Uses of Ecosystem Modeling for Range Management


Figure 1. The functioning of a grassland ecosystem and the relations between its components. The system includes an infinite pool (Climate and air) and seven finite pools. Between pairs of components there may be one or more fluxes of materials such as water, carbon, nitrogen or controls of temperature or water on some processes. (1) Carbon (C) flux from air to plant (photosynthesis); C flux from plant to air (respiration); water flux from plant to air (transpiration); effect of temperature on plant; (2) fluxes of soil soluble nitrogen (N) and water to plant; (3) fluxes of C, N and water from plant to litter (composed of metabolizable cellulose and lignin sub-types); (4) output of C and N from lignin litter to soil organic matter (SOM); SOM is composed of unprotected (uSOM), protected (pSOM) and stabilized (sSOM) sub-types; (5) output of C and N from SOM to soil solutes (mineralization); fluxes N from soil solutes to SOM (immobilization); effects of water on SOM; (6) output of C and N from litter to soil solutes; effect of water on litter decay; (7) respiratory C flux from SOM to air; temperature effect to SOM dynamics; (8) respiratory C flux from soil solutes to air; rainfall input from air to soils; temperature effect on soil solutes dynamics; (9) respiratory C flux from litter to air; temperature effect on litter decay; (10) C flux from animal respiration to air; temperature effect to animal physiology; (11) animal feces; (12) animal urine. (Modified from Thornley, 1998).

 


 

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