The Reproductive Processes of Siberian Coniferous Species in Ecological Stress Conditions

摘要

The publication is intended to reveal changes going in crown morphostructure as well asrnviability of generative organs of conifers in disturbed forest and urbanized systems of Siberia and itrnis also intended to determine the perspectivity of their growth under ecological stress.rnThe study objects the main forest forming coniferous species of Siberia were growing inrndisturbed forest and urbanized systems of West and East Sayan, the Khamar- Daban ridge and closernto the pollution sources of Krasnoyarsk and Irkutsk cities. Methods of morphological, biochemicalrnand cytophysical studies with which help the assessment of tree vitality were used in thernexperimental work. Under ecological stress of Siberia the apical dominance (Pinus) of trees is lost,rnthe zone of subapical degradation (Abies) appears, the crown form gets flat.rnOrgans of sexual reproduction develop a certain strategy under ecological stress conditions.rnStress mostly affects on the male generative sphere. The loss of pollen quality is one of the reasons ofrnsterilization of female embriological structures. However, the female generative organs of conifersrnare more conservative than the male ones under ecological stress conditions. It is supposed to use thernconifer pollen as a bioindicator of stress in case when the visual damage of the tree is absent. Thus,rnthe appearance of crowns of trees and their reproductive activity reflected by quality of pollen,rnovules and seeds can be the parameters of state of the trees based on which we can judge aboutrnspecies response to ecological stress.