Global climate changes have a great impact on the plant physiology. In accordance to the natural volatile compounds the typical response of plants coping with stressors is the increased and chemically modified emissions. The altered bouquets affect the plant-plant and plant-insect communication. By today especially the plantinsect interactions affected by the changes of climate are poorly known. Therefore the goal of the present application is to study the response of plants coping with the interacting stressors (drought, temperature, chemical compounds similar to plant hormones, etc). The experiments will be carried out by the far-spread conifers of Europe and by the exotic conifer species from southern hemisphere. The results of the stress reaction of conifers will be essential for the further studies related to the forest pests and to the ecological forest management.