ABSTRACT
As opposed to energy that flows, matter recycles on Earth. Chapter 22 outlines different ways matter is categorized by ecologists. This includes matter in major compartments on Earth such as lithosphere, hydrosphere, biosphere, and atmosphere. Additionally, matter is identified in nutrient cycles, which are covered in detail for water, carbon, and nitrogen. The water cycle is particularly important because nutrients are carried from compartment to compartment via water. Carbon is important because nothing can live without it. Beyond that, carbon spans the divide between energy and matter. Carbon burns, which means it can be measured in units of energy or matter. With the percentage of carbon in the atmosphere now doubled compared to what it was before the industrial revolution, the carbon cycle is at the forefront of greenhouse gas concerns. The nitrogen cycle is important because it has been altered by humans even more dramatically than the carbon cycle, mainly through fertilizer production using the Haber-Bosch technique. This chapter can serve as an introduction to the study of further nutrient cycles like sulfur.
