Photos courtesy of R.O. Megard Photos courtesy R.O. Megard

Ecological Principles of Algal Crop Protection

Val H. Smith, University of Kansas, Lawrence, KS

Mass cultivation of algae for biofuels production

Nutrients and light

Carbon dioxide

(CO2)

Phosphate

(PO4-3)

Light Nitrate

(NO3-)

Modified from www.fish.washington.edu/classes/fish210/data/Lectures/Lecture%2013.ppt

Silicate

(SiO2)

This is the vision:

kmle.co.kr

http://brae.calpoly.edu/CEAE/biofuels.html

And this is what the algal crops will be cultivated in:

Closed photobioreactors

Open pond systems

Daphnia and other

cladocerans

Herbivorous

copepods

Nutrients and light

Carbon dioxide

(CO2)

Phosphate

(PO4-3)

Light Nitrate

(NO3-)

Modified from www.fish.washington.edu/classes/fish210/data/Lectures/Lecture%2013.ppt

Silicate

(SiO2)

But contamination is inescapable, and the world is full of aquatic herbivores…

Rotifers Protozoa

Robert L. Wallace

calanoid-copepod-NOAA.jpg

calanoid-copepod-NOAA.jpg

Alan Wilson

…as well as aquatic pathogens

Pests and pathogens are a problem!

Disease (-)

Bacterial, fungal, and viral pathogens

Cause cellular losses

Hydrothermal liquefaction, processing

Pesticides potentially have a role…

Crop not treated

Insecticide applied

kconline.kaskaskia.edu

…but their use creates new capital and operating costs…

… and Biological Control of pests is widely-used in agriculture

(After Van der Bosch et al. 1982)

自然科学の英語-ENS-L7; Miller, 17th Ed.

Herbivorous zooplankton can be biologically controlled !

Hydrothermal liquefaction, processing

Trophic Cascades in a 3-link aquatic food chain

Alan Wilson

Herbivorous zooplankton can be biologically controlled !

Hydrothermal liquefaction, processing

Carnivorous rotifers

Herbivorous zooplankton can be biologically controlled !

Hydrothermal liquefaction, processing

Carnivorous copepods

Alternative Cultivation Methods

From: carrollenvironmentalscience.wikispaces.com/.../agriculture+notes+ppt.ppt.Algae photos: R.O. Megard

Multiple Species Polycultures

Single Species Monocultures

Polyculture may have benefits for algal biofuels production as well

Number of plant species (species richness)

Over-yielding Reduced variance in yield

From Silva-Benavides and Torzillo. 2012. J. Applied Phycology 24:267–276

Biomass over-yielding indeed can occur with algae!

ww.nies.go.jp/biology/mcc/home.htm www.botany.natur.cuni.cz

Polyculture may have benefits for algal biofuels production as well

Number of algal species (species richness)

Over-yielding Reduced variance in yield

Additional benefits of algal polycultures

ww.nies.go.jp/biology/mcc/home.htm www.botany.natur.cuni.cz

• Compensatory dynamics: • Reductions in losses to

grazing herbivores • Reductions in losses to

specialist pathogens

These real-world benefits of diversity have been observed in

terrestrial plants for decades

Where do we go from here?

• Design optimal food web structure to maximize algal biomass and biofuel production

• Explore new, non-chemical methods to control the growth of algal pathogens

• Further examine the effects of algal biodiversity on biomass yield and biofuel production capacity

Acknowledgments

• Bob Honea, Director, KU TRI

• KU Feedstock to Tailpipe team

• Tim Crews, The Land Institute

• U.S. DOE and NSF EPSCoR

Trophic Cascades in a 2-link food chain

Alan Wilson

The fish predation hypothesis was tested

HRT = 10 days; TP = 3.7 mg P/L, Predicted Chla = ~ 1,000 µg/L

0

200

400

600

800

1000

1200

1400

1600

1800

0 50 100 150 200

Ch

loro

ph

yll a

(µ

g/L

)

Time (Days)

Control

Fish

Photos from http://www4.samford.edu/schools/artsci/biology/zoology/vertzoo-05s/pages/50.htm; http://outdoornebraska.ne.gov/blogs/2010/02/hang-time/

Mosquitofish added

No fish

Adding a predator indeed enhanced algal biomass yields!