İNŞaat mühendiSLİĞİ anabiLİm dali

Seasonal Varıatıon Of Soıl Arthropods (Arthropoda) İn Fır (Abies Bornmulleriana Mattf.) Ecosystems İn Bolu-Aladag
In the forest ecosystems, the most important component of nutrient cycling is litter decomposition. Soil arthropods have a role as primary and seconder consumers in process of litter decay and decomposition. Abundance, diversity and community structure of arthropods in soil ecosystem; give rapid response to change of physical, chemical and climatic characteristics of site.
In this study, to determine of seasonal changes of soil arthropods was aimed in Uludağ Fir (Abies bornmulleriana Mattf.) ecosystem which is an important forest tree species in Turkey. Study was conducted in pure fir stands at 1200-1600 m altitudes (4 elevation gradients) in Aladağ, Bolu. The samples were taken separately from top mineral soil (0–5 cm), forest floor and intact point of surface soil and forest floor (pitfall traps). Also, soil, forest floor and climate characteristics in samples plots were evaluated.
Arthropods’ characteristics and their relationships with site properties were determined in the soil ecosystem. Abundance and diversity of arthropods were also evaluated according to seasons and altitudes. The distribution in soil layers and habitat preferences of the arthropods have been revealed. In addition, distribution in trophic levels and biological diversity of arthropods were determined.
During the study, some characteristics of soil and forest floor, in addition to climatic conditions such as temperature and humidity, were significantly different depending on seasons and altitudes. The average abundance of arthropods were 90116 in the soil, 167716 in the forest floor and 4437 in the pitfall traps; and was 262269 individuals/m² in total. The most effective factors on the abundance and diversity of arthropods were temperature and humidity that changes depending on the season in their habitats. Shannon-Wiener Index (H′) and Species Richness (S′) values were arranged in forest floor (H′= 2.96; S′= 45), in the soil (H′= 2.63; S′= 30) and in the pitfall traps (H′= 2.22; S′= 22) according to their habitats.