Vascular plant systematics

1. SPATIAL MODELS OF
ENERGY FLOW AND NUTRIENT
DYNAMICS
ROQUE MERRICK A. DACULLO, BSBIO-3; BOTANY
VISAYAS STATE UNIVERSITY

2. ECOSYSTEM
SCIENCE
SIMULATION
MODELING
LANDSCAPE
DYNAMICS
ECOSYSTEM
PROCESSES
MODELS OF ENERGY FLOW
& NUTRIENT DYNAMICS
CENTURY FOREST-BGC FIRE-BGC

3. CENTURY
• A widely used model developed to simulate
grassland ecosystems (Parton et al.,1987, 1988).

5. CENTURY COMBINED WITH GIS DATA
(BURKE, ET AL. 1990)
• Inputs- spatial data for climate and soils
• Outputs- spatial patterns of NPP, soil organic carbon, net
nitrogen mineralization, and oxidized nitrogen emissions
• Their study aimed to simulate spatial variability in storage
and flux of carbon and nitrogen for the northeastern quarter
of Colorado in the U.S. Central Grasslands

6. CENTURY COMBINED WITH GIS DATA
(BURKE, ET AL. 1990)
• Scale-dependent effects identified in their study
• Climate data aggregated at coarse-scale yet still produce
reasonable estimates of NPP
• Soil texture must be represented at finer scale due to nonlinear
relationships between soil texture and soil organic matter
(SOM)

7. • Costanza et al. (1990) developed another model for the
Atchafalaya Basin to evaluate a variety of alternative
management strategies to reduce coastal erosion.
• 2479 1-km2 grid cells connected to one another by simulated
fluxes of water, nutrients, and sediments

8. FOREST-BGC MODEL
• Started as a single-tree water balance model for a year and
developed into an integrated carbon, nitrogen, and water
cycle model (Running and Hunt, 1993)
• Predicts photosynthesis, respiration, evapotranspiration,
decomposition, and nitrogen mineralization over broad
landscapes
• Used to calibrate simple models for implementation at the
global scale (Hunt et al, 1991; Running, 1994)

10. • Calibration of simple models offers a powerful approach for
scaling (Running and Hunt, 1993).
• Overton (1975) suggested to use multiscale models that
contain submodels operating at different scales and degrees
of complexity.
• This promises new insight into simulating ecosystem pattern
and processes (DeAngelis et al.)

11. FIRE-BGC MODEL
• Forest gap model linked with BGC and effects of fire
disturbances and succession were incorporated (Keane et al.,
1996)

14. IMPORTANT POINTS DEMONSTRATED BY
MODELING STUDIES• Spatial variations in abiotic variables often produce
substantial variation, themselves, in ecosystem processes.
• Abiotic template is a powerful constraint on ecosystem
function.
• Abiotic factors vary over multiple spatial scales; appropriate
scales must be determined for developing predictive
relationships.

15. • Furthest limit of knowledge in landscape ecology is the
implications of the dynamic landscape mosaic for ecosystem
processes.
• Absence of a spatially explicit, well-developed theory of
ecosystem function
• Lack of empirical studies as sources of general conclusions

16. REFERENCES:
1. Picket, S.T.A., Cadenasso, M.L. (2004). Landscape Ecology: Spatial Heterogeneity in
Ecological Systems. Science. Retrieved from http://links.jstor.org/sici?sici=0036-
8075%2819950721%293%3A269%3A269%3A5222%3C331%3ALESHIE%3E2.0.CO%
3B2-Z
2. Turner et al. (2001). Landscape Ecology in Theory and Practice. New York, USA:
Springer.
3. http://www.ncgia.ucsb.edu/conf/SANTA_FE_CD-
ROM/sf_papers/mckeown_rebecca/figure1.gif
4. http://firelab.org/sites/default/files/images/projects/fbgc-clime_fire.jpg

17. THANK YOU!