Introduction to Ecosystem Models

1. Introduction to EcosystemModels Class Presentation for Landscape Ecology Soung-Ryoul Ryu

2. Pattern & Process Scale Why Models? • Make it possible To examine landscape change • Complex process & their interaction Logic & Math To deduce results, which is impossible to do experimentally due to complexity • landscape change over long time periods • ecological effect of large disturbances

3. Experiment Model

4. Contents • Classifying Models • Introducing various hybrid models • TREE-BGC • LINKAGES • CENTURY • LANDIS

5. Model Classification (Method) • Empirical Based Model • Built on empirical relationships b/w outputs and inputs (i.e. stand yield & site index) • Easy to use & apply • Site, species, and age specific • Not for biogeochemical or climatic changes over period • Process Based Model • Built on physiological mechanisms (i.e. Atm CO2 & ecosystem growth) • Far more flexible than empirical models • Used to evaluate the consequences of environmental changes. • Need a lot of parameters

6. Hybrid Model Model Classification (Objective) • Biogeochemical Model • Tree growth and nutrient cycling • Individual trees are not growing • Forest Dynamics Model • Succession and the structure change • No growth allocation mechanisms

7. Hybrid models • TREE-BGC model • FOREST-BGC (compute carbon and water balances) • GAP model (tree growth and mortality) • LINKAGES model • Most advanced GAP model • Composed of subroutines BIRTH, GROW, and KILL • Use empirical relationship b/w tree growth & condition

8. CENTURY • Generic plant-soil interaction • Grow is proportional to Navailable • Soil-organic matter decomposition and turnover • LANDIS model • Plot level Gap model (FORET) • Landscape scale LANDSIM model (life history characteristics)

9. Conclusions • Model is very necessary to study patterns & processes in landscape • GIS is very important tool to study landscape dynamics (spatial and temporal scale) • Models for Whom?

10. Thank you ! Questions?

11. BIOMASS FOREST-BGC BEX PnET