Floral Splendour and Shortage of Nutrients - Soil: Reflections on the Basis of our Existence - page 53

Heavy metals. This cross-section comes from a spruce that grew very slowly because it stood on
serpentinite bedrock. Over twenty-five years, the trunk diameter increased by just two centime-
tres, whereas another nearby spruce, which stood on amphibolite bedrock, grew as much in four
years. Soils on serpentinite bedrock are high in heavy metals but low in potassium, which is the
most critical element for plants after nitrogen