In geoecology, the nature of the effect of tectonic faults on the environment is not well studied. The influence of natural landscapegeochemical factors on the state and properties of some components of biota of different hierarchical levels is studied at the intersection of two tectonic faults (Velsko-Ust'yanskiy tectonic knot (TK)) in the Arkhangelsk region. Two species of shrubby lichens (Cladonia stellaris Opiz. and Usnea subfloridana Stirt.) and woody plants (spruce -Picea abies L. and Scots pine -Pinus sylvestris L.) were chosen as test systems. The field studies were carried out at nine test sites (in the centre, on the periphery and some distance from TK -the background reference point) in different types of forest. The ash content of samples of the lichen Cladonia growing in the centre of the TK (1.12-1.22%) is double that in the control area (0.56-0.58%), and for the lichen Usnea, it is seven times higher (6.82-6.99% at the centre and 0.97-1.09% in the control area). The ash content of tree bark collected at the centre of TK (1.27-1.29%) is double that at the control site (0.56-0.76%). This indicates a significant accumulation of metals in the vegetation in the TK zone. The accumulation of heavy metals, the low water content of plants, the influence of geomagnetic fields and other factors provoke excessive generation of active oxygen radicals and plants have various physiological, biochemical and morpho-biometric means of combating their adverse effects. The synergism of the cooperative protective action of lichen matrix components on oxidative stress is expressed in terms of changes in biochemical parameters. At the centre of the TK, the lichens contains up to 190 μg g −1 of ascorbic acid, whereas in the control area it does not exceed 130 μg g −1 . The content of usninic acid in the centre is 1.5-2 times higher for the Usnea subfloridana and is 1.5 times higher for Cladonia stellaris compared to the level in the control area.