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ECOSYSTEM ECOLOGY. … the integrated study of biotic and abiotic components of ecosystems and their interactions. To achieve this integration: follow the path of matter and energy. Divides ecosystems into stores and fluxes. Modeling pools and fluxes:.
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ECOSYSTEM ECOLOGY … the integrated study of biotic and abiotic components of ecosystems and their interactions. To achieve this integration: follow the path of matter and energy. Divides ecosystems into stores and fluxes.
Modeling pools and fluxes: • XP : quantity of compound x in pool P in units of • mass/area or mass/volume • kg carbon m-2 • mmol NO3 l-1 • Qx, P1-P2 : flux density for compound X from pool P1 to pool P2 in units of mass/(area*time) or mass/(volume*time) • kg carbon m-2 yr-1 • mmol NO3 l-1 s-1 Q Q X, Pi -Pj X, Pj -Pk X Pj
Modeling pools and fluxes: Q Q X, Pi -Pj X, Pj -Pk X Pj
Fluxes are controlled by different sorts of processes, which determine their mathematical representation: Case 1A: Chemostat (mixing of a constant volume): Q Q X, Pi -Pj X, Pj -Pk X Pj
Case 1B: Mixing with volume change: Q Q Q Q X, Pi -Pj X, Pj -Pk W, Pi -Pj W, Pj -Pk X W Pj Pj
Concentration C: Amount X: Cin = 0.2
Case 2: Biochemical cycles: Nmin Plant uptake Microbial mineralization Plant senescence Nlitter Nplant
Nmin Plant uptake • Notes: • Michaelis-Menton relationship • for nutrient uptake assumes saturation of uptake; • Nutrients in a constant relation to total biomass in living organisms; • stoichiometric ratios between nutrients maintained. Plant senescence Nplant
Microbial mineralization • Notes: • Rates of loss are the same for all plant nutrients, when nutreint concentrations are assumed fixed. Plant senescence Nlitter Nplant
Microbial mineralization Nmin Plant uptake Nlitter Nplant
Microbial mineralization Nmin Plant uptake • Notes: • Total mass should be conserved in closed cycles. Plant senescence Nlitter Nplant