca et al., 2006).
Thus, the numbered traps were hanged at the heights of 1.3-1.6 m as to be 100 m apart from each other, representing the area, on 8th May. Elevation, slopes and aspects of the traps were measured, which were placed by leaving at least 6-10 m distance from trees (Kesinalemdaroğlu, 1995). The first commercial pheromone dispenser was hanged to traps at the date of its placement, and these dispensers were renewed