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ŠUMARSKI LIST 7-8/2015 str. 60     <-- 60 -->        PDF

makes the litter decomposition an important part of the global carbon budget (Liski et al., 2003).
There has been several studies on the importance of litter decomposition (such as Prescott, 1997; Sariyildiz, 2002; Girisha et al., 2003; Sariyildiz and Küçük, 2008; Sariyildiz et al., 2008; Çakıroğlu 2011). In these studies, it was revealed that there were three main factors influencing the litter decomposition and nutritional element release. These are (1) the climatic characteristics (especially temperature and precipitation) of the environment in which the litter decomposition occurs, (2) number, type and activity of micro-organisms and edaphones that perform the litter decomposition, and (3) the chemical components of the litter (especially total carbon, nitrogen, hemicellulose, lignin and nutritional element concentrations and their ratios such as C:N or lignin: N). In general, while climatic characteristics are effective on the litter decomposition in different geographic regions, the chemical composition of the litter is particularly effective in more limited, local areas (Sam et al. 2004).
The relationship between the quality of decomposing material and decomposition rate was emphasized in numerous studies and it was reported that there could be another dominant factor in addition to the two main factors that influences the course of micro-organism activities (climatic characteristics and chemical composition of the litter) (Sariyildiz, 2002). In these studies, the effects of forest stands and organic matters in the area on the litter decomposition in different wood raw material production regimes (Prescott, 1997) and the effects of soil erosion and compaction that occur as a result of activities carried out in forest ecosystem during wood raw material production on the biological characteristics of the soil were investigated (Startsev et al., 1997). There have also been studies that were conducted in order to determine the efficiency of sustainable forestry activities and interventions that were made in order to meet forests’ silvicultural requirements, especially after clear-cutting (Bird and Chatarpaul, 1988). Although there have been studies in the literature on the differences between litter decomposition mechanisms on different micro-ecological areas formed after harvestingactivities in the remaining stand (Kranabetter and Chapman, 1999; Bird and Chatarpaul, 1988; Jordon et al., 2003), there are no studies on the effects of different methods used in wood raw material production on the litter decomposition.
Therefore, this study aims to investigate the possible effects of harvesting activities on stands belonging to 3 different species (Trojan fir (Abies nordmanniana subsp. Equi-trojani (Aschers & Sint. ex. Boiss) Coode & Cullen), scots pine (Pinus sylvestris L.) and sweet chestnut (Castanea sativa Miller)) and logging residues in the stand as a result of these activities on the litter decomposition. To this end, litter decomposition experiments were carried out on these three species. The litter decomposition specimens were placed on (1) nonharvesting activity areas (control) (C), (2) intra-forest skidding roads (Skidding road) (SR), (3) under logging residues (Logging residue) (LR) and areas with a 20 % slope and top-soil damaged during harvesting activities and (4) scalped mineral soil (SMS) micro ecologic areas. The decomposition processes were observed for 18 months and mass change values were calculated every 6 months.
STUDY AREA
Područje istraživanja
This study was conducted in Kastamonu (41° 22´ N, 33° 47´ E) located in the western Blacksea region of Turkey (Fig. 1). Fifty percent of the forests in Kastamonuis made up of coniferous trees (such as larch, scots pine, Trojan fir, calabrian pine), 28 % broad-leaved trees (beech, oak, sweet chestnut, alder, aspen, hornbeam, etc.), and 22 % mixed stands (OGM, 2006). Although the industrial wood harvesting in Kastamonu varies between years, the annual average production is approximately 1 Million m3. In the areas where the study was carried out, the annual production average is 2,500 m3 in coniferous forests and 500 m3 in broad-leaved forests. The mechanization level of the study area in harvesting activities is motor-manual level. Chainsaws are used in tree felling and limbing, and tractors or manpower is used in skidding. The harvesting method is cut to length.
Scots pine and Trojan fir stands were selected in Handüzü Forest Sub-district Directorate forests. Harvesting activities in this area were completed previous year. Trojan fir stands were selected on northeast facing slope with an altitude of 1,630 m, and Scots pine stands on north facing slope with an altitude of 1,530 m. The Trojan fir trees were 120-130 years old and 30–32 m tall, and the Scots pine trees were 100–110 years old and 18–21 m tall on average. The annual average temperature was 9.8°C, the average high temperature was 16.2°C, the highest temperature was 38.9°C, the lowest temperature was –26.9° C, the average rainfall was 449.7 mm and the average relative humidity was 70 % (Climate Data collected from 1975–2011).
The study area for sweet chestnut was selected among sections that were within the boundaries of Gemiciler Forest Sub-district Directorate and the harvesting activities on these sections were completed a year ago as well. The area faced north and had an altitude of 300 m. The trees in the sweet chestnut stand were 160–170 years old and 22–29 m tall on average. Examining the climate values, the annual average temperature was 13°C, the highest temperature was 26.5°C, the lowest average temperature was 2.3°C, the average rainfall was 1027.7 mm and the average relative humidity was 75.4%. The climate values of the study areas were determined by interpolating the data of the nearest Kastamonu Central Meteorological Station (791 m, facing north) to altitudes of 1,530 m, 1,620 m and 300 m.