Invertebrate fauna of Norway spruce ( Picea abies) saplings and its connection with the nitrogen, sulphur and phenolics concentration of the needles

Abstract

The composition of the invertebrate fauna living on young Norway spruce (Picea abies) branches was studied in northern Finland both in urban and rural areas during the summer months of 1988. Attention was given to the total nitrogen, sulphur and phenolics concentration of the needles. The material consisted of 52627 invertebrates from 300 separate spruce saplings. Mites formed the majority of the invertebrates. Most numerous were Ameronothrus dubinini, Diapterobates humeralis and Ceratoppia bipilis. Springtails and spiders were also numerous. The invertebrate abundances were highest in the urban areas of Isko and Linnanmaa, where the sulphur and nitrogen concentration of the needles was high and the phenolics/nitrogen ratio low. The lowest invertebrate abundances were found in Rusko, the most urban area, and Taivalkoski, the most rural area. Nitrogen and sulphur concentrations were highest at Rusko and lowest at Taivalkoski. Possible reasons for the results are discussed.