Cycling of Organic Matter

Abstract

One of the useful ways of integrating concepts of energy flow and nutrient cycling in a terrestrial ecosystem is to focus on the cycling of organic matter. The chemical energy and nutrients sequestered in terrestrial plant biomass or within a forest soil are part of a larger ecosystem cycle of organic matter characterized by (i) multiple storage pools with different residence times and (ii) multiple component processes, including trophic transfers among consumer organisms, production of detritus or necromass from senescent or dead life forms, release of elements from organic matter via decomposition and mineralization processes, evolution of gaseous CO2 from respiration, and recycling of nutrients into new growth of organisms. This chapter examines how organic matter pools are distributed in the landscape, what processes control organic matter cycling, and how organic matter cycling is influenced by environmental and ecological conditions.