Ecological modeling algae
This presentation is the property of its rightful owner.
Sponsored Links
1 / 31

Ecological Modeling: Algae PowerPoint PPT Presentation


  • 60 Views
  • Uploaded on
  • Presentation posted in: General

Ecological Modeling: Algae. -Why? Who? What? How?. Who?. What?. Examples of Models with Algal Modeling Included. CIAO- Coupled Ice Atmosphere Ocean Model ERSEM- European Regional Seas Ecosystem Model CE QUAL DSSAMt HSPF WASP Aquatox Ecosim FFFMSIPaAG, John’s Model, Don’s model

Download Presentation

Ecological Modeling: Algae

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Ecological modeling algae

Ecological Modeling: Algae

-Why?

Who?

What?

How?


Ecological modeling algae

  • Who?


Ecological modeling algae

  • What?


Examples of models with algal modeling included

Examples of Models with Algal Modeling Included

  • CIAO- Coupled Ice Atmosphere Ocean Model

  • ERSEM- European Regional Seas Ecosystem Model

  • CE QUAL

  • DSSAMt

  • HSPF

  • WASP

  • Aquatox

  • Ecosim

  • FFFMSIPaAG,

  • John’s Model,

  • Don’s model

  • …………..Yada, Yada, Yada,


What is typically modeled phytoplankton periphyton

What is typically modeled?- Phytoplankton- Periphyton


Pennate diatoms

Pennate Diatoms


Centric diatoms

Centric Diatoms


Filamentous green algae

Filamentous Green Algae


Chrysophyte

Chrysophyte


Cryptophyte

Cryptophyte


Dinoflagellates

Dinoflagellates


Filamentous cyanobacteria

Filamentous Cyanobacteria


Coccoid cyanobacteria

Coccoid Cyanobacteria


Red algae

Red Algae


Brown algae

Brown Algae


The point is that is it is a diverse group

The point is that is…. it is a Diverse “Group”

  • Size (pico, nano,micro)

  • Physiologically

  • Biochemically

  • Life Histories

  • And Therefore, Ecosystem Function!!


The how algal population growth formula

The How: Algal Population Growth Formula

  • dA/dt = mmax(T)A*MIN(NLIM)* LightLIM

  • - grazing

    • +/- advection/dispersion

    • +/- settling

Be a bit skeptical: ask can the equations capture “algal” physiologies and community dynamics that you are after?


Ecological modeling algae

7

7

6

6

5

5

max

max

4

4

m

m

3

3

2

2

1

1

0

0

0

0

10

10

20

20

30

30

40

40

o

o

Temperature (

Temperature (

C)

C)

uMax

  • Usually set by Temperature:

    • Eppley 1972 (most common*)

  • Other approaches

    • species-genera specific temperature relationships

    • Multiple Topt, Tmax Tmin, fxns


Nutrient limitation

Nutrient Limitation

  • Monod kinetics

  • Usually applied as the single most limiting nutrient (Leibig’s “Law of The Minimum” improperly invoked).

    • Half saturation coefficients (ks) and nutrient concentrations are all that are needed.

m= mmax*(N/(Ks+N)


Challenges

Figure 1. Model formulation for velocity enhancement in DSSAMt (Caupp et al 1998).

Challenges:

  • How to set the Ks.

  • What nutrient concentration to use: bulk or microscale?

Half Saturation Constants

Figure 2. Predictions from biofilm theory using hypothetical model parameters.


Light

Light

  • Photosynthesis versus Irradiance Curves (PE curves)

    • Ek is needed.

  • Challenges:

    • How to calculate effective E.

    • How to set Ek (remember….. plants/algae physiologically adapt).

Pmax

Ek


Ecological modeling algae

  • Effective E:

    • Typically Calculated by 1st order attenuation accounting for water+ constituents

    • Ed or Eod, or Eo?

    • PAR, PUR, or PHAR?


Ecological modeling algae

Integrate over depth and time for applicable Dt.

WASP 6 manual


Ecological modeling algae

Note:

  • dA/dt = mmax(T)A*MIN(NLIM)* LightLIM

  • This is “net primary production”

  • Also, this is the “net cellular growth rate”

  • Equation readily allows addition of other environmental constraints such as salinity, pH, etc….


Grazing

Grazing

  • Zero Order loss term/Constant

  • First order loss term

  • Kinetics based on constant grazer biomass/abundance but accounts for monod kinetics

  • Kinetics with grazer abundance predicted as well (Lotkka-Volterra, NPZ models)


Other losses

Other losses….

  • Settling?

  • Mortality-

    • Viral, fungal, Ecotox pollutants (e.g. phototoxins, LD50’s) other..?

  • Drift/scour (fxn velocity and biomass)


Ecological modeling algae

  • Algal Algorithms embedded in spatial models


Still not very satisfying

Still Not Very Satisfying....

  • Uncertainties in Temperature and mmax

    • can lead to large variations in accumulation rates and biomass.. (exponentially compounding uncertainty)

  • Treatment of Ks’s and Ek’s as constants

  • Transient luxury uptake of nutrients rarely accounted for (e.g. Carbon storage and growth at night, i.e. “unbalanced” growth).

  • Minimal Constraints on loss terms

  • Stability issues


Other approaches

Other Approaches…

  • More Empirical Relationships

    • e.g. TP vs. Chlorophyll a

  • Quantum Yield Approach

    • Eo*A* = Primary Production


Free stuff

Free stuff

  • I (Heather/Laurel) will post Stella models

  • http://www.hps-inc.com/

  • Download isee Player (its free)


Background readings

Background Readings

  • Eppley 1972

  • Chapra pages 603-615

  • Brush et al. 2002

  • Chapra  742-747 (Solar Radiation and light extinction sections)

  • WASP Manual

  • Kirk: Light and Photosynthesis in the sea

  • Sverdrup: Conditions for phytoplankton blooms


  • Login