Among a wide variety of natural compounds synthesized by conifer trees, terpenes seem to be the most important group of secondary metabolites. They are a vital part of constitutive or induced defense mechanisms to protect the plant from invading pathogens and herbivore. Furthermore, they can take part in chemo-ecological interactions with co-evolved insects, e.g. bark beetles. Some of terpenes are known to manifest antioxidant properties which may contribute to their role in overcoming oxidative stress. It has been also suggested that
volatile compounds such as terpenes can be involved in interplant signaling, especially concerning biotic or mechanical stress. Numerous studies have shown that abiotic and biotic stress factors such as drought, temperature fluctuations, air and soil pollution or pathogen attack may affect the biosynthesis and emission of terpenes, and the response may depend on the stressor type and stress intensity. Although the general composition of terpenes is characteristic for each species, it has been shown that it can even differ between two individual trees, depending on tree chemotype. Despite many comprehensive studies in this area, the role of terpenes in plants is not completely understood. Some of the available results are contradictory. Here we present an overview of recent literature in this area to systematize the observed changes in terpene quantity and quality in conifer trees. The study is focused on three most important forest-forming conifer genera of European temperate climate zone – pine (Pinus sp.), spruce (Picea sp.) and fir (Abies sp.) due to their high utility and wide range of occurrence. Moreover, we tried to shed light on a complex function of these interesting compounds in view of progressive climate change.

Joanna Maria Kopaczyk is a Biologist, PhD student at Poznan University of Life Sciences, Faculty of Forestry, Department of Forest Utilization, in cooperation with the Department of Plant Ecophysiology at Adam Mickiewicz University in Poznan, Faculty of Biology. Her current work focuses specifically on molecular and biochemical aspects of xylem formation in conifer trees.