Organic matter in lotic ecosystems

Abstract

The study of ecosystems includes non-living matter as well as the biota. The flux of energy, expressed as organic matter or carbon, and of materials, referred to as elements, minerals or nutrients, are principal areas of ecosystem-level investigations. Both organic matter and elements are present in organisms and in various nonliving organic forms. In addition, the elements necessary for life cycle back and forth between organic and inorganic states. Whether the quantity being measured is organic carbon, nitrogen, or some other material, it exists in various states (stores) and moves among these states by various processes (transfers) that may be broadly classified as biological or physicalchemical. Ecosystem studies attempt to understand the processes that govern the movement and transformation of energy and materials from one state to another. Valuable insights into ecosystem function are gained by study of either the stores or the transfers, but both are necessary to a full understanding.