Chapter 2 - Importance and roles of soil respiration

Abstract

This chapter places soil respiration in the context of ecosystem carbon balance, nutrient cycling, regional and global carbon cycling, climate change, and carbon storage and trading. Soil respiration releases a large portion of carbon fixed by photosynthesis and strongly regulates net ecosystem productivity. Soil respiration is also intimately associated with nutrient processes such as decomposition and mineralization. Carbon dioxide released via microbial decomposition of litter and SOM is accompanied by either immobilization or mineralization of nutrients and is thus related to soil nutrient dynamics. Soil respiration plays a critical role in regulating global and regional carbon cycles. It also plays a critical role in regulating atmospheric CO2 concentration and climate dynamics in the earth system. Its temperature sensitivity is a key issue in modeling feedback between global carbon cycling and climate change in response to anthropogenic warming. Moreover, soil respiration plays a critical role in regulating atmospheric CO2 concentration and climate dynamics in the earth system. Although it is not the direct mechanism underlying land carbon storage, soil respiration is relevant to understanding carbon sequestration and global carbon trading markets.