Nutrition-physiological responses of spruce to different levels of sulphurdioxide stress in the Erzgebirge Mountains and the Thuringian Forest, Germany

Eleven middled-aged Norway spruces (Picea abies (L.) Karst) growing in stan ds in the two highlands Erzgebirge Mountains and Thuringian Forest which ha ve been subject to different SO2 deposition were investigated in a field st udy. Measurements were made of total element contents and the water-soluble proportions of the element contents. Low-temperature scanning-electron mic roscopy (LTSEM) techniques were used for structural observations. Energy di spersive microanalyses (EDX) on bulk-frozen hydrated samples led to the dir ect determination of element contents in the vacuoles of both the mesophyll and endodermis. Chemicals analysis of the element contents of needles revealed a significan t dependency of sulphate sulphur, organic sulphur, and potassium on the SO2 pollution of the air. However, a significant influence of soil parameters on the nutrient status of the spruce growing on the different plots could n or be verified. The EDX-analyses proved that potassium is the chief ion for neutralisation of the sulphate ions at the SO2 loaded sites of Erzgebirge Mountains. To a lower extent, magnesium and, at sites rich in manganese, also manganese are involved in sulphuric acid neutralisation.