1. General Model Information

Name: SAGE

Acronym: SAGE

Contact:

Author(s):

Abstract:

The plant component of SAGE simulates carbon, nitrogen and sulfur dynamics of three categories of grassland plants. Growth of roots and shoots is represented as an exponential function of young tissue carbon content. This function is then modified by temperature and moisture. Structural tissue is assumed to be synthesized with fixed carbon : nitrogen and carbon sulfur ratios. Carbon growth requirements, therefore, dictate nitrogen and sulfur growth requirements. ELM and SPUR use a similar approach for simulating plant nitrogen dynamics. Carbon growth is reduced if the nitrogen or sulfur levels in the plant are suboptimal. The processes simulated by the model are photosynthesis, aging, ion uptake, nutrient allocation, growth translocations, respiration, senescence, and litterfall.

Aboveground processes simulated in the SAGE model:

1. Photosynthesis (atmospheric CO2 concentration, phenology or leaf age, temperature, solar radiation, leaf water potential)
2. Growth (nutrient)
3. Carbon allocation (variable allocation to nutrient ratio, phenology or leaf age, leaf area).
4. Death (phenology or leaf age).

1. Carbon allocation (variable allocation to soil nutrient ratio)
2. Root growth (soil water, soil nutrient)
3. Death (soil water, soil temperature)
4. Uptake (soil nutrient, sulfur)
5. Respiration (soil water, soil temperature).

II. Technical Information

II.1 Executables:

II.2 Source-code:

II.3 Manuals:

II.4 Data:

III. Mathematical Information

III.1 Mathematics

III.2 Quantities

III.2.1 Input

III.2.2 Output

IV. References