Bedrock and Quaternary sediment geochemistry and biodiversity in Eastern Fennoscandia and Estonia

Crystalline bedrock and Quaternary sediments are the parent materials for soil, which is a substrate for plant roots and also a supplier of nutrients. Through interactions within the bedrock-soil-plant-animal-human beings system, bedrock geology and geochemistry influence all forms of life on the planet. There are 11 major elements or macronutrients that are nutritionally essential for plants and animals in constructing and maintaining cells and tissues, and up to 43 trace elements or micronutrients involved in the regulation of metabolic processes. Element concentrations in soils reflect those of parent rocks, but for healthy growth and development of plant and animal tissues there are very strict constraints on trace element concentrations. Chemical analysis of different organic materials shows that all forms of life, marine and terrestrial plants and animals, and bacteria consist of comparable proportions of the of macronutrients: O, H, C, N, P, S, Ca, Mg, K, Na, Cl, as well as trace elements. Some differences are noted in elements that are more available in sea water (Mg, I, Br, Sr, Fe, Pb) or are essential for life outside of water (terrestrial animals need more Ca and P for stronger skeletons, etc.). Limestone and dolostone of northern and central Estonia are rich in Ca and Mg, whereas the sandstones that predominate in southern Estonia consist mainly of quartz (SiO₂) and contain very few nutrients. Glacial activity in Fennoscandia transported predominantly Si-rich granite rock material to Estonia, in which trace element concentrations are very low, as in the local bedrock. The bedrock geochemistry, Quaternary cover and their influence on vegetation in some selected areas in Fennoscandia and Estonia are discussed.